JP7384283B2 - pattern forming device - Google Patents

Description

The present invention relates to a pattern forming apparatus having an alignment system that aligns a pattern forming position when forming a pattern in a forming area on a substrate.

In order to form a pattern on a long flexible substrate, an exposure section is provided in which multiple exposure heads are arranged in the short direction (width direction) perpendicular to the long direction of the substrate, and the substrate is moved in the long direction. For example, Japanese Patent Application Laid-Open No. 2006-106097 discloses a drawing apparatus that draws (exposes) a pattern using each of a plurality of exposure heads while moving the exposure head.

In the drawing apparatus disclosed in JP-A No. 2006-106097, as shown in FIGS. 1 to 4, there is, for example, a device located downstream of the exposure section 30 that exposes a pattern on the flexible substrate 100 in the conveyance direction of the substrate 100. An alignment section 22 having two camera sections 40 is provided. The alignment section 22 uses a camera section 40 to detect an alignment mark 102 (FIG. 10) formed on the flexible substrate 100. As shown in FIG. 4, the camera unit 40 is provided movably along the guide rail 34 so that the imaging position on the board 100 can be changed in the width direction of the board 100. Further, a ring-shaped strobe 46 is disposed at the protruding tip of the lens 44 provided on the substrate 100 side of the camera unit 40, and when capturing images of the alignment marks 102 and the like on the substrate 100, the substrate 100 is illuminated with strobe light. It's lit.

In the device configuration disclosed in Japanese Patent Application Laid-open No. 2006-106097, the camera unit 40 of the alignment unit 22 is configured to be movable, so there is an error that the camera unit 40 is slightly tilted when it moves to a desired position and stands still. That is, a telecenter error in which the optical axis of the lens 44 is slightly tilted from being perpendicular to the surface of the substrate 100 is likely to occur. Generally, in this type of pattern drawing device, it is necessary to measure the position of the alignment mark with an accuracy of 1/10 or less of the minimum line width value that can be drawn. The images must have good contrast and be uniform. However, when a telecenter error occurs, the symmetry between the image contrasts of the edge portions on both sides of the alignment mark is disrupted, and an error occurs in the position measurement result of the alignment mark. In the case of Japanese Unexamined Patent Application Publication No. 2006-106097, a mechanism for finely adjusting the tilt of the entire camera section 40 is required to correct the telecentering error, but the configuration of the alignment section 22 is correspondingly large-scale.

A first aspect of the present invention is a pattern forming mechanism that forms a pattern in a predetermined area on a substrate that moves in a first direction, and a mark detection mechanism that detects marks formed on the substrate. A forming device,
The mark detection mechanism is
an objective optical system that projects illumination light into a first detection area set on the substrate, and into which reflected light generated within the first detection area is incident; and the reflected light that is incident on the objective optical system. an image detection system that detects an image within the detection area generated by light; and a light splitter disposed in an optical path between the objective optical system and the image detection system;
an illumination system that projects the illumination light toward the light splitter to form a light source image of the illumination light on a pupil plane of the objective optical system;
an adjustment mechanism that changes the position of the light source image formed in the pupil plane of the objective optical system;
a reference bar member;
a synthetic optical member provided between the objective optical system and the substrate;
Equipped with
The synthetic optical member divides the illumination light from the objective optical system and guides it to each of the first detection area and a second detection area set on the reference bar member, and The reflected light from the area and the reflected light from the second detection area are combined .

1 is a perspective view showing a schematic overall configuration of a pattern drawing apparatus EX according to a first embodiment; FIG. 2 is a diagram specifically showing the arrangement of drawing units U1 to U6 and the arrangement of alignment system ALGn in the pattern drawing apparatus EX of FIG. 1. FIG. 2 is a perspective view showing a detailed configuration of a representative drawing unit U1 among the drawing units U1 to U6 in the pattern drawing apparatus EX of FIG. 1. FIG. 3 is a perspective view schematically showing the arrangement relationship among the rotating drum DR, seven alignment systems ALG1 to ALG7, and a reference bar member RB shown in FIG. 2. FIG. The arrangement relationship between the drawing lines SL1 to SL6 shown in FIG. 4 and the detection areas AD1 to AD7 of each of the alignment systems ALG1 to ALG7, and the arrangement of the encoder measurement system that measures changes in the rotation angle of the rotary drum DR are shown. It is a diagram. FIG. 6A is a diagram showing an example of the arrangement of the reference marks RM1 to RM7 formed at seven locations on the reference bar member RB, and FIG. 6B is an exaggerated view of an example of the arrangement relationship between the imaging area DIS' and the reference mark RM1. FIG. 6C is an exaggerated diagram illustrating an example of the arrangement relationship between the imaging region DIS' and the reference mark RM2. 3 is a diagram showing an example of a detailed optical configuration of alignment system ALGn (ALG1 to ALG7) and an optical configuration of illumination system ILU that supplies illumination light to alignment system ALGn. FIG. FIG. 7 is a diagram showing a detection state of reflected light LRf generated from the substrate P by epi-illumination from the objective lens system OBL of the alignment system ALGn when there is a telecenter error. FIG. 7 is a diagram illustrating a detection state of reflected light LRf generated from the substrate P by epi-illumination from the objective lens system OBL of the alignment system ALGn when the influence of telecentering errors is corrected. FIG. 7 is a diagram showing an optical configuration according to a second embodiment of a light guide member for supplying illumination light to alignment system ALGn. 3 is a graph showing an example of emission wavelength characteristics of a metal halide lamp filled with tin halide as illumination light supplied to alignment system ALGn. 11 is a schematic diagram showing a first modification of the illumination system (illumination unit) ILU for the alignment system ALGn shown in FIG. 10. FIG. 2 is a graph schematically showing an example of the wavelength selection characteristics of the dichroic mirror DCM and the emission wavelength characteristics of each of the LED light sources LD1 and LD2. 11 is a diagram showing a modification of the optical configuration of the light guide member that transmits the illumination light ILb from the illumination system ILU to the alignment system ALGn shown in FIG. 7 or FIG. 10. FIG. 15 is a diagram schematically showing a state of a light source image SOa formed within the plane of the input end ILFa of the optical fiber bundle ILF shown in FIG. 14. FIG. 11 is a diagram schematically showing an optical configuration according to a modification of the alignment system ALGn shown in FIGS. 7 and 10. FIG. 15 is a diagram showing a modification of the light source unit ILS that forms a light source image SOa' in the illumination system (illumination unit) ILU shown in FIG. 14. FIG. 18 is a diagram illustrating a modification of the vicinity of the dichroic mirror DCM in the light source unit ILS applied to FIGS. 12 and 17. FIG. 15 is a diagram showing a modification of the light source section ILS shown in FIG. 14. FIG. 14 is used to supply illumination light ILb to each of the alignment systems ALGn in FIG. 7, FIG. 10, and FIG. 16. It is a diagram. FIG. 7 is a diagram showing a schematic configuration of an alignment system ALGn and an illumination system (illumination unit) ILU according to a third embodiment. FIG. 22 is a perspective view exaggerating the functions of wedge prisms DP1 and DP2 shown in FIG. 21;

DESCRIPTION OF THE PREFERRED EMBODIMENTS A substrate processing apparatus (pattern forming apparatus) according to an aspect of the present invention will be described in detail below by citing preferred embodiments and referring to the accompanying drawings. Note that aspects of the present invention are not limited to these embodiments, but also include those with various changes or improvements. That is, the components described below include those that can be easily assumed by those skilled in the art and are substantially the same, and the components described below can be combined as appropriate. Moreover, various omissions, substitutions, or changes of the constituent elements can be made without departing from the gist of the present invention.

[First embodiment]
FIG. 1 is a perspective view showing a schematic configuration of a pattern forming device (pattern drawing device) EX that exposes a pattern to a substrate (irradiated object) P as a substrate processing device according to the first embodiment. , International Publication No. 2017/191777, and International Publication No. 2018/061633. In the following description, unless otherwise specified, an XYZ orthogonal coordinate system is set in which the direction of gravity is the Z direction, and the X direction, Y direction, and Z direction are set according to the arrows shown in the figures.

The pattern drawing apparatus EX is used in a device manufacturing system that manufactures electronic devices by exposing a photosensitive functional layer such as a photoresist coated on a substrate P to a fine pattern for electronic devices. In device manufacturing, for example, in order to manufacture electronic devices such as flexible displays, film-like touch panels, film-like color filters for liquid crystal display panels, flexible wiring, and flexible sensors, in addition to pattern drawing equipment, we also use Multiple types of manufacturing equipment are used. In the device manufacturing system, a flexible sheet-like substrate (sheet substrate) P is fed out from a supply roll (not shown) wound into a roll, and various processes are continuously performed on the fed-out substrate P. The production method is a so-called roll-to-roll production method in which the variously processed substrates P are wound up with a recovery roll (not shown) after being subjected to various treatments. Therefore, at least on the substrate P during the manufacturing process, a large number of patterns corresponding to the unit device (one display panel, etc.) that will become the final product are arranged in a row with a predetermined gap in the transport direction of the substrate P. be done. The substrate P is in the form of a belt, with its long direction being the moving direction (transportation direction) of the substrate P, and its short direction orthogonal to the long direction being the width direction of the substrate P.

As the substrate P, for example, a resin film, a foil made of metal or alloy such as stainless steel, or the like is used. Examples of materials for the resin film include polyethylene resin, polypropylene resin, polyester resin, ethylene vinyl copolymer resin, polyvinyl chloride resin, cellulose resin, polyamide resin, polyimide resin, polycarbonate resin, polystyrene resin, and vinyl acetate resin. Of these, one containing at least one may be used. In addition, the thickness and rigidity (Young's modulus) of the substrate P are set within a range that will not cause creases or irreversible wrinkles due to buckling in the substrate P when passing through the transport path of the device manufacturing system or pattern drawing apparatus EX. That's fine. As the base material of the substrate P, a film of PET (polyethylene terephthalate), PEN (polyethylene naphthalate), polyimide, etc. having a thickness of approximately 25 μm to 200 μm is a typical sheet substrate suitable for use. Further, the substrate P may be a single layer of ultra-thin glass with a thickness of about 30 to 100 μm manufactured by a float method or the like, a laminate in which the above-mentioned resin film, metal foil, etc. are bonded to the ultra-thin glass, or It may also be a piece of paper containing nanocellulose and having a smoothed surface.

The photosensitive functional layer applied to the surface of the substrate P is applied as a solution onto the substrate P and becomes a layer (film) by drying. A typical photosensitive functional layer is a photoresist (liquid or dry film), but as a material that does not require development processing, it is a photosensitive material whose lyophobicity is modified in areas exposed to ultraviolet rays. Examples include silane coupling agents (SAM), photosensitive reducing agents that expose plating reducing groups in areas irradiated with ultraviolet rays, and remove plating reducing groups in areas irradiated with ultraviolet rays. When a photosensitive silane coupling agent is used as the photosensitive functional layer, the patterned portion of the substrate P exposed to ultraviolet rays is modified from liquid repellent to lyophilic. Therefore, by selectively applying a conductive ink (ink containing conductive nanoparticles such as silver or copper) or a liquid containing a semiconductor material onto the lyophilic part, thin film transistors (TFTs), etc. It is possible to form a pattern layer that becomes an electrode, a semiconductor, an insulation, or a connection wiring.

When a photosensitive reducing agent is used as the photosensitive functional layer, the plating reducing group is exposed on the patterned portions of the substrate P that are exposed to ultraviolet rays or the patterned portions that are not exposed. Therefore, after exposure, a pattern layer is formed (deposited) by electroless plating in which the substrate P is immediately immersed in a plating solution containing palladium ions, copper ions, etc. for a certain period of time. Although such plating processing is an additive process, etching processing may also be performed as a subtractive process. In that case, the substrate P sent to the pattern drawing device EX has a base material of PET or PEN, and a thin metal film such as aluminum (Al) or copper (Cu) is deposited on the entire surface or selectively on the surface of the substrate P. A photoresist layer is laminated thereon.

The pattern drawing apparatus EX shown in FIG. 1 is a direct drawing type exposure apparatus that does not use a mask, a so-called spot scanning type exposure apparatus, and a substrate P transported from a previous process process apparatus is transferred to a subsequent process process apparatus. (including a single processing section or a plurality of processing sections) at a predetermined speed. In synchronization with the conveyance, the pattern drawing device EX draws wiring patterns of signal lines and power supply lines constituting electronic devices, electrodes constituting TFTs, semiconductor regions, through holes, etc. on the photosensitive functional layer of the substrate P. A light pattern corresponding to the pattern shape is formed by high-speed scanning in the Y direction (main scanning) of a spot light whose intensity is modulated according to drawing data and movement in the longitudinal direction of the substrate P (sub scanning). .

In FIG. 1, the pattern drawing device EX includes a rotating drum DR that supports and transports the substrate P in the longitudinal direction for sub-scanning, and a pattern drawing device for each portion of the substrate P supported in a cylindrical shape by the rotating drum DR. Each of the plurality of drawing units Un (U1 to U6) is equipped with a plurality of (six in this case) drawing units Un (U1 to U6) that perform exposure, and each of the plurality of drawing units Un (U1 to U6) is configured to emit a pulsed beam LB (pulsed beam) for exposure. While scanning the spot light one-dimensionally (main scanning) in the Y direction on the irradiated surface (photosensitive surface) of the substrate P with a polygon mirror PM (scanning member), the intensity of the spot light is adjusted at high speed according to the drawing data. Modulate (on/off). As a result, a light pattern corresponding to a predetermined pattern of an electronic device, circuit, wiring, etc. is drawn and exposed on the irradiated surface of the substrate P. Furthermore, since the substrate P is continuously conveyed along the longitudinal direction, the exposed area (device formation area) on the substrate P where the pattern is exposed by the pattern drawing apparatus EX is in the longitudinal direction of the substrate P. A plurality of pieces can be set at predetermined intervals (margins) along the line. In this embodiment, each or all of the six drawing units U1 to U6 constitute a pattern forming mechanism.

As shown in FIG. 1, the rotating drum DR has a central axis AXo extending in the Y direction and in a direction intersecting the direction in which gravity acts, and a cylindrical outer peripheral surface having a constant radius from the central axis AXo. The rotating drum DR curves a part of the substrate P in a cylindrical shape in the longitudinal direction and supports (holds it in close contact with) a part of the substrate P along its outer peripheral surface (circumferential surface), and rotates around the central axis AXo. The substrate P is transported in the longitudinal direction. The rotating drum DR supports, on its outer peripheral surface, a region (portion) on the substrate P onto which the beam LB (spot light) from each of the plurality of drawing units Un (U1 to U6) is projected. Note that shafts (not shown) supported by bearings are provided on both sides of the rotating drum DR in the Y direction so as to rotate the rotating drum DR around the central axis AXo. Rotational torque is applied to the shaft from a rotational drive source (for example, a motor, a speed reduction mechanism, etc.) not shown, and the rotating drum DR rotates around the central axis AXo at a constant rotational speed.

A light source device (pulsed light source device) LS generates and emits a pulsed beam (pulsed beam, pulsed light, laser) LB. This beam LB has sensitivity to the photosensitive functional layer of the substrate P, and has a peak wavelength (for example, a center wavelength of any one of 405 nm, 365 nm, 355 nm, 344 nm, 308 nm, 248 nm, etc.) in a wavelength band of 410 to 200 nm. It has ultraviolet light. The light source device LS emits a pulsed beam LB at a frequency (oscillation frequency, predetermined frequency) FPL in the range of 100 MHz to 400 MHz, for example, under the control of a drawing control device (not shown). In this embodiment, the light source device LS is a laser light source device that generates ultraviolet light using a wavelength conversion element.

Specifically, the semiconductor laser elements that generate pulsed light in the infrared wavelength range, fiber amplifiers, and wavelength conversion elements (harmonics) that convert the amplified pulsed light in the infrared wavelength range to pulsed light in the ultraviolet wavelength range A fiber amplifier laser light source is used. By configuring the light source device LS in this manner, it is possible to obtain high-intensity ultraviolet pulsed light having a light emission time of one pulsed light of ten or more picoseconds to several tens of picoseconds or less. The light source device LS is a fiber amplifier laser light source, and pulse generation of the beam LB is turned on and off at high speed (spot light is The configuration (intensity modulation) is disclosed in International Publication No. 2015/166910 and International Publication No. 2017/057415. It is assumed that the beam LB emitted from the light source device LS is a narrow parallel light flux with a beam diameter of about 1 mm or about half thereof.

The beam LB emitted from the light source device LS is transmitted through a plurality of selection optical elements OSn (OS1 to OS6) as switching elements, a plurality of reflection mirrors M1 to M12, and a plurality of incident mirrors (also called selection mirrors) IMn ( The light is selectively supplied to each of the drawing units Un (U1 to U6) via a beam switching unit composed of the absorber TR and the like (IM1 to IM6) and the absorber TR. The selection optical element OSn (OS1 to OS6) is transparent to the beam LB, and is driven by an ultrasonic signal to efficiently generate only one of the ±1st-order diffracted lights of the incident beam LB. It is composed of an acousto-optic modulator (AOM) arranged under black diffraction conditions. The plurality of selection optical elements OSn and the plurality of reflection mirrors IMn are provided corresponding to each of the plurality of drawing units Un. For example, the selection optical element OS1 and the reflected mirror IM1 are provided corresponding to the drawing unit U1, and similarly, the selection optical elements OS2 to OS6 and the reflected mirror IM2 to IM6 are provided to correspond to the drawing units U2 to U6, respectively. It is provided.

The optical path of the beam LB from the light source device LS is bent into a serpentine shape in a plane parallel to the XY plane by reflecting mirrors M1 to M12, and is guided to the absorber TR. In the following, a case will be described in detail in which the selection optical elements OSn (OS1 to OS6) are all in an off state (a state in which no ultrasonic signal is applied and no first-order diffracted light is generated). Although not shown in FIG. 1, a relay system including a plurality of lenses is provided in the beam optical path from the reflecting mirror M1 to the absorber TR. Specifically, as disclosed in International Publication No. 2017/057415, the relay system is arranged between each of the selection optical elements OS1 to OS6 that are arranged in series along the optical path of the beam LB from the light source device LS. , each of the six selection optical elements OS1 to OS6 is brought into an optically conjugate relationship (imaging relationship) with each other. Furthermore, each relay system maintains the diameter of the beam LB to be a narrow parallel beam of 1 mm to 0.5 mm at each position of the six selection optical elements OS1 to OS6, while the diameter becomes 0 at an intermediate position within each relay system. .Converge to a beam waist of 2mm or less. Each of the reflecting mirrors IM1 to IM6 is arranged at a beam waist position in the optical path of each relay system.

In FIG. 1, a beam LB from a light source device LS travels in the -X direction, is reflected in the -Y direction by a reflection mirror M1, and enters a reflection mirror M2. The beam LB reflected in the +X direction by the reflecting mirror M2 passes straight through the selection optical element OS5 and reaches the reflecting mirror M3. The beam LB reflected in the -Y direction by the reflecting mirror M3 is reflected in the -X direction by the reflecting mirror M4, and passes straight through the selection optical element OS6 to reach the reflecting mirror M5. The beam LB reflected in the -Y direction by the reflecting mirror M5 reaches the reflecting mirror M6. The beam LB reflected in the +X direction by the reflecting mirror M6 passes straight through the selection optical element OS3 and reaches the reflecting mirror M7. The beam LB reflected in the -Y direction by the reflecting mirror M7 is reflected in the -X direction by the reflecting mirror M8, and then passes straight through the selection optical element OS4 to reach the reflecting mirror M9. The beam LB reflected in the −Y direction by the reflection mirror M9 is reflected in the +X direction by the reflection mirror M10, and then passes straight through the selection optical element OS1 to reach the reflection mirror M11. The beam LB reflected in the -Y direction by the reflecting mirror M11 is reflected in the -X direction by the reflecting mirror M12, and then passes straight through the selection optical element OS2 and is guided to the absorber TR. This absorber TR is an optical trap that absorbs the beam LB in order to suppress leakage of the beam LB to the outside, and is equipped with a temperature control (air cooling or water cooling) mechanism to reduce heat generation due to absorption of optical energy. ing.

When an ultrasonic signal (high-frequency signal) is applied, each selection optical element OSn diffracts the incident beam LB (0-order light) at a diffraction angle corresponding to the frequency of the high-frequency wave, and outputs a first-order diffracted light beam as an output beam. (beam LBn). Therefore, the beam emitted as first-order diffracted light from the selection optical element OS1 becomes LB1, and similarly, the beam emitted as first-order diffracted light from each of the selection optical elements OS2 to OS6 becomes LB2 to LB6. In this way, each selection optical element OSn (OS1 to OS6) functions to deflect the optical path of the beam LB from the light source device LS. In addition, in the present embodiment, the optical elements (not shown) are arranged such that only one selected one of the selection optical elements OSn (OS1 to OS6) is in an on state (a state in which a high frequency signal is applied) for a certain period of time. Controlled by a drawing control device. When one selected optical element for selection OSn is in the ON state, about 10 to 20% of the zero-order light that is not diffracted by the optical element for selection OSn and travels straight remains, but this is ultimately absorbed by the absorber TR. Absorbed.

Each of the selection optical elements OSn is installed so as to deflect the beam LBn (LB1 to LB6), which is the deflected first-order diffracted light, in the -Z direction with respect to the traveling direction of the incident beam LB. The beams LBn (LB1 to LB6) that are deflected and emitted by each of the selection optical elements OSn are reflected by a reflection mirror IMn (beam waist position) provided at a position (beam waist position) that is a predetermined distance away from each of the selection optical elements OSn. IM1 to IM6). Each incident mirror IMn reflects the incident beam LBn (LB1 to LB6) in the −Z direction, thereby guiding the beam LBn (LB1 to LB6) to the corresponding drawing unit Un (U1 to U6).

The configuration, function, operation, etc. of each selection optical element OSn are the same, and each of the plurality of selection optical elements OSn is controlled by turning on/off the driving signal (high frequency signal) from the drawing control device. A switching (beam selection) operation is performed to turn on/off the generation of diffracted light (beams LB1 to LB6) obtained by diffracting the beam LB. By such a switching operation of each selection optical element OSn, the beam LB from the light source device LS can be guided to any one drawing unit Un, and the drawing unit Un into which the beam LBn is incident can be switched. . In this way, a configuration in which a plurality of selection optical elements OSn are arranged in series on the optical path of the beam LB and the beam LBn is supplied to the corresponding drawing unit Un in a time-sharing manner is disclosed in International Publication No. 2015/166910. has been disclosed.

The order in which each of the selection optical elements OSn (OS1 to OS6) constituting the beam switching section is turned on for a certain period of time depends on the scan start timing by the spot light set for each drawing unit Un (U1 to U6). determined by order. In this embodiment, by synchronizing the rotational speed of the polygon mirror PM provided in each of the six drawing units U1 to U6 and also synchronizing the phase of the rotation angle, one of the drawing units U1 to U6 can be One reflective surface of the polygon mirror in can be switched in a time-division manner so that one spot scan is performed on the substrate P. Therefore, as long as the rotation angle phases of the respective polygon mirrors of the drawing unit Un are synchronized in a predetermined relationship, the spot scanning order of the drawing unit Un may be in any order. In the configuration of FIG. 1, three drawing units U1, U3, and U5 are arranged side by side in the Y direction on the upstream side in the conveyance direction of the substrate P (the direction in which the outer circumferential surface of the rotary drum DR moves in the circumferential direction). Three drawing units U2, U4, and U6 are arranged side by side in the Y direction on the downstream side in the transport direction.

In this case, pattern drawing for one exposed area on the substrate P starts from the upstream odd-numbered drawing units U1, U3, and U5, and after the substrate P has been fed a certain length, the even-numbered drawing units on the downstream side start drawing the pattern for one exposed area on the substrate P. Since units U2, U4, and U6 will also start pattern drawing, the spot scanning order of drawing unit Un can be set as U1→U3→U5→U2→U4→U6→U1→... . Therefore, the order in which each of the selection optical elements OSn (OS1 to OS6) is turned on for a certain period of time is also determined as follows: OS1→OS3→OS5→OS2→OS4→OS6→OS1→...

As shown in FIG. 1, each of the drawing units U1 to U6 is provided with a polygon mirror PM for main scanning the incident beams LB1 to LB6. In this embodiment, each of the polygon mirrors PM of each drawing unit Un is synchronously controlled so as to precisely rotate at the same rotational speed and maintain a constant rotation angle phase with each other. Thereby, the main scanning timings (main scanning periods of the spot lights) of the beams LB1 to LB6 projected onto the substrate P from each of the drawing units U1 to U6 can be set so as not to overlap with each other. Therefore, the light source device Efficient exposure processing can be performed by distributing the beam LB from LS to each of the plurality of drawing units Un in a time-sharing manner. Synchronous control of the phase alignment of the rotation angles of each of the six polygon mirrors PM and the on/off switching timing of each of the selection optical elements OSn (OS1 to OS6) is also disclosed in International Publication No. 2015/166910. ing.

As shown in FIG. 1, the pattern drawing apparatus EX is a so-called multi-head type direct drawing exposure system in which a plurality of drawing units Un (U1 to U6) having the same configuration are arranged. Each of the drawing units Un draws a pattern for each partial area partitioned in the Y direction (main scanning direction) of the substrate P supported by the outer peripheral surface (circumferential surface) of the rotary drum DR. Each drawing unit Un (U1 to U6) focuses (converges) the beam LBn on the substrate P while projecting the beam LBn from the beam switching section onto the substrate P (on the irradiated surface of the substrate P). As a result, the beams LBn (LB1 to LB6) projected onto the substrate P become spot lights with a diameter of 2 to 4 μm. Furthermore, by rotating the polygon mirror PM of each drawing unit Un, each spot light of the beam LBn (LB1 to LB6) projected onto the substrate P is scanned in the main scanning direction (Y direction). By scanning this spot light, a linear drawing line (scanning line) SLn (n=1, 2, . . . , 6) for drawing one line of pattern is defined on the substrate P. Ru. The drawing line SLn is a scanning trajectory of the spot light of the beam LBn on the substrate P.

Each drawing line SLn (SL1 to SL6) of the plurality of drawing units Un (U1 to U6) is arranged in two directions in the circumferential direction of the rotating drum DR, with a central plane parallel to the YZ plane including the central axis AXo of the rotating drum DR in between. The odd-numbered drawing lines SL1, SL3, and SL5 are arranged in a staggered array in a row, and the odd-numbered drawing lines SL1, SL3, and SL5 are located on the irradiated surface of the substrate P on the upstream side (−X direction side) in the conveyance direction of the substrate P with respect to the center plane. , and are arranged in one row at a predetermined interval along the Y direction. The even-numbered drawing lines SL2, SL4, and SL6 are located on the irradiated surface of the substrate P on the downstream side (+X direction side) in the transport direction of the substrate P with respect to the center plane, and are arranged at predetermined positions along the Y direction. They are arranged in a row with an interval of . Therefore, the odd-numbered drawing units U1, U3, and U5 and the even-numbered drawing units U2, U4, and U6 are symmetrically provided with respect to the center plane when viewed in the XZ plane (viewed from the Y direction). There is.

Regarding the X direction (transfer direction of the substrate P), the odd numbered drawing lines SL1, SL3, SL5 and the even numbered drawing lines SL2, SL4, SL6 are separated from each other, but in the Y direction (the width direction of the substrate P) , main scanning direction), the patterns drawn on the substrate P are set so that they are joined together without being separated from each other. The drawing lines SL1 to SL6 are set to be substantially parallel to the width direction of the substrate P, that is, to the central axis AXo of the rotating drum DR. Note that joining the drawing lines SLn in the Y direction means that the positions of the ends of the drawing lines SLn in the Y direction are adjacent to each other or partially overlap. If the ends of the drawing lines SLn overlap each other in the Y direction, for example, the length of each drawing line SLn should be within a range of 1 to 5% in the Y direction including the drawing start point or the drawing end point. It is good to have duplicates.

The plurality of drawing units Un (U1 to U6) share the scanning area in the Y direction (division of the main scanning range) so as to cover the widthwise dimension of the exposure area (pattern formation area) on the substrate P in total. are doing. For example, if the main scanning range in the Y direction (the length of the drawing line SLn) by one drawing unit Un is about 30 to 60 mm, it is possible to draw by arranging six drawing units U1 to U6 in the Y direction. The width of the exposure area in the Y direction is increased to about 180 to 360 mm. Note that the length of each drawing line SLn (SL1 to SL6) (the length of the drawing range) is, in principle, the same. That is, the scanning distance of the spot light SP of the beam LBn scanned along each of the drawing lines SL1 to SL6 is, in principle, the same.

Each drawing unit Un (U1 to U6) includes a telecentric fθ lens system (scanning optical system for drawing) FT that receives a beam LBn that is reflected by each reflecting surface RP of the polygon mirror PM and is deflected in the main scanning direction. , each beam LBn emitted from the fθ lens system FT and projected onto the substrate P is set to travel toward the central axis AXo of the rotating drum DR when viewed in the XZ plane. As a result, the principal ray of the beam LBn traveling from each drawing unit Un (U1 to U6) toward the substrate P is directed to the tangential plane at the position of the drawing line SLn on the curved surface of the substrate P in the XZ plane. The light is always projected toward the substrate P vertically. That is, the beams LBn (LB1 to LB6) projected onto the substrate P are scanned in a telecentric state with respect to the main scanning direction of the spot light SP and the sub-scanning direction (circumferential direction along the outer peripheral surface of the rotary drum DR). .

FIG. 2 shows the arrangement of the rotating drum DR and six drawing units U1 to U6 of the pattern drawing apparatus EX shown in FIG. 2 is a diagram specifically showing the arrangement of a plurality of alignment systems ALGn (n is an integer of 2 or more) for detecting . The setting of the orthogonal coordinate system XYZ in FIG. 2 is the same as in FIG. 1. The basic arrangement of the rotating drum DR, drawing units U1 to U6, and alignment system ALGn shown in FIG. 2 is disclosed in, for example, International Publication No. 2016/152758 and International Publication No. 2017/199658.

A shaft Sft supported by an annular bearing so as to rotate around the central axis AXo is provided on both sides in the Y direction of the rotating drum DR that supports the substrate P in an angular range of about 180 degrees, and the shaft Sft is not shown. It is connected to the rotating shaft of the rotational drive source (direct drive motor, etc.). Further, a plane including the central axis AXo and parallel to the YZ plane is defined as a central plane CPo. When viewed from the Y direction (width direction of the substrate P), the odd-numbered drawing units U1, U3, and U5 and the even-numbered drawing units U2, U4, and U6 are arranged symmetrically with the central plane CPo in between. As shown in FIG. 2, in a plane parallel to the XZ plane of the orthogonal coordinate system and U4, U6) are tilted clockwise by a certain angle θc from the center plane CPo. Since each of the drawing units U1 to U6 has the same configuration, FIG. 3 shows the configuration of the drawing unit U1 as a representative.

FIG. 3 shows a beam LB1 (a parallel light beam with a diameter of about 0.5 mm whose intensity is modulated according to drawing data) supplied from the reflection mirror IM1 shown in FIG. FIG. 3 is a perspective view showing a detailed configuration of a drawing unit U1 including an fθ lens system FT for condensing light, a polygon mirror PM for main-scanning the spot light SP in the Y direction to form a drawing line SL1, and the like. The optical axis AXf1 passing from the polygon mirror PM of the drawing unit U1 (and U2 to U6) through the fθ lens system FT is tilted within the orthogonal coordinate system XYZ as shown in FIG. , an orthogonal coordinate system XtYtZt tilted with respect to the orthogonal coordinate system XYZ is set. In the orthogonal coordinate system XtYtZt, the Yt direction is the same as the Y direction, and the Zt direction is the traveling direction of the principal ray (center ray) of the beam LB1 that enters the drawing unit U1 from the incident mirror IM1, or the position of the drawing line SL1. The direction Xt is taken to be the normal direction of the substrate P, and the direction Xt is taken to be the direction of the optical axis AXf1 passing through the fθ lens system FT. Note that the optical axis of each fθ lens system FT of the even-numbered drawing units U2, U4, and U6 is optical axis AXf2.

In FIG. 3, the drawing unit U1 (and U2 to U6) includes a mirror M30, a lens L6, a lens L7, a tiltable parallel plate made of quartz HVP, lenses L8 and L9, a mirror M31, a polarizing beam splitter PBS, and an aperture. Aperture AP, quarter wavelength plate QW, mirror M32, first cylindrical lens CYa, lens L10, mirror M33, lens L11, mirror M34, M35, M36, 8-sided polygon mirror PM, fθ lens system FT, mirror M37, The second cylindrical lenses CYb are arranged in that order. Mirror M30 reflects beam LB1 at 90 degrees so that the traveling direction of incident beam LB1 is in the -Xt direction. Lenses L6, L7, L8, and L9 arranged along the optical path of the beam LB1 reflected by the mirror M30 convert the narrow beam LB1 (about 0.5 mm in diameter) reflected by the mirror M30 to a distance of several mm or more (5 mm). A beam expander system is constructed that expands the beam into a parallel beam with a diameter in the range of ~10 mm).

The parallel plate HVP is provided in the optical path between the lenses L6 to L9 of the beam expander system, and is configured to be rotatable (tiltable) around a rotation axis AXh parallel to the Zt axis. By changing the amount of inclination of the parallel plate HVP, the position of the spot light SP projected onto the substrate P can be changed in the sub-scanning direction (Xt direction, the sub-scanning direction which is the moving direction of the substrate P), and the effective It is possible to shift the distance within a range of several times to more than ten times the diameter φp. The polarizing beam splitter PBS receives a beam LB1 (parallel beam) which is expanded through a lens L9 and reflected in the -Yt direction by a mirror M31. Assuming that the beam LB1 is linear S-polarized light, the polarizing beam splitter PBS reflects the beam LB1 with an intensity of 90% or more on the polarization separation surface and directs it to the aperture stop AP in the subsequent stage. The beam LB transmitted through the circular aperture of the aperture stop AP is converted from linearly polarized light to circularly polarized light when transmitted through the quarter-wave plate QW.

The beam LB1 (parallel light beam) transmitted through the quarter-wave plate QW is reflected by the mirror M32 in the −Zt direction, enters the first cylindrical lens CYa (generating line is parallel to the Yt axis), and is reflected at the plane Pv in space. The light is focused into a slit-like intensity distribution that has an extremely small width in the Xt direction and extends several mm in the Yt direction (same as the aperture diameter of the aperture stop AP). The beam LB1, which is converged in only one dimension on the surface Pv, passes through the first group of spherical lenses L10 of the two-lens spherical lens system, is reflected in the +Xt direction by the mirror M33, and then passes through the two-lens spherical lens system. It passes through the spherical lens L11 of the rear group and proceeds in the +Xt direction. The beam LB1 emitted from the spherical lens L11 is reflected in the +Zt direction by the mirror M34, and then reflected in the +Yt direction by the mirror M35. Mirror M34 and mirror M35 are arranged so that the principal ray (center ray) of beam LB1 traveling in the +Yt direction from mirror M35 and the optical axis AXf1 of fθ lens system FT are orthogonal to each other in a plane parallel to the XtYt plane. There is. The beam LB1 traveling in the +Yt direction from the mirror M35 is reflected by the mirror M36 disposed on the opposite side of the mirror M35 across the optical axis AXf1 of the fθ lens system FT, and is projected onto the reflective surface RPa of the polygon mirror PM.

Due to the action of the first cylindrical lens CYa and the two-piece spherical lens system, the beam LB1 that enters the mirror M34 immediately after passing through the spherical lens L11 becomes a nearly parallel beam in the Zt direction, and is convergent in the Yt direction. It becomes a state of luminous flux. In addition, in FIG. 3, the spherical lens system is configured with two spherical lenses L10 and L11 in order to adjust the distance between principal points, but it may be configured with only one spherical lens.

The reflective surface of the mirror M36 is parallel to the Zt axis, parallel to the XtZt plane, and arranged at a narrow angle of 22.5° with respect to a plane that includes the optical axis AXf1. As a result, the chief ray (center ray) of the beam LB1 traveling from the mirror M36 to the reflective surface RPa of the polygon mirror PM, that is, the extension of the optical axis of the first cylindrical lens CYa and the spherical lens system (lenses L10, L11), The optical axis from to the polygon mirror PM is set at an angle of 45° with respect to the optical axis AXf1 of the fθ lens system FT in a plane parallel to the XtYt plane. In addition, in FIG. 3, the beam LB1 reflected by the mirror M36 and directed toward the reflective surface RPa of the polygon mirror PM becomes a convergent light flux in the Zt direction so as to be condensed on the reflective surface RPa of the polygon mirror PM, and XtYt In a plane parallel to the surface, the beam becomes almost parallel, and on the reflective surface RPa, an intensity distribution extends in the main scanning direction, that is, in the tangential direction of the inscribed circle centered on the rotation center axis AXp of the polygon mirror PM, in the form of a slit. The light is focused so that

The beam LB1 reflected by the reflective surface RPa of the polygon mirror PM passes through the telecentric fθ lens system FT, and then is reflected by the mirror M37 at right angles to the −Zt direction, and is reflected by the second cylindrical lens CYb (the direction of the generatrix is Yt). direction) and is focused onto the substrate P as a spot light SP. In this embodiment, the optical axis AXf1 of the fθ lens system FT is bent perpendicularly to the -Zt direction by the mirror M37 and is perpendicular to the surface of the substrate P (the outer peripheral surface of the rotating drum DR), and the optical axis AXf1 is bent toward the mirror M30. - The center ray of the beam LB1 incident in the Zt direction is set to be coaxial with a line segment LE1 (line segments LE2 to LE6 for each of the other drawing units U2 to U6) parallel to the Zt axis. ing. With such a setting, when the drawing line SL1 is slightly tilted within the substrate P (plane parallel to the XtYt plane), each optical member from the mirror M30 to the second cylindrical lens CYb shown in FIG. It becomes possible to slightly rotate the entire supported casing (unit support frame) around the line segment LE1. In this way, a mechanism that allows the entire support frame of the drawing unit U1 (and the other units U2 to U6 as well) to be slightly rotated around the line segment LE1 (LE2 to LE6) is described in, for example, International Publication No. 2016/152758. Disclosed.

Furthermore, in this embodiment, the intensity of reflected light generated when the spot light SP is projected onto the surface of an irradiated object (substrate P or outer peripheral surface of rotating drum DR) placed on the scanned surface is detected. For this purpose, a photoelectric sensor DTR and a lens system GF are provided. The reflected light from the surface of the irradiated object (particularly regular reflected light) is transmitted to the second cylindrical lens CYb, the fθ lens system FT, the reflective surface RPa of the polygon mirror PM, the mirrors M36, M35, M34, the spherical lens L11, the mirror M33, The light returns to the polarizing beam splitter PBS via the spherical lens L10, the first cylindrical lens CYa, the mirror M32, the quarter-wave plate QW, and the aperture stop AP. The spot light SP projected onto the surface of the irradiated object is circularly polarized light, and its reflected light also contains many circularly polarized components, so the reflected light passes through the quarter-wave plate QW and enters the polarizing beam splitter PBS. When directed, its polarization properties are converted to linear P polarization. Therefore, the reflected light from the surface of the irradiated object passes through the polarization separation surface of the polarization beam splitter PBS and enters the lens system GF. The light receiving surface of the photoelectric sensor DTR is set in an optically conjugate relationship with the spot light SP on the surface to be scanned so that the reflected light from the irradiated object is focused on the light receiving surface of the photoelectric sensor DTR by the lens system GF. be done.

Although not shown in FIG. 3, as disclosed in International Publication No. 2015/166910 or International Publication No. 2016/152758, the reflective surface of the polygon mirror PM on which the drawing beam LB1 is projected. On the reflective surface RPb one position before the rotation direction of RPa, there is a transmitter for the origin sensor for outputting a pulsed origin signal indicating that each reflective surface of the polygon mirror PM has reached the angular position immediately before starting drawing. A light beam is projected. Further, the detailed internal configuration of the drawing unit U1 shown in FIG. 3 is the same for the other drawing units U2 to U6, but each of the even-numbered drawing units U2, U4, and U6 The entire area is rotated 180 degrees around the line segment LE1.

Here, referring again to FIG. 2, the configuration of the pattern drawing apparatus EX will be further described. In the odd-numbered drawing units U3 and U5 including the drawing unit U1 shown in FIG. The line segments LE1, LE3, and LE5 are installed so as to face the rotation center axis AXo of the rotary drum DR when viewed from the Y direction of FIG. On the other hand, in the even-numbered drawing units U2, U4, and U6, the extension lines of each of the line segments LE2, LE4, and LE6 (that is, the extension line of the optical axis AXf2 of the fθ lens system FT) are The line segments LE2, LE4, and LE6 are installed so as to be inclined clockwise by an angle +θc with respect to the central plane CPo. The angle ±θc is set to be as small as possible within a range where the odd numbered drawing units U1, U3, U5 and the even numbered drawing units U2, U4, U6 do not spatially interfere (do not collide).

In this embodiment, the plurality of alignment systems ALGn are arranged at predetermined intervals in the Y direction, and each includes an objective lens system (objective optical system) for detecting marks and the like on the substrate P. The detection area (observation field) set on the substrate P through these objective lens systems is determined by the drawing by each of the drawing units U1 to U6 with respect to the moving direction of the substrate P (circular direction of the outer circumferential surface of the rotary drum DR). It is arranged upstream from the positions of lines SL1 to SL6. The extension line of each optical axis AXs of the objective lens system passing through the center of the detection area (observation field) is directed toward the rotation center axis AXo of the rotary drum DR, and the surface of the substrate P is located at the position of the detection area (observation field). Alternatively, it is set perpendicular to the outer peripheral surface of the rotating drum DR. A reference bar member RB serving as a reference index member on which a reference mark (reference index mark) is formed is attached near the tip of the alignment system ALGn.

The reference mark of the reference bar member RB calibrates the mutual positional relationship of the detection areas (observation fields) by each of the objective lens systems or the mutual positional relationship of the drawing lines SL1 to SL6 by each of the drawing units U1 to U6. It is used to measure the distance (baseline length) and positional relationship between the positions of the drawing lines SL1 to SL6 and each position of the plurality of detection areas in the circumferential direction (direction of movement of the substrate P). When viewed in a plane parallel to the XZ plane, each optical axis AXs of the alignment system ALGn has an angle θa larger than the angle θc of the drawing lines SL1, SL3, and SL5 formed by the odd-numbered drawing units U1, U3, and U5. It is set so that it is tilted counterclockwise from the center plane CPo.

FIG. 4 is a perspective view showing the arrangement relationship among the rotating drum DR, alignment system ALGn, and reference bar member RB shown in FIG. 2, and the orthogonal coordinate system XYZ is the same as the orthogonal coordinate system XYZ in FIG. set to the same. In this embodiment, seven alignment systems ALG1 to ALG7 (collectively referred to as ALGn) having the same configuration are linearly arranged at predetermined intervals in the Y direction. The optical axis AXs of the objective lens system (objective optical system) OBL of the alignment system ALGn is bent by a plane mirror Mb arranged between the objective lens system OBL and the substrate P (outer peripheral surface DRs of the rotating drum DR), and It is set to pass through the center point of the detection area (observation field) ADn (AD1 to AD7) on P. A plate-shaped beam splitter BS1 (synthesizing optical member) inclined with respect to a plane perpendicular to the optical axis AXs is provided in the optical path between the objective lens system OBL and the plane mirror Mb.

The alignment system ALGn further includes a light splitter (beam splitter) BS2 for making the illumination light ILb supplied from the optical fiber bundle ILF incident on the objective lens system OBL to epi-illuminate the detection area ADn, and an objective lens system OBL. The reflected light from the detection area ADn that enters through the light splitter BS2 is received via the imaging lens system Gb, and an enlarged image of the alignment mark (substrate mark) on the substrate P appearing within the detection area ADn is obtained. It has an imaging unit (imaging device) DIS that images the image. In FIG. 4, only the configuration of the alignment systems ALG1 and ALG2, which includes the plane mirror Mb, beam splitter BS1, objective lens system OBL, light splitter BS2, imaging lens system Gb, and imaging unit (imaging element) DIS, is illustrated. , each of the other alignment systems ALG3 to ALG7 has a similar configuration, and the optical axis AXs of each of the alignment systems ALG3 to ALG7 also has a detection area AD3 to AD7 set on the substrate P (not shown in FIG. 4). (omitted).

Further, similarly to the configurations shown in FIGS. 1 and 2, six drawing lines SL1 to SL6 are set on the substrate P in FIG. 4 as well. The odd-numbered drawing lines SL1, SL3, and SL5 are arranged downstream of the detection area ADn of the alignment system ALGn with respect to the conveyance direction (sub-scanning direction) of the substrate P due to the rotation of the rotary drum DR, and the even-numbered drawing lines SL2 , SL4, and SL6 are arranged downstream of the odd-numbered drawing lines SL1, SL3, and SL5. The drawing line SL1 draws a pattern in the area between the line OL01 and the line OL12 extending in the circumferential direction on the substrate P in the Y direction, and the drawing line SL2 draws a pattern in the area between the line OL12 and the line OL12 extending in the circumferential direction on the substrate P. A pattern is drawn in the area between the line OL23 and the Y direction. The line OL12 represents a joint portion (or a portion exposed in a partially overlapping manner) where the pattern exposed by the drawing line SL1 and the pattern exposed by the drawing line SL2 are joined in the Y direction.

The same applies to the other lines OL23, OL34, OL45, and OL56, where the line OL23 represents the joining part of the pattern exposed by the drawing line SL2 and the drawing line SL3, and the line OL34 represents the joint part of the pattern exposed by the drawing line SL3 and the drawing line SL4. The line OL45 represents the joint between the patterns exposed by the drawing line SL4 and the drawing line SL5, and the line OL56 represents the joint between the patterns exposed by the drawing line SL5 and the drawing line SL6. represents the division. In this embodiment, the detection area AD1 of the alignment system ALG1 is arranged around the drawing area defined by the drawing line SL1 shifted in the +Y direction from the line OL01, and the detection area AD7 of the alignment system ALG7 is similarly arranged. It is arranged around the drawing area defined by the drawing line SL6. Detection areas AD2 to AD6 of other alignment systems ALG2 to ALG6 are arranged on lines OL12, OL23, OL34, OL45, and OL56, respectively.

The reference bar member RB is made of a material with a low coefficient of thermal expansion (invar, ceramics, quartz, etc.) and is molded to be elongated in the Y direction, and is attached near the beam splitter BS1 of each of the seven alignment systems ALG1 to ALG7. As the material of the reference bar member RB, it is desirable to use ceramics which can be lightweight, and in particular, it is composed of three components: magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), and silicon dioxide (SiO ₂ ). It is best to use cordierite ceramics. On the reference surface RBa of the reference bar member RB facing the beam splitter BS1, there is a detection area AR1 at a position corresponding to the detection area AD1 (AD2 to AD7) on the substrate P of the alignment system ALG1 (the same applies to ALG2 to ALG7). Set. A reference mark (reference pattern) RM1 that can be observed with the objective lens system OBL via the beam splitter BS1 is formed in the detection area AR1 of the reference surface RBa. On the reference surface RBa of the reference bar member RB, there are detection areas AR2 to AR7 (AR3 to AR7 are omitted) that can be observed by the objective lens system OBL via the beam splitter BS1 of each of the other alignment systems ALG2 to ALG7. Similar reference marks (reference patterns) RM2 to RM7 are formed in each detection area AR2 to AR7.

Therefore, the alignment system ALGn (n=1 to 7) in this embodiment appears in the detection area ADn (n=1 to 7) via the beam splitter BS1 arranged on the tip side of the objective lens system OBL. The alignment mark on the substrate P (or the reference pattern formed on the outer peripheral surface DRs of the rotating drum DR) and the reference mark of the reference bar member RB set within the detection area ARn (n = 1 to 7), The imaging unit DIS allows simultaneous or alternative observation. The reference marks (reference index marks) RM1 to RM7 formed on the reference surface RBa of the reference bar member (reference index member) RB correspond to the interval distance in the Y direction of the detection areas AD1 to AD7 set in the design. formed in each position.

FIG. 5 shows the arrangement relationship between the drawing lines SL1 to SL6 by each of the drawing units U1 to U6 shown in FIG. 4 and the detection areas AD1 to AD7 of each of the alignment systems ALG1 to ALG7, and changes in the rotation angle of the rotary drum DR. FIG. 3 is a diagram illustrating the arrangement of an encoder measurement system that measures (changes in position of the substrate P in the circumferential direction) as viewed in a plane parallel to the XY plane of the orthogonal coordinate system XYZ. Scale disks SDa and SDb are fixed to each of the shafts Sft at both ends of the rotary drum DR in the Y direction coaxially with the central axis AXo so as to rotate together with the rotary drum DR. The diameters of the scale disks SDa and SDb are preferably the same as the diameter of the rotating drum DR, but it is sufficient if the relative difference in diameter is within ±20%. Diffraction grating-like graduations Gm are formed on the cylindrical outer circumferential surfaces of the scale disks SDa and SDb, and are marked at a constant pitch in the circumferential direction. Note that the scale Gm may be directly formed on the outer circumferential surface of each end of the rotary drum DR in the Y direction.

Around the scale disk SDa, three optical encoder heads EHa1, EHa2, and EHa3 for measuring the amount of movement of the scale Gm in the circumferential direction are arranged in a line in the circumferential direction of the outer circumferential surface of the scale disk SDa, and the scale disk SDb Around the scale disc SDb, three optical encoder heads EHb1, EHb2, and EHb3 for measuring the amount of movement of the scale Gm in the circumferential direction are arranged in a line in the circumferential direction of the outer peripheral surface of the scale disc SDb. The circumferential reading position of the scale Gm by the pair of encoder heads EHa1 and EHb1 is set to be the same as the circumferential angular position of each detection area AD1 to AD7 of the alignment systems ALG1 to ALG7 aligned in the Y direction. Ru. Similarly, the circumferential reading position of the scale Gm by the pair of encoder heads EHa2 and EHb2 is set to be the same as the circumferential angular position of the odd-numbered drawing lines SL1, SL3, and SL5 lined up in the Y direction. The circumferential reading position of the scale Gm by the pair of encoder heads EHa3 and EHb3 is set to be the same as the circumferential angular position of even-numbered drawing lines SL2, SL4, and SL6 lined up in the Y direction. Ru. An encoder measurement system having such an encoder head arrangement can minimize Abbe errors in measurement, as disclosed in WO 2013/146184, for example.

In addition, in FIG. 5, if the maximum dimension in the Y direction that can be jointly exposed by six drawing lines SL1 to SL6 is WAy, and the dimension (short length) in the width direction (Y direction) of the substrate P is LPy, then the short length of the substrate P is The length LPy is smaller than the dimension in the Y direction of the outer circumferential surface of the rotary drum DR, and is smaller than the interval dimension in the Y direction between the detection areas AD1 and AD7 of each of the alignment systems ALG1 and ALG7 set at both ends in the Y direction. is set to be larger. Alignment marks (substrate marks) MK1 are arranged in a row at regular intervals (for example, 5 to 20 mm) in the X direction (sub-scanning direction) at the edge of the -Y direction on the substrate P, and in the +Y direction on the substrate P. Alignment marks MK7 are arranged in a row at regular intervals (for example, 5 to 20 mm) in the X direction (sub-scanning direction) at the end of the . Alignment mark MK1 is formed at a position where it appears within detection area AD1 of alignment system ALG1, and alignment mark MK7 is formed at a position where it appears within detection area AD7 of alignment system ALG7.

On the substrate P, alignment marks (MK2 to MK6, not shown in FIG. 5) are also formed so as to appear in each of the detection areas AD2 to AD6 of the alignment systems ALG2 to ALG6. The alignment marks MK1 and MK7 on both end sides are formed continuously along the longitudinal direction on the substrate P, but the other alignment marks MK2 to MK6 are formed at appropriate distances (dimensions) in the longitudinal direction. be done. In this embodiment, a linear region formed by each of the drawing lines SL1 to SL6 or a rectangular region surrounded by the entire drawing lines SL1 to SL6 corresponds to the pattern formation region.

FIG. 6A is a diagram showing an example of the arrangement of reference marks RM1 to RM7 (RM3 to RM6 are omitted) formed at seven locations in the Y direction on the reference surface RBa of the reference bar member RB. In FIG. 6A, a plane parallel to the reference plane RBa is the X'Y' plane of the orthogonal coordinate system X'Y'Z', and an axis parallel to the normal to the reference plane RBa is the Z' axis. Again, the Y' axis of the orthogonal coordinate system X'Y'Z' is parallel to the Y axis of the orthogonal coordinate system XYZ. On the reference surface RBa of the reference bar member RB, reference marks RM1 to RM7 are formed at predetermined intervals in the Y' direction along a virtual straight line CRy extending in the Y' direction (Y direction). . That is, the center points CR1, CR2, . . . CR7 of each of the reference marks RM1 to RM7 are precisely positioned on the virtual straight line CRy.

Here, the distance in the Y' direction (Y direction) between the center point CR1 of the reference mark RM1 and the center point CR2 of the reference mark RM2 is the dimension LBS12, and the distance in the Y' direction (Y direction) between the center point CR3 and the center point CR2 of the reference mark RM3 ( The distance in the Y direction (Y direction) is the dimension LBS23, the distance in the Y' direction (Y direction) between the center point CR4 and the center point CR3 of the reference mark RM4 is the dimension LBS34, and the distance Y' between the center point CR5 and the center point CR4 of the reference mark RM5 is the dimension LBS23. The distance in the direction (Y direction) is the dimension LBS45, the distance in the Y' direction (Y direction) between the center point CR6 and center point CR5 of the reference mark RM6 is the dimension LBS56, and the center point CR7 and the center point CR6 of the reference mark RM7. The interval in the Y' direction (Y direction) is defined as dimension LBS67. In this embodiment, the dimension LBS12 and the dimension LBS67 are set to the same value, and the dimensions LBS23, LBS34, LBS45, and LBS56 are set to the same value.

FIG. 6B is an exaggerated representation of an example of the arrangement relationship in the X'Y' plane between the imaging area DIS' by the image sensor DIS of the alignment system ALG1 and the reference mark RM1 on the reference bar member RB. , FIG. 6C is an exaggerated representation of an example of the arrangement relationship in the X'Y' plane between the imaging region DIS' by the image sensor DIS of the alignment system ALG2 and the reference mark RM2 on the reference bar member RB. . In FIG. 6B, if the center point (reference point) in the X' direction and Y' direction of the two-dimensional imaging area DIS' is CC1, the reference bar member RB and the alignment system ALG1 may be The center point CR1 of the mark RM1 in the X' and Y' directions and the center point CC1 of the imaging area DIS' are shifted by a predetermined installation error ΔC1. In FIG. 6B, the installation error ΔC1 is +ΔXC1 (μm) in the X' direction and +ΔYC1 (μm) in the Y' direction, with the center point CR1 of the reference mark RM1 as the reference (origin).

Similarly, in FIG. 6C, if the center point (reference point) in the X' direction and Y' direction of the two-dimensional imaging region DIS' is CC2, the relative installation error between the reference bar member RB and the alignment system ALG2 Therefore, the center point CR2 of the reference mark RM2 in the X' and Y' directions and the center point CC2 of the imaging area DIS' are shifted by a predetermined installation error ΔC2. In FIG. 6C, the installation error ΔC2 is -ΔXC2 (μm) in the X' direction and -ΔYC2 (μm) in the Y' direction, with the center point CR2 of the reference mark RM2 as the reference (origin). Note that the center points CC1 and CC2 of the imaging area DIS' correspond to one specific imaging pixel located at the center of a large number of imaging pixels distributed in a two-dimensional matrix on the imaging surface. , does not need to be strictly the true center point of the imaging area DIS'; for example, it may be the position of a specific imaging pixel that is shifted from the true center point in the X' direction or Y' direction by several to ten pixels. The center points (reference points) CC1 and CC2 may also be used.

Similarly, for each of the other alignment systems ALG3 to ALG7, there are installation errors between each of the center points CC3 to CC7 of each imaging area DIS' and each of the center points CR3 to CR7 of the reference marks RM3 to RM7. Assume that there are ΔC3 to ΔC7. Information regarding these installation errors ΔC1 to ΔC7 is obtained from the alignment system ALG1 when assembling the device, during adjustment (calibration) work performed at an appropriate timing during device operation, or during maintenance inspection (maintenance) work of the device. It is obtained by image analysis of the video signal from each image sensor DIS of ~ALG7, and can be updated as appropriate. Note that in FIGS. 6B and 6C, the reference marks RM1 and RM2 (as well as RM3 to RM7) are set to appear in an L-shape at the four corners of the imaging area DIS'; It may be set so that it appears in the central part of the imaging area DIS', or in a part to the left or right of the center.

FIG. 7 is a diagram showing the optical configuration of the alignment system ALGn (n=1 to 7) according to the present embodiment, and the orthogonal coordinate system XYZ is set in the same manner as in FIGS. 1 to 5 above. Further, the orthogonal coordinate system XtYtZt is the same as that shown in FIG. 3 above. Furthermore, in FIG. 7, the same members and structures as those described in FIGS. 4 and 5 are given the same reference numerals. In this embodiment, an optical microscope whose working distance is set to 10 cm or more is used as the alignment system ALGn. Such a microscope is sold as a machine vision lens by Moritex Co., Ltd., for example, and can also be used.

In this embodiment, as shown in FIG. 7, the entire alignment system ALGn is fixed to a support bracket (not shown) made of metal or ceramics with a low coefficient of thermal expansion. The support bracket is formed into a plate shape parallel to the XZ plane, and is fixed to a structural part (metrology frame) connected to the apparatus frame part that supports the drawing units U1 to U6. The support bracket has an angle θe (θe>0 ) A plate-type (parallel plate-like) beam splitter BS1 (synthetic optical member) made of a transmission optical glass material such as quartz, which is arranged at an angle of 100 degrees, and an illumination system (illumination unit) that epi-illuminates the detection area ADn of the alignment system ALGn. A beam splitter BS2 that guides the illumination light ILb from the ILU, an imaging lens system Gb, and an image sensor DIS are fixed.

As shown in FIG. 7, the illumination light ILb for epi-illumination is supplied from the illumination system ILU to the beam splitter BS2 from the output end ILFb of the optical fiber bundle ILF via the optical fiber bundle (multimode fiber) ILF. . In FIG. 7, the pupil plane (aperture stop plane) Ep of the objective lens system OBL is formed on the imaging lens system Gb side of the beam splitter BS2, and the pupil plane (aperture stop plane) Ep of the objective lens system OBL is also formed on the optical fiber bundle ILF side of the beam splitter BS2. A pupil plane (aperture stop plane) Ep' is formed. The output end ILFb of the optical fiber bundle ILF is arranged to substantially coincide with the pupil plane Ep', and the output end ILFb becomes a surface light source image of the illumination light ILb that is irradiated onto each detection area ADn or ARn. The optical fiber bundle ILF is configured as a light guide member made by bundling a large number of optical fiber strands, and the surface light source image formed at the output end ILFb has the shape of the light intensity distribution of the illumination light ILb formed at the input end ILFa. It will be saved.

The illumination light ILb from the output end ILFb of the optical fiber bundle ILF is reflected by the beam splitter BS2, enters the objective lens system OBL, passes through the beam splitter BS1, and is then reflected by the plane mirror Mb to reach the detection area on the substrate P. It is projected onto ADn (alignment mark MKn). The light reflected by the detection area ADn on the substrate P passes through the beam splitter BS1 and the objective lens system OBL, becomes an imaging light beam (reflected light) Bma, passes through the beam splitter BS2, and passes through the imaging lens system Gb. The image sensor DIS is reached through the image sensor DIS. The imaging surface Pis of the image sensor DIS is set to have an optically conjugate relationship (imaging relationship) with the surface of the detection area ADn on the substrate P, and is also set to have an optically conjugate relationship (imaging relationship) with the surface of the detection area ADn on the substrate P, and is connected to the reference surface RBa of the reference bar member RB via the beam splitter BS1. (Detection area ARn) is also set in an optically conjugate relationship (imaging relationship).

In this embodiment, approximately 20 to 40% of the intensity of the illumination light ILb emitted from the objective lens system OBL is transmitted to the surface of the plate-shaped beam splitter BS1 (the light splitting surface) depending on the angle θe. , photosynthesis surface) Bsp, and heads toward the reference bar member RB. The reference surface RBa of the reference bar member RB is set at a position optically corresponding to the surface of the substrate P, and the detection area ARn set on the reference surface RBa is illuminated with a uniform illuminance distribution by a part of the illumination light ILb. Ru. The reflected light beam Bmr generated by the reference mark RMn arranged in the detection area ARn reaches the beam splitter BS1 along the optical axis AXs', is reflected by the surface Bsp, and is combined with the imaging light beam Bma to be sent to the objective lens system. Enter the OBL. Note that the plate-type beam splitter BS1 shown in FIG. 7 is of a non-polarizing type, and may be made of a glass material other than quartz.

Therefore, when the illumination light ILb is projected from the output end ILFb of the optical fiber bundle ILF, both the detection area ADn set on the substrate P and the detection area ARn set on the reference bar member RB are simultaneously illuminated by the illumination light ILb. It is epi-illuminated by. Therefore, the image of the alignment mark MKn of the substrate P appearing in the detection area ADn (or the image of the reference pattern on the rotating drum DR) and the reference mark in the detection area ARn are included in the imaging area DIS' of the image sensor DIS. The image of RMn is combined and formed simultaneously. The image sensor DIS outputs a video signal corresponding to each captured image of the alignment mark MKn and reference mark RMn. In this embodiment, the output end ILFb of the optical fiber bundle ILF is set to be located at the position of the pupil plane Ep' of the microscope optical system by the objective lens system OBL, and the output end ILFb, which has a substantially circular outer shape, is located at the pupil plane Ep' of the microscope optical system. It becomes a secondary light source image within the plane Ep', and telecentric epi-illumination (Kohler illumination) is performed.

The plate-type beam splitter BS1 shown in FIG. It was configured to face the reference bar member RB arranged in the space below ALGn. However, when the reference bar member RB is installed in the space above the alignment system ALGn, the inclination of the beam splitter BS1 with respect to the plane perpendicular to the optical axis AXs may be set in the opposite direction (-θe). In addition, the thickness of the plate-type beam splitter BS1 should be made as thin as possible to reduce the occurrence of various optical aberrations (such as asperity) and to maintain rigidity that does not cause deformation or distortion that would deteriorate surface accuracy. good.

In addition, by leaving the surface of the plate-type beam splitter BS1 in a solid state without forming an antireflection film (AR coat), the light splitting surface (photosynthesis surface) Bsp can have an appropriate reflectance depending on the angle θe. can be set. Further, the angle θe is determined by the angle 2θe formed by the optical axis AXs and the optical axis AXs' (the arrangement of the reference bar member RB within the XZ plane), but if the angle θe becomes, for example, 45° or more, the reference bar member Since the intensity of the illumination light ILb directed toward RB increases and the intensity of the illumination light ILb directed toward the substrate P decreases extremely, the angle θe is set in the range of 0°<θe<45°, more preferably 5°. It is preferable to set it in the range of ≦θe≦30°. Further, the thickness of the plate-type beam splitter BS1 may be 1 mm or less, for example, 0.1 mm, and a structure that allows adjustment of the angle θe may be provided.

The illumination system (illumination unit) ILU shown in FIG. 7 includes a light source section ILS including a solid-state light source such as an LED or a halogen lamp light source, a lens system GR, and two parallel flat plates SFy and SFz made of a transparent glass material. The lens system GR condenses the illumination light ILb from the light source part ILS so that it forms a circular distribution with a predetermined diameter on the circular input end ILFa of the optical fiber bundle ILF. The parallel plate SFy is provided so as to be tiltable around an axis parallel to the Zt axis in the coordinate system XtYtZt in FIG. Adjust the shift. The parallel plate SFz is provided so as to be tiltable around an axis parallel to the Yt axis in the coordinate system XtYtZt in FIG. Adjust the shift.

In this embodiment, since the input end ILFa and the output end ILFb of the optical fiber bundle ILF correspond optically, the output can be adjusted by shifting and adjusting the position of the illumination light ILb condensed onto the input end ILFa. The distribution of the illumination light ILb (circular) formed as a light source image on the end ILFb can be shifted laterally within the pupil plane Ep' (in a plane perpendicular to the optical axis AXs). In this embodiment, the position of the light source image is changed by tiltable parallel flat plates SFy and SFz to reduce the telecenter error of the alignment system ALGn (the tilt error of the optical axis AXs of the objective lens system OBL with respect to the perpendicular to the surface of the substrate P). An adjustment mechanism is configured to compensate for the influence of Incidentally, the inclination adjustment of the parallel plates SFy and SFz may be performed manually or may be motorized using a small actuator (such as a piezo motor).

Here, the occurrence of a telecenter error in the alignment system ALGn and its influence will be explained with reference to FIG. 8. FIG. 8 is a diagram schematically showing the optical arrangement of the objective lens system OBL, beam splitter BS2, and output end ILFb of the optical fiber bundle ILF in FIG. 7, and the plane mirror Mb and beam splitter BS1 are not shown. There is. Further, in FIG. 8, it is assumed that the optical axis AXs passing through the objective lens system OBL is bent at 90° by the beam splitter BS2 and passes through the center of the circular output end ILFb of the optical fiber bundle ILF. Furthermore, in order to explain the telecenter error, it is assumed that the angle formed by the surface of the substrate P (detection area ADn) and the optical axis AXs is slightly tilted from 90 degrees.

The maximum diameter of the output end ILFb of the optical fiber bundle ILF located on the pupil plane Ep' on the illumination system ILU side of the beam splitter BS2 is set to be equal to or slightly smaller than the diameter φe of the pupil plane Ep'. If the light source image formed by the illumination light ILb formed at the output end ILFb is SOb, its diameter φs is set to about half (40 to 60%) of the maximum diameter of the output end ILFb. The numerical aperture (spread angle) NAi of the illumination light ILb irradiated onto the detection area ADn on the substrate P is determined based on the focal length fob of the objective lens system OBL and the diameter φs of the light source image SOb on the pupil plane Ep'. It is defined as ≒sin(φs/2/fob). Also, the ratio (φs/φe) between the diameter φe of the pupil plane Ep' and the diameter φs of the light source image SOb is called the σ value (≦1), and changing the diameter φs of the light source image SOb, that is, changing the σ value By this, the numerical aperture NAi of the illumination light ILb can be adjusted.

As shown in FIG. 8, assuming that the optical axis AXs coincides with the center point of the light source image SOb (the intersection of the Y axis and the Z' axis), the principal ray ( The light rays generated from the center point on the optical axis AXs of the light source image SOb reach the substrate P in parallel with the optical axis AXs. However, since the normal to the surface of the substrate P and the optical axis AXs are relatively slightly tilted, the chief ray of the reflected light LRf that is regularly reflected at the detection area ADn is also tilted with respect to the optical axis AXs. and enters the objective lens system OBL. The principal ray of the reflected light LRf that has passed through the objective lens system OBL is decentered from a position on the optical axis AXs in the pupil plane Ep on the imaging lens system Gb side of the beam splitter BS2, for example, in a direction along the Z' axis. The light intersects (focuses) at the position. Therefore, in the pupil plane Ep, eccentric from the center point (the intersection of the Y axis and the Z' axis) in the +Z' direction, there are an output end image ILFb' of the optical fiber bundle ILF and a reflected light source image of diameter φs caused by the reflected light LRf. SOb' is formed.

In FIG. 8, the entire reflected light source image SOb' is located within the pupil plane Ep, but around the reflected light source image SOb' there are scattered lights and other light generated from the surface of the substrate P (detection area ADn). The diffracted light is distributed with a predetermined spread. Due to the telecentering error, some of the scattered light and diffracted light will protrude from the circular pupil plane Ep, which will destroy the symmetry of the imaging light beam Bma that enters the imaging lens system Gb, and the image sensor The image quality of the alignment mark MKn imaged by the DIS, especially the edge image of the alignment mark MKn in the direction in which the telecentering error occurs, deteriorates. Therefore, an error occurs in position measurement of the alignment mark MKn by image analysis based on the video signal.

When the telecentering error becomes larger than the state shown in FIG. 8, the reflected light source image SOb' itself also protrudes (is vignetted) from the circular pupil plane Ep, and the amount of light of the reflected light source image SOb' entering the imaging lens system Gb decreases. (0th-order reflected light amount) decreases, and the symmetry of scattered light and diffracted light within the pupil plane Ep is significantly disrupted. Therefore, the brightness of the mark image of the alignment mark MKn captured by the image sensor DIS is significantly reduced, and the image quality of the mark image is also significantly degraded.

Therefore, in this embodiment, the light source image of the illumination light ILb condensed on the input end ILFa of the optical fiber bundle ILF is shifted within the plane of the input end ILFa using the parallel plates SFy and SFz shown in FIG. to correct the influence of telecenter error. Similar to FIG. 8, FIG. 9 is a diagram schematically showing the optical arrangement of the objective lens system OBL, beam splitter BS2, and output end ILFb of the optical fiber bundle ILF in FIG. As shown in FIG. 9, by adjusting the parallel flat plates SFy and SFz (particularly the parallel flat plate SFz), the center point of the light source image SOb formed at the output end ILFb of the optical fiber bundle ILF is moved in the +Z' direction from the position of the optical axis AXs. can be shifted to.

As a result, the principal ray of the illumination light ILb irradiated from the objective lens system OBL to the detection area ADn on the substrate P is tilted from a state parallel to the optical axis AXs by an angle corresponding to the telecenter error of the alignment system ALGn, and The chief ray of the reflected light LRf from the surface of P can be set parallel to the optical axis AXs. Therefore, in the pupil plane Ep, there is an output end image ILFb' of the optical fiber bundle ILF concentrically with the center point (the intersection of the Y axis and the Z' axis), and a reflected light source image SOb' with a diameter φs caused by the reflected light LRf. is formed. Therefore, the symmetry of the imaging light beam Bma incident on the imaging lens system Gb is maintained, and deterioration of the image quality (edge image) of the alignment mark MKn imaged by the image sensor DIS can be prevented. By adjusting the inclination of the two parallel plates SFy and SFz, the position of the light source image SOb formed at the output end ILFb of the optical fiber bundle ILF can be independently adjusted in the Y-axis direction and the Z'-axis direction within the pupil plane Ep'. Since it can be adjusted, it can cope with two-dimensional (Y-axis direction and Z'-axis direction) telecentering errors.

As described above, in this embodiment, the influence of the telecenter error of the alignment system ALGn is corrected by adjusting the inclination of the parallel plates SFy, SFz. However, if the parallel plates SFy, SFz are not provided, The lens system GR in 7 may be made tiltable, and the relative positional relationship between the illumination system ILU and the input end ILFa of the optical fiber bundle ILF may be physically adjusted in the Y-axis direction or Z'-axis direction. A mechanism (fine movement mechanism) may be provided. Further, an adjustment mechanism (fine movement mechanism) may be provided to finely move the output end ILFb of the optical fiber bundle ILF two-dimensionally along the pupil plane Ep' with respect to the beam splitter BS2. In short, in this embodiment, the alignment system ALGn is assembled by laterally shifting (decentering) the position of the light source image formed on the pupil plane Ep' of the objective lens system OBL of the epi-illumination type alignment system ALGn. It is possible to correct the image quality deterioration of the mark image due to the telecentering error that remains afterwards. Furthermore, in this embodiment, the light source image is shifted on the incident end ILFa side of the optical fiber bundle ILF that transmits the illumination light ILb for epi-illumination. Therefore, even if multiple alignment systems ALGn are closely lined up and it is difficult to manually adjust the telecentering error to the allowable range (such as adjusting the posture of the support bracket that supports the alignment system ALGn), it is easy to eliminate the negative effects of the remaining telecentering error. can be reduced to

[Second embodiment]
FIG. 10 is a diagram showing a schematic optical configuration of the alignment system ALGn according to the second embodiment, and the orthogonal coordinate system XYZ and the orthogonal coordinate system XtYtZt are set in the same manner as in FIG. 7 above. Further, in the alignment system ALGn of FIG. 10, the same reference numerals are given to the same optical members and arrangement relationships as those of the alignment system ALGn of FIG. In this embodiment, the plate-shaped beam splitter BS1 disposed in the optical path between the objective lens system OBL and the plane mirror Mb is provided with wavelength selection characteristics, and the beam splitter BS1 that appears within the detection area ADn set on the substrate P is provided with wavelength selection characteristics. A configuration in which the wavelength component of the illumination light ILb that irradiates the alignment mark MKn is different from the wavelength component of the illumination light ILb that irradiates the reference mark RMn within the detection area ARn set on the reference surface RBa of the reference bar member RB. do.

In FIG. 10, the output end ILFb of the optical fiber bundle ILF is arranged at or near the pupil plane Ep' of the objective lens system OBL, and the output end ILFb of the optical fiber bundle ILF is located at or near the pupil plane Ep'. A thin diffuser plate (frosted glass) Gdf is provided at the position. The output end ILFb of the optical fiber bundle ILF and the diffuser plate Gdf may be placed in close contact with each other without leaving a gap in the optical axis direction as shown in FIG. The diffuser plate Gdf smoothes the intensity distribution of the light source image SOb formed on the pupil plane Ep', improving its uniformity.

In this embodiment, the illumination light ILb transmitted by the optical fiber bundle ILF is supplied from an illumination system (illumination unit) ILU including a metal halide lamp having an intensity distribution in a wavelength band of 400 nm to 700 nm, for example. Of the illumination light ILb, for example, a component with a wavelength shorter than 480 nm is defined as illumination light ILb1, and a component with a wavelength longer than 480 nm is defined as illumination light ILb2. The illumination light ILb from the output end ILFb of the optical fiber bundle ILF is reflected by the beam splitter BS2 which is non-polarized and has no wavelength selection characteristics, enters the objective lens system OBL, and reaches the beam splitter BS1.

The beam splitter BS1 in FIG. 10 is configured, for example, as a dichroic mirror with a wavelength of 480 nm as a crossover wavelength, and among the illumination light ILb, the illumination light ILb1 whose wavelength component is shorter than 480 nm is connected to the objective lens system OBL of the beam splitter BS1. It is reflected by the side surface Bsp and heads toward the reference bar member RB. At the same time, of the illumination light ILb, the illumination light ILb2 having a wavelength component longer than 480 nm passes through the surface Bsp of the beam splitter BS1 on the objective lens system OBL side, and heads toward the substrate P via the plane mirror Mb. A dielectric multilayer film designed to serve as a dichroic mirror with a crossover wavelength of 480 nm is formed on the front surface Bsp of the beam splitter BS1, and an antireflection film (AR coating layer) is formed on the back surface Bsp' of the back side of the beam splitter BS1. ) is formed.

The reflected light flux Bmr from the reference mark RMn (detection area ARn) of the reference bar member RB, which is irradiated with the illumination light ILb1 reflected by the beam splitter BS1, is reflected again by the surface Bsp of the beam splitter BS1 and enters the objective lens system OBL. incident. On the other hand, the imaging light flux (reflected light) Bma from the alignment mark MKn (detection area ADn) on the substrate P, which has been irradiated with the illumination light ILb2 that has passed through the beam splitter BS1, passes through the beam splitter BS1 again and is set in the objective lens system. Enter the OBL. The reflected light flux Bmr and the imaging light flux (reflected light) Bma that entered the objective lens system OBL are transmitted through the beam splitter BS2 and become an imaging light flux via the imaging lens system Gb, which is then imaged by the image sensor DIS. The plane Pis is reached. Thereby, the image of the alignment mark MKn and the image of the reference mark RMn can be detected simultaneously by the image sensor DIS.

In this embodiment as well, as in FIG. 7, the illumination light ILb incident on the input end ILFa of the optical fiber bundle ILF is shifted in the Y-axis direction and the Z'-axis direction by the parallel plates SFy and SFz, and the remaining It is possible to reduce the negative effects caused by telecenter errors. In this embodiment, for example, a metal halide lamp having wavelength characteristics as shown in FIG. 11 is used as the light source part ILS of the illumination system ILU that supplies illumination light ILb (ILb1, ILb2) to the optical fiber bundle ILF. FIG. 11 is a graph showing an example of the emission wavelength characteristics of a metal halide lamp containing tin halide, where the horizontal axis represents wavelength (nm) and the vertical axis represents relative emission intensity (%).

In the emission wavelength characteristics shown in FIG. 11, the illumination light ILb1 having a wavelength component (ultraviolet wavelength) shorter than 480 nm may expose the photosensitive layer (photoresist, etc.) formed on the surface of the substrate P. In this embodiment, the substrate P is not irradiated with a photosensitive wavelength component due to the wavelength selection characteristics of the beam splitter BS1. In addition, since the illumination light ILb2 irradiated onto the substrate P has a wide wavelength band of 480 nm to 650 nm, interference phenomena may occur when observing the alignment mark MKn on the substrate P through a light-transmitting photosensitive layer or thin film layer. can be reduced. Note that in this embodiment, the crossover wavelength of the beam splitter BS1 as a dichroic mirror is set to 480 nm, but it may be set to any wavelength depending on the photosensitive wavelength characteristics of the photosensitive layer formed on the surface of the substrate P. .

Further, the dichroic mirror of beam splitter BS1 emits illumination light ILb1 from a first light source that generates light in a wavelength band shorter than the crossover wavelength, and illumination light ILb1 from a second light source that generates light in a wavelength band longer than the crossover wavelength. The illumination light ILb2 from the light source may be coaxially combined and made to enter the input end ILFa of the optical fiber bundle ILF. In that case, the illuminance balance between the image of the alignment mark MKn and the image of the reference mark RMn observed by the image sensor DIS can be adjusted by individually controlling the emission intensity of the first light source and the second light source. Can be done. Alternatively, a liquid crystal shutter whose transmittance can be electrically changed may be provided in the optical path between the beam splitter BS1 and the reference bar member RB to adjust the balance. When a liquid crystal shutter is provided, by minimizing its transmittance, observation of the reference mark RMn of the reference bar member RB by the image sensor DIS is prevented, and only the alignment mark MKn on the substrate P is observed.

As described above, according to the present embodiment, the beam splitter BS1 of the alignment system ALGn is provided with wavelength selection characteristics, and the illumination light ILb1 is directed to the detection area ARn on the reference bar member RB and the detection area ADn on the substrate P. Since the illumination light ILb2 is separated by the wavelength band, compared to the configuration shown in FIG. It can be suppressed. Furthermore, if the image sensor DIS is a color image sensor, the image of the alignment mark MKn on the substrate P and the image of the reference mark RMn on the reference bar member RB can be easily separated by color during image processing. Therefore, there is an advantage that false detections and the like can be reduced.

[Modification 1]
FIG. 12 is a schematic diagram showing a modification of the illumination system (illumination unit) ILU for the alignment system ALGn of FIG. 10. In this modification, two types of high-intensity LED (light emitting diode) light sources with different emission wavelength characteristics are used by utilizing the wavelength selection characteristics of the beam splitter BS1 of the alignment system ALGn. In FIG. 12, an LED light source LD1 as a first light source outputs illumination light ILb1 having an emission peak wavelength in a wavelength range (for example, blue) shorter than the crossover wavelength (for example, 480 nm) of the beam splitter BS1, and The LED light source LD2 as a light source outputs illumination light ILb2 having a plurality of emission peak wavelengths in a wavelength range (eg, green to red) longer than the crossover wavelength (eg, 480 nm) of the beam splitter BS1. The illumination light ILb1 from the LED light source LD1 is focused by the condensing lens system GS1 and reflected at right angles by the dichroic mirror DCM, and then transmitted through parallel plates SFy and SFz onto the input end ILFa of the optical fiber bundle ILF. The light source image SOa is formed.

Similarly, the illumination light ILb2 from the LED light source LD2 is focused by the condenser lens system GS2, passes through the dichroic mirror DCM, is coaxially combined with the illumination light ILb1, and then passes through the parallel plates SFy and SFz. Then, the light source image SOa is formed on the input end ILFa of the optical fiber bundle ILF. The wavelength selection characteristics of the dichroic mirror DCM in FIG. 12 are set similarly to the wavelength selection characteristics of the beam splitter BS1 of the alignment system ALGn, and the crossover wavelength is set to, for example, 480 nm.

FIG. 13 is a graph schematically showing the wavelength selection characteristics of the dichroic mirror DCM and the emission wavelength characteristics of each of the LED light sources LD1 and LD2, where the horizontal axis represents the wavelength (nm) and the vertical axis represents the wavelength selection characteristics of the dichroic mirror DCM. represents the transmittance/reflectance (%) of The dichroic mirror DCM has a reflectance of 90 to 95% for light in a wavelength band shorter than 480 nm, and has a transmittance of 5% or less for light in a wavelength band longer than 480 nm. It has a transmittance of 90 to 95% and a reflectance of 5% or less. For example, the LED light source LD1 outputs blue illumination light ILb1 having an emission peak wavelength near 440 nm, but the emission peak wavelength may be shorter than 460 nm. The LED light source LD2 is composed of a multicolor light emitting diode, and as an example, it emits green light having a peak emission wavelength around 520 nm, yellow light having a peak emission wavelength around 590 nm, and light having a wavelength around 670 nm. The illumination light ILb2 is synthesized with red light having an emission peak wavelength.

Further, as shown in FIG. 12, the emission intensity (drive current) of each of the LED light sources LD1 and LD2 can be adjusted individually by the lighting control unit LCU, and according to changes in the reflectance of the surface of the substrate P, The illuminance balance of the illumination lights ILb1 and ILb2 can be optimally adjusted. Note that the LED light source LD2 is replaced with a halogen lamp instead of a multicolor light emitting diode, and the illumination light ILb2 is made incident on the condensing lens system GS2 through a wavelength filter that cuts a wavelength band shorter than 520 nm. It's okay. Furthermore, by adopting a configuration in which the focal length (f value) and the position in the optical axis direction of the condensing lens systems GS1 and GS2 in FIG. 12 can be changed, the light source image SOa formed on the input end ILFa of the optical fiber bundle ILF is As a result, the numerical aperture (NA value) of the epi-illumination via the objective lens system OBL of the alignment system ALGn can be adjusted. In addition, when the focal lengths and positions in the optical axis direction of the condenser lens systems GS1 and GS2 are individually made variable, the diameter of the light source image SOa by the illumination light ILb1 formed on the input end ILFa of the optical fiber bundle ILF, The diameter of the light source image SOa caused by the illumination light ILb2 can be made different.

[Modification 2]
FIG. 14 is a diagram showing a modification of the optical configuration of the light guide member that transmits the illumination light ILb from the illumination system ILU to the alignment system ALGn shown in FIG. 7 or FIG. 10. The detection area ADn on the substrate P and the detection area ARn on the reference bar member RB by the objective lens system OBL of the alignment system ALGn have a size of about 1 mm square to 0.6 mm square, and the pupil plane Ep of the objective lens system OBL, The maximum diameter φe of Ep' is about 5 mm to 10 mm. On the other hand, from the viewpoint of cost and flexibility, the optical fiber bundle ILF may be one in which the effective diameter (bundle diameter) of the input end ILFa and output end ILFb is about 1 mm to 3 mm. In this case, the light source image SOb (see FIG. 8 or 9) formed at the output end ILFb of the optical fiber bundle ILF is largely positioned (shifted) from the center point in the pupil plane Ep' in the Y-axis direction or Z'-axis direction. It becomes difficult to move.

Therefore, in this modification, as shown in FIG. 14, the illumination light ILb from the light source image SOa' with a diameter φc created by the light source part ILS in the illumination system ILU is transmitted through parallel plates SFy and SFz to a positive The light is focused on the input end ILFa of the optical fiber bundle ILF through a reduction imaging system LK1 with a magnification MJ1 formed by a lens Gw1 and a positive lens Gw2. The reduction imaging system LK1 makes the position of the light source image SOa' of the light source section ILS and the input end ILFa of the optical fiber bundle ILF into an optically conjugate relationship, and reduces the light source image SOa' having a diameter φc by a magnification MJ1. An image is formed on the incident end ILFa. For example, when the diameter φc of the light source image SOa' is 6 mm and the bundle diameter of the optical fiber bundle ILF is 1 mm, the magnification MJ1 of the reduction imaging system LK1 is set to about 1/10 times, and the input end of the optical fiber bundle ILF is The diameter φs' of the light source image SOa formed on ILFa is 0.6 mm. Further, when the diameter φc of the light source image SOa' is 6 mm and the bundle diameter of the optical fiber bundle ILF is 2 mm, the magnification MJ1 of the reduction imaging system LK1 is set to about 1/5 times, and the input end of the optical fiber bundle ILF is The diameter φs' of the light source image SOa formed on ILFa is 1.2 mm.

As shown in FIG. 14, at the input end ILFa (and the output end ILFb as well) of the optical fiber bundle ILF, the end faces of a large number of bundled optical fiber strands FBu are densely arranged in a circular shape. The optical fiber bundle ILF is a multi-mode optical fiber bundle ILF similar to the optical fiber bundles ILF shown in FIGS. 7 and 10, and the light source image SOa formed at the input end ILFa is maintained in its shape, size, and arrangement. A light source image SOb is formed at the output end ILFb. The illumination light ILb from the light source image SOb formed at the output end ILFb of the optical fiber bundle ILF passes through the magnifying imaging system LK2 with a magnification MJ2 of a positive lens Gw3 and a positive lens Gw4 to the pupil shown in FIG. 7 or FIG. The light is focused on the plane Ep'. The magnifying imaging system LK2 makes the position of the output end ILFb of the optical fiber bundle ILF and the pupil plane Ep' in an optically conjugate relationship, and enlarges the diameter of the light source image SOb of the output end ILFb by a magnification MJ2 to form the pupil plane. A light source image SOc' with a diameter φs is formed on Ep'. In this modification, as shown in FIG. 14, a diffuser plate Gdf similar to that in FIG. 10 is provided at the position of the pupil plane Ep', but it may be omitted as shown in FIG.

As in the previous numerical example, when the bundle diameter of the optical fiber bundle ILF is 1 mm and the magnification MJ1 of the reduction imaging system LK1 is 1/10 times, the magnification MJ2 of the expansion imaging system LK2 is set to about 8 times, The light source image SOb having a diameter of 0.6 mm formed at the output end ILFb of the optical fiber bundle ILF is expanded to a light source image SOc' having a diameter φs of about 4.8 mm at the pupil plane Ep'. Furthermore, when the bundle diameter of the optical fiber bundle ILF is 2 mm and the magnification MJ1 of the reduction imaging system LK1 is 1/5, the magnification MJ2 of the expansion imaging system LK2 is set to about 4 times, and the output end of the optical fiber bundle ILF is The light source image SOb with a diameter of 1.2 mm formed on the ILFb is expanded into a light source image SOc' with a diameter φs of about 4.8 mm at the pupil plane Ep'. As an example, when the maximum diameter of the pupil plane Ep' (Ep) is 8 mm, and the diameter φs of the light source image SOc' is 4.8 mm, the σ value is approximately 0.6 (=4.8/8). .

In the above configuration of FIG. 14, the magnification MJ1 of the reduction imaging system LK1 and the magnification MJ2 of the expansion imaging system LK2 are the dimensions (diameter) of the light source image SOa' created by the light source section ILS, and the size (diameter) of the light source image SOa' formed on the pupil plane Ep'. It is appropriately set depending on the size (diameter) of the light source image SOc' and the bundle diameter of the optical fiber bundle ILF. However, between the bundle diameter of the input end ILFa of the optical fiber bundle ILF, the diameter φs' of the light source image SOa formed at the input end ILFa, and the shift range of the light source image SOa by the parallel plates SFy and SFz in FIG. Certain conditions exist. This will be explained with reference to FIG. 15.

FIG. 15 is a diagram schematically showing the state of the light source image SOa formed within the plane of the input end ILFa of the optical fiber bundle ILF shown in FIG. be done. In FIG. 15, the periphery of an optical fiber bundle ILF in which optical fiber wires are bundled is covered with a light-shielding covering material (tube) indicated by diagonal lines. Let the center point of the circular incident end ILFa be the intersection Oc of the Y-axis and the Z' axis (also called the origin Oc through which the optical axis AXs shown in FIG. 14 passes), and let the diameter (bundle diameter) of the incident end ILFa be φbd. . In addition, the range in which the position of the light source image SOa having a circular diameter φs' can be shifted without protruding from within the incident end ILFa is such that the center point Cso of the light source image SOa is a circular region Cs with a radius Rss centered on the origin Oc. This is the range located within.

When the respective inclination angles of the parallel plates SFy and SFz shown in FIG. 14 are in the initial state (perpendicular to the optical axis AXs), the center point Cso of the light source image SOa coincides with the origin Oc, and the parallel plates SFy, It is assumed that by adjusting each inclination angle of SFz, the center point Cso of the light source image SOa is shifted by ΔYs from the origin Oc in the Y-axis direction and by ΔZs in the Z'-axis direction. As shown in FIG. 15, the diameter φbd of the incident end ILFa and the diameter φs' of the light source image SOa are set to have a relationship of φbd>φs', which is a natural premise. Furthermore, taking into account the optical characteristics of the alignment system ALGn and the adjustment range of the telecenter error (corresponding to the length of the radius Rss of the region Cs), the diameter φs' of the light source image SOa is 0.2 to 0.8 of the diameter φbd. Set to twice the range. Then, the range of the positional shift amounts ΔYs and ΔZs of the light source image SOa is as follows under the precondition of φbd>φs'.
(φbd-φs')/2≧Rss ² =(ΔYs) ² +(ΔZs) ²
is set to satisfy the relationship.

As an example, when the diameter φbd of the input end ILFa of the optical fiber bundle ILF is 2 mm and the diameter φs' of the light source image SOa is 0.4 mm, the maximum value of the radius Rss of the region Cs is 0.8 mm. In this case, the light source image SOb formed at the output end ILFb of the optical fiber bundle ILF shown in FIG. 14 also has a diameter of 0.4 mm, which is the same as the diameter φs'. The diameter φs' of the light source image SOc' formed on the pupil plane Ep' of ALGn is 1.6 mm, and the maximum range of position shift of the center point of the light source image SOc' is the maximum radius Rss (0.8 mm). It falls within a circular area with a radius of 3.2 mm. Note that the effective diameter of the pupil plane Ep' of the alignment system ALGn in this case is set to 8 mm to 10 mm.

In the case of the above conditions, the diameter φc of the light source image SOa' of the light source part ILS in FIG. becomes. Furthermore, the inclination angle of the parallel plates SFy and SFz is such that when viewed from the input end ILFa side of the optical fiber bundle ILF, the center point of the light source image SOa' is a circle with the maximum radius Rss/MJ1 (=8 mm) from the optical axis AXs. It is adjusted within a range that causes a relative position shift within the range of . That is, the adjustment range of the inclination angles of the parallel plates SFy and SFz can be widened, and the positions of the light source image SOa formed at the entrance end ILFa and the light source image SOc' formed at the pupil plane Ep' can be precisely shifted. In FIG. 14, the parallel plates SFy and SFz are provided between the light source section ILS and the reduction imaging system LK1, but the parallel plates SFy and SFz are provided between the enlargement imaging system LK2 and the pupil plane Ep'. Also good.

Furthermore, a movable mechanism that moves the light source unit ILS itself two-dimensionally in the Y-axis direction and the Z'-axis direction by omitting the parallel plates SFy and SFz, or a movable mechanism that moves the light source unit ILS itself in two dimensions in the Y-axis direction and the Z'-axis direction, or A movable mechanism may be provided that integrally holds and moves two-dimensionally within a plane along the pupil plane Ep'. In particular, the reciprocal of the magnification MJ1 of the reduction imaging system LK1 is made larger than the magnification MJ2 of the expansion imaging system LK2, and the parallel plates SFy, SFz provided on the reduction imaging system LK1 side or the light source unit ILS itself are moved. By using the movable mechanism, it is possible to easily and precisely improve the influence of the remaining telecenter error at a remote position that is away from the alignment system ALGn by the length of the optical fiber bundle ILF.

In each of the above-described embodiments and modifications, in order to reduce the adverse effects of residual telecentering errors that occur when detecting the alignment mark MKn on the substrate P, a The resulting light source image SOb or SOc' was shifted. Therefore, the influence of the telecentering error on each of the reference marks RMn on the reference bar member RB arranged corresponding to each of the plurality of alignment systems ALGn (ALG1 to ALG7) may occur. However, since the reference mark RMn on the reference bar member RB is made of a metal such as chromium as a thin film of 0.1 μm or less (for example, about 500 Å), within the range of the remaining telecenter error, the reference mark RMn There is almost no deterioration in image quality at the edges.

[Modification 3]
FIG. 16 is a diagram schematically showing an optical configuration according to a modification of the alignment system ALGn shown in FIGS. 7 and 10. In this modification, the beam splitter BS1 is changed to a cube shape. In FIG. 16, the orthogonal coordinate system XtYtZt is set the same as in FIGS. 7 and 10, and the optical members and their arrangement in FIG. 16 are the same for those with the same functions as in FIG. A code is attached.

As shown in FIG. 16, in the optical path between the objective lens system OBL and the plane mirror Mb, there is a first prism PSMa made of quartz having a pentagonal cross-sectional shape in a plane parallel to the XtZt plane, and a first prism made of quartz having a triangular shape. A cube-shaped beam splitter BS1 that is bonded to a second prism at a light splitting surface Bsp is arranged. The prism PSMa has a transmission surface BS1a that is perpendicular to the optical axis AXs facing the objective lens system OBL, and a transmission surface BS1a that is parallel to the reference surface RBa of the reference bar member RB arranged parallel to the optical axis AXs and perpendicular to the surface BS1a. A surface BS1c, a light splitting surface Bsp that is inclined at an angle θe' with respect to a plane perpendicular to the optical axis AXs when viewed in the XtZt plane, and a light splitting surface Bsp that is located on the opposite side of the surface BS1c across the optical axis AXs in the Zt direction. It has a reflective surface BS1b. Further, the prism PSMb is inclined with respect to the light splitting surface Bsp and is located on the plane mirror Mb side, and has a transmission surface BS1d perpendicular to the optical axis AXs.

The angle θe' of the light splitting surface Bsp is set to 22.5 degrees in this modification, and the reflecting surface BS1b is also set to be inclined by 22.5 degrees with respect to the optical axis AXs when viewed within the XtZt plane. Ru. Therefore, the optical axis AXs1 reflected by the light splitting surface Bsp is at 45 degrees with respect to the optical axis AXs, and the optical axis AXs' reflected by the reflecting surface BS1b is at 90 degrees with respect to the optical axis AXs. Further, the light splitting surface Bsp of the beam splitter BS1 of this modification may be configured to amplitude-split the illumination light ILb from the objective lens system OBL into transmitted light and reflected light at a predetermined ratio, as in FIG. 7 above. Alternatively, a configuration (dichroic mirror surface) that wavelength-divides the illumination light ILb from the objective lens system OBL into a transmission wavelength component and a reflection wavelength component according to the wavelength distribution of the illumination light ILb from the objective lens system OBL may be used. Furthermore, it may be formed of a dielectric multilayer film that uses the light splitting surface Bsp of the beam splitter BS1 as a polarization splitting surface. In that case, the illumination light ILb forming the light source image SOb or SOc' is configured to include two mutually orthogonal linearly polarized lights (P polarized light and S polarized light) at a predetermined illuminance.

In the configuration of FIG. 16, the beam splitter BS2 reflects the illumination light ILb including P-polarized light and S-polarized light and makes it incident on the objective lens system OBL, and the illumination light ILb from the objective lens system OBL is transmitted to the transmission surface of the beam splitter BS1. The light enters from BS1a and reaches the light splitting surface Bsp. The incident angle of the optical axis AXs with respect to the light splitting surface Bsp is an angle (90-θe'), and if the light splitting surface Bsp is set to be the Brewster angle at that incident angle, P in the illumination light ILb Most of the light amount of the polarized component is transmitted, exits from the transmission surface BS1d of the beam splitter BS1, and is irradiated onto the substrate P via the plane mirror Mb. Furthermore, more than half of the S-polarized light component in the illumination light ILb is reflected by the light splitting surface Bsp, and the remaining light amount is transmitted.

The imaging light flux (reflected light) Bma from the substrate P (alignment mark MKn) due to the irradiated illumination light ILb includes a P-polarized light component and an S-polarized light component whose light amount ratio is smaller than that of the P-polarized light component. The imaging light flux Bma travels backward through the beam splitter BS1 and reaches the beam splitter BS2 via the objective lens system OBL. Most of the P-polarized component of the imaging beam Bma passes through the light splitting surface Bsp of the beam splitter BS1, and only half or less of the S-polarized component of the imaging beam Bma passes through the objective lens system. Enter the OBL.

On the other hand, the S polarization component of the illumination light ILb reflected by the light splitting surface Bsp of the beam splitter BS1 is reflected by the reflecting surface BS1b of the beam splitter BS1, passes through the transmitting surface BS1c, and passes through the reference surface RBa of the reference bar member RB. is irradiated. The reflected light beam Bmr (only the S polarization component) from the reference surface RBa (reference mark RMn) caused by the irradiated illumination light ILb travels backward through the beam splitter BS1 and reaches the beam splitter BS2 via the objective lens system OBL. As a result, the image by the reflected light beam Bmr from the reference mark RMn and the image by the imaging light beam (reflected light) Bma from the alignment mark MKn on the substrate P are combined, and the image sensor shown in FIG. 7 or 10 is Imaged by DIS.

In the case of this modification, the wavelength band of the illumination light ILb forming the light source image SOb or SOc' is set, for example, to a wavelength band that is insensitive to the photosensitive layer on the substrate P. Further, it is preferable that the amount of light of the P-polarized light component and the amount of light of the S-polarized light component included in the illumination light ILb are individually adjustable. Furthermore, when the light splitting surface Bsp of the beam splitter BS1 in this modification is a dichroic mirror surface having wavelength selectivity, the illumination light ILb has a wavelength distribution, as in the configuration described in FIGS. 10 to 13 above. It is good to have characteristics.

[Modification 4]
FIG. 17 shows a modification of the light source section ILS that forms the light source image SOa' within the illumination system (illumination unit) ILU shown in FIG. The light source unit ILS of this modification includes an LED light source LD1, a condenser lens system GS1, and a dichroic mirror DCM similar to the configuration shown in FIG. 12, and the LED light source LD1 has a wavelength range shorter than 480 nm ( Illumination light ILb1 having an emission peak wavelength in, for example, blue) is output toward the dichroic mirror DCM so that its principal rays are parallel. The light source unit ILS of this modification further includes a small halogen lamp or discharge lamp (hereinafter simply referred to as a lamp light source) LVp, an ellipsoidal mirror Mh, a mirror Mg, and a condensing lens system GS2, and includes a lamp light source LVp. The illumination light ILb2 from the light emitting point (bright spot) Sv is focused by the ellipsoidal mirror Mh so that the intensity distribution in the plane perpendicular to the optical axis becomes annular, and then the mirror Mg and the condensing lens system It is output to the dichroic mirror DCM via GS2.

As shown in the wavelength characteristics shown in FIG. 13 above, the dichroic mirror DCM has a crossover wavelength set to about 480 nm, and has a reflectance of 90% or more for the illumination light ILb1 from the LED light source LD1, It has a transmittance of 90% or more for light in a wavelength band longer than 480 nm. Therefore, the illumination light ILb2 from the lamp light source LVp becomes light that is restricted to a wavelength band longer than 480 nm after passing through the dichroic mirror DCM. The light emitting point (bright spot) Sv of the lamp light source LVp is arranged at the first focal point of the ellipsoidal mirror Mh, and the illumination light ILb2 is focused at the second focal point at or near the mirror Mg. It diverges and enters the condenser lens system (condenser lens system) GS2, where the chief ray is converted into a parallel light beam.

In the light source section ILS of this modification, the illumination light ILb2 transmitted through the dichroic mirror DCM is set to have an annular intensity distribution having a predetermined outer diameter and inner diameter, and the illumination light ILb1 reflected by the dichroic mirror DCM is The circular intensity distribution is set to have a diameter that is equal to or slightly larger than the inner diameter of the annular intensity distribution of the illumination light ILb2. The illumination light ILb2 with the annular intensity distribution and the illumination light ILb1 with the circular intensity distribution become the illumination light ILb coaxially combined around the optical axis AXs, which enters the micro fly's eye lens system MFL. The micro fly's eye lens system MFL is a micro fly's eye lens system in which a large number of micro convex lens elements (for example, diameter of 0.5 mm or less) are arranged in a matrix in a plane perpendicular to the optical axis AXs. The exit surface Epo of the system MFL has an optically conjugate relationship with the light emitting point of the LED light source LD1 and the light emitting point Sv of the lamp light source LVp, and a large number of point light source images are arranged in a matrix shape in a circular area on the exit surface Epo. A secondary light source image is formed.

The illumination light ILb from the light source image formed on the exit surface Epo enters the reduction relay optical system composed of lens systems GS3 and GS4, and the light source image is reduced to a surface optically conjugate with the exit surface Epo. SOa' is formed. A field stop FAP is arranged between the lens system GS3 and the lens system GS4, and its position is optically in a conjugate relationship with the surface of the substrate P and the reference surface RBa of the reference bar member RB. . The light source image SOa' shown in FIG. 17 is formed by illumination light ILb2 having an annular distribution with an outer diameter of radius Rr2 and inner diameter of radius Rr2', and illumination light ILb1 of circular distribution with radius Rr1, and has a radius Rr2'. By establishing the relationship <radius Rr1<radius Rr2, both the illumination light ILb1 and the illumination light ILb2 are distributed in the area between the radius Rr2' and the radius Rr1 within the plane of the light source image SOa'.

The light source image SOa' in FIG. 17 becomes the light source image SOa' shown in FIG. 14 above, and the illumination light ILb from the light source image SOa' enters the reduction imaging system LK1 via the parallel plates SFy and SFz. The light intensity distribution of the light source image SOa' in FIG. 17 is reduced and formed at the input end ILFa of the optical fiber bundle ILF in FIG. 14. The optical fiber bundle ILF transmits the light intensity distribution to the output end ILFb while preserving the shape of the light intensity distribution at the input end ILFa (congruent or similar state). Therefore, the light intensity distribution of the light source image SOc' formed on the pupil plane Ep' via the enlarged imaging system LK2 in FIG. 14 is similar to the light intensity distribution of the light source image SOa' in FIG. 17.

Furthermore, the illumination light ILb (circular distribution illumination light ILb1 and annular distribution illumination light ILb2) generated in this modification is transmitted to the beam splitter BS2 of the alignment system ALGn shown in FIG. 16 (or FIG. 10), Via the objective lens system OBL, a beam splitter BS1 with wavelength selective properties is reached. For example, the beam splitter BS1 transmits light in a wavelength band longer than 480 nm and reflects light in a wavelength band shorter than 480 nm, so that the illumination light ILb2 having an annular distribution among the illumination light ILb is split by the light splitting surface Bsp. (dichroic mirror surface) to epi-illuminate the alignment mark MKn on the substrate P (or the reference pattern on the outer peripheral surface DRs of the rotating drum DR). On the other hand, the circularly distributed illumination light ILb1 of the illumination light ILb is reflected by the light splitting surface Bsp to epi-illuminate the reference mark RMn on the reference surface RBa of the reference bar member RB.

In this modification, the illumination light ILb (ILb2) irradiated onto the substrate P via the objective lens system OBL is so-called annular illumination, so that the alignment mark MKn formed on the imaging surface of the image sensor DIS (or the reference pattern on the rotating drum DR) can improve the image quality (particularly the edge contrast) and widen the depth of focus. In addition, as described in the configuration of FIG. 12 above, by individually varying the focal length (f value) and position in the optical axis direction of each of the condenser lens systems GS1 and GS2 in FIG. , the diameter of the circular surface light source image formed by the illumination light ILb1 (corresponding to the radius Rr1 in FIG. 17) finally formed on the pupil plane Ep' of the objective lens system OBL of the alignment system ALGn, and the ring formed by the illumination light ILb2. The outer diameter (corresponding to radius Rr2 in FIG. 17) of the band-shaped surface light source image can be adjusted individually.

[Modification 5]
FIG. 18 shows a modified example of the portion near the dichroic mirror DCM of the light source section ILS applied to FIGS. 12 and 17. In this modification, the parallel flat plates SFy and SFz shown in FIGS. It is arranged in the optical path between the condensing lens system GS2 that condenses or collimates the light ILb2 and the dichroic mirror DCM. As a result, the light source image formed by the illumination light ILb1 (short wavelength band) and the light source image formed by the illumination light ILb2 (long wavelength band) formed at the input end ILFa of the optical fiber bundle ILF are aligned in the Y-axis direction and the Z'-axis direction. The position can be shifted individually. Therefore, according to this modification, by combining the configuration in which the beam splitter BS1 of the alignment system ALGn has wavelength selectivity, the influence of the telecenter error between the objective lens system OBL and the surface of the substrate P and the objective lens It becomes possible to independently correct the influence of the telecenter error between the system OBL and the reference surface RBa of the reference bar member RB.

Note that after correcting the influence of the telecenter error between the objective lens system OBL and the surface of the substrate P using the parallel plates SFy and SFz shown in FIG. 7 or FIG. The influence of the telecenter error between the objective lens system OBL and the reference surface RBa of the reference bar member RB can be reduced by parallel plate SFy, SFz, which is provided between the condenser lens system GS1 and the dichroic mirror DCM and transmits the illumination light ILb1. It may be corrected by In that case, the parallel plates SFy and SFz that transmit the illumination light ILb2 between the condenser lens system GS2 and the dichroic mirror DCM in FIG. 18 can be omitted.

[Modification 6]
In addition, the light splitting surface Bsp of the beam splitter BS1 of the alignment system ALGn as shown in FIGS. 10 and 16 is used as a polarization splitting surface, and the illumination light ILb irradiated onto the surface of the substrate P and the reference surface RBa of the reference bar member RB are irradiated. Even when separating the illumination light ILb into orthogonal P-polarized light components and S-polarized light components, changing the arrangement of the parallel plates SFy and SFz can reduce the influence of telecentering errors on the substrate P of the alignment system ALG and the reference bar. The influence of telecentering errors on member RB can be individually corrected.

For example, FIG. 19 is a diagram showing a modification of the light source section ILS shown in FIG. 14 above. When using the light source section ILS shown in FIG. The beam splitter BS2 of the alignment system ALGn is set to be an amplitude splitting type, and the light splitting surface Bsp of the beam splitter BS1 is a polarization splitting surface, and the P polarized light component included in the illumination light ILb of epi-illumination is transmitted through the light splitting surface Bsp. , S-polarized light components are configured to be reflected by the light splitting plane Bsp. In FIG. 19, a circularly polarized light beam ILo from a solid-state light source (semiconductor laser light source, LED light source, etc.) is incident on an amplitude-split beam splitter BS4. The circularly polarized light beam ILo that has passed through the beam splitter BS4 passes through a wavelength plate (1/4λ plate) QWP, is converted into linear S-polarized illumination light ILb1, is bent at right angles by a mirror MJa, and is then transferred to a parallel plate. The light passes through SFz and SFy and enters the polarizing beam splitter BS5. The linear S-polarized illumination light ILb1 is reflected at right angles at a polarization separation surface of the polarization beam splitter BS5 with a reflectance of 90% or more, and is focused as a light source image SOa'.

On the other hand, the circularly polarized light beam ILo reflected at right angles by the beam splitter BS4 passes through a wavelength plate (1/2 λ plate or two 1/4 λ plates) HWP and is converted into linear P-polarized illumination light ILb2. After that, the light passes through parallel plates SFz and SFy, is reflected at right angles by mirror MJb, and then enters polarizing beam splitter BS5. The linearly P-polarized illumination light ILb2 travels straight through the polarization separation surface of the polarization beam splitter BS5 with a transmittance of 90% or more, and is condensed as a light source image SOa'. Also in this modification, the illumination light ILb from the light source image SOa' including the linear S-polarized illumination light ILb1 and the linear P-polarized illumination light ILb2 is transmitted through the reduction imaging system LK1 shown in FIG. The light enters the input end ILFa of the optical fiber bundle ILF, and is finally formed as a light source image SOc' on the pupil plane Ep' of the alignment system ALGn.

The light source image SOc' formed on the pupil plane Ep' includes a P-polarized light component and an S-polarized light component, but the light source image SOc' of the P-polarized light component is located in the optical path of the illumination light ILb2 in FIG. By adjusting the inclination angles of the arranged parallel plates SFz and SFy, the positions can be shifted two-dimensionally within the pupil plane Ep', and the influence of telecentering errors on the surface of the substrate P can be corrected. Further, the light source image SOc' of the S-polarized component can be shifted two-dimensionally within the pupil plane Ep' by adjusting the inclination angle of the parallel plates SFz and SFy arranged in the optical path of the illumination light ILb1 in FIG. The influence of telecentering errors on the reference surface RBa of the reference bar member RB can be corrected. Note that, as shown in FIG. 14, when parallel plates SFz and SFy are provided between the light source image SOa' and the reduction imaging system LK1, parallel plates SFz and SFy arranged in the optical path of the illumination light ILb1 shown in FIG. Either one of the flat plates SFz, SFy and the parallel flat plates SFz, SFy disposed in the optical path of the illumination light ILb2 may be omitted.

[Modification 7]
FIG. 20 shows a light guide member having the configuration shown in FIG. 14, in order to supply illumination light ILb to each of the alignment systems ALGn (n=1 to 7) shown in FIG. 7, FIG. 10, or FIG. 16. 2 is a diagram illustrating a schematic configuration of an illumination system ILU when using an illumination system ILU. FIG. In this modification, the illumination light ILb supplied to each of the seven alignment systems ALG1 to ALG7 is obtained via a light distribution unit BDU that distributes light from one light source unit LPO. In FIG. 20, since the seven alignment systems ALG1 to ALG7 have the same configuration, only the schematic configuration of the alignment system ALG1 will be described as a representative, and the detailed configurations of the other alignment systems ALG2 to ALG7 will be omitted. The light source unit LPO includes a high-intensity mercury discharge lamp, a halogen lamp, etc., and the light distribution unit BDU uses a plurality of amplitude-splitting type beam splitters and a plurality of mirrors to divide the luminous flux from the light source unit LPO into eight beams of the same intensity. Divide into luminous flux.

Each of the eight light beams divided by the light distribution unit BDU is supplied to the optical fiber bundles FB1 to FB8, and the seven optical fiber bundles FB1 to FB7 are respectively connected to the reduction imaging system LK1 shown in FIG. is supplied to Further, in FIG. 20, the optical fiber bundle FB8 is provided as a spare and is not normally used. The light source image formed at the output end of each of the optical fiber bundles FB1 to FB7 corresponds to the light source image SOa' of the light source unit ILS shown in FIG. 14, and the light beam (illumination light ILb) from each of the optical fiber bundles FB1 to FB7 are incident on the optical fiber bundle ILF via the reduction imaging system LK1 and the parallel plates SFz and SFy, respectively, and are further formed into the light source image SOc' on the pupil plane Ep' of each of the alignment systems ALG1 to ALG7 via the enlargement imaging system LK2. The light is focused as

In this modification, when a mercury discharge lamp or a halogen lamp is used as the light source LPO, the wavelength characteristics of the luminous flux (illumination light ILb) from the light source LPO are divided into a wavelength band shorter than the wavelength 480 nm and a wavelength band longer than the wavelength 480 nm, for example. Therefore, by giving the light splitting surface Bsp of each beam splitter BS1 of the alignment systems ALG1 to ALG7 wavelength selection characteristics, the illumination light ILb that epi-illuminates the surface of the substrate P (alignment mark MKn) and It is also possible to individually adjust the intensity of the illumination light ILb that epi-illuminates the reference surface RBa (reference mark RMn) of the reference bar member RB. For this purpose, for example, a neutral density filter (ND filter) or an electrically transparent A liquid crystal shutter or the like that can adjust the rate may be provided. Further, a wavelength filter is provided between each beam splitter BS1 of the alignment system ALGn and the plane mirror Mb, for example, to block light in a wavelength band shorter than 400 nm (a wavelength that is insensitive to the photosensitive layer). Also good.

In addition, in FIG. 20, a light guide member composed of a reduction imaging system LK1, an enlargement imaging system LK2, and an optical fiber bundle ILF is used, but the output end of each of the optical fiber bundles FB1 to FB7 is connected to an alignment system ALG1 to ALG7. They may be placed directly at or near each pupil plane Ep'. In that case, the correction for the telecenter error is achieved by using a tiltable transmittance system to horizontally shift the relative position between the light beam (illumination light ILb) irradiated to the input end of each of the optical fiber bundles FB1 to FB7 and the input end. This becomes possible by providing a parallel plate within the light distribution unit BDU. In this case, the optical fiber bundles FB1 to FB7 are set to a type such that the intensity distribution of the light beam (illumination light ILb) formed at the output end thereof preserves the shape of the intensity distribution of the light beam formed at the input end.

Note that the light distribution unit BDU in FIG. 20 is set to divide the luminous flux from the light source unit LPO into eight divisions (even number division), but this is due to the reflectance and transmittance of each of the plurality of amplitude division type beam splitters. This is because it is possible to reduce the amount of light to 50%, and to make the intensity of each of the divided luminous fluxes equal. Further, a bandpass filter may be provided in the light distribution unit BDU to limit the wavelength band of the light beam incident on each of the optical fiber bundles FB1 to FB7 to about 400 to 700 nm.

[Third embodiment]
FIG. 21 is a diagram showing a schematic configuration of an alignment system ALGn and an illumination system (illumination unit) ILU according to the third embodiment. In this embodiment, two rotatable wedge prisms DP1 and DP2 are used as a configuration for laterally shifting the position of the light source image SOb formed on the pupil plane Ep' of the objective lens system OBL of the alignment system ALGn. In FIG. 21, members having the same functions as those shown in FIG. 7, FIG. 10, or FIG. 16 are designated by the same reference numerals, so detailed explanation thereof will be omitted. Furthermore, in this embodiment, since the configuration is such that the reference mark RMn of the reference bar member RB is not detected, the beam splitter BS1 disposed between the substrate P and the objective lens system OBL is omitted.

The alignment system ALGn in FIG. 21 includes, from the substrate P side, a plane mirror Mb, an objective lens system OBL, a beam splitter BS2, an imaging lens system Gb, and an image sensor DIS, and includes alignment marks MKn on the substrate P. The enlarged image is formed on the imaging surface Pis of the image sensor DIS. The illumination system ILU in this embodiment includes relay lens systems G10 and G11 that image the light source image SOa generated by the light source unit ILS on the pupil plane Ep' of the objective lens system OBL as a light source image SOb. A field diaphragm plate FAP is arranged between the lens systems G10 and G11 in the optical axis AXj direction, and the lens system G10 telecentrically illuminates the field diaphragm plate FAP with Koehler illumination. Field diaphragm plate FAP is set to have a conjugate relationship (imaging relationship) with the surface of substrate P by lens system G11, beam splitter BS2, plane mirror MJc, objective lens system OBL, and plane mirror Mb. The illumination light ILb passing through the rectangular opening (transparent part) of the field diaphragm plate FAP illuminates the detection area (observation field) ADn on the substrate P with a uniform illuminance distribution. That is, the shape of the detection area (observation field) ADn on the substrate P is similar to the shape of the rectangular opening (transparent part) of the field diaphragm plate FAP.

Furthermore, in this embodiment, two wedge prisms DP1 and DP2 that can rotate 360 degrees around the optical axis AXj of the relay lens systems G10 and G11 are provided between the lens system G10 of the illumination system ILU and the field diaphragm plate FAP. (having the same apex angle) are arranged along the optical axis AXj. For example, as exaggeratedly shown in FIG. 22, the wedge prisms DP1 and DP2 can change the original optical axis AXj of the lens system G10 to an arbitrary direction like the optical axis AXj' by adjusting their respective rotation angles. Can be used in small amounts. In FIG. 22, the entrance surface DP1a of the wedge prism DP1 on the lens system G10 side is set perpendicular to the optical axis AXj, and the exit surface DP1b is set as a slope inclined with respect to the plane perpendicular to the optical axis AXj. DP1a and output surface DP1b form an apex angle. Similarly, the entrance surface DP2a of the wedge prism DP2 on the side of the wedge prism DP1 is set to a slope inclined with respect to a plane perpendicular to the optical axis AXj, and the exit surface DP2b is set perpendicular to the optical axis AXj, and the entrance surface DP2a and the output surface DP2b form an apex angle.

Therefore, by changing the rotational angle position of each of the wedge prisms DP1 and DP2, the optical axis AXj' can be moved to any position within the circle Cdp centered on the original optical axis AXj at a position a certain distance Lxx from the wedge prism DP2. It can be tilted to pass through the position. Therefore, the chief ray of the illumination light ILb that illuminates the field diaphragm plate FAP shown in FIG. 21 can be tilted with respect to the original optical axis AXj by the wedge prisms DP1 and DP2, and is formed on the pupil plane Ep'. The light source image SOb can be shifted laterally. Since the aperture of the field diaphragm plate FAP and the surface of the substrate P are set in a conjugate relationship, the principal ray of the illumination light ILb illuminating the detection area ADn on the substrate P is directed toward the optical axis AXs of the objective lens system OBL. It is possible to correct the remaining telecenter error of the alignment system ALGn. In this embodiment, the wedge prisms DP1 and DP2 that tilt the optical axis AXj of the illumination system (illumination unit) ILU correspond to an adjustment mechanism that horizontally shifts the light source image SOb within the pupil plane Ep' of the objective optical system (OBL). do.

In addition, in FIG. 21, when the position of the beam splitter BS2 is changed in the direction away from the objective lens system OBL along the optical axis AXs, the pupil planes Ep and Ep' are the positions inside the cube-shaped beam splitter BS2, or It is formed to overlap with the surface of the beam splitter BS2 near the objective lens system OBL. As shown in FIG. 21, when some kind of lens system (G10, G11) is arranged in front of the beam splitter BS2, for example, when the magnifying imaging system LK2 as shown in FIG. By changing the position in the optical axis AXs direction, the pupil planes Ep and Ep' can be formed to overlap between the beam splitter BS2 and the objective lens system OBL. Further, in FIG. 21, the field diaphragm plate FAP is provided at a position conjugate with the surface of the substrate P in the illumination system ILU, but the field diaphragm plate FAP may be omitted.

In FIGS. 21 and 22, only two wedge prisms DP1 and DP2 are provided as adjustment mechanisms, but another set of wedge prisms (two pieces) may be added along the optical path. When adjusting the rotation of only one set of wedge prisms DP1 and DP2, the tilt direction of the optical axis AXj' is set based on polar coordinates, whereas adding a second set of wedge prisms (two pieces) (in total) With the four wedge prisms, the tilt direction of the optical axis AXj' can be set based on orthogonal coordinates, making it easier to handle and reducing the area where adjustment is impossible due to apex angle tolerance (error). be able to. Note that the optical axis angle adjustment mechanism using two wedge prism sets (two pieces) may be provided in the optical path of the beam emitted from the light source device (pulsed light source device) LS shown in FIG. can.

In each of the above embodiments and modifications, a plurality of alignment systems ALGn (two or more) are assumed, but a single alignment system ALGn may be used. In addition to the exposure device, the alignment system ALGn also includes a printing device that can draw a precise pattern using an inkjet method, an inspection device that inspects the pattern formed on the substrate P, and a laser beam that scans a part of the formed pattern. It can be installed in the same way in processing equipment that removes, corrects, and repairs. Furthermore, the object to be observed by the alignment system ALGn is not limited to the alignment mark (substrate mark) provided on the substrate P, but also any arbitrary pattern (for example, a line & space pattern on a resolution chart, a BOXinBOX pattern for checking overlay errors). , some patterns for actual devices).

ADn, ARn...Detection area ALGn...Alignment system AXs, AXs', AXj...Optical axis BS1, BS2...Beam splitter Bsp...Light splitting surface DIS...Image sensor DP1, DP2...Wedge prism Ep, Ep'...Pupillary plane EX...Pattern Drawing device Gb...Imaging lens system ILb...Illumination light ILF...Optical fiber bundle ILS...Light source section ILU...Illumination system, illumination unit MKn...Alignment mark OBL...Objective lens system P...Substrate RMn...Reference mark SFy, SFz...Parallel plate SOa, SOa', SOb, SOb', SOc'...Light source image Un...Drawing unit (pattern forming mechanism)

Claims (10)

A pattern forming apparatus comprising: a pattern forming mechanism that forms a pattern in a predetermined area on a substrate that moves in a first direction; and a mark detection mechanism that detects marks formed on the substrate.
The mark detection mechanism is
an objective optical system that projects illumination light into a first detection area set on the substrate, and into which reflected light generated within the first detection area is incident; and the reflected light that is incident on the objective optical system. an image detection system that detects an image within the detection area generated by light; and a light splitter disposed in an optical path between the objective optical system and the image detection system;
an illumination system that projects the illumination light toward the light splitter to form a light source image of the illumination light on a pupil plane of the objective optical system;
an adjustment mechanism that changes the position of the light source image formed in the pupil plane of the objective optical system;
a reference bar member;
a synthetic optical member provided between the objective optical system and the substrate;
Equipped with
The synthetic optical member divides the illumination light from the objective optical system and guides it to each of the first detection area and a second detection area set on the reference bar member, and A pattern forming device that combines the reflected light from the area and the reflected light from the second detection area . The pattern forming device according to claim 1 ,
The lighting system is
a light source unit including a condensing lens system that condenses the illumination light generated from the light source to form the light source image;
a light guide member that relays the light source image to the pupil plane of the objective optical system;
has
The adjustment mechanism adjusts the position of the light source image formed at the entrance end of the light guide member within the plane of the entrance end, and adjusts the position of the light source image formed within the pupil plane of the objective optical system. A pattern forming device that changes position. The pattern forming device according to claim 2 ,
The light guide member is an optical fiber bundle,
A pattern forming device, wherein the shape of the intensity distribution of the light source image formed at the output end of the optical fiber bundle is congruent or similar to the shape of the intensity distribution of the light source image formed at the input end. The pattern forming device according to claim 3 ,
A pattern forming apparatus, wherein the position of the output end of the optical fiber bundle substantially coincides with the position of the pupil plane of the objective optical system. The pattern forming device according to claim 3 or 4 ,
The light guide member is
a reduction imaging system that reduces and forms the light source image at the input end of the optical fiber bundle; and a reduction imaging system that expands the light source image transmitted to the output end of the optical fiber bundle into the pupil plane of the objective optical system. and an enlarged imaging system for forming a pattern. The pattern forming apparatus according to any one of claims 2 to 5 ,
The adjustment mechanism includes a tiltable parallel flat plate that transmits the illumination light directed toward the incident end of the light guide member and horizontally shifts the traveling direction of the illumination light. 7. The pattern forming device according to claim 6 ,
The parallel plate is composed of a first parallel plate and a second parallel plate arranged in parallel along the traveling direction of the illumination light, and the inclination direction of the first parallel plate and the second parallel plate are arranged in parallel. A pattern forming device that is perpendicular to the direction of inclination of the flat plate. The pattern forming apparatus according to any one of claims 2 to 5 ,
In the pattern forming apparatus, the adjustment mechanism includes a fine movement mechanism that relatively slightly moves the incident end of the light guide member and the illumination system. The pattern forming apparatus according to any one of claims 1 to 8 ,
A pattern forming apparatus including a substrate support mechanism that supports and moves the substrate in the first direction. The pattern forming apparatus according to any one of claims 1 to 9 ,
A pattern forming apparatus, wherein the pattern is a pattern for an electronic device.

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