KR102439363B1 - Exposure head for exposure device and projection optical system for exposure device - Google Patents

Abstract

It is possible to realize improvement in throughput while maintaining the sharpness of a pattern image.
In the exposure apparatus, an image segmentation optical system 30 having six mirror pairs, each of which is a pair of parallel planes composed of a segmentation mirror and a guide mirror, generates a pattern image from the DMD22 on the divided area of the DMD22. It divides into 6 according to (DM1-DM6), and moves the projection position so that six division|segmentation pattern images DA1-DA6 may be separated from each other along the main scanning direction X and the sub-scan direction Y.

Description

The exposure head for exposure apparatuses, and the projection optical system for exposure apparatuses TECHNICAL FIELD

The present invention relates to a maskless exposure apparatus that directly draws a pattern by means of an optical modulation element array such as a digital micro-mirror device (DMD). It's about optics.

In a maskless exposure apparatus equipped with a DMD, the exposure operation is performed by controlling the optical modulation element array in which the optical modulation elements (cells) are two-dimensionally arranged in a matrix shape, and the pattern is directly formed on the drawing surface of the substrate. . Specifically, when the illumination light emitted from the light source is guided to the DMD, each micromirror of the DMD is controlled ON/OFF according to the pattern to be formed in the area to be projected. The light reflected on the DMD is imaged by the projection optical system, and a pattern image is formed on the exposure surface.

In the exposure apparatus, in order to improve the throughput, it is possible to divide the light (pattern light) reflected by the DMD and project it onto a plurality of divided patterns. For example, a division optical system is arranged on the conjugate plane (image-forming plane) between the substrate and the DMD, and the pattern image is divided along the sub-scan direction on the conjugate plane. The pattern images divided on the conjugate plane are arranged at predetermined intervals along the main scanning direction, and are projected at positions of scan bands separated from each other along the sub-scan direction (see Patent Document 1). It is also possible to divide the pattern image by arranging the splitting optical system on the exit end side of the imaging optical system (see Patent Document 2).

[Patent Document 1] Japanese Patent Laid-Open No. 2012-247711 [Patent Document 2] Japanese Patent Laid-Open No. 2014-092707

When dividing the whole pattern image on the conjugate plane, it becomes the structure which arrange|positions the optical system which assembled the several parallel plane (mirror), and it becomes an optical system of complicated mirror arrangement|positioning. Therefore, even if it tries to divide a pattern image into many (for example, 4 division|segmentation or more), the adjacent mirror interferes and it leads to light quantity loss. Further, when a plurality of pattern images are divided on the exit end side of the imaging optical system, since the pattern images are not divided in the conjugate plane, the light quantity loss due to the diffusion of the light flux is large.

Accordingly, an optical system for an exposure apparatus that divides more pattern images and forms each divided pattern image on an exposure surface with sufficient resolution is required.

The exposure head for an exposure apparatus of the present invention is applicable to a maskless exposure apparatus, and includes an optical modulation element array in which a plurality of optical modulation elements are two-dimensionally arranged, and the light reflected by the optical modulation element array, to the image of an object. A projection optical system for forming an image on an exposure surface is provided, wherein the projection optical system includes a first optical system, an image division optical system, and a second optical system.

The first optical system forms the light on the pattern reflected by the optical modulation element array on the first imaging plane. The image division optical system divides the pattern image (as an intermediate image) formed on the first imaging plane according to the division area, and is provided with a plurality of mirror pairs that form a plurality of divided pattern images.

The arrangement of the plurality of mirror pairs is in accordance with the division area. For example, the division area is defined on the light-receiving surface of the optical modulation element array. The second optical system forms the light on the plurality of division patterns formed by the image division optical system onto the exposure surface.

In the present invention, each of the plurality of mirror pairs has a split mirror arranged to intersect the first imaging plane, and a guide mirror parallel to the split mirror and guide light from the split mirror to the second optical system. The image division optical system divides the pattern image in the vicinity of the first image forming plane by the dividing mirror. That is, the pattern image is divided in a range along the optical axis direction in the vicinity of the first imaging plane in the vertical direction of the first imaging plane in which the pattern resolution allowed in the range of the adjustable depth of focus can be obtained.

The plurality of split mirrors are each inclined at a predetermined angle with respect to the first imaging plane so that the plurality of split pattern images are projected apart from each other in the main scanning direction and the sub-scan direction. Here, "it is inclined with respect to the first imaging plane" means that the normal direction of the reflective surface of the split mirror is inclined with respect to the normal direction of the first imaging plane.

In this case, the projection line defined when each side of the reflective surface is orthogonally projected onto the first imaging plane is inclined with respect to at least one of the main scanning direction and the sub-scan direction, or both the main scanning direction and the sub-scan direction If it is parallel to , it is included in both. For example, if the reflective surface is spherical, the projection lines on each side of the reflective surface are parallel to the main scanning direction and the sub-scan direction, or are inclined to both.

By projecting the divided pattern images apart from each other in the main and sub-scan directions, it becomes possible to project the pattern image on each of a plurality of scanning bands, and the area that can be scanned at one time is enlarged by the number of divided pattern images, and the throughput is improved do.

As for the arrangement of the plurality of split mirrors, it is possible to incline each of the plurality of split pattern images so as to be projected in a ring shape on the exposure surface. Here, the projection on the ring is not the projection of the divided pattern image diagonally along the line direction as in the prior art, and on the other hand, it is not a random projection, and the trajectory when tracing on the plurality of division patterns is approximately circular. It means the projection characterized by the pattern arrangement of the image which becomes a shape (either a circle or an ellipse may be sufficient, and the shape may be collapsed like a rubber band). In this case, it is preferable to project so that the lines that become the lines in the longitudinal direction on the division pattern line up along the sub-scan direction.

For example, the plurality of split mirrors are inclined at respective angles so that at least one split pattern is projected onto the exposure surface in each of the four upper limits defined by the exposure surface projection center. Here, the exposure surface projection center refers to an imaginary point assuming that the light beam located at the center on the pattern has reached the exposure surface of the object (substrate W) without being split (reflected) by the image segmentation optical system. indicates. Further, when the optical modulator array is positioned at the optical center of the imaging optical system, the point where the optical axis of the imaging optical system and the exposure surface intersect can be regarded as the projection center.

In order to place the distance on the division pattern as close as possible, for example, the center side division mirror located on the center side is such that the division pattern image is projected at a position away from the exposure surface projection center along the sub-scan direction than the main scanning direction. , it is better to have a sloping configuration. Further, the split mirror adjacent to the center-side split mirror may be inclined so that the split pattern image is projected at a position away from the exposure surface projection center along the main scanning direction from the sub-scan direction.

In consideration of timing adjustment of drawing data, etc., in the plurality of split mirrors, the split pattern image along one half area on the pattern and the split pattern image along the other half area on the pattern have a point symmetrical relationship with respect to the exposure surface projection center. It is preferable to incline each as much as possible.

In consideration of preventing non-uniformity of sharpness on each split pattern, it is preferable that the plurality of guide mirrors be arranged so that the respective optical path lengths from the plurality of split mirrors to the exposure surface are the same.

In consideration of making the pattern image as clear as possible, it is preferable that the plurality of split mirrors be inclined at an angle corresponding to the depth of focus of the projection optical system with respect to the first imaging plane. That is, what is necessary is just to set it as the inclination angle which the reflective surface enters within the range of the depth of focus according to the sharpness of the pattern image allowed. For example, it is possible to configure the plurality of split mirrors to be inclined at 45 degrees or less with respect to the first imaging plane, and more preferably, they are inclined at 30 degrees or less and 15 degrees or less.

A projection optical system for an exposure apparatus according to another aspect of the present invention comprises: a first imaging optical system for imaging on a first imaging plane light reflected by an optical modulation element array in which a plurality of optical modulation elements are two-dimensionally arranged; an image division optical system for forming at least four divided pattern images by dividing the pattern image formed on the first imaging plane into at least four in the vicinity of the first imaging plane; A second imaging optical system for forming an image is provided, wherein the image segmentation optical system forms at least four segmented pattern images such that the plurality of segmented pattern images are projected apart from each other along the main and sub-scan directions.

ADVANTAGE OF THE INVENTION According to this invention, a through-put improvement can be implement|achieved while maintaining the vividness of a pattern.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which showed typically the exposure apparatus which is this embodiment.
2 is a diagram schematically showing the internal configuration of an exposure head.
3 is a diagram illustrating a divided region on a pattern in a DMD.
4 is a view showing positions on six divided patterns projected on an exposure surface of a substrate.
Fig. 5 is a view showing the arrangement of mirror pairs along the center-side divided area;
6 is a diagram illustrating an arrangement of a mirror pair according to an intermediate divided area.
7 is a view showing the arrangement of mirror pairs according to the outer division area.
Fig. 8 is a diagram showing the arrangement of the split mirror with respect to the conjugate plane.
9 is a diagram illustrating an arrangement angle of a split mirror.
10 is a view showing the arrangement relationship of three split mirrors and a guide mirror.
11 is a perspective view showing three split mirrors.
12 is a view showing the arrangement of the guide mirror.
13 is a block diagram of a drawing control unit provided in the drawing apparatus.
Fig. 14 is a diagram showing a divided area in the DMD when dividing by odd numbers.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to drawings.

1 is a perspective view schematically showing an exposure apparatus according to the present embodiment.

The exposure apparatus 10 is a maskless exposure apparatus that directly irradiates pattern light onto a substrate W coated with (or pasted) a photosensitive material such as photo-resist, and has a gate shape structure ( 12) and expectations (14). An X-Y stage mechanism 56 for supporting the drawing table 18 is mounted on the base 14 , and the substrate W is installed on the drawing table 18 .

Light sources 20a and 20b are provided in the gate-like structure 12 , and exposure heads 20 ₁ , 20 ₂ for pattern formation are arranged in parallel above the substrate W . The exposure head 20 ₁ is equipped with a DMD (Digital Micro-mirror Device) and a projection optical system (not shown here), and projects the pattern image onto the substrate W based on the light emitted from the light source 20a. . The exposure head ₂₀₂ also has the same structure, and projects a pattern image with the light of the light source 20b.

The spherical substrate W is, for example, a substrate for electronic circuits such as a printed circuit board, a dry film, and a glass substrate, and is a blank to which a pre-bake process, a photosensitive material application/pasting process, etc. have been performed. ) in the state of being mounted on the drawing table 18 . An X-Y-Z coordinate system orthogonal to each other is defined in the substrate W (the drawing table 18), and the drawing table 18 is movable along the X and Y directions, and is also rotatable about the Z axis. Here, the X direction is defined as the main scanning direction, and the Y direction is defined as the sub scanning direction.

The exposure apparatus 10 is equipped with the drawing control part (not shown here) which controls exposure operation|movement. A monitor, a keyboard, etc. not shown here are connected to the drawing control section, and settings related to drawing processing are performed according to an operator's operation. The CCD sensor 19 provided on the protrusion 31 detects the deformation state of the substrate W, and the exposure operation is performed after alignment is adjusted.

FIG. 2 is a diagram schematically showing the internal configuration of the exposure head 20 ₁ . The exposure head ₂₀₂ also has the same internal structure.

The illumination light emitted from the light sources 20a and 20b shown in FIG. 1 is guided to the DMD 22 through an illumination optical system (not shown). The DMD 22 is an optical modulation device in which micro-spherical micromirrors of several micrometers to several tens of micrometers are two-dimensionally arranged in a matrix form, and is constituted by, for example, 1024x768 micromirrors.

In the DMD 22, each micromirror is selectively ON/OFF controlled, respectively, based on the control signal (exposure data) stored in the memory cell. The light reflected by the micromirror in the ON state is a light flux according to the pattern to be projected, and is guided to the projection optical system 24 through a mirror (not shown).

The projection optical system 24 is an optical system for imaging the light from the DMD 22 on the exposure surface of the substrate W, and includes a first imaging optical system 25 , a second imaging optical system 26 , and an image segmentation optical system 30 . ) is equipped with The first imaging optical system 25 forms an image of the light according to the pattern from the DMD 22 on the imaging plane (first imaging plane) at the focal position, and magnifies the entire pattern image by a predetermined magnification.

The image division optical system 30 divides the pattern image formed on the imaging plane of the first imaging optical system 25 into six, and forms six partial pattern images (hereinafter referred to as divided pattern images). The six division pattern images formed by the image division optical system 30 are formed on the exposure surface of the substrate W by the second imaging optical system 26 .

Speaking of image formation, the image segmentation optical system 30 can be regarded as an optical system incorporated into the second imaging optical system 26 , and the imaging at the anterior focal position of the second imaging optical system 26 . The plane coincides with the imaging plane (focus position) of the first imaging optical system 25 , and the imaging plane at the rear focal position coincides with the exposure plane of the substrate W . Hereinafter, the imaging plane of the first imaging optical system 25 is also referred to as a conjugate plane.

As the substrate W moves along the main scanning direction X, the projection area (exposure area) by the DMD 22 moves relative to the substrate W. An exposure operation is performed according to a predetermined exposure pitch to irradiate a pattern light according to the position of the projection area. Accordingly, a pattern is formed along the main scanning direction.

The same is true for the other exposure heads ₂₀₂ , and an exposure operation is performed while raster scanning is performed to form a pattern on the entire substrate. When the drawing process is finished, a developing process, etching or plating, a resist stripping process, etc. are performed, and the board|substrate on which the pattern was formed is manufactured.

Although the moving direction of the board|substrate W is made to correspond to the main scanning direction here, you may arrange|position the board|substrate W on the drawing table 18 in the state with a slight inclination with respect to the main scanning direction X. In this case, when the drawing table 18 moves along the main scanning direction X, the exposure area moves relative to the longitudinal direction (X direction) of the board|substrate W in the inclined state.

As the exposure method, a step-and-repeat method or a multiple exposure method using a continuous movement method is applicable. In the step-and-repeat method, the drawing table 18 intermittently moves along the X direction, and each micromirror is controlled ON/OFF accordingly. On the other hand, in the continuous movement method, each micromirror is controlled ON/OFF according to the exposure pitch while the drawing table 18 moves continuously. Here, the continuous movement method is applied.

Next, the division|segmentation and projection position on a pattern are demonstrated using FIGS. In addition, below, the center point of the exposure area when a pattern image is not divided|segmented (when a division|segmentation optical system is not provided), ie, the projection point of the center position of DMD, is set and demonstrated as the origin of an X-Y-Z coordinate system.

Fig. 3 is a diagram showing a divided region on a pattern in the DMD. Fig. 4 is a diagram showing positions on six divided patterns projected on an exposure surface of a substrate.

As shown in FIG. 3 , on the reflective surface of the DMD 22 , partial regions DM1 to DM6 equally divided in the lateral direction along the main scanning direction (hereinafter referred to as divided regions) are defined. The light on the pattern formed by the DMD 22 as a whole is projected to a different position for each partial area DM1 to DM6 by the image division optical system 30 as shown in FIG. 4 . The projected divided pattern images DA1 to DA6 are formed by the pattern light of the divided regions DM1 to DM6, respectively.

As shown in Fig. 4 , the six division pattern images DA1 to DA6 are projected at a predetermined distance apart from each other along the main scanning direction X, and are spaced apart from each other so as not to overlap along the sub-scanning direction Y, and are adjacent to each other. It is projected in accordance with the positions of the scanning bands SB1 to SB6 to That is, if the divided pattern images DA1 to DA6 are arranged at the same position in the main scanning direction X, it becomes one continuous image in the sub scanning direction Y. As shown in FIG.

The arrangement order of the pattern image along the sub-scan direction Y at this time is arranged in the order of division pattern image DA1, DA6, DA2, DA5, DA3, DA4 from the top. That is, the division pattern images DA1 and DA4 along the division areas DM1 and DM4 located on the center side of the DMD 22 are projected at a position far from the origin along the sub-scan direction Y, and the division next to it is projected. The division pattern images DA2 and DA5 of the areas DM2 and DM5 are projected at positions closer to the origin along the sub-scan direction Y within the same upper limit as the division pattern images DA1 and DA4, respectively.

On the other hand, division pattern images DA3 and DA6 of division areas DM3 and DM6 are projected within an upper limit different from division pattern images DA1 and DA4 and division pattern images DA2 and DA5, and divided pattern image DA2 .

As a result, the projection positions on the division pattern images DA1 to DA6 have a point-symmetrical projection positional relationship with respect to the sub-scan direction Y. That is, division pattern images DA1, DA4, division pattern images DA2, DA5, and division pattern images DA3, DA6 exist in a symmetrical positional relationship with respect to the origin. In addition, since the divided pattern image is alternately projected along the sub-scan direction between the right half partial areas DM1 to DM3 and the left half partial areas DM4 to DM6 of the DMD 22, the divided pattern image ( DA1 to DA3) and the divided pattern images DA4 to DA6 have a complementary relationship that complements each other.

On the other hand, the distance from the origin (distance to the projection center position) XL on each division pattern does not match. The projection center as used herein is an imaginary when it is assumed that the light beam located at the center on the pattern by the DMD 22 has not been split (reflected) by the image division optical system and has reached the exposure surface of the object (substrate W). point. Further, when the DMD 22 is positioned at the optical center of the projection optical system 24, the point where the optical axes of the first and second imaging optical systems 25 and 26 intersect the exposure plane is the projection center. can be seen as

In this way, the image segmentation optical system 30 projects the segmented pattern images DA1 to DA6 in a substantially ring form so as to be distributed within all upper limits, not in the diagonal line direction as in the prior art. Here, on the ring, not only the circle but also the meaning of a non-circular ring or polygon is included. The divided pattern images DA1 to DA6 are arranged according to such a figure outline, but the direction of the divided pattern images DA1 to DA6 is not bound to the ring tangential direction and is arranged at a predetermined angle. In addition, it is not necessary for the arrangement|positioning on the division|segmentation pattern to remind a ring, for example, even if the division|segmentation pattern image was four, it is regarded as ring shape.

The image segmentation optical system 30 for realizing ring-like projection is provided with six mirror pairs according to the division areas DM1 to DM6 of the DMD 22, and each mirror pair is configured as a set of parallel planes. Hereinafter, the mirror pair will be described.

5 is a diagram showing the arrangement of mirror pairs along the divided area DM1. 6 is a diagram showing the arrangement of mirror pairs along the divided area DM2. 7 is a diagram showing the arrangement of mirror pairs along the divided area DM3.

5 to 7, the mirror pairs 32, 34, and 36 project the reflected light from the divided areas DM1, DM2, and DM3 onto the divided patterns DA1, DA2, and DA3 respectively at the projection positions (Fig. 4), and is composed of spherical split mirrors 32A, 34A, and 36A and spherical guide mirrors 32B, 34B, and 36B. However, the size of each mirror shown in Figs. 5 to 7 is drawn to fit each divided region of the DMD 22 for ease of explanation here.

In the split mirror 32A, the entire reflection surface thereof is not parallel to the conjugate plane CS, but intersects the conjugate plane CS. That is, the normal direction is not parallel to the normal direction of the conjugate plane CS, but is disposed so as to be inclined. Accordingly, the distance from the conjugate plane CS along the Z-axis direction perpendicular to the conjugate plane CS varies depending on the location of the split mirror 32A.

Further, the spherical reflection surface of the split mirror 32A is inclined at a predetermined angle in the oblique main scanning direction X and the sub scanning direction Y, respectively. That is, when each side of the split mirror reflection surface is projected onto the conjugate surface CS, the projection line prescribed is not parallel to the X axis and the Y axis, but is inclined. Here, the arrangement of the split mirror 32A with respect to the conjugate plane CS is referred to as "slanted arrangement in the vicinity of the conjugate plane CS".

The inclination angles with respect to the main scanning direction X, the sub scanning direction Y, and the Z axis are determined according to the projection position of the division pattern image DA1 shown in FIG. In Fig. 4, the divided pattern image DA1 is shifted in the sub-scan direction Y by a distance of 2.5 scanning bands by the division mirror 32A and the guide mirror 32B.

Since the division pattern image DA1 is projected at a position away from the origin with respect to the sub-scan direction Y rather than the main scanning direction X, the inclination angle with respect to the X-axis is larger than the inclination angle with respect to the Y-axis. In addition, the normal direction of the reflection surface faces the +Y direction and the +X direction. The guide mirror 32B in a parallel plane relationship with the split mirror 32A guides the light from the split mirror 32A to the second optical system 26 .

The split mirrors 34A of the mirror pair 34 shown in Fig. 6 are also arranged to intersect the conjugate plane CS, and are inclined at different angles with respect to the main scanning direction X and the sub scanning direction Y. . Since the division pattern image DA2 is projected at a position further away from the origin in the main scanning direction X than in the sub-scan direction Y, the inclination angle with respect to the Y-axis is larger than the inclination angle with respect to the X-axis. Further, in order not to interfere with the light reflected by the split mirror 32A, the normal direction of the reflective surface is larger than the split mirror 32A and is inclined toward the +X side. In Fig. 6, the division mirror 34A and the guide mirror 34B shift in the sub-scan direction Y by 0.5 scanning bands.

In addition, the split mirror 36A of the mirror pair 36 shown in Fig. 7 is also arranged to intersect the conjugate plane CS, and at different angles with respect to the main scanning direction X and the sub scanning direction Y respectively. is inclined Here, in order to project division|segmentation pattern image DA1 to a 4th upper limit, the normal direction of the reflection surface is facing -X, -Y direction. In Fig. 7, the division mirror 36A and the guide mirror 36A shift by 1.5 scanning bands in the negative direction of the sub-scan direction Y. As shown in FIG.

Fig. 8 is a diagram showing the arrangement of the split mirror 36A with respect to the conjugate plane CS. Fig. 9 is a diagram showing an arrangement angle of the split mirror 36A.

The split mirror 36A is inclined so that its center is located on the conjugate plane CS, and is positioned upward (-Z direction) from the conjugate plane CS with a line 36A _C intersecting the conjugate plane CS therebetween. ) and the lower area (+Z direction). The inclination angle with respect to the conjugate plane CS of the side (henceforth divided side) 36A _L of the split mirror 36A is the split mirror 34A (refer to FIG. 6) which is extended. It is different from the inclination angle of the divided sides of , and the sides intersect each other when viewed from the X-axis direction. As is clear from the split mirror 36A and the guide mirror 36B moving the projection pattern image DA3 from the origin in the +X direction and the -Y direction, the intersection line 36A _C is in the main scanning direction X, It is inclined with respect to the sub-scan direction Y.

The inclination angle α of the split mirror 36A shown in Fig. 9 with respect to the conjugate plane CS is determined at an angle at which both mirror lines 36A _E do not depart from the conjugate plane CS as much as possible. For example, it is set to 30 degrees or less and 15 degrees or less. By setting the inclination angle α to a minute angle, interference with adjacent split mirrors can be avoided. The other split mirrors 32A and 34A are similarly defined.

In addition, the depth of focus of the projection optical system 24 is a depth of focus at which the divided pattern image falls into the in-focus range, respectively. The inclination angle with respect to the conjugate plane CS of each split mirror is set to fall within the range of the depth of focus for maintaining the sharpness required on the split pattern. The range of the depth of focus depends on the required pattern resolution, optical characteristics of the projection optical system 24 , and the like. For example, the inclination angle of the split mirror 36 may be set to be at least 45°, 30°, or 15° or less.

Fig. 10 is a diagram showing the arrangement relationship of three split mirrors and a guide mirror. 11 is a perspective view showing three split mirrors. And FIG. 12 is a figure which showed arrangement|positioning of a guide mirror.

As described above, the division pattern images DA1, DA2, DA3 are a pair of mirrors 32A, 32B, 32, a pair of mirrors 34A, 34B, 34, and a mirror constituted by a pair of parallel planes. The pair 36A, 36B 36 is projected at the position shown in FIG. 10 . The sizes of the split mirrors 32A, 34A, and 36A and the guide mirrors 32B, 34B, and 36B are larger than the projection area on the conjugate plane CS according to each divided area of the DMD 22 .

In particular, since the guide mirrors 32B, 34B, and 36B are inclined with respect to the conjugate plane CS, which is the imaging plane, the split mirrors 32A, 34A, and 36A are sized in consideration of the diffusion of the light flux on the split pattern. In addition, in FIGS. 5-7, 10, the expanded range LM of the light beam on division|segmentation pattern image DA1-DA3 is shown.

In addition, the guide mirrors 32B, 34B, and 36B are arranged so that the distance from any X-Y plane along the -Z direction (distance to the mirror center position) becomes the same. In FIG. 12, it has shown that the distance Z0 from each guide mirror to the conjugate surface CS is the same. Moreover, the guide mirror 32B is arrange|positioned so that all the optical path lengths from the division mirrors 32A, 34A, 36A to the exposure surface on which division pattern images DA1-DA3 are projected may become equal.

The three mirror pairs (not shown) arranged in accordance with the divided areas DM4 to DM6 of the DMD 22 are also arranged in the same manner, and the six divided mirrors are adjacent to each other, respectively, in the main scanning direction X and the sub-scan direction. It is inclined at different angles depending on the direction (Y). The inclination angles of the split mirrors along the split areas DM4, DM5, and DM6 are symmetrical angles to the split mirrors 32A, 34A, and 36A, respectively, and the positive and negative sides of the main scanning direction X and the sub-scan direction Y are respectively.正負) becomes inverse (逆). The optical path lengths from the six split mirrors to the split pattern images DA1 to DA6 are all the same.

13 is a block diagram of a drawing control unit provided in the drawing apparatus.

The drawing control part 50 is connected with an external workstation (not shown), and is equipped with the exposure control part 52 to which the monitor 50B and the keyboard 50C are connected. The exposure control unit 52 controls exposure operation processing, and outputs a control signal to circuits such as the exposure data generation unit 76 , the timing control circuit 73 , the drawing table control circuit 53 , and the light source control unit 61 . do. A program for controlling the exposure operation processing is stored in a ROM (not shown) in the exposure control unit 52 .

The pattern data input from the workstation (not shown) to the exposure control unit 52 is vector data (CAD/CAM data) having position information (contour position information) of the drawing pattern, as position coordinate data based on the X-Y coordinate system. is shown

The first to sixth raster data generation units 72 ₁ to 72 ₆ convert vector data and sequentially generate raster data of a pattern to be drawn on the scan bands SB1, SB2, and SB3, respectively. The generated raster data is temporarily stored in the first to sixth buffer memories 74 ₁ to 74 ₆ , respectively.

The raster data temporarily stored in each buffer memory is output according to the exposure pitch. That is, when the partial projection area moves by the exposure pitch and the next exposure operation becomes executable, raster data output is performed. The raster data output control in the first to sixth raster data generating units 72 ₁ to 72 ₆ is performed based on a control signal output from an address control circuit (not shown) provided in the exposure control unit 52 . .

When the raster data is sent to the exposure data generation unit 76 , the exposure data generation unit 76 integrates the raster data corresponding to the positions of the respective projection areas on the division pattern DA1 to DA6, and the DMD 22 A signal for controlling ON/OFF of each micromirror is generated as one exposure data for the entire DMD 22 . In the DMD 22 , the micromirror is controlled ON/OFF based on the exposure data output from the exposure data generation unit 76 .

The timing control circuit 73 outputs a clock pulse signal as a synchronization signal for timing adjustment to the buffer memories 74 ₁ to 74 ₆ , the exposure data generation unit 76 , and the like. Moreover, based on the image signal output from the CCD sensor 19, the image processing part 62 detects the position of the alignment mark formed in the board|substrate W. As shown in FIG.

The drawing table control circuit 53 controls the X-Y stage mechanism 56 equipped with a motor (not shown) via the drive circuit 54, so that the moving speed of the drawing table 18, the substrate transport direction, etc. are controlled. Controlled. The position detection sensor 55 detects a position relative to the drawing table 18 with respect to the position of the drawing table 18 , ie, the projected position on the partial pattern images DA1 to DA6 .

Similarly to the exposure head 202 , circuits (not _shown ) related to raster data conversion processing, DMD driving processing, and the like are provided, and the same exposure operation processing is performed.

As described above, according to the present embodiment, the image division optical system 30 provided with six mirror pairs in parallel planes each composed of a division mirror and a guide mirror divides the pattern image from the DMD 22 into the division of the DMD 22 . It divides into 6 according to area|regions DM1-DM6, and moves projection position so that six division pattern images DA1-DA6 may be separated from each other along the main scanning direction X and the sub-scan direction Y. Thereby, a through-put improvement can be aimed at.

By dividing the pattern image by arranging a plurality of mirror pairs in parallel plane relationship, it becomes possible to constitute a simple optical system, and it is possible to divide the pattern image by four or more. In particular, since the image of the division pattern on the center side is projected at the most distant position with respect to the sub-scan direction, the distance interval on the division pattern can be widened.

Then, for the split mirror at an intermediate position adjacent to the split mirror on the center side, the split pattern image is projected at the position furthest away from the main scanning direction, and the distance between the projection positions on the split pattern between adjacent split mirrors is increased. Accordingly, interference between adjacent mirrors can be avoided. In particular, by arranging the divided pattern images of the right half and the left half on the pattern alternately along the sub-scan direction, a larger distance interval of the projection position can be taken. In addition, by suppressing the inclination angle of the split mirrors so that there is no interference of light between adjacent mirrors, loss of light quantity can be suppressed and required resolution can be obtained.

Furthermore, since the projection positions on the division pattern images DA1 to DA6 have a point-symmetric positional relationship with respect to the center thereof, and the left half and right half division pattern images on the pattern have a complementary positional relationship, the writing timing in the writing process can be easily adjusted. Then, while arranging the split pattern images DA1 to DA in a ring shape, the split mirror pair (each guide mirror) is set so that the total optical path length to the exposure surface on which the split pattern images DA1 to DA6 is projected becomes the same. By arranging, the sharpness on each division pattern becomes uniform.

The number of divisions on the pattern is arbitrary, and divisions can be made by any even number. In this case, what is necessary is just to arrange|position a mirror pair according to the division|segmentation number. It is also possible to divide the pattern image into odd numbers.

Fig. 14 is a diagram showing a divided area in the DMD when dividing by odd numbers. Five mirror pairs are arranged in accordance with the five division areas DM1 to DM5 determined by dividing the reflective surface of the DMD 22' into 5 equal parts. The inclination angle of the split mirror is determined in the same manner as in the case of even-numbered splits.

In this embodiment, the inclination angle of the split mirror is set so that the split pattern image is separated from the projection center in the X and Y directions, respectively. For example, the side of the middle split mirror 32A is orthogonal You may make it incline so that the projection line at the time of doing it may become parallel along an X direction and a Y direction.

10: drawing apparatus (exposure apparatus)
22: DMD (optical modulation element array)
24: projection optical system
25: first imaging optical system (first optical system)
26: second imaging optical system (second optical system)
30: image segmentation optical system
32, 34, 36: mirror pair
32A, 34A, 36A split mirror
32B, 34B, 36B guide mirror

Claims (10)

an optical modulation element array in which a plurality of optical modulation elements are arranged in two dimensions;
and a projection optical system for imaging the light reflected by the light modulator array on an exposure surface of an object to be drawn;
The projection optical system,
a first optical system for imaging the patterned light from the optical modulation element array on a first imaging plane;
an image segmentation optical system having a plurality of mirror pairs that divide a pattern image formed on the first imaging plane according to a divided area to form a plurality of divided pattern images;
a second optical system for imaging the light on the plurality of split patterns on the exposure surface;
Each of the plurality of mirror pairs has a split mirror disposed to intersect a first imaging plane, and a guide mirror parallel to the split mirror and guide light from the split mirror to the second optical system,
An exposure apparatus characterized in that a plurality of split mirrors are respectively inclined with respect to the first imaging plane so that the plurality of split pattern images are projected on the exposure surface at intervals from each other in accordance with the positions of the scan bands arranged in the sub-scan direction. For exposure head. According to claim 1,
An exposure head for an exposure apparatus according to claim 1, wherein the plurality of split mirrors are each inclined so that the plurality of split pattern images are projected on the ring from the exposure surface. According to claim 1,
The exposure head for an exposure apparatus according to claim 1, wherein the plurality of split mirrors are each inclined so that at least one split pattern is projected onto the exposure surface within each of four upper limits defined by an exposure surface projection center. 4. The method according to any one of claims 1 to 3,
An exposure head for an exposure apparatus, characterized in that the center-side split mirror positioned on the center side is inclined so that the split pattern image is projected at a position away from the exposure surface projection center along the sub-scan direction rather than the main-scan direction. 4. The method according to any one of claims 1 to 3,
An exposure apparatus characterized in that the center-side split mirror positioned on the center side and the adjacent split mirror are inclined so that the split pattern image is projected at a position away from the exposure surface projection center along the main scanning direction rather than the sub-scan direction. exposure head. 4. The method according to any one of claims 1 to 3,
Each of the plurality of split mirrors is inclined so that the split pattern image along one half region of the pattern and the split pattern image along the other half region have a point-symmetric relationship with respect to the exposure surface projection center. An exposure head for an exposure apparatus. 7. The method of claim 6,
The plurality of guide mirrors are arranged at the same center in the vertical direction of the first image forming plane so that the respective optical path lengths from the plurality of split mirrors to the exposure surface are the same. exposure head. 4. The method according to any one of claims 1 to 3,
An exposure head for an exposure apparatus, wherein the plurality of split mirrors are inclined at an angle corresponding to the depth of focus of the projection optical system with respect to the first imaging plane. An exposure apparatus comprising the exposure head for an exposure apparatus according to any one of claims 1 to 3. a first imaging optical system for imaging a patterned light from an optical modulation element array in which a plurality of optical modulation elements are arranged two-dimensionally on a first imaging plane;
an image segmentation optical system for forming at least four segmented pattern images by dividing the pattern image formed on the first image plane into at least four in the vicinity of the first image plane according to the segmented area;
a second imaging optical system for imaging the light on at least four divided patterns on the exposure surface of the object to be drawn;
Exposure characterized in that the image segmentation optical system forms at least four segmented pattern images so that at least four segmented pattern images are projected on the exposure surface at intervals from each other in accordance with the positions of the scan bands lined up along the sub-scan direction. Projection optics for the device.

Images