KR20170051297A - Exposure head for exposure device and projection optical system for exposure device - Google Patents

Abstract

The present invention can improve throughput, while maintaining clarity of a pattern image. In an exposure device, an image dividing optical system (30), having six mirror pairs, each of which is a group of parallel planes composed of a split mirror and a guide mirror divides the pattern image from the DMD (22) into six according to divided regions (DM1-DM6) of the DMD (22), to move a projection position according to a main scanning direction (X) and a sub-scanning direction (Y), so as to separate six divided pattern images (DA1-DA6) from each other.

Description

TECHNICAL FIELD [0001] The present invention relates to an exposure head for an exposure apparatus and a projection optical system for an exposure apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a maskless exposure apparatus for directly drawing a pattern by an optical modulation element array such as a DMD (Digital Micro-mirror Device), and more particularly to a maskless exposure apparatus for projecting a pattern image onto an exposure surface Optical system.

In a maskless exposure apparatus equipped with a DMD, an optical modulation element array in which light modulation elements (cells) are two-dimensionally arrayed in a matrix shape is controlled to perform an exposure operation, and a pattern is formed directly on a seedling screen of a substrate . Specifically, when the illumination light emitted from the light source is guided to the DMD, each micromirror of the DMD is ON / OFF controlled according to a pattern to be formed in an area to be a projection target. 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 a plurality of divided pattern images. For example, a splitting optical system is disposed on a conjugate plane (image plane) between the substrate and the DMD, and the pattern image is divided on the conjugate plane along the sub-scanning direction. The pattern images divided on the conjugate plane are arranged at predetermined intervals along the main scanning direction and are projected to the positions of the scanning bands spaced apart from each other in the sub-scanning direction (see Patent Document 1). It is also possible to arrange a dividing optical system on the emitting end side of the imaging optical system to divide the pattern image (refer to Patent Document 2).

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

In the case of dividing the entirety of the pattern image on the conjugate plane, an optical system in which a plurality of parallel planes (mirrors) are superimposed is arranged, resulting in an optical system of a complicated mirror arrangement. Therefore, even if an attempt is made to divide a pattern image into a plurality of (for example, four or more divisions), adjacent mirrors interfere with each other, leading to a light amount loss. Further, in the case where a pattern image is divided into a plurality of patterns on the side of the emission end of the imaging optical system, the pattern image is not divided on the conjugate plane, and the light amount loss due to the diffusion of the light beam (light beam) is large.

Therefore, there is a need for an optical system for an exposure apparatus that divides a pattern image into a larger number of parts and forms each divided pattern image on an exposure surface with sufficient resolution.

An exposure head for an exposure apparatus of the present invention is an exposure head applicable to a maskless exposure apparatus and includes a light modulation element array in which a plurality of light modulation elements are two-dimensionally arrayed, And a projection optical system for forming an image on an exposure surface, wherein the projection optical system has a first optical system, an image division optical system, and a second optical system.

The first optical system causes the light on the pattern reflected by the optical modulation element array to form an image on the first imaging plane. The image division optical system has a plurality of mirror pairs for dividing a pattern image (as an intermediate image) formed on the first imaging plane according to the division region and forming a plurality of division pattern images.

The arrangement of the plurality of mirror pairs depends on the divided area. For example, the divided area is defined on the light receiving surface of the light modulation element array. The second optical system causes the light on a plurality of divided patterns formed by the image dividing optical system to form an image on the exposure surface.

In the present invention, each of the plurality of mirror pairs has a split mirror disposed so as to intersect with the first imaging plane, and a guide mirror that is parallel to the split mirror and guides the light from the split mirror to the second optical system. The image division optical system divides the pattern image near the first imaging plane by the division mirror. That is, the pattern image is divided at a range along the optical axis direction in the vicinity of the first imaging plane along the first imaging plane vertical direction in which an allowable pattern resolution in a range of adjustable depth of focus can be obtained.

The plurality of divided mirrors are each inclined at a predetermined angle with respect to the first imaging plane so that the plurality of divided patterns are projected away from each other in the main scanning direction and the sub scanning direction. Here, "tilted relative to the first imaging plane" means that the normal direction of the reflection plane 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 orthogonal projection of each side of the reflection surface to the first imaging plane is inclined relative to at least one of the main scanning direction and the sub-scanning direction, or both the main scanning direction and the sub- And is included in both cases. For example, when the reflecting surface is rectangular, the projection lines of the respective sides of the reflecting surface become parallel to the main scanning direction and the sub scanning direction, or are inclined to both.

It is possible to project the pattern image onto each of the plurality of scan bands by projecting the divided pattern image apart from each other according to the main scanning direction and the sub scanning direction and the area which can be scanned one time is enlarged by the number of divided pattern images, do.

With respect to the arrangement of the plurality of divided mirrors, it is possible to make each of the divided pattern images be inclined so as to be projected from the exposure surface to the ring shape. Here, the projection on the ring is not a projection of a divided pattern image in an oblique direction in a row as in the conventional case, but a projection on a ring is not a random projection on the one hand, Means a projection that is characterized by a pattern arrangement of an image that has a shape (a circle, an ellipse, and the shape may collapse like a rubber band). In this case, it is preferable to project the line that is the line in the longitudinal direction on the divided pattern so as to be aligned in the sub-scanning direction.

For example, the plurality of divided mirrors are inclined at respective angles such that at least one divided pattern is projected onto the exposure surface in each of four upper quadrants defined along the center of the projection surface of the exposure surface. Here, the projection plane center of projection means a virtual point when it is assumed that a light ray located at the center of the pattern reaches the exposure surface of the object to be imaged (substrate W) without being divided (reflected) by the image- . Further, when the optical modulation element array is aligned with the optical center of the imaging optical system, a point at which the optical axis of the imaging optical system intersects the exposure surface can be regarded as the projection center.

In order to keep the distance on the adjacent divided patterns as far as possible, for example, the center-side split mirror located at the center side is designed so that the divided pattern image is projected at a position apart from the center of the exposure surface projection center in the sub- , And a slope is preferable. The divisional mirror adjacent to the center-side divided mirror may be inclined so that the divided pattern image is projected at a position where the distance from the center of the exposure surface projection is distant from the sub-scanning direction in the main-scan direction.

Considering the timing adjustment of the drawing data and the like, the plurality of divided mirrors are arranged such that the divided pattern image according to one half region of the pattern and the divided pattern image corresponding to the other half region have a point symmetrical relationship with respect to the center of the exposure surface projection It is preferable that they are each inclined.

It is preferable to arrange the plurality of guide mirrors such that the respective optical path lengths from the plurality of divided mirrors to the exposure surface become equal in consideration of preventing unevenness of sharpness on each divided pattern.

Considering that the pattern image is 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, the inclination angle may be set such that the reflective surface is within the range of the depth of focus according to the clearness on the permissible pattern. For example, the plurality of divided mirrors may be configured to be inclined at 45 degrees or less with respect to the first imaging plane, and more preferably, be 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 includes a first imaging optical system for imaging light reflected by an optical modulation element array in which a plurality of optical modulation elements are arranged two-dimensionally on a first imaging plane, An image forming optical system for forming at least four divided pattern images by dividing a pattern image formed on the first imaging plane into at least four regions near the first imaging plane by irradiating light on at least four divided patterns onto the exposure surface And the image dividing optical system forms at least four divided pattern images so that a plurality of divided pattern images are projected away from each other in accordance with the main scanning direction and the sub scanning direction.

According to the present invention, the throughput can be improved while maintaining the clarity of the pattern.

1 is a perspective view schematically showing an exposure apparatus according to the present embodiment.
2 is a diagram schematically showing an internal configuration of an exposure head.
3 is a view showing a divided area on a pattern in the DMD.
4 is a view showing positions of six divided patterns projected on an exposure surface of a substrate.
Fig. 5 is a diagram showing the arrangement of mirror pairs according to the center-side divided area. Fig.
6 is a view showing the arrangement of mirror pairs according to the intermediate divided area.
FIG. 7 is a diagram showing the arrangement of mirror pairs according to the outer divided region. FIG.
8 is a view showing the arrangement of the split mirror with respect to the conjugate plane.
9 is a view showing the arrangement angle of the split mirror.
10 is a diagram showing the arrangement relationship of three split mirrors and guide mirrors.
11 is a perspective view showing three divided mirrors.
12 is a view showing the arrangement of the guide mirror.
13 is a block diagram of a rendering control unit provided in the rendering apparatus.
14 is a diagram showing a divided area in the DMD when dividing into odd numbers.

Hereinafter, embodiments of the present invention will be described with reference to the 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 adhered to) a photosensitive material such as a photo-resist, and has a gate shape structure ( 12), and an expectation (14). An X-Y stage mechanism 56 supporting the drawing table 18 is mounted on the base 14 and a substrate W is mounted on the drawing table 18. [

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

The rectangular substrate W is an electronic circuit substrate such as a printed substrate, a dry film, or a glass substrate. The substrate W is a blanks subjected to a pre-bake process, a photosensitive material application / ) In the drawing table 18 as shown in Fig. The X-Y-Z coordinate system orthogonal to each other is defined in the substrate W (the drawing table 18). The drawing table 18 is movable along the X and Y directions, and further 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 provided with a drawing control section (not shown here) for controlling the exposure operation. A monitor, a keyboard, and the like not shown here are connected to the drawing control section, and the setting relating to the drawing process is performed according to the operation of the operator. The CCD sensor 19 provided on the projection 31 detects the deformation state of the substrate W and performs the exposure operation after the alignment is adjusted.

Fig. 2 is a diagram schematically showing the internal structure of the exposure head 20 ₁ . The exposure head 20 ₂ 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 a light modulation device in which micro-spherical micromirrors of several micrometers to several tens of micrometers are arranged in a matrix in a two-dimensional array, and is constituted by, for example, a micro mirror of 1024 x 768.

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

The projection optical system 24 includes a first imaging optical system 25, a second imaging optical system 26 and an image division optical system 30 ). The first imaging optical system 25 causes the light according to the pattern from the DMD 22 to form an image on the imaging plane (first imaging plane) at the focal point, and enlarges the entire pattern image at a predetermined magnification.

The image dividing optical system 30 divides the pattern image formed on the image forming surface of the first imaging optical system 25 into six and forms six partial pattern images (hereinafter, referred to as a divided pattern image). Six divided 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. [

With respect to image formation, the image-splitting optical system 30 can be regarded as an optical system inserted into the second imaging optical system 26 and can be regarded as an image-forming optical system at the front focal position of the second imaging optical system 26. [ And the imaging plane at the rear focal position coincides with the exposure plane of the substrate W. The imaging plane of the first imaging optical system 25 is aligned with the imaging plane (focus position) of the first imaging optical system 25, Hereinafter, the imaging plane of the first imaging optical system 25 is also referred to as a conjugate plane.

The projection area (exposure area) by the DMD 22 moves relative to the substrate W as the substrate W moves along the main scanning direction X. [ The exposure operation is performed in accordance with the exposure pitch determined to irradiate the pattern light corresponding to the position of the projection area. Thus, a pattern is formed in accordance with the main scanning direction.

The same is true of the other exposure heads 20 ₂ , and an exposure operation is performed while raster scanning, whereby a pattern is formed over the entire substrate. Upon completion of the drawing process, development processing, etching or plating, resist stripping, and the like are performed to produce a substrate having a pattern formed thereon.

Although the moving direction of the substrate W is in this case coincided with the main scanning direction, the substrate W may be arranged in the drawing table 18 in a slightly inclined state with respect to the main scanning direction X. In this case, when the drawing table 18 moves in the main scanning direction X, the exposure area moves relative to the substrate W in a tilted state with respect to the longitudinal direction (X direction).

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

Next, with reference to Figs. 3 to 12, the division on the pattern image and the projection position will be described. In the following description, the center point of the exposure area when the pattern image is not divided (when the division optical system is not provided), that is, the projection point of the center position of the DMD is defined as the origin of the X-Y-Z coordinate system.

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

As shown in Fig. 3, partial regions DM1 to DM6 (hereinafter, referred to as divided regions) equally divided in the lateral direction in accordance with the main scanning direction are defined on the reflective surface of the DMD 22. [ As shown in Fig. 4, light on the pattern formed by the entire DMD 22 is projected to different positions for each of the partial regions DM1 to DM6 by the image dividing optical system 30. [ The projected divided pattern images DA1 to DA6 are formed by the pattern light of the divided areas DM1 to DM6, respectively.

As shown in Fig. 4, the six divided pattern images DA1 to DA6 are projected at a predetermined distance apart from one another in the main scanning direction X, are not overlapped with each other in the sub-scanning direction Y, And is projected in accordance with the positions of the scanning bands SB1 to SB6. That is, if the divided pattern images DA1 to DA6 are arranged at the same position with respect to the main scanning direction X, one image is formed with respect to the sub-scanning direction Y. [

The arrangement order on the pattern in the sub-scanning direction Y at this time is arranged in the order of the divided pattern images DA1, DA6, DA2, DA5, DA3, DA4 from above. That is, the divided pattern images DA1 and DA4 along the divided regions DM1 and DM4 located on the center side of the DMD 22 are projected at positions far from the origin along the sub-scanning direction Y, The divided pattern images DA2 and DA5 of the areas DM2 and DM5 are projected to positions closer to the origin in accordance with the sub scanning direction Y within the same upper limit as the divided pattern images DA1 and DA4 respectively.

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

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

On the other hand, the distance (distance from the origin to the projection center position) XL on each divided pattern does not coincide. The projection center referred to here is a virtual center in the case where it is assumed that a light beam positioned at the center of the pattern by the DMD 22 reaches the exposure surface of the object to be imaged (substrate W) without being divided (reflected) by the image- It is a point. When the DMD 22 is aligned with the optical center of the projection optical system 24, a point at which the optical axis of the first imaging optical system 25 and the second imaging optical system 26 intersects the exposure surface is called a projection center .

In this way, the image division optical system 30 projects the divided pattern images DA1 to DA6 in a ring shape so as to be distributed in all the upper limits, not in a row direction, as in the conventional case. Here, the ring includes not only a circle but also a non-circular ring or polygon. The divided pattern images DA1 to DA6 are arranged along the contour of the figure but the divided pattern images DA1 to DA6 are not bound to the ring tangent direction and are arranged at a predetermined angle. Further, it is not necessary to arrange the divided patterns on the divided patterns, for example, even if the divided pattern images have four divided patterns, they are regarded as ring-shaped.

The image division optical system 30 for realizing the ring image projection has six mirror pairs according to the divided regions 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.

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

As shown in Figs. 5 to 7, the mirror pairs 32, 34, and 36 are arranged so that the reflected light from the divided areas DM1, DM2, and DM3 is projected onto the projection positions (degrees) of the divided pattern images DA1, DA2, 4), and is composed of spherical split mirrors 32A, 34A, 36A and spherical guide mirrors 32B, 34B, 36B. The sizes of the mirrors shown in Figs. 5 to 7 are drawn to fit the respective divided areas of the DMD 22 for ease of explanation.

The split mirror 32A is not parallel to the conjugate plane CS but crosses the conjugate plane CS. That is, the normal direction is not parallel to the normal direction of the conjugate plane CS but inclined. Therefore, the distance from the conjugate plane CS along the Z-axis direction perpendicular to the conjugate plane CS differs depending on the location of the division mirror 32A.

Further, the spherical reflecting surface of the split mirror 32A is inclined in the inclined main scanning direction X, the sub scanning direction Y, and a predetermined angle, respectively. That is, the projection lines defined when each side of the split mirror reflection surface is projected on the conjugate plane CS are not parallel to the X axis and the Y axis, but are inclined. Here, the arrangement of the divided mirror 32A with respect to the conjugate plane CS is referred to as " inclined arrangement near 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 positions of the divided pattern image DA1 shown in Fig. In Fig. 4, the divided mirror 32A and the guide mirror 32B shift the divided pattern image DA1 in the sub-scanning direction Y by a distance of 2.5 scanning bands.

The inclined angle with respect to the X-axis is larger than the inclined angle with respect to the Y-axis, since the divided pattern image DA1 is projected at a position away from the origin about the sub-scanning direction Y with respect to the main-scanning direction X. The normal direction of the reflection surface is directed to 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 mirror 34A of the mirror pair 34 shown in Fig. 6 is arranged so as to cross the conjugate plane CS and is inclined at different angles with respect to the main scanning direction X and the sub scanning direction Y . The division pattern image DA2 is projected at a position away from the origin about the main scanning direction X with respect to the sub-scanning direction Y, so that the tilt angle with respect to the Y-axis is larger than the tilt angle with respect to the X-axis. Further, the normal direction of the reflection surface is inclined so as to be larger on the split mirror 32A and toward the + X side so as not to interfere with the light reflected on the split mirror 32A. In Fig. 6, the divided mirror 34A and the guide mirror 34B shift the sub scanning direction Y by 0.5 scan band.

The division mirror 36A of the mirror pair 36 shown in Fig. 7 is also arranged so as to intersect with the conjugate plane CS and is arranged at a different angle with respect to the main scanning direction X and the sub scanning direction Y There is an incline. Here, in order to project the divided pattern image DA1 to the fourth upper limit, the normal direction of the reflection surface thereof is directed to the -X and -Y directions. In Fig. 7, the divided mirror 36A and the guide mirror 36A shift in the negative direction of the sub-scanning direction Y by 1.5 scanning bands.

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

The upper side from the dividing mirrors (36A) has its center is a conjugated surface (CS), and inclined so as to be positioned on, the conjugated surfaces (CS) conjugate surface (CS) across the line (36A _C) intersecting the (-Z direction ) And the lower region (+ Z direction). The inclined angle with respect to the conjugate plane CS of the side of the divided mirror 36A (hereinafter referred to as the divided side) 36A _L is set so that the divided mirror 34A (see FIG. 6) And the sides of each of them intersect in the X-axis direction. As is apparent from the fact that the projection pattern image DA3 is moved in the + X direction and the -Y direction from the origin by the split mirror 36A and the guide mirror 36B, the intersection line 36A _C is in the main scanning direction X, Is inclined with respect to the sub-scanning direction (Y).

The inclination angle alpha with respect to the conjugate plane CS of the split mirror 36A shown in Fig. 9 is defined as an angle at which the mirror positive line 36A _E does not fall away from the conjugate plane CS. For example, 30 DEG or less and 15 DEG or less. By making the inclination angle alpha a micro angle, it is possible to avoid interference with the adjacent divided mirror. The other divided mirrors 32A and 34A are similarly determined.

The depth of focus of the projection optical system 24 is the depth of focus at which the divided pattern images fall within the in-focus range, respectively. The tilt angle of each split mirror with respect to the conjugate plane CS is set so as to fall within the range of the depth of focus for maintaining the sharpness required on the divided pattern. The range of the depth of focus depends on the resolution of the required pattern, the optical characteristics of the projection optical system 24, and the like. For example, the angle of inclination of the split mirror 36 may be set to at least 45 deg., 30 deg., Or 15 deg.

10 is a diagram showing the arrangement relationship of three split mirrors and guide mirrors. 11 is a perspective view showing three divided mirrors. 12 is a diagram showing the arrangement of the guide mirrors.

As described above, the divided pattern images DA1, DA2, and DA3 include mirror pairs 32A, 32B, and 32, a pair of mirrors 34A, 34B, and 34 that are made up of one set of parallel planes, Is projected to the position shown in Fig. 10 by the pair (36A, 36B) 36. The sizes of the split mirrors 32A, 34A and 36A and the guide mirrors 32B, 34B and 36B are larger than the projected area on the conjugate plane CS according to each divided area of the DMD 22. [

Particularly, the guide mirrors 32B, 34B, and 36B are determined to have a size considering the diffusion of the light flux on the divided pattern because the split mirrors 32A, 34A, and 36A are inclined with respect to the conjugate plane CS as the image plane. Figs. 5 to 7 and 10 show the enlargement range LM of the luminous flux of the divided pattern images DA1 to DA3.

The guide mirrors 32B, 34B, and 36B are arranged so that the distance from an arbitrary X-Y plane along the -Z direction (distance from the mirror center position) is the same. In Fig. 12, it is shown that the distance Z0 from each guide mirror to the conjugate plane CS is the same. A guide mirror 32B is arranged so that the optical path lengths from the split mirrors 32A, 34A, and 36A to the exposure surface on which the divided pattern images DA1 to DA3 are projected are all the same.

Three mirror pairs (not shown) arranged in alignment with the divided areas DM4 to DM6 of the DMD 22 are arranged in the same manner, and six divided mirrors are arranged adjacent to each other in the main scanning direction X, And are inclined at different angles according to the direction (Y). The inclination angles of the divided mirrors corresponding to the divided regions DM4, DM5 and DM6 are angles symmetrical to the divided mirrors 32A, 34A and 36A and are inclined at the central portions in the main scanning direction X and the sub scanning direction Y Positive and negative) is reversed. The optical path lengths from the six divided mirrors to the divided pattern images DA1 to DA6 are all the same.

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

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

The pattern data input from the work station (not shown) to the exposure control section 52 is vector data (CAD / CAM data) having position information (contour position information) of the rendering pattern and is position coordinate data based on the XY coordinate system .

The first to sixth raster data generation units 72 ₁ to 72 ₆ convert vector data and sequentially generate raster data of patterns to be drawn on the scanning bands SB 1, SB 2 and SB 3, 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 outputted in accordance with the exposure pitch. That is, when the partial projection area moves by the exposure pitch and the next exposure operation becomes possible, raster data output is performed. The output control of the raster data in the first to sixth raster data generators 72 ₁ to 72 ₆ is performed based on the control signal outputted from the address control circuit (not shown) provided in the exposure control section 52 .

When the raster data is sent to the exposure data generation unit 76, the exposure data generation unit 76 integrates the raster data according to the positions of the respective projection areas of the divided pattern images DA1 to DA6, A signal for ON / OFF controlling each micromirror is generated as one exposure data for the entire DMD 22. [ In the DMD 22, the micromirrors are ON / OFF controlled 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 synchronizing signal to the buffer memories 74 ₁ to 74 ₆ , the exposure data generating section 76, etc. for timing adjustment. Based on the image signal outputted from the CCD sensor 19, the image processing section 62 detects the position of the alignment mark formed on the substrate W. [

The drawing table control circuit 53 controls the XY stage mechanism 56 provided with a motor (not shown) through the drive circuit 54 so that the moving speed of the drawing table 18, Respectively. The position detection sensor 55 detects a relative position with respect to the drawing table 18 with respect to the position of the drawing table 18, that is, the projection positions of the partial pattern images DA1 to DA6.

Similarly to the exposure head 20 ₂ , a circuit (not shown) relating to raster data conversion processing, DMD driving processing, and the like is provided, and the same exposure operation processing is performed.

As described above, according to the present embodiment, the image dividing optical system 30 having six mirror pairs of the parallel planes composed of the split mirror and the guide mirror divides the pattern image from the DMD 22 into the division of the DMD 22 The projection positions are shifted so that the six divided pattern images DA1 to DA6 are separated from each other in the main scanning direction X and the sub scanning direction Y. [ As a result, the throughput can be improved.

It is possible to construct a simple optical system by dividing the pattern image by arranging a plurality of pairs of mirrors in a parallel planar relationship, and it is possible to divide the pattern image by four or more. Particularly, since the divided pattern image on the center side is projected at the farthest position with respect to the sub-scanning direction, the distance interval on the divided pattern can be widened.

Then, for the divided mirror at the intermediate position adjacent to the center-side divided mirror, the divided pattern image is projected at the position most distant from the main-scan direction, and the projection position distance interval on the divided pattern between the adjacent divided mirrors is lengthened. Thus, interference between adjacent mirrors can be avoided. In particular, by arranging the divided pattern images on the right half and the left half of the pattern alternately along the sub-scan direction, a distance interval of a larger projection position can be obtained. In addition, by suppressing the tilting angle of the split mirror so that there is no interference of light between adjacent mirrors, the loss of light amount can be suppressed and necessary resolution can be obtained.

In addition, since the projection positions of the divided pattern images DA1 to DA6 are in point-symmetrical positional relationship with respect to the center thereof and the left half and the right half of the divided pattern image in the right half are in a complementary positional relationship, Can be easily set. Then, the divided pattern images DA1 to DA are arranged in a ring shape, and the divided mirror pairs (each guide mirror) is arranged so that the total optical path length to the exposure surface on which the divided pattern images DA1 to DA6 are projected becomes the same The clearness on each divided pattern becomes uniform.

The number of divisions on the pattern is arbitrary, and can be divided into any even number. In this case, the mirror pair may be arranged in accordance with the number of divisions. 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 into odd numbers. Fig. Five mirror pairs are arranged in accordance with five divided areas DM1 to DM5 determined by dividing the reflecting surface of the DMD 22 into five equal parts. The inclination angle of the split mirror is determined in the same manner as in the even-numbered division.

In this embodiment, the tilt angle of the split mirror is set such that the divided pattern image is spaced apart from the center of the projection in the X and Y directions. However, for example, the side of the stop side split mirror 32A may be orthogonal, The projection line may be inclined so as to be parallel to the X direction and the Y direction.

10: Drawing device (exposure device)
22: DMD (Optical Modulator Array)
24: projection optical system
25: First imaging optical system (first optical system)
26: Second imaging optical system (second optical system)
30: Image division optical system
32, 34, 36: mirror pair
32A, 34A, 36A split mirror
32B, 34B, 36B guide mirrors

Claims (10)

An optical modulator array in which a plurality of optical modulators are two-dimensionally arrayed,
And a projection optical system for imaging the light reflected by the optical modulation element array onto an exposure surface of the imaging element,
Wherein the projection optical system includes:
A first optical system for forming light on a pattern from the optical modulation element array on a first imaging plane,
An image division optical system having a plurality of mirror pairs for dividing a pattern image formed on the first imaging plane according to a division region and forming a plurality of division pattern images;
And a second optical system for forming light on the plurality of divided patterns on the exposure surface,
Each of the plurality of mirror pairs includes a split mirror disposed so as to intersect the first imaging plane and a guide mirror that is parallel to the split mirror and guides the light from the split mirror to the second optical system,
Wherein the plurality of split mirrors are inclined relative to the first imaging plane so that a plurality of divided pattern images are projected away from each other in the main scanning direction and the sub scanning direction. The method according to claim 1,
Wherein the plurality of divided mirrors are each inclined so that a plurality of divided pattern images are projected from the exposure surface to the ring surface. The method according to claim 1,
Wherein each of the plurality of divided mirrors is inclined such that at least one divided pattern is projected on the exposure surface in each of four upper limits defined along the center of the projection surface of the exposure surface. 4. The method according to any one of claims 1 to 3,
Wherein the center-side split mirror located at the center side is inclined such that the divided pattern image is projected at a position where the distance from the center of the exposure surface projection is more distant from the main scanning direction in the sub-scan direction. 4. The method according to any one of claims 1 to 3,
Wherein the divisional mirror adjacent to the center-side split mirror is inclined so that the divided pattern image is projected at a position where the distance from the center of the exposure surface projection center is away from the sub-scan direction in the main-scan direction. 4. The method according to any one of claims 1 to 3,
Wherein the plurality of divided mirrors are each inclined such that a divided pattern image according to one half region of the pattern and a divided pattern image corresponding to the other half region have a point symmetrical relationship with respect to the center of the projection surface of the exposure surface An exposure head for an exposure apparatus. The method according to claim 6,
Wherein the plurality of guide mirrors are disposed at the same center in the vertical direction of the first imaging plane so that the respective optical path lengths from the plurality of divided mirrors to the exposure plane become equal to each other Exposure head. 4. The method according to any one of claims 1 to 3,
Wherein the plurality of split mirrors are inclined at an angle in accordance with 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 forming light on a pattern from a light modulation element array in which a plurality of optical modulation elements are two-dimensionally arrayed on a first imaging plane,
An image division optical system for forming at least four divided pattern images by dividing a pattern image formed on the first imaging plane according to a divided area into at least four near the first imaging plane,
And a second imaging optical system for forming light on at least four divided patterns on the exposure surface,
Wherein the image forming optical system forms at least four divided pattern images so that a plurality of divided pattern images are projected away from each other in accordance with the main scanning direction and the sub scanning direction.

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