JP5859352B2 - Exposure drawing apparatus, program, and exposure drawing method - Google Patents

Description

  The present invention relates to an exposure drawing apparatus, a program, and an exposure drawing method, and in particular, an exposure drawing apparatus that draws an image on a substrate, a program executed by the exposure drawing apparatus, and an exposure that draws an image on the substrate. It relates to a drawing method.

  In recent years, when performing exposure drawing of an image to be exposed on a substrate to be exposed, a spatial light modulation element such as a digital micromirror device (DMD) is used as a pattern generator. Development of an exposure drawing apparatus that performs exposure drawing on a substrate to be exposed with a light beam modulated in accordance with image data indicating the above is underway.

  The DMD is a mirror device in which a large number of micromirrors whose reflecting surfaces change in response to a control signal, for example, are two-dimensionally arranged on a semiconductor substrate such as silicon, and the electrostatic force due to charges stored in each memory cell. Thus, the angle of the reflection surface of the micromirror is changed. Further, in an exposure drawing apparatus having a DMD, each of the DMD micromirrors is controlled to be turned on / off based on a control signal generated in accordance with image data or the like to modulate a light beam for each pixel. Exposure is performed on the substrate to be exposed.

  In such an exposure drawing apparatus, the lens used in the optical system in the exposure head has a unique distortion characteristic called distortion (distortion aberration). Therefore, the image to be exposed formed on the reflecting surface by each micromirror of the DMD and the image actually drawn on the surface to be exposed do not have a similar relationship, and the image to be exposed is deformed due to distortion. It will be drawn on the exposed surface. In particular, when a precise exposure target image such as a circuit pattern is exposed on a substrate to be exposed, it is necessary to accurately draw a circuit pattern as designed.

  Therefore, the amount of distortion of the drawn image is derived by detecting the exposure position of each light beam when each light beam corresponding to each pixel is exposed to the exposed surface, and based on the derived amount of distortion. There has been proposed an exposure drawing apparatus capable of drawing an exposure target image with high accuracy by correcting the exposure target image. This exposure drawing apparatus calculates the relative positional deviation from the position of the pixel under measurement in the spatial modulation element and the exposure position of the light beam corresponding to each pixel modulated by the spatial modulation element. This is a device for obtaining the amount of distortion of an image drawn by. In this exposure drawing apparatus, it is possible to draw an exposure target image with high accuracy by correcting the exposure target image based on the derived distortion amount.

JP 2005-316409 A

  In the exposure drawing apparatus disclosed in Patent Document 1, the position of the pixel to be measured and the exposure position of the light beam in the spatial modulation element are determined using a light beam emitted from a laser light source for drawing an image to be exposed. Can be detected, and the amount of mutual deviation can be obtained. However, when an extremely sensitive material such as a silver salt sensitive material is used as an exposure target, the amount of light of the light beam when drawing the image to be exposed is small. However, there is a problem in that the exposure position detection signal S / N cannot be sufficiently obtained because the light beam is insufficient, and the exposure position detection accuracy decreases.

  The present invention has been made in view of the above problems, and provides an exposure drawing apparatus, a program, and an exposure drawing method capable of performing exposure position correction with high accuracy even when the exposure target is an ultrasensitive material. Objective.

  In order to achieve the above object, an exposure drawing apparatus according to the present invention includes a plurality of micro optical elements, and each of the plurality of micro optical elements is two-dimensionally arranged so as to correspond to each pixel. A light source that includes an element and a plurality of light-emitting portions that respectively emit light that irradiates the optical modulation element, and is disposed between the optical modulation element and the exposed surface; A light collecting optical system for condensing the light from the optical modulation element, and the light quantity irradiated from the light source is adjusted so that the light quantity is larger than the light quantity when the exposed surface is exposed, On the detection surface corresponding to the surface to be exposed, a position detection unit that detects a condensing position where light from each of the plurality of optical elements collects, and a detection result from the reference position based on the detection result of the position detection unit. Condensing position of light from the plurality of optical elements An obtaining means for the displacement amount to get the, on the basis of the shift amount acquired by the acquisition means, and a correcting means for correcting the focusing position in the exposure surface.

  According to this exposure drawing apparatus, an optical modulation element that includes a plurality of optical elements and that is arranged two-dimensionally so that each of the plurality of optical elements corresponds to each pixel, and irradiates the optical modulation element A plurality of light emitting units each emitting light, a light source capable of adjusting the amount of emitted light, and a light condensing optical system disposed between the optical modulation element and the surface to be exposed, the surface to be exposed The light from the optical modulation element is condensed, and the position detection means adjusts the amount of light emitted from the light source so that the amount of light is larger than the amount of light when the exposed surface is exposed. On a detection surface corresponding to the surface, a condensing position where light from each of the plurality of optical elements is collected is detected.

  Here, in the present invention, the acquisition unit acquires the deviation amount of the light collection positions of the light from the plurality of optical elements from the reference position based on the detection result of the position detection unit. Based on the amount of deviation acquired by the acquisition means, the condensing position on the exposed surface is corrected.

  As described above, according to the exposure drawing apparatus of the present invention, the amount of light emitted from the light source is adjusted so that the amount of light is larger than the amount of light when the exposed surface is exposed. By detecting the condensing position where the light from each of the plurality of optical elements condenses on the detection surface, the exposure position can be accurately corrected even if the exposure target is an ultrasensitive material.

  In the present invention, the light source includes a light emitting unit having a predetermined light emission amount and a light emitting unit having a larger light amount than the light emission unit having the predetermined light emission amount, and the light emitting unit having the predetermined light emission amount when exposing the exposed surface. When the position is detected, the light emitting unit with a large amount of light, or the light emitting unit with the predetermined light emitting amount and the light emitting unit with a large amount of light may be adjusted to emit light. good. Thereby, the light quantity of a light source can be easily switched between exposure drawing and position detection.

  According to the present invention, the light source includes a plurality of light emitting units having the same light emission amount, and when detecting the position, the light source emits light from a larger number of light emitting units than when exposing the exposed surface. May be adjusted to emit light. The light quantity of the light source can be easily switched between exposure drawing and position detection.

  In the present invention, light in the same wavelength range may be emitted from each of the light emitting units of the light source. Thereby, the error between the exposure position at the time of exposure drawing and the exposure position at the time of position detection can be reduced.

  In the present invention, a rod integrator may be disposed between the light source and the optical modulation element. Thereby, a uniform irradiation distribution can be obtained.

  Further, the present invention provides the temperature detecting means for detecting the temperature of the optical modulation element, the temperature adjusting means for adjusting the temperature of the optical modulation element, and the optical modulation based on the temperature detected by the temperature detection means. Control means for controlling the temperature adjusting means so that the temperature of the element is in a predetermined range may be further provided. Thereby, the thermal influence by the light quantity change can be suppressed.

  According to the present invention, the position detection unit detects the position in a state where the position detection unit is controlled to have a temperature in the predetermined range, and the correction unit has a temperature in the predetermined range. In such a controlled state, the condensing position on the exposed surface may be corrected. Thereby, the thermal influence by the light quantity change can be suppressed.

  According to the present invention, the correction means corrects image data of an image drawn on the exposed surface so that the condensing position is corrected at a position where distortion is reduced, based on the shift amount. You may do it. Thereby, the exposure target image can be drawn with high accuracy.

  Further, according to the present invention, the correction means may be configured such that a plurality of optical elements of the optical modulation element and a pixel of image data of an image drawn on the exposed surface so that distortion is reduced based on the shift amount. You may make it correct | amend a corresponding relationship. Thereby, the exposure target image can be drawn with high accuracy.

  On the other hand, in order to achieve the above object, the program of the present invention causes a computer to function as an acquisition unit and a correction unit in the exposure drawing apparatus according to the present invention.

  According to this program, the computer can be operated in the same manner as the exposure drawing apparatus of the present invention. Therefore, as with the exposure drawing apparatus of the present invention, the exposure position can be accurately detected even if the exposure target is an ultrasensitive photosensitive material. Correction can be performed.

  On the other hand, in order to achieve the above object, the exposure drawing method of the present invention includes an optical modulation including a plurality of optical elements, each of the plurality of optical elements being arranged two-dimensionally so as to correspond to each of the pixels. A light source that includes an element and a plurality of light-emitting portions that respectively emit light that irradiates the optical modulation element, and is disposed between the optical modulation element and the exposed surface; An exposure drawing method in an exposure drawing apparatus comprising a condensing optical system for condensing light from the optical modulation element, wherein the light source has a light quantity larger than that when the exposed surface is exposed. A position detecting step for detecting a position where light from each of the plurality of optical elements is collected on a detection surface corresponding to the surface to be exposed in a state where the amount of light emitted from the light source is adjusted; Based on the detection results, An acquisition step for acquiring a deviation amount of the light collection position of the light from the plurality of optical elements from a position, and a correction for correcting the light collection position on the exposed surface based on the deviation amount obtained in the acquisition step And steps.

  According to this exposure drawing method, since it operates in the same manner as the exposure drawing apparatus of the present invention, exposure position correction is performed with high accuracy even if the exposure target is an ultrasensitive material as in the exposure drawing apparatus of the present invention. be able to.

  According to the present invention, there is an effect that exposure position correction can be performed with high accuracy even if the exposure target is an ultrasensitive material.

It is a perspective view which shows the structure of the exposure drawing apparatus which concerns on embodiment. It is a principal part schematic perspective view which shows the state which performs exposure drawing with respect to a to-be-exposed board | substrate by each exposure head provided in the exposure drawing apparatus which concerns on embodiment. It is a principal part expansion schematic perspective view which shows the state exposed to a to-be-exposed board | substrate by the exposure head of the exposure drawing apparatus which concerns on embodiment. It is a principal part expansion perspective view which shows the structure of DMD of the exposure drawing apparatus which concerns on embodiment. (A) And (B) is sectional drawing of the operation direction along an optical axis which shows the structure of the exposure head of the exposure drawing apparatus which concerns on 1st Embodiment. It is a block diagram which shows the electric system of the exposure drawing apparatus which concerns on embodiment. In the exposure drawing apparatus which concerns on 1st Embodiment, it is the schematic for demonstrating the switching method of a laser light source. It is a flowchart which shows the flow of a process of the exposure control processing program which concerns on embodiment. It is a flowchart which shows the flow of a process of the position correction process program which concerns on embodiment. (A) is an enlarged schematic diagram for explaining a method of detecting the position of a pixel to be measured in the exposure drawing apparatus according to the embodiment, and (B) is a measurement target in the exposure drawing apparatus according to the embodiment. It is explanatory drawing which showed the detection signal of the photo sensor with respect to a pixel corresponding to (A). It is the schematic which shows an example of distortion correction of exposure drawing in the exposure drawing apparatus which concerns on embodiment. (A) And (B) is sectional drawing of the operation direction along an optical axis which shows the structure of the exposure head of the exposure drawing apparatus 1 which concerns on 2nd Embodiment. In the exposure drawing apparatus which concerns on 2nd Embodiment, it is the schematic for demonstrating the switching method of a laser light source.

[First Embodiment]
Hereinafter, the exposure drawing system according to the present embodiment will be described in detail with reference to the accompanying drawings. In the present embodiment, as the exposure drawing apparatus 1, a flat substrate such as a film, a printed wiring board, and a glass substrate for a flat panel display, which is an ultrasensitive photosensitive material, is used as the exposed substrate C, and the exposed substrate C is exposed. An apparatus that performs exposure drawing will be described as an example.

  FIG. 1 is a perspective view showing a configuration of an exposure drawing apparatus 1 according to the present embodiment. In the following, the direction in which the stage 10 moves is defined as the Y direction, the direction perpendicular to the Y direction on the horizontal plane is defined as the X direction, and the direction perpendicular to the Y direction on the vertical plane is defined as the Z direction. The direction of rotation about the Z axis is defined as the θ direction.

  As shown in FIG. 1, the exposure drawing apparatus 1 includes a flat plate stage 10 for fixing a substrate C to be exposed. On the upper surface of the stage 10, a suction mechanism (not shown) having a plurality of suction holes for sucking air is provided in a region where the substrate C to be exposed is placed. The suction mechanism vacuums the exposed substrate C to the upper surface of the stage 10 by sucking air between the exposed surface C and the stage 10 from the suction holes when the exposed substrate C is fixed to the upper surface of the stage 10. The substrate C to be exposed is sucked and held on the stage 10 by suction.

  Further, the stage 10 is configured to be movable, and the exposure target substrate C fixed to the stage 10 moves to the exposure position as the stage 10 moves, and then is irradiated with a light beam by the exposure unit 16 described later. Then, an image such as a circuit pattern is drawn on one surface.

  The stage 10 is supported by a flat base 12 that is movably provided on the upper surface of a table-like base 11. In addition, a moving mechanism unit 13 having a moving drive mechanism (not shown) configured by a motor or the like is provided between the base 12 and the stage 10, and the stage 10 is connected to the stage 10 by the moving mechanism unit 13. It can be translated in the thickness direction (Z direction; hereinafter also referred to as height direction).

  One or a plurality of (in this embodiment, two) guide rails 14 are provided on the upper surface of the base 11. The base 12 is supported by a guard rail 14 so as to be reciprocally movable, and is moved by a stage driving unit (stage driving unit 71 described later) constituted by a motor or the like. The stage 10 is moved along the guide rail 14 by being supported on the upper surface of the movable base 12.

  A gate-type gate 15 is erected on the upper surface of the base 11 so as to straddle the guide rail 14, and an exposure unit 16 is attached to the gate 15. The exposure unit 16 is composed of a plurality (16 in the present embodiment) of exposure heads 16 a and is fixedly arranged on the moving path of the stage 10. An optical fiber 18 drawn from the light source unit 17 and a signal cable 20 drawn from the image processing unit 19 are connected to the exposure unit 16.

  Further, a gate 22 is provided on the upper surface of the base 11 so as to straddle the guide rail 14. One or a plurality of (two in the present embodiment) imaging units 23 for imaging the alignment mark of the substrate C to be exposed placed on the stage 10 are attached to the gate 22. The photographing unit 23 is a CCD camera or the like having a built-in strobe with a very short light emission time. Each photographing unit 23 is installed to be movable in a direction (X direction) perpendicular to the moving direction (Y direction) of the stage 10 on a horizontal plane. When the exposure drawing apparatus 1 draws a circuit pattern on the substrate C to be exposed, the exposure drawing apparatus 1 measures the position of the alignment mark photographed by the photographing unit 23 and adjusts the drawing position based on the measured position of the alignment mark.

  FIG. 2 is a main part schematic perspective view showing a state in which exposure drawing is performed on the substrate C to be exposed by each exposure head 16a provided in the exposure drawing apparatus 1 according to the present embodiment. In FIG. 2, the number of the exposure heads 16 a is drawn small for easy understanding. As shown in FIG. 2, a plurality of (for example, 16) exposure heads 16 a are arranged in a substantially matrix (for example, 2 rows and 8 columns) inside the exposure head unit 16.

  For example, the exposure area R1 by the exposure head 16a is formed in a rectangular shape having a short side in the scanning direction of the exposure head 16a (the Y direction that is the moving direction of the stage 10). In this case, a strip-shaped exposed area R2 is formed for each exposure head 16a on the exposed substrate C as the stage 10 moves in the Y direction.

  In addition, as shown in FIG. 2, each of the exposure heads 16a in each row arranged adjacent to each other is adjacent to each other so that the strip-shaped exposed areas R2 are arranged without gaps in the direction orthogonal to the scanning direction (X direction). It is arranged so that the position in the X direction is shifted from the adjacent exposure head 16a in the row to be processed. For this reason, for example, even when there is an area that cannot be exposed between the exposure area R1 of the first row and the exposure area R1 of the second row, the unexposed area is exposed by the exposure area R1 of the second row. .

  FIG. 3 is an enlarged schematic perspective view of a main part showing a state in which the substrate to be exposed C is exposed by the exposure head 16a of the exposure drawing apparatus 1 according to the present embodiment. As shown in FIG. 3, a slit plate 24 is provided integrally with the stage 10 on the side surface upstream of the moving direction 10 of the stage 10 (the side on which the substrate C to be exposed is placed). The slit plate 24 has a light-shielding thin chrome film (chrome mask, emulsion mask) formed on a rectangular long quartz glass plate having a length equal to the width of the stage 10 (length in the X direction). It is formed by. By forming the slit plate 24 from quartz glass in this way, errors due to temperature changes can be reduced.

  Detection slits 25 are formed in each of a plurality of predetermined positions of the chromium film to allow the light beam from the exposure head 16a to pass therethrough. This detection slit 25 has an etching process (for example, a mask formed by masking the chrome film and slitting so that two line segments open in the X-axis direction at each end in the chrome film. And is removed by a process of eluting the slit portion of the chromium film with an etching solution.

  A plurality of photosensors 26 corresponding to each of the inspection slits 26 are provided on the lower surface of the slit plate 24 (the surface opposite to the side on which the substrate C to be exposed is placed). The photosensor 26 detects the light beam that has passed through the inspection slit 26 when the light beam is exposed by the exposure head 16a. The exposure position of the light beam can be detected based on whether or not each of the plurality of photosensors 26 detects the light beam. In this way, by using the light shielding thin chrome film, the exposure position of the light beam can be detected with high accuracy.

  Each exposure head 16a has a digital micromirror device (DMD) 27 as a reflective spatial light modulator, and controls the DMD based on image data input from the image processing unit 19 to control the light source unit 16a. Then, the exposure drawing apparatus 1 performs exposure drawing of the image indicated by the image data on the substrate C to be exposed by irradiating the substrate C with this light beam. Note that a transmissive spatial light modulator such as liquid crystal may be used as the spatial light modulator.

  FIG. 4 is an essential part enlarged perspective view showing the configuration of the DMD 27 of the exposure drawing apparatus 1 according to the present embodiment. As shown in FIG. 4, the DMD 27 has a rectangular micromirror (micromirror) as an optical element on an SRAM cell (memory cell) 28 such as a silicon gate CMOS that temporarily stores image data representing an image to be exposed. A mirror 29 is supported and arranged by a support column including a hinge and a yoke (not shown), and a large number (for example, 600 × 800) of micromirrors 29 constituting a pixel (pixel) are arranged in a lattice shape. It is configured as an array of mirror devices. A material having high reflectivity such as aluminum is deposited on the surface of the micromirror 29, and each pixel in the image to be exposed is exposed and drawn by the light beam reflected by the micromirror 29.

  In the SRAM cell 28 of the DMD 27, a digital signal indicating an on state or an off state is written for each pixel, which is created based on image data indicating an exposure target image. The micromirror 29 corresponding to the pixel in the on state is set to be tilted within a range of ± a degrees (for example, ± 10 degrees) around one diagonal line. On the other hand, the micromirror 29 corresponding to the pixel in the off state is set in a state where it is not tilted.

  Thus, by controlling the inclination of each micromirror 29 so as to correspond to each pixel in the image data of the image to be exposed, the surface of the micromirror 29 at the incident position when the light beam is incident on the DMD 27. Thus, the light beam is reflected in the direction corresponding to the inclination of the micromirror 29, and exposure drawing of the image to be exposed is performed.

  The on / off control of the micromirror 29 is performed by the image processing unit 19 connected to the DMD 27. The light reflected by the on-state micromirror 29 is modulated into an exposure state and provided on the light emitting side of the DMD 27. The light enters the lens system 32 described later. The light reflected by the off-state micromirror 29 is modulated into a non-exposure state and enters a light absorber (not shown).

  5A and 5B are cross-sectional views in the operation direction along the optical axis showing the configuration of the exposure head 16a of the exposure drawing apparatus 1 according to the first embodiment. As shown in FIGS. 5A and 5B, on the light incident side of the DMD 27, a plurality of laser light sources 30 (in this embodiment, a laser light source 30A (for example, 20 mW) and a light amount larger than the laser light source 30A). Uniform irradiation distribution that includes a light source unit 17 having a laser light source 30B (for example, 10,000 mW) and emits light beams emitted from a plurality of laser light sources 30 with uniform illumination. A rod integrator 31 that is an optical system for obtaining a lens, a lens system 32 that corrects an incident light beam and collects it on the DMD 27, and a reflecting mirror 33 that reflects the laser light transmitted through the lens system 32 toward the DMD 27 in order. Has been placed.

  The rod integrator 31 is, for example, a light-transmitting rod formed in a square columnar shape. When a light beam is incident, the intensity distribution in the beam cross section travels while the incident light beam travels while totally reflecting inside the light-transmitting rod. Is made uniform and emitted to the outside. The light beams emitted from the laser light sources 30 are incident on the same rod integrator 31 through the optical fibers 18.

  The lens system 32 corrects the combination lens 32a including a pair of lenses that collimate the laser beams emitted from the laser light sources 30A and 30B so that the light quantity distribution of the collimated laser beams is uniform. A combination lens 32b including a pair of lenses and a condensing lens 32c that condenses the laser light with the corrected light quantity distribution on the DMD 27 are configured. In the combination lens 32b, with respect to the arrangement direction of the laser emitting ends, the portion close to the optical axis of the lens expands the light beam, and the portion away from the optical axis contracts the light beam, and in a direction orthogonal to the arrangement direction. On the other hand, it has a function of allowing light to pass through as it is, and corrects the laser light so that the light quantity distribution is uniform.

  On the light reflection side of the DMD 27, a lens system 34 and a lens system 35 for forming an image of the laser light reflected by the DMD 27 on the exposed surface of the substrate C to be exposed are disposed. The lens system 34 and the lens system 35 are arranged so that the DMD 27 and the exposed surface of the substrate C to be exposed have a conjugate relationship.

  In the present embodiment, the laser light emitted from the laser light source 30 is made uniform and incident on the DMD 27, and then each pixel is enlarged by about 5 times by the lens system 34 and the lens system 35, and collected. It is set to be illuminated.

  On the exit side of the lens system 35, there is further provided a focusing mechanism 36 for forming an image of the focal point of the light beam emitted from the laser light source 30 on the exposed surface of the substrate C to be exposed. The focusing mechanism 36 includes a pair of paired wedge glasses 36a and 36b. In the focusing mechanism 36, an actuator (not shown) is actuated by a signal from the system control unit 40, which will be described later, and the pair wedge glass 36a is moved along the inclined surface of the pair wedge glass 36b with respect to the pair wedge glass 36b by the actuator. By moving in the direction, the optical path length is changed, and the focus position of the light beam emitted from the laser light source 30 is changed.

  Here, the electrical system of the exposure drawing apparatus 1 according to the present embodiment will be described together with the description of the exposure head 16a.

  FIG. 6 is a configuration diagram showing an electrical system of the exposure drawing apparatus 1 according to the present embodiment. As shown in FIGS. 5 and 6, the exposure drawing apparatus 1 is provided with a system control unit 40 that is electrically connected to each part of the apparatus. The system control unit 40 includes storage means such as a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), and a hard disk drive (HDD), and the system control unit 40 performs exposure drawing. Each part of the apparatus 1 is controlled in an integrated manner.

  The exposure drawing apparatus 1 includes a switching control unit 41 that switches on / off the emission of the optical laser from the plurality of laser light sources 30A and 30B. The driving of the plurality of laser light sources 30A and 30B is controlled by light source drivers 42A and 42B, respectively. The switching control unit 41 controls the driving of each of the laser light sources 30A and 30B with respect to the light source drivers 42A and 42B based on the control of the system control unit 40, thereby emitting light beams from the laser light sources 30A and 30B. Switch on / off.

  The exposure drawing apparatus 1 also includes a temperature detection unit 43 that detects the temperature of the DMD 27. The temperature detection unit 43 includes a temperature sensor 43a such as a thermistor connected to the DMD 27, and transmits information indicating the temperature detected by the temperature sensor 43a to the system control unit 40 as information indicating a detection result. .

  The exposure drawing apparatus 1 also includes a temperature adjustment unit 44 that adjusts the temperature of the DMD 27. On the other hand, the DMD 27 is provided with a temperature adjusting member 45 such as a Peltier element. The temperature adjustment unit 44 adjusts the temperature of the DMD 27 by controlling cooling and heating of the DMD 27 by the temperature adjustment member 45 based on the control of the system control unit 40.

  The system control unit 40 receives a detection signal from each photo sensor 26 provided on the stage 10 and determines whether or not the light beam is detected by each photo sensor 26, thereby determining the exposure position of the light beam. Identify. A method for specifying the exposure position of the light beam will be described later.

  Further, the system control unit 40 controls the stage driving unit 46 to move the stage 10 on which the substrate C to be exposed is placed to the exposure position of the light beam by the exposure head 16a, and the light source unit 17 and the image processing unit. 19 is controlled to cause the exposure head 16a to perform exposure drawing. The operation device 47 includes a display unit that displays data and an input unit that inputs data such as a substrate size by a user operation.

  Further, the system control unit 40 generates a digital signal for driving and controlling each micro mirror 29 of each exposure head 16a based on the image data of the exposure target image at the time of exposure drawing, and the generated digital signal is generated. The image is transmitted to the image processing unit 19.

  The movement control unit 48 controls driving of each of the plurality of imaging units 23 based on an instruction from the system control unit 40.

  Here, as described above, in the conventional exposure drawing apparatus, the positional deviation of each pixel is obtained by obtaining the positional deviation for each pixel during exposure drawing based on the position of the pixel under measurement in DMD and the exposure position of the light beam. By performing this, the distortion amount of the exposure target image can be corrected.

The sensitivity of the dry film resist used in pattern exposure to the exposed substrate C is generally 10 to 100 mJ / cm ² or so, if the case of exposure with 50 mJ / cm ^2, when the exposure rate of 25 mm / sec, an exposure width If 1024 × 512 pixels are used for 70 mm, the amount of light per pixel is about 1.6 μW. If the amount of light for one pixel is this amount of light, the position of one pixel can be detected. When the light utilization efficiency of this optical system is about 10%, the light amount of the laser light source necessary for position detection is 8,700 mW. That is, conventionally, if there is a laser light source of 10,000 mW, it is possible to perform both maskless exposure drawing on a dry film resist and position detection of 1.6 μW per pixel.

  However, when an ultra-sensitive material such as a silver salt sensitive material is used as a photosensitive material, the amount of light beam used for exposure drawing is small, so this light beam is used as it is for position correction. When performing, there is a problem that the detection signal S / N of the exposure position of the light beam cannot be sufficiently obtained because the light beam is insufficient, and the position detection accuracy is lowered.

Specifically, when an ultrasensitive material is used as an exposure target, the amount of light beam necessary for exposure drawing is 0.1 mJ / cm ² , which is about 3 per pixel when converted to the amount of light per pixel. Since the amount of light is as extremely low as 3 nW, the detection signal S / N for detecting the exposure position of the light beam cannot be sufficiently obtained. When exposing an ultrasensitive material as an exposure target, the amount of light for detecting the exposure position of the light beam is about 500 times the amount of light for obtaining the detection signal S / N, for example, the amount of light for exposure. It is desirable that the amount of light per pixel is about 1.6 μW.

  Therefore, in the exposure drawing apparatus 1 according to the present embodiment, the light amount of the light beam is changed by switching the laser light source 30 that emits the light beam between the case of performing exposure drawing and the case of performing position correction. At this time, by making the light beam from each laser light source 30 enter the same rod integrator 31, the exposure position of the light beam can be made the same in the case of performing exposure drawing and in the case of performing position correction.

  FIG. 7 is a schematic diagram for explaining a method of switching the laser light source 30 in the exposure drawing apparatus according to the first embodiment. As shown in FIG. 7, in the exposure drawing apparatus 1 according to this embodiment, a laser light source 30A (for example, 20 mW) for exposure drawing is used when performing exposure drawing, and position correction when performing position correction. The laser light source 30 is switched so that the laser light source 30B for use (for example, 10,000 mW) is used.

  In this case, it is desirable that the laser light sources 30A and 30B have the same wavelength range of the emitted light beam in order to reduce the error in the exposure position when the laser light source 30 is switched. For example, when the wavelength range of the light beam from the laser light source 30A is 400 to 406 nm, the wavelength range of the light beam from the laser light source 30B is preferably 400 to 406 nm. Alternatively, the amount of deviation may be calculated based on the difference in wavelength in the derivation of the amount of deviation described later without making the wavelength ranges of the light beams from the laser light sources 30A and 30B the same.

  Note that the exposure position of the light beam is affected by the measurement even if there is a change in the light amount distribution when changing the light amount of the light beam between exposure drawing and position correction. Absent.

  Next, the flow of exposure drawing processing in the exposure drawing apparatus 1 according to the present embodiment will be described.

  FIG. 8 is a flowchart showing a flow of processing of the exposure control processing program according to the present embodiment, and the program is stored in advance in a predetermined area of a ROM that is a recording medium provided in the system control unit 40 of the exposure drawing apparatus 1. Has been. The system control unit 40 of the exposure drawing apparatus 1 executes the exposure control processing program at a predetermined timing (in this embodiment, timing when the power of the exposure drawing apparatus 1 is turned on).

  In step S <b> 101, the system control unit 40 determines whether it is a position correction timing. That is, when the power of the exposure drawing apparatus 1 is turned on, if the operator wants to correct the position of each pixel of the exposure target image, a predetermined operation for instructing the position correction using the operation device 47 is performed. I do. Therefore, the system control unit 40 determines that it is the timing of position correction when a predetermined operation for instructing position correction is performed.

  If it is determined in step S101 that it is not the timing of position correction, in step S103, the system control unit 40 determines that normal exposure drawing has been instructed, drives the exposure drawing laser light source 30A, and performs position correction. The laser light source 30B is controlled not to be driven. Thus, the light beam from the exposure drawing laser light source 30 </ b> A enters the rod integrator 31. In step S105, the system control unit 40 performs normal exposure drawing on the substrate C to be exposed.

  In the exposure drawing apparatus 1, when performing exposure drawing, image data indicating an exposure target image is input to the image processing unit 19 connected to the DMD 27 and temporarily stored in a memory in the image processing unit 19. This image data is data representing the density of each pixel constituting the image by binary values (whether or not dots are recorded).

  The stage 10 on which the substrate C to be exposed is placed is moved at a constant speed in the Y direction by the stage driving unit 46. When the stage 10 moves to the exposure position, the image processing unit 19 sequentially reads the image data stored in the memory in the image processing unit 19 for a plurality of lines, and generates a digital signal for each exposure head 16a. Then, on the basis of the generated digital signal, each micro mirror 29 of each DMD 27 of each exposure head 16a is on / off controlled.

  On the other hand, when a light beam is irradiated from the light source unit 17 to the DMD 27, the laser light reflected by the micromirror 29 in the on state in the DMD 27 is imaged on the exposed surface of the substrate C to be exposed. In this way, the laser light emitted from the light source unit 16 is exposed to the exposed substrate C for each pixel so as to correspond to the on / off state of the micromirror 29.

  Further, as the substrate C to be exposed moves at a constant speed as the stage 10 moves, a strip-shaped exposed area R2 is formed for each exposure head 16a on the substrate C to be exposed. In this way, exposure drawing on the substrate C to be exposed is performed by the exposure drawing apparatus 1 according to the present embodiment.

  On the other hand, if it is determined in step S101 that the position correction timing is reached, in step S107, the system control unit 40 drives the position correction laser light source 30B and does not drive the exposure drawing laser light source 30A. Control. As a result, the light beam from the laser light source 30B for position correction enters the rod integrator 31. In step S109, the system control unit 40 performs position correction processing.

  FIG. 9 is a flowchart showing a processing flow of the position correction processing program according to the present embodiment, and the program is stored in advance in a predetermined area of a ROM that is a recording medium provided in the system control unit 40 of the exposure drawing apparatus 1. Has been.

  In step S201, the system control unit 40 determines the pixel to be measured, and sets an exposure reference position corresponding to the position on the exposure surface with respect to the position of the micromirror 29 that reflects the light beam of the pixel to be measured. Remember. When determining the pixel to be measured, it is preferable to sequentially select, for example, corner pixels in the exposure area of each exposure head 16a.

  In step S <b> 203, the system control unit 40 drives the DMD 27 by inputting the position correction image data generated based on the pixel under measurement to the image processing unit 19 connected to the DMD 27. This image data is image data for position correction, and is data in which the density of each pixel is expressed in binary (the pixel under measurement has dots and the other pixels have no dots). The image processing unit 19 sequentially reads the input image data for a plurality of lines, and generates a digital signal for each exposure head 16a. Then, on the basis of the generated digital signal, each micro mirror 29 of each DMD 27 of each exposure head 16a is on / off controlled.

  Next, in step S205, the system control unit 40 acquires the temperature of the DMD 27. At this time, the system control unit 40 acquires the temperature of the DMD 27 by acquiring information indicating the detection result from the temperature detection unit 43.

  In step S207, the system control unit 40 determines whether or not the temperature acquired in step S205 is within a predetermined range. The predetermined range is that the difference in temperature of the DMD 27 is preferably ± 0.5 ° C. or less between the case of performing exposure drawing and the case of performing position correction. It is good to set so that it may become -0.5 degreeC or more and 0.5 degrees C or less. Note that the temperature of the DMD 27 at the time of exposure drawing may be detected a plurality of times at an arbitrary timing while normal exposure drawing is performed, and an average value of the detected temperatures may be stored in advance.

  If it is determined in step S207 that the temperature is outside the predetermined range, in step S209, the system control unit 40 adjusts the temperature adjustment unit 44 so that the temperature of the DMD 27 is within the predetermined range. Then, the process proceeds to step S205.

  The above steps S205 to S209 are processes for suppressing the thermal influence associated with changing the light amount of the light beam when performing exposure drawing and when performing position correction. By these processes, the temperature of the DMD 27 is reduced. It is adjusted to be within the optimum range.

  If it is determined in step S207 that the temperature is within the predetermined range, in step S211, the system control unit 40 derives the exposure position on the exposed surface. At this time, the system control unit 40 receives a detection signal from each of the plurality of photosensors 26, and derives an exposure position of the light beam on the exposed surface from the received detection signal.

  Here, in the exposure drawing apparatus 1 according to the present embodiment, a method for detecting the exposure position of the light beam using the detection slit 25 will be described.

  In the exposure drawing apparatus 1, the position actually irradiated on the exposed surface when the micromirror 29 corresponding to the measured pixel Z <b> 1 is turned on as the measured pixel is detected using the detection slit 25. .

  The system control unit 40 moves the stage 10 in the Y direction so that the light beam from the exposure head 16a is incident on the detection slit 25 for detecting the light beam from the exposure head 16a to be subjected to position correction. In addition, the detection slit 25 is positioned below the exposure unit 16.

  FIG. 10A is an enlarged schematic diagram for explaining a method of detecting the position of the pixel under measurement in the exposure drawing apparatus 1 according to the present embodiment, and FIG. 10B relates to the present embodiment. In the exposure drawing apparatus 1, it is explanatory drawing which showed the detection signal of the photosensor 26 with respect to a to-be-measured pixel corresponding to (A).

  As shown by a solid line in FIG. 10A, the system control unit 40 moves the stage 10 in the Y direction so that the detection slit 25 becomes a required position (for example, a position to be the origin) on the exposure area R1. . At this time, the system control unit 40 sets the intersection point of the two straight portions (here, the first straight portion 25A and the second straight portion 25B) in the saddle-shaped detection slit 25 as (X0, Y0). The coordinates are temporarily stored.

  Next, as shown in FIG. 10A, the system control unit 40 starts the movement of the detection slit 25 in the Y direction (right side of the front view) by moving the stage 10 in the Y direction. Then, the system control unit 40 passes the first linear portion 25A through the first linear portion 25A as shown in FIG. 10B at the position indicated by the two-dot chain line on the right side of the front view. The stage 10 is stopped at the position where the detection by the sensor 26 is detected. The system control unit 40 sets the intersection of the first straight line portion 25A and the second straight line portion 25B at this time as (X0, Y11), and temporarily stores the coordinates.

  Next, the system control unit 40 starts moving the detection slit 25 in the Y direction (leftward in front view) by moving the stage 10 in the Y direction. Then, the system control unit 40 transmits the light beam of the pixel under measurement Z1 through the second linear portion 25B at the position indicated by the two-dot chain line on the left side of the front view as shown in FIG. 10B. The stage 10 is stopped at the position where the detection by the sensor 26 is detected. The system control unit 40 sets the intersection of the first straight line portion 25A and the second straight line portion 25B at this time as (X0, Y12), and temporarily stores the coordinates.

  Next, the system control unit 40 reads the stored coordinates (X0, Y11) and (X0, Y12), obtains the coordinates of the pixel to be measured Z1, and performs an operation according to the following formula to calculate the actual exposure position. . Here, assuming that the coordinates of the pixel to be measured Z1 are (X1, Y1), X1 = X0 + (Y11−Y12) / 2 and Y1 = (Y11 + Y12) / 2.

  As described above, when the photosensor 26 is used in combination with the detection slit 25 having the first straight portion 25A and the second straight portion 25B intersecting the first straight portion 25A, the photosensor 26 Only a predetermined range of light passing through the first straight part 25A or the second straight part 25B needs to be detected. Therefore, in this configuration, a commercially available inexpensive photosensor is used without making the photosensor 26 a fine and special configuration that detects a light amount in a narrow range corresponding to the first linear portion 25A or the second linear portion 25B. it can.

  In step S213, the system control unit 40 derives and stores a deviation amount between the exposure reference position of the pixel to be measured stored in step S201 and the exposure position of the light beam derived in step S211.

  In step S215, the system control unit 40 determines whether the derivation of the deviation amount has been completed. At this time, when the system control unit 40 derives the shift amount for each pixel (corresponding to each micromirror 29 of the DMD 27) subject to position correction of each exposure head 16a by the processing of steps S201 to S215, It is determined that the derivation of the deviation amount has been completed.

  If it is determined in step S215 that the derivation of the deviation amount has not been completed, the process proceeds to step S201, and the system control unit 40 performs the processes of steps S201 to S215 for the next pixel to be measured.

  When it is determined in step S215 that the derivation of the deviation amount has been completed, the system control unit 40 performs image data indicating the exposure target image based on the deviation amount derived in step S213 for the image data indicating the exposure target image. Correct the data. The shift amount is corrected by modifying the exposure target image, changing the mapping between each pixel in the exposure target image and each micromirror 29 in the DMD 27, or the like. For example, when distortion correction is performed on an exposure target image, the distortion amount is derived based on the shift amount, and the image data of the exposure target image is corrected so that the exposure position is corrected at a position where distortion is reduced. It is preferable to correct the correspondence between the micromirrors 29 of the DMD 27 and the pixels of the image data of the exposure target image so that the distortion aberration is reduced.

  FIG. 11 is a schematic view showing an example of exposure drawing distortion correction in the exposure drawing apparatus 1 according to the present embodiment.

  If the plurality of optical systems and the substrate C to be exposed are not distorted, the image data input to the DMD 27 is exposed to the substrate C as it is even if it is not corrected as shown in FIG. By drawing, an ideal image is drawn as shown in FIG.

  However, when an image drawn by the exposure head 16a is distorted due to factors such as temperature and vibration when performing exposure drawing with a light beam, the DMD 27 is not corrected as shown in FIG. Is input, the image is deformed as shown in FIG.

  Therefore, as shown in FIG. 11 (F), if the image data input to the DMD 27 is corrected and the image to be exposed and drawn on the substrate C to be exposed is appropriately corrected, the final image is obtained as shown in FIG. 11 (E). A correct image without any distortion is drawn.

  In this way, the exposure drawing apparatus 1 according to the present embodiment switches whether to emit a light beam for each of the plurality of laser light sources 30 when performing exposure drawing and when correcting the exposure position. When correcting the exposure position of the light beam, the light beam is exposed for a predetermined pixel, the exposure position on the surface to be exposed is detected, and the exposure target position of the predetermined pixel and the detected exposure position are The relative shift amount is derived, and the exposure position by the light beam is corrected for each pixel according to the derived shift amount. Thereby, it is possible to perform exposure position correction with high accuracy even if the exposure target is an ultrasensitive material.

  In the exposure drawing apparatus 1 according to the present embodiment, the light beams from the laser light source 30A and the laser light source 30B are incident on the rod integrator 31, but the present invention is not limited to this, and the laser light source A is used without using the rod integrator 31. In addition, the light beam from the laser light source B may be incident on the lens system 32.

  Moreover, in the exposure drawing apparatus 1 which concerns on this embodiment, although the Peltier device is used as the temperature control member 45, it is not limited to this, A fan etc. which cools may be sufficient.

  In the exposure drawing apparatus 1 according to the present embodiment, the DMD 27 is used as a spatial light modulation element used for the exposure head 16a. For example, a micro electro mechanical systems (MEMS) type spatial light modulation element (SLM; Special Light) is used. A spatial light modulator other than the MEMS type, such as a modulator, an optical element (PLZT element) that modulates transmitted light by an electro-optic effect, or a liquid crystal light shutter (FLC), may be used instead of the DMD 27.

  Note that MEMS is a general term for a micro system that integrates micro-sized sensors, actuators, and control circuits based on a micro-machining technology based on an IC manufacturing process, and a MEMS type spatial light modulator is an electrostatic force. It means a spatial light modulation element driven by an electromechanical operation using

  In the exposure drawing apparatus 1 according to the present embodiment, the light amount of the light beam is changed between exposure drawing and position correction using a plurality of laser light sources 30, but the present invention is not limited to this. A single laser light source may be used, and the light amount of the light beam may be changed by, for example, extracting a part of the light beam from the laser light source with a beam splitter.

[Second Embodiment]
Hereinafter, the exposure drawing apparatus 1 according to the second embodiment will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  In the exposure drawing apparatus 1 according to the first embodiment, the light source unit 17 includes two laser light sources, that is, a laser light source 30A and a laser light source 30B, each having a different amount of light. In the exposure drawing apparatus 1 according to the second embodiment, the light source The unit 17 includes a large number of laser light sources 30C having the same amount of light.

  12A and 12B are cross-sectional views in the operation direction along the optical axis showing the configuration of the exposure head 16a of the exposure drawing apparatus 1 according to the second embodiment. As shown in FIGS. 12A and 12B, a light source unit including a plurality of laser light sources 30 (in the second embodiment, 500 laser light sources 30C (for example, 20 mW)) on the light incident side of the DMD 27. 17A, a rod integrator 31 that emits a light beam emitted from a plurality of laser light sources 30C and emits it with uniform illuminance, and a lens system 32 that corrects the incident light beam and focuses it on the DMD 27. A reflecting mirror 33 that reflects the laser light transmitted through the lens system 32 toward the DMD 27 is sequentially arranged.

  Further, the exposure drawing apparatus 1 includes a switching control unit 41 that switches on / off the emission of the optical laser from the plurality of laser light sources 30C. Each of the plurality of laser light sources 30C includes a light source driver 42C that controls on / off of emission of the optical laser. The switching control unit 41 controls each of the light source drivers 42C based on the control of the system control unit 40, and instructs each switching of the plurality of laser light sources 30C.

  In the exposure drawing apparatus 1 according to the second embodiment, similarly to the first embodiment, the laser light source 30 that emits the light beam is switched between when exposure drawing is performed and when position correction is performed. Change the amount of light. At this time, by making the light beams from the respective laser light sources 30 enter the same rod integrator 31, the optical axes of the light beams can be made the same for exposure drawing and position correction.

  FIG. 13 is a schematic diagram for explaining a method of switching the laser light source 30 in the exposure drawing apparatus 1 according to the second embodiment. As shown in FIG. 13, in the exposure / drawing apparatus 1 according to the present embodiment, when performing exposure / drawing, one or a plurality of laser light sources 30C (one in the present embodiment) are used to perform position correction. In this case, on / off of each laser light source 30C is controlled so that a larger number (500 in this embodiment) of laser light sources 30C is used than when exposure drawing is performed.

  Also in the exposure drawing apparatus according to the second embodiment, the exposure control process shown in FIG. 8 and the position correction process shown in FIG. 9 are performed as in the first embodiment, and the same operations and effects as in the first embodiment are obtained. can get.

  In the exposure / drawing apparatus 1 according to the second embodiment, a plurality of the same laser light sources 30C are used, so that the cost can be reduced and a plurality of the same laser light sources 30C are used. Even if any of the light sources 30C fails, the failed laser light source 30C can be replaced immediately.

  DESCRIPTION OF SYMBOLS 1 ... Exposure drawing apparatus, 10 ... Stage, 11 ... Base | substrate, 12 ... Base, 13 ... Movement mechanism part, 14 ... Guide rail, 15 ... Gate, 16 ... Exposure part, 16a ... Exposure head, 17 ... Light source unit, 18 DESCRIPTION OF SYMBOLS ... Optical fiber, 19 ... Image processing unit, 20 ... Signal cable, 22 ... Gate, 23 ... Imaging | photography part, 24 ... Slit board, 25 ... Detection slit, 26 ... Photo sensor, 27 ... DMD, 28 ... SRAM cell, 29 ... Micromirror, 30, 30A to 30C ... Laser light source, 31 ... Rod integrator, 32, 34, 35 ... Lens system, 33 ... Reflector, 36 ... Focusing mechanism, 40 ... System control unit, 41 ... Switching control unit, 42 42A thru | or 42C ... Light source driver, 43 ... Temperature detection part, 44 ... Temperature adjustment part, 45 ... Temperature control member, 46 ... Stage drive part, 47 ... Operation equipment , 48 ... movement driving section, C ... substrate to be exposed.

Claims (11)

An optical modulation element comprising a plurality of micro optical elements, each of the plurality of micro optical elements being arranged two-dimensionally so as to correspond to each pixel;
A light source comprising a plurality of light emitting portions each emitting light irradiated to the optical modulation element, the light emission amount can be adjusted;
A condensing optical system disposed between the optical modulation element and an exposed surface, and condensing light from the optical modulation element on the exposed surface;
Each of the plurality of micro optical elements on the detection surface corresponding to the exposed surface in a state where the light amount irradiated from the light source is adjusted so that the light amount is larger than the light amount when the exposed surface is exposed. Position detecting means for detecting a condensing position where light from the light is collected;
Based on the detection result of the position detection means, acquisition means for acquiring a deviation amount of the light collection position of the light from the plurality of micro optical elements from a reference position;
Correction means for correcting the light collection position on the exposed surface based on the shift amount acquired by the acquisition means;
An exposure drawing apparatus comprising: The light source includes a light emitting unit having a predetermined light emission amount and a light emitting unit having a larger light amount than the light emission unit having the predetermined light emission amount,
When the surface to be exposed is exposed, light is emitted from the light emitting unit with the predetermined light emission amount, and when detecting the position, the light emitting unit with the large light amount, or the light emitting unit with the predetermined light emission amount and the light emission with the large light amount. The exposure drawing apparatus according to claim 1, wherein the exposure drawing apparatus is adjusted so that light is emitted from the unit. The light source includes a plurality of light emitting units having the same light emission amount,
The exposure drawing apparatus according to claim 1, wherein the position is detected so that light is emitted from a larger number of light emitting units than when the exposed surface is exposed. The exposure drawing apparatus according to claim 1, wherein light in the same wavelength range is emitted from each of the light emitting units of the light source. The exposure drawing apparatus according to any one of claims 1 to 4, wherein a rod integrator is disposed between the light source and the optical modulation element. Temperature detecting means for detecting the temperature of the optical modulation element;
Temperature adjusting means for adjusting the temperature of the optical modulation element;
Control means for controlling the temperature adjusting means so that the temperature of the optical modulation element becomes a temperature in a predetermined range based on the temperature detected by the temperature detecting means. The exposure drawing apparatus according to any one of 5. The position detecting means detects the position in a state where the temperature is controlled to be in the predetermined range, and the correction means is in a state controlled to be the temperature in the predetermined range. The exposure drawing apparatus according to claim 6, wherein the condensing position on the exposed surface is corrected. The correction means corrects image data of an image drawn on the exposed surface based on the shift amount so that the condensing position is corrected at a position where distortion is reduced. The exposure drawing apparatus according to any one of the preceding claims. The correction means determines the correspondence between the plurality of micro optical elements of the optical modulation element and the pixels of the image data of the image drawn on the exposed surface so that distortion is reduced based on the shift amount. The exposure drawing apparatus according to claim 1, wherein correction is performed.   The program for functioning a computer as an acquisition means and correction | amendment means in the exposure drawing apparatus in any one of Claims 1 thru | or 9. An optical modulation element that includes a plurality of micro optical elements, each of which is arranged in a two-dimensional manner so that each of the plurality of micro optical elements corresponds to each of the pixels, and a plurality of light that emits light that irradiates the optical modulation element. A light source capable of adjusting the amount of emitted light, a condensing optical system disposed between the optical modulation element and the exposed surface, and condensing light from the optical modulation element on the exposed surface An exposure drawing method in an exposure drawing apparatus comprising:
Each of the plurality of micro optical elements on the detection surface corresponding to the exposed surface in a state where the light amount irradiated from the light source is adjusted so that the light amount is larger than the light amount when the exposed surface is exposed. A position detecting step for detecting a position where light from the light is collected;
Based on the detection result of the detection step, an acquisition step of acquiring a deviation amount of a light collection position of light from the plurality of micro optical elements from a reference position;
A correction step for correcting the light collection position on the exposed surface based on the deviation amount acquired in the acquisition step;
An exposure drawing method comprising:

Images