JP3320340B2 - Projection exposure apparatus, projection exposure method, and circuit manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a mask.
Exposure of the pattern image onto the photosensitive substrate from the projection optical system
Equipment, for example, step-and-repeat exposure
The present invention relates to an optical device, a method, and a circuit manufacturing method. [0002] 2. Description of the Related Art In recent years, the manufacture of semiconductor devices such as VLSI has been advanced.
Many reduction projection type exposure devices, so-called steppers, are used
It has become. Stepper is used for circuit patterns, etc.
Set the drawn reticle exactly at the specified position on the
The stage on which the semiconductor wafer as the optical substrate is placed is xy
Stepping a certain amount in the direction
The projection exposure is repeated. This place
The exposure image by the projection lens as the projection optical system
Precise positioning to a predetermined position on the wafer (alignment
G) need to be done. This alignment method
An off-axis alignment method is known. [0003] The off-axis alignment method is an
Wafer alignment installed separately from the shadow lens
Alignment marks on the wafer using a microscope for
After detecting and aligning the wafer with the microscope,
Move the wafer (stage) by a fixed amount based on the position
And send it under the projection lens, where it
This is to perform exposure in a round-and-repeat manner. This place
The projected position of the arbitrary point on the wafer and the reference point on the reticle
If you do not know the distance between the
Overlay exposure cannot be performed. Find the exact distance
ForToIs the optical axis position of the off-axis microscope,
The position of the reference point (alignment mark, etc.) on the reticle
Observation system for detection, so-called reticle alignment
Distance between the optical axis position of the microscope (hereinafter referred to as baseline measurement
Value) is assumed to be measured correctly.
Baseline measurement is performed using the reference marker set on the stage.
Off-axis wafer alignment
Stage position when the microscope detects the fiducial mark
And a reticle alignment microscope through a projection lens
The position of the stage when the fiducial mark is detected
Laser interferometer (hereinafter referred to as laser
By using an interrogator).
You. Generally, a reticle alignment microscope is
Before aligning the reticle, align the reticle
Illuminating light for exposure
Irradiates the entire surface and provides a reference point near the reticle
Observe the image of the reticle alignment mark as
It is. During this reticle alignment, the stage
Placing a wafer on it is prohibited. like this
To expose the entire reticle during reticle alignment
For the type that irradiates the illumination light of
Similarly, when measuring the slope, the illumination light passes through the projection lens.
Irradiate the fiducial mark on the stage and re-image the fiducial mark.
Through a reticle alignment microscope
Will be guessing. By the way, this type of projection lens is used for exposure.
When the illumination light is incident, part of that light is turned into heat.
And changes imaging characteristics such as the focal position and the imaging magnification.
You. For this reason, when measuring baseline or reticle alignment
Large amount of illumination light for exposure
The accuracy of the measured baseline measurement or
Missing such as deterioration of reticle alignment accuracy
There was a point. [0006] The present invention overcomes these disadvantages.
Resolve, baseline measurement accuracy, reticle alignment
Of the projected image to be exposed
Alignment accuracy on the substrate or overlay exposure
Exposure equipment with improved alignment accuracy, etc.
It is an object to obtain an apparatus, a method, and a circuit manufacturing method. [0007] In order to solve the above problems, the present invention provides:
Image of the circuit pattern formed on the maskVia projection optics
do itIn order to transfer to a predetermined image plane, the masklight source
fromAn illumination optical system that emits illumination light;light sourcefrom
Detecting a mark formed on the mask under illumination light;
A projection exposure apparatus having a detection systemThe illumination light
UnderWhen detecting the mark by the detection system
To, The maskIncident on the projection optical system via
The intensity of the illuminating light is determined by converting the image of the circuit pattern to the predetermined intensity.
When transferring to the image surface,The maskThrough the projection optics
Said incident on the systemFrom the intensity of the illumination lightAlso the detection system
Out of the wayStrength adjustment means to reduce
It was decided to have. Further,Circuit pattern formed on mask
Through the illumination optical system to transfer the image of
And irradiates the mask with illumination light from a light sourceProjection exposure
In the method,Under the illumination lightFormed on the mask
MarkIn the detection systemWhen detectingTo, The maskThrough
The incident on the projection optical systemThe intensity of the illumination light,
When transferring the image of the circuit pattern to the predetermined image forming surface,
The maskIncident on the projection optical system viaillumination
Than the light intensityDoes not affect the detection operation of the detection system.
To the extentIt was decided to lower it. [0009] FIG. 1 shows a reduction according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a schematic configuration of a projection type exposure apparatus. Light source and
The light from the mercury lamp 1 is collected by the elliptical mirror 2 and
After being reflected by the ichroic mirror 3, it has four blades
Rotary shutter. Through shutter 4
The luminous flux passed is optical and
The light enters the integrator 5 and forms a number of secondary light source images.
You. The light emitted from the optical integrator 5 is
Reflected by dichroic mirror 6
The light enters the sun lens 7. Below the condenser lens 7
As an illumination field stop with four independently movable blades
Reticle blind 8 is provided. The light from the condenser lens 7 passes through the mask
Reticle 12 is uniformly illuminated with light intensity.
Between the condenser lens 7 and the reticle blind 8
Is used to align the reticle 12 with respect to the apparatus body.
Reticle alignment microscope as a detection optical system for
(Hereinafter referred to as R-Mic) 9. FIG.
Shows only R-Mic9, but actually
Two-dimensional in the x direction of the vehicle 12 and the y direction orthogonal thereto
Misalignment by detecting the cross mark on the reticle 12
Microscope Rxy-Mic9a to obtain
Detects linear marks provided at positions different from
To determine the displacement of the reticle 12 in the rotational direction.
Two microscopes, Rθ-Mic9b, are provided. The circuit pattern drawn on the reticle 12 will now be described.
An image such as an image is formed on a predetermined image plane by the reduction projection lens 21.
Formed within. The wafer 16 located in the image plane is x,
y directionToThe stage 17 is held on a stage 17 that moves two-dimensionally.
The stage 17 is driven by a motor 19. And su
The coordinate position of the stage 17 is always set by the laser interferometer 18.
It has been measured. On this stage 17 are various
Used to measure the baseline between
The mark plate 15 provided with the reference mark FM is fixed.
You. The mark plate 15 has a light reflecting surface such as chrome
A layer that is reflective, and etching a portion of that layer
A quasi-mark FM is provided. This mark plate 15
The surface forms an image of the projection lens 21 when measuring the baseline.
Adjustment in the height direction is performed so as to match the plane. Further, the apparatus according to the present embodiment has a reticle 12
Die-by-die alignment tool provided above
And the die-by-die die provided on the wafer 16.
Back projection of alignment mark by projection lens 21
Steps for superimposing and observing an image (enlarged image)
・ Alignment microscope (hereinafter referred to as S-Mic) 11
Are arranged in the exposure light path directly above the reticle 12 so as to be able to advance and retreat.
Have been. Only one S-MiCII is shown in FIG.
Not provided, but provided at two different locations on reticle 12
Spoop mark for x direction and step mark for y direction
Microscope Sx-Mi so that each of the
c11a and microscope Sy-Mic11b are provided.
Have been. The projection lens 2 is located below the reticle 12.
Within 1ToWhen the laser beam 29 is incident, the projection laser
To form a sheet-like spot light in the image plane of the lens 21
At the same time, the spot light illuminates the mark on the wafer 16.
Light information (diffraction light, scattered light, etc.) generated when
Receives light through the shadow lens 21 and detects the position of the wafer 16
Laser alignment system (hereinafter referred to as LS)
F) 35 is provided. This LS system 35 is actually
Generates a spot light extending in the x direction, and
Y-LS system 35a for detecting the position in the
Generated spot light, and adjusts the position of the wafer 16 in the x direction.
It is composed of two sets of the x-LS system 35b to be detected. this
The laser beam 29 of the LS system 35 was applied to the wafer 16
The wavelength is set so that the photoresist is not exposed.
I have. The off-axis is located around the projection lens 21.
Three wafers for x-axis wafer alignment
C alignment microscope (hereinafter referred to as W-Mic) 13
a, 13b and 13c are provided at predetermined intervals. Was
However, the W-Mic 13c is not shown in FIG. this
About arrangement of three W-Mic 13a, 13b, 13c
For details, see JP-A-56-102823.
The description is omitted here. The aboveR-Mic9a, 9b, SMic1
1a, 11b, LS system 35, and W-Mic 13a, 1
Both the alignment sensors 3b and 13c
A photoelectric signal for outputting a photoelectric signal corresponding to the detected mark.
And the photoelectric signals are transmitted to the control unit 20.
To enter. Unit 20 is an alignment sensor
Detects the misalignment of the detected mark,
Stage 7 so that it is corrected or
The motor 19 and the like are controlled so as to be positioned. Also unity
20 controls the opening and closing of the shutter 4 and
The coordinate position information from the interferometer 18 is also input. FIG. 2 shows each of the above alignment sensors.
The relationship between the arrangement on the image plane and the projected image of the reticle 12 is modeled.
It is a top view which shows a formula. In FIG. 2, it is indicated by a broken line.
The circular area is the image field If of the projection lens 21.
And a square area of approximately the same size
This is the outer shape of the file 12. Pattern area PA of reticle 12
Is dimensioned to fit within the image field if
Have been. The center of the image field lf, ie
The coordinate system x is set so that the optical axis of the projection lens 21 is set to the origin CC.
When y is determined, the detection center 90a of the Rxy-Mic 9a is
Located on the x-axis, the detection center 90b of Rθ-Mic9b is
Located on the y-axis. The detection center 90a is a cross on the reticle 12
Finger in Rxy-Mic 9a that pinches the shape mark
Mark 2NextIt is the original center, and the detection center 90b is
A linear mark extending in the x direction on the tickle 12 will be inserted.
This is the center of the index mark in Rθ-Mic 9b.
However, the detection center 90b is set in the y direction in Rθ-Mic9b.
In the y direction with respect to the detection center 90a.
An optical axis correction mechanism for adjusting the interval Y1 is incorporated.
I have. The opposite of the origin CC of Rθ-Mic9b
On the side, Sx-Mic11a is located on the y-axis,
On the opposite side of the origin CC of Mic9a, Sy-Mic
11b is located on the x-axis. In addition, the image file
Field if and on the x-axis outside the pattern area PA
Is a sheet-like spot light S by the Y-LS system 35a.
Py is elongated in the x direction, and similarly, the pattern
The X-LS system 35b scans the y-axis outside the area PA.
The pot light SPx is positioned to be elongated in the y direction.
The W-Mic 13a is placed on the wafer 16 or on a mark plate.
15 to detect the position in the y direction of the mark extending in the x direction.
Has a detection center 130y, and this center 130y
Positioned on the y-axis away from the detection center 90a by Wy in the y-direction
It is location. Similarly, W-Mic 13b extends in the y direction.
Detection center 130 for detecting the position in the direction of the marked mark
x, and the center 130x is in the x direction from the detection center 90a.
Are located on the x-axis separated by Wx. The W-Mic 13c is a W-Mic 13a.
W-Mic
13a in cooperation with two separate markers on the wafer 16.
The rotation error of the wafer 16 is detected by observing the
Things. By the way, the mark plate 15 on the stage 17
A cross-shaped reference mark FM as shown in FIG.
Provided, linear marks extending in the y direction are denoted by FMx, x
A linear mark extending in the direction is defined as FMy. This reference marker
FM is a detection center 90a of each alignment sensor,
90b, 130y, 130x, 130θ and spot light S
Px, SPy, Sx-Mic11a, Sy-Mic
11b can be detected together by
Detected by each alignment sensor during line measurement
Move around like that. FIG. 3 shows a reticle alignment in the above apparatus.
Optical system showing a specific configuration of the R-Mic9
FIG. Prism block at the tip of R-Mic9
G0 is provided, and illumination light LB from the condenser lens 7 is provided.
Is transmitted through the prism block G0 and the reticle 1
Illuminate 2. Marker on pattern surface PT of reticle 12
The light from the mirror is reflected by the slope g of the prism block G0.
After that, the light enters the first objective lens G1 and becomes parallel light.
Converges on a predetermined image plane FP by the two objective lens G2,
An enlarged image of the mark is formed. In FIG. 2, the image forming plane FP
An index representing the detection center 90a or 90b as shown in FIG.
A glass plate waiting for the mark is placed, further behind it
Although not shown, the index mark and the mark on the reticle 12 are
Eyepiece (TV camera) for superimposing observations
Light) and the deviation between the index mark and the reticle mark
A photoelectric element and the like for electrical detection are provided. In FIG. 3, the dashed line 11 is R-Mi.
The optical axis of c9 is shown, and the solid line 12 represents the principal ray. Chief light
Line l2 is set to pass through the center of the entrance pupil of projection lens 21.
Is being used. This R-Mic 9 is the pattern of the reticle 12.
It is configured to focus on the zoom plane PT. others
Therefore, the reference mark FM is positioned within the image plane of the projection lens 21.
Then, the image is transferred to the pattern plane P via the projection lens 21.
Will be imaged on T and eventually RMiImage of c9
An image of the reference mark FM is formed in focus on the surface FP.
In addition, the system shown in FIG.
Although the optical axis is fixed to the device, Rθ-Mic9
For b, the optical axis correction mechanism described above is incorporated.
I have. Next, a series of baseline measurement of this embodiment will be described.
The flow will be described. In this embodiment, the reticle alignment
The shutter 4 is used as dimming means when using a microscope.
Shall be used. In the apparatus shown in FIGS.
The management of the slope measurement value is performed by the Rxy-Mic shown in FIG.
The detection center 90a of 9a serves as a reference. First, reticle 12
Is set on the device. At this time, the retic on the reticle 12
The cross mark RM for circle alignment is shown in FIG.
Sea urchin Rxy-MiIndex indicating detection center 90a of c9a
Position so as to deviate from the mark in a predetermined direction. Next
The four blades of reticle blind 8 are shown in FIG.
Rxy-Mic9a, Rθ-M
Both ic9b can observe the reticle alignment mark
To be able to Then, as shown in FIG.
-4 is opened halfway. Conventionally, the shutter 4 is fully opened.
To allow all of the illumination light beam LB 'to pass through,
The same amount of light as at the time of exposure was given to the entire surface of the lens. However
In this embodiment, the shutter 4 is opened halfway, and the illumination light flux L
I let some of B 'pass through and the rest was shaded
And the amount of light illuminating the reticle 21, ie, the projection lens
The amount of light incident on 21 is much lower than the amount of light during exposure.
Lower. Here, half-opening of the shutter 4 is not necessarily
Limited to the meaning that half of the illumination light beam LB 'passes
Not something. Light intensity (intensity) for illuminating reticle 12
Can be reduced by R-Mic9
Depends on the sensitivity of the photoelectric element inside. In other words, when the mark is detected
The signal-to-noise (S / N) ratio of the electrical signal
Shutter to reduce the illumination light intensity within the range
4 is determined. Next, the stage 17 is moved to
The reference mark FM is at the detection center of Rxy-Mic9a.
Positioning is performed so as to coincide with 90a. Control unit
20 are coordinate values (X0, Y) of the stage 17 at this time.
0) is read from the laser interferometer 18 and stored. This seat
The standard value (X0, Y0) is the moving plane (xy
Rxy-Mic9a (center 90a)
The projection position. At this time, Rxy-Mic 9a is
Projection lens of fiducial mark FM through transparent portion of tickle 12
Back-projected image is detected. This is R-Mi
c9 is focused on the pattern surface PT on the back surface of the reticle 12.
This is because it is configured as follows. Next, the control unit 20 moves the stage 17.
Moving the reference mark FM to detect Rθ-Mic9b
The center 90b is arranged at a position where it is to be designed. this
Is based only on the coordinate values read by the laser interferometer 18,
This is performed by controlling the motor 19. This and
The position of the reference mark FM is determined by the previous coordinate value (X0, Y
0), as shown in FIG.
The design interval (X1, Y1) from the detection center 90a is added.
And the coordinate values (X0 + X1, Y0 + Y1)
You. When the reference mark FM is positioned, Rθ-Mic
9b extends in the x-direction between the detection center 90b and the reference mark FM
So that the linear mark FMy matches in the y direction.
Adjust the optical axis correction mechanism. This makes two reticks
The alignment microscope uses the coordinate system of the stage 17
The alignment is accurate. Next, the detection center of the above Rxy-Mic9a
90a matches the mark RM of the reticle 12, and Rθ−
Mic9b detection center 90b and another reticle
Finely move reticle 12 so that
Make a decision (reticle alignment). At this time
In general, the reflection surface of the mark plate 15 without the reference mark FM is
Be within the field of view of Rxy-Mic9aOn stage17
Is positioned, the cross mark RM is positioned at the detection center 9
0a, the x direction and the y direction of the reticle 12
Adjust the position of. After that, the reflection surface of the mark plate 15 becomes R
Position the stage 17 within the field of view of θ-Mic 9b.
The linear mark coincides with the detection center 90b in the positioned state.
As shown in FIG.
Is slightly rotated. By the above operation, reticle 12
Also accurately aligned with the coordinate system of stage 17
It will be. When this reticle alignment is completed
And shutter4Block the illumination light beam LB '. Shout
The illumination light passes through the reticle 12 until the
Will continue to enter the projection lens 21
The incident energy itself is
The imaging characteristics of the projection lens 21 (focus position, projection
The fluctuation of the shadow magnification) can be kept sufficiently small. Imaging characteristics
If there is a fluctuation in the baseline measurement,
Sometimes errors will occur. Next, Step Aligne
Microscope Sx-Mic11a, Sy-Mic11b
The projection position is detected using the reference mark FM. This and
Reticle 12 is already correctly aligned
Therefore, in the field of view of Sx-Mic11a, as shown in FIG.
Provided around the pattern area PA of the reticle 12.
The marked step mark SxM is positioned so as to be observable.
The step mark SxM is formed in a transparent rectangular window shape.
ing. The projection position of the step mark SxM is designed in advance.
I know, the control unit20Is stage 17
Move it,FIG.AsToWindow centerToFiducial mark FM
so that the linear mark FMx extending in the y direction is sandwiched
Perform positioning. Specifically, the window of the step mark SxM
Sx-Mic with the linear mark FMx positioned inside
11a based on the photoelectric signal from the photoelectric element in the
Xx, Δx2 in the x-direction within the window of the FMx
And the center of the left / right distribution, that is, Δx1 = Δx
Finely moving the stage 17 in the x-direction so that it becomes 2.
The positioning is completed by. The control unit 20
The position X3 of the stage 17 in the x direction at the time
Read from 18 and store. Similarly, Sy-Mic11
b, the step mark SyM on the reticle 12
(Not shown) and a linear marker extending in the x direction of the reference mark FM
Stage 17 at that time
Is detected in the y direction. This allows you to
Base of alignment microscope Sx-Mic11a
The in-measurement value SX is measured as SX = X3-X0,
The baseline measurement value SY of y-Mic11b is SY = Y
Measured as 3-YOToBecome. Note that Δx1 =
Even if you do not drive mark FMx to Δx2,
The center position of the step mark SxM can be obtained.
You. Next, a laser step alignment system,
Each spot light S of the Y-LS system 35a and the X-LS system 35b
Detects the projected position of Py, SPx using fiducial mark FM
I do. First, as shown in FIG.
So that the mark FM and the linear mark FMx are aligned in parallel.
After positioning the stage 17, the reference mark FM is
Move in the x direction as indicated by the mark. The X-LS system 35b is
Pot light SPx is a linear mark FMxOptical information from
And the control unit 20 converts the
When the spot light SPx matches the mark FMx,
The position X4 of the stage 17 in the x direction is detected and stored. same
In this way, the control unit 20 performs the linear mark of the reference mark FM.
FMy in y directionToRun, spot light Sy and mark F
The position Y in the y direction of the stage 17 when My coincides with My
4 is detected and stored. This allows the laser step
Baseline measurement of alignment system and Y-LS system 35a
The value LSY is measured as LSY = Y4-Y0, and X-L
The baseline measurement value LSX of the S system 35b is LSX = X4
This means that it has been measured as -X0. Finally, a wafer alignment microscope
The projection position of the W-Mic 13a, 13b is used as a reference mark F
M is used for detection. First, the control unit 20
The linear mark FMy of the mark FM is detected by the W-Mic 13a.
Position the stage 17 so that it matches the outgoing center 130y
And determine the position Y5 of the stage 17 in the y direction at that time.
Detect and store. Next, the control unit 20 is a linear marker.
FMx matches the detection center 130x of W-Mic13b
The stage 17 is positioned so that
The position X5 of the stage 17 in the x direction is detected and stored. This
Thereby, the wafer alignment microscope W-Mic13a
Is the baseline measurement value Wy of Wy = Y5-YO
Measured, W-Mic 13b baseline measurement Wx
Is measured as Wx = X5-XO. Various baselines measured as described above
Measurement values (SX, SY), (LSX, LSY), (W
x, Wy) based on the step and repeat method
The positioning and exposure of the wafer 16 according to the formula are performed.
Thus, according to the present embodiment, the reticle alignment
When using a microscope, open the shutter 4 halfway and project
Since the energy incident on the lens 21 has been reduced,
When measuring various baselines after tickle alignment,
Alignment system with shadow lens 21 interposed (detection optics
The amount by which the position of the projection point at the detection center of the system fluctuates in the xy directions
Is extremely small, resulting in step and repeat
Positioning accuracy of the wafer 16 and the superposition
The effect of improving the accuracy of the exposure is obtained. Next, a second embodiment of the present invention will be described with reference to FIG.
explain. In this embodiment, a reticle alignment microscope is used.
Use a reticle bridge as a means of dimming the illumination light during use.
8 is used. As shown in Fig. 8, four blinds 8
Consisting of rectangular blades 8a, 8b, 8c, 8d of
The blades 8a and 8b can move linearly in the y direction.
The blades 8c and 8d can move linearly in the x direction. FIG.
As shown in the figure, a reticle alignment microscope Rxy-M
When using ic9a and Rθ-Mic9b, Rθ-M
The blade 8a located on the ic 9b side is almost fully opened,
The blade 8b located on the opposite side of the Rθ-Mic 9b has an R
xy-Mic9a extended to a position that does not block the visual field
Rxy-Mic9a sideToLocated blade8dHaho
Fully openToAnd Rxy-MiOn the other side of C9a
The blade 8c to be placed cuts off the visual field of Rθ-Mic 9b
To the next position. In this embodiment, the shutter 4 is fully opened.
Into the projection lens 21 when illuminating the reticle 12
The firing energy fully opens the blind 8ToIncident when
Lighting area is almost 1/4 compared to energyToSqueezed
As a result, the projection lens 21
Fluctuations in the imaging characteristics are also extremely small. In this embodiment, the shutter 4 is fully opened.
ToRxy-Mic9a, Rθ-Mic9
Of course, the photoelectric signal from the photoelectric element in b has a high S / N ratio,
The detection accuracy of the mark is accordingly improved. However
With the reticle blind 8 squeezed as shown in FIG.
The shutter 4 is half-opened as in the first embodiment.
Then, the energy incident on the projection lens 21 is markedly
Lower and more effective. Incidentally, in addition to the embodiments of the present invention, a reticle
Use a mercury lamp 1 only when using a liment microscope.
In the illumination optical path from the reticle 12 to the reticle 12,
A similar effect can be obtained even if a
Can be [0035] As described above, according to the present invention, the mask formed on the mask is formed.
When detecting a broken mark, the intensity of the illumination light illuminating the mask
The mask when transferring the image of the circuit pattern to the predetermined surface.
Can be lower than the intensity of illumination light applied to
The fluctuation of the imaging characteristics of the projection optical system is extremely small.
Can be.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a competitive configuration of a reduction projection type exposure apparatus according to an embodiment of the present invention, and FIG. 2 is a projection of various alignment sensors of the apparatus shown in FIG. FIG. 3 is a plan view showing an arrangement relationship in an image plane. FIG. 3 is an optical arrangement diagram showing a configuration of a reticle alignment microscope. FIG. 4 is a plan view showing an example of alignment by a reticle alignment microscope. ] Is a plan view showing a configuration of a shutter as a dimming means, [Fig. 6] is a plan view showing an alignment state at the time of base line measurement by a top alignment microscope, [Fig. 7] is a laser step alignment system FIG. 8 is a plan view showing a state of alignment at the time of baseline measurement by using FIG. 8, and FIG. [Description of Signs] 1 ... Mercury lamp, 4 ... Shutter, 8 ... Reticle blind, 9 ...
..Reticle alignment microscope as detection optical system, 11 ... Step alignment microscope, 1
2. Reticle 13 Wafer alignment microscope ... . Fiducial mark plate, 16
... wafer, 17 ... stagen 1
8 Laser interferometer, 2 Control unit, 35
Laser step alignment system.

Continuation of front page       (56) References JP-A-52-109875 (JP, A)                 JP-A-50-46080 (JP, A)                 JP-A-60-76728 (JP, A)                 JP-A-60-26343 (JP, A)

Claims (1)

(57) [Claims] Projection optical system that projects the image of the circuit pattern formed on the mask
In order to transfer to a predetermined imaging surface through
In the projection exposure apparatus having an illumination optical system for irradiation and detection system which detects a mark formed on the basis in the mask of the light source or <br/> these illumination light illumination light from the light source, the when detecting the mark by under the detection system of the illumination light incident on the projection optical system through the mask
The intensity of the illumination light, in transferring an image of the circuit pattern on the predetermined imaging plane, said through the mask
Than the intensity of the illumination light incident on the projection optical system, said analyzing
A projection exposure apparatus comprising an intensity adjusting means for lowering the output system so as not to affect the detection operation . 2. The illumination optical system, and a optical integrator for uniformly illuminating the mask by light incident from the light source, the intensity controlling unit is being provided between the light source and the optical integrator The projection exposure apparatus according to claim 1, wherein: 3. 3. The projection exposure apparatus according to claim 1, wherein the detection system is an alignment microscope that performs alignment of the mask with respect to an apparatus main body. 4. The illumination optical system illuminates substantially the entire surface of the mask including the mark with the illumination light, and the alignment microscope detects the mark under the illumination light whose intensity has been reduced by the intensity adjusting unit. The projection exposure apparatus according to any one of claims 1 to 3, wherein the projection exposure apparatus is configured to: 5. The illumination optical system includes: an illumination field stop having a plurality of independently movable blades for arbitrarily defining an illumination area for illuminating the mask; and controlling the illumination field stop when the mark is detected by the detection system. The projection exposure apparatus according to any one of claims 1 to 3, further comprising a control device that performs the control. 6. Holds a photosensitive substrate disposed on the predetermined image plane
A stage which is controlled by the detection system.
When detecting the mark, through the projection optical system
A reference plate to which the illumination light is applied.
Any one of claims 1 to 5
3. The projection exposure apparatus according to claim 1. 7. Predetermined imaging of circuit pattern image formed on mask
The light from the light source passes through the illumination optics to transfer to the surface.
In a projection exposure method for irradiating the mask with bright light, a mark formed on the mask under the illumination light is detected.
When detecting in the output system, the projection optical
The intensity of the illumination light incident on the system, when transferring an image of the circuit pattern on the predetermined imaging plane, through the mask
And the intensity of the illumination light incident on the projection optical system
A projection exposure method characterized in that the detection operation is reduced so as not to affect the detection operation of the detection system . 8. A circuit manufacturing method using the projection exposure apparatus according to any one of claims 1 to 6 .