JP2001125284A - Split successive approximation aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide a split successive appproximation aligner having excellent accuracy. SOLUTION: This device is provided with an aligning means 3 provided with an illuminating optical system for pattern alignment to radiate parallel beams to a material to be aligned, a work stage 2 to which the material to be aligned is placed, a mask stage 1 to which a mask is placed, a stage feeding mechanism 7 to relatively position the work stage 2 and the mask stage 1 so as to make the mask opposed to a consecutive aligning position on the material to be aligned, a gap adjusting means 6 to adjust a gap between the opposed surfaces of the mask and the material to be aligned and a mask position adjusting means 14 to adjust the direction of the mask within a pattern surface by taking the feeding direction by the stage feeding mechanism 7 as a reference, and the mask or the work stage 2 is provided with plural pairs of alignment marks arranged so as to be separated with each other in a direction nearly orthogonal with a joining direction by having a specified interval in the joining direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal substrate, for example,
The present invention relates to a proximity exposure apparatus used for printing a mask pattern on a substrate such as a color filter for a liquid crystal display, and in particular, a divisional sequential proximity exposure suitable for performing a proximity exposure of a mask pattern on a large substrate by a divisional sequential exposure method. Related to the device.

[0002]

2. Description of the Related Art In proximity exposure, a work is made of a light-transmitting substrate having a surface coated with a photosensitive agent, and the work is held on a work stage of a proximity exposure apparatus (hereinafter referred to as a proximity exposure apparatus). The gap (gap) between the mask and the mask attached to the mask stage on which the pattern is drawn is brought close to several tens μm to several hundreds of μm, and the mask is exposed on the work surface by irradiating parallel light from above the mask. In the exposure process of, for example, a color filter for a liquid crystal display, batch exposure has conventionally been common. However, recently, the screen size of the liquid crystal display has been increased, and it has become impossible to cope with the batch exposure, and it has become necessary to sequentially expose and connect a plurality of divided mask patterns. However, in the case of the divisional sequential exposure, there is a technical difficulty that the accuracy of alignment at the divisional boundary is strictly required.

[0003]

However, the conventional proximity exposure apparatus is basically a one-shot exposure system, and does not basically have a divided sequential exposure function for dividing a pattern and exposing and connecting the patterns. On the other hand, the conventional divisional sequential exposure apparatus does not have a highly accurate alignment function between the work stage and the mask, that is, an alignment function. There is an unsolved problem that the matching accuracy cannot be satisfied. FIG. 10 is a schematic diagram showing the deviation between the exposure pattern of the first shot and the exposure pattern of the second shot in the case where the pattern formation of the first layer, for example, the black matrix, is performed by sequential exposure in two without the alignment function. It is shown in a typical manner. Now, as shown in FIG.
In a state where the mask M having
If the second shot exposure is performed after the shot exposure is performed and then the workpiece W and the mask M are relatively moved and the positions are shifted as shown in FIG. 4B, as shown in FIG. In addition, both of the divided patterns P ₁ and P ₂ formed by the first and second shots formed on the work W by exposure are shifted by an angle θ with respect to the feed direction of the work stage.

The present invention has been made in order to solve such an unsolved problem of the prior art, and can realize divisional and sequential proximity exposure with higher precision than ever before, thereby reducing the mask cost associated with the enlargement of the pattern. It is an object of the present invention to provide at a low cost a divided sequential proximity exposure apparatus capable of preventing an increase.

[0005]

In order to achieve the above object, a divided sequential proximity exposure apparatus according to the present invention is an exposure apparatus having an illumination optical system for pattern exposure for irradiating a material to be exposed with parallel light. Means, a work stage on which a material to be exposed is mounted, a mask stage on which a mask is mounted, and a work stage and a mask stage are relatively positioned so that the mask is opposed to a joint exposure position on the material to be exposed. Stage feeding mechanism, gap adjusting means for adjusting a gap between the mask and the surface to be exposed, and a pair of alignment marks spaced apart from each other in a direction intersecting a connecting direction to the mask and the work stage. Alignment mark detecting means for detecting a plane shift amount between the mask side alignment mark pair and the work stage side alignment mark pair; A mask position adjusting means for adjusting the direction of the mask in the pattern plane with reference to a feed direction by the stage feed mechanism, and a drive control of the mask position adjusting means in accordance with the plane deviation detected by the alignment mark detecting means. Control means for aligning the mask side alignment mark and the work stage side alignment mark, wherein at least one of the mask side alignment mark pair and the work stage side alignment mark pair is connected in a predetermined direction in a connecting direction. A plurality of pairs are provided at intervals.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a part of a divided sequential proximity exposure apparatus according to a first embodiment of the present invention, and FIG. 2 is an enlarged perspective view of a mask stage portion.
Reference numeral 1 in the drawing denotes a mask stage for holding a mask (M) having a mask pattern (P), and reference numeral 2 denotes a work (a material to be exposed) made of a glass substrate coated with a photosensitive agent to print the mask pattern (P). A work stage 3 for holding W is an illumination optical system as exposure means for pattern exposure.

The illumination optical system 3 includes, for example, a high-pressure mercury lamp 31, which is a light source for irradiating ultraviolet rays, a concave mirror 32 for condensing the irradiation light, an optical integrator 33 disposed near the focal point of the concave mirror, and a plane mirror 35. , 36, and a concave mirror 37, and an exposure control shutter 34 for blocking the irradiation light. When the shutter 34 is opened during exposure, light emitted from the high-pressure mercury lamp 31 is emitted. L passes through the optical path as shown,
Irradiation is made perpendicular to the surface of a mask (M) (not shown) held on the mask stage 1.

The mask stage 1 has a mask stage base 11 and is fixedly supported on an apparatus base 4 via a mask stage support 12. The mask stage base 11 has an opening 111 at the center, and a mask holding frame 13 is slidably mounted in the X and Y directions surrounding the opening 111. FIG. 3 shows a sliding drive structure of the mask holding frame 13. As shown in FIG. 3A, which is a cross-sectional view taken along the line III-III in FIG. 2, the mask holding frame 13 is inserted along the opening 111 of the mask stage base 11, and Rim 131
And a lower edge portion 1 is provided on the lower end face of the holding frame 13.
The upper and lower edges 132 and 132 are slidably engaged with each other so as to sandwich the mask stage base 11 therebetween.

Then, the mask holding frame 13 is moved on the upper surface of the mask stage base 11 in the X and Y planes to adjust the mask position with respect to the work surface. Direction drive 14x
And two Y-axis direction driving devices 14y.
The adjustment in the X-axis direction is performed by the former 14x, and the adjustment of the latter two 14
The swing direction about the Y axis and the Z axis is adjusted by y. Each of the mask holding frame driving devices 14x and 14y includes a driving actuator (electric actuator in this embodiment) 141 and a rod 14 that expands and contracts in its axial direction.
A linear motion guide bearing (linear guide) 143 engaged with the tip of 1r via a pin support mechanism 142 is provided.

The slider 143s of the linear guide engages with the pin support mechanism 142, and the guide rail 143
r is fixedly attached to the side surface of the mask holding frame 13 as shown in FIG. 3B which is a plan view. A mask M on which a mask pattern is drawn is detachably held on the lower surface of the movable mask holding frame 13 via a vacuum suction device (not shown). In this holding state, the lower surface of the mask M is positioned below the lower surface of the mask stage base 11. Since the lower surface of the mask M is projected downward as described above, when the work stage 2 is moved in the Y-axis direction,
Evacuation in the Z-axis direction can be minimized.

A gap sensor 15 for measuring a gap between the mask M and the work and a work stage side alignment mark formed on the work stage 2 are provided inside the two opposite sides of the mask holding frame 13. 75
An alignment camera 16 serving as an alignment mark detecting means for detecting a plane deviation amount between a mask-side alignment mark 76 (described later) formed on the mask M and a mask-side alignment mark 76 (described later) formed on the mask M, both via a moving mechanism 17. It is arranged movably in the X-axis direction.

Specifically, the gap sensor / alignment camera moving mechanism 17 includes two holding frames 171 and 171 movably arranged in the X-axis direction along the upper surfaces of a pair of left and right frames of the mask holding frame 13. And a linear guide 172 supporting one end thereof, and a drive actuator 173 similar to the above, which drives a slider (not shown) that moves on the guide rail 172r provided on the mask stage base 11. Holding stand 171
Are fixed, and the gap sensor 15 is
And an alignment camera 16. Then, by driving a driving actuator (in this case, a motor, a ball screw and a linear guide) 173, the gap sensors 15 and the alignment camera 16 are moved in the X-axis direction via the holding pedestal 171.

The mask stage base 11 is provided with a masking aperture (shielding plate) 18 for shielding the end of the mask M if necessary, above the mask M in the opening of the mask holding frame 13. A masking aperture driving device 181 composed of a motor, a ball screw, and a linear guide is movable in the Y-axis direction. The masking aperture (shielding plate) 18 has a large number of patterns arranged regularly as described in a method of transferring a large substrate, which was previously filed by the present applicant (Japanese Patent Application No. 10-42451). The rectangular exposure pattern is divided into an end pattern at both ends in the long side direction and a pattern on the inner side thereof, and the inner pattern is equally divided in the long side direction and divided and sequentially exposed. One divided pattern and the end patterns provided on both sides thereof are formed on one mask, and the end patterns on both sides of the mask are shielded when the inner pattern is divided and sequentially exposed using the mask. Used to do.

The work stage 2 is provided with a Z-axis feed base 6 as a gap adjusting means for adjusting a gap between the opposing surfaces of the mask M and the work W to a predetermined amount, and the work stage 2 And a work stage feed mechanism 7 for moving the workpiece in the Y-axis direction. The Z-axis feed base 6 includes a Z-axis coarse movement stage 62 supported by a vertical coarse movement device 61 erected on the apparatus base 4, and a Z-axis fine movement stage 64 supported thereon by a vertical fine movement device 63. It is composed of For example, a pneumatic cylinder is used for the vertical coarse moving device 61, and the Z-axis coarse moving stage 62 is moved up / down to a preset position without measuring a gap by performing a simple vertical operation.

On the other hand, the vertical fine-movement device 63 is a movable wedge mechanism that combines a motor, a ball screw and a wedge. That is, in the present embodiment, for example, the motor 631 is installed on the upper surface of the Z-axis coarse movement stage 62 to rotate the screw shaft 632 of the ball screw, and the ball screw nut 633 is formed in a wedge shape. The movable wedge mechanism 63 configured by engaging the slope of the nut 633 with the slope of a wedge 641 protruding from the lower surface of the Z-axis fine movement stage 64 constitutes a vertical fine movement device. When the screw shaft 632 is driven to rotate, the wedge-shaped nut 633 is guided by a guide (not shown) and moves in the Y-axis direction.
Due to the slope action of 41, it is converted into high-precision vertical movement. An up-down fine movement device comprising the movable wedge mechanism 63 is
Using two units, two units are arranged on one end side of the Z-axis fine movement stage 64 in the Y-axis direction, and one unit is arranged on the other end side, and each is independently driven and controlled. This allows
The vertical fine movement device 63 has a tilt function of finely adjusting the inclination with respect to the horizontal plane in addition to the function of finely adjusting the height of the Z-axis fine movement stage 64 to a target value while measuring the gap. .

In the case of performing the divided sequential exposure, the direction of the mask pattern of the mask M is deviated from the feed direction (Y-axis direction) of the work stage 2 even if there is no feed error of the work stage 2 at all. In addition, the seam between the patterns formed by the joint exposure is shifted and does not match. However, as described above, the mask M is sucked and held on the lower surface of the mask holding frame 13 via the vacuum suction device.
It is difficult to precisely match the direction of the mask pattern with the work stage feed mechanism 7 feed direction (Y-axis direction) during the suction holding. Further, there is also a problem that the first half pattern and the second half pattern are shifted due to a feed error generated when the work stage feed mechanism 7 feeds the work stage 2.

Therefore, in this embodiment, referring to FIG. 7, at least one pair of, for example, a cross-shaped work stage side alignment mark 75 is provided on the upper surface of work stage 2 (specifically, a work chuck mounted on the stage). The mask M is spaced apart in the X-axis direction. On the other hand, on the mask M, a pair of mask-side alignment marks 76 corresponding to the pair of work-stage-side alignment marks 75 is connected at a pitch equal to the connecting pitch (in this embodiment, a step distance). And Y
A plurality of pairs are provided in the axial direction (two pairs in this embodiment because two-division sequential exposure is used, and n pairs in the case of n-division sequential exposure).

Prior to the exposure of the first shot, an alignment camera 16 as an alignment mark detecting means is used to determine the amount of plane shift between the work stage side alignment mark 75 and the upper mask side alignment mark 76 in FIG. And the control means (not shown) controls the driving of the mask holding frame X-axis direction driving device 14x and the two Y-axis direction driving devices 14y as the mask position adjusting means 14 in accordance with the detected plane shift amount. The position of the mask holding frame 13 is adjusted so that the centers of the stage-side alignment mark 75 and the mask-side alignment mark 76 substantially coincide in the XY plane, and before the exposure of the second shot. That is, the work stage 2 is connected in the Y-axis direction by the work stage feed mechanism 7 and the work stage 2 is relatively moved by the pitch. 7A, the amount of plane deviation between the work stage side alignment mark 75 and the lower mask side alignment mark 76 in FIG. 7C is detected by the alignment camera 16 as an alignment mark detecting means. The work stage side alignment mark 75 and the mask are controlled by controlling the driving of the mask holding frame X-axis direction driving device 14x and the two Y-axis direction driving devices 14y as the mask position adjusting device 14 by control means (not shown) according to the amount of displacement. The position of the mask holding frame 13 is adjusted so that the centers of the side alignment marks 76 substantially coincide with each other in the XY plane.

The work stage feed mechanism 7 includes two sets of linear guides 71 extending parallel to the Y-axis direction on the upper surface of a Z-axis fine movement stage 64, and a Y-axis feed base attached to a slider (not shown) of the linear guides 71. 72, and a Y-axis feed drive 73, and the motor 7 of the feed drive 73 is provided.
The Y-axis feed base 72 is connected to a ball screw nut (not shown) screwed to a ball screw shaft 732 rotated and driven by 31. The work stage 2 is mounted on the Y-axis feed base 72.

Here, the feed error of the work stage 2 according to the present embodiment will be described. The feed error when the work stage 2 is fed by a predetermined distance in the Y-axis direction is an error of the feed position (distance). In addition, there may be straightness and inclination of the work stage surface. The straightness of the former is
The amount of deviation (in the XZ plane) at the feed end point between the Y axis passing through the feed start point and the actual feed travel direction straight line, and X
It comprises an axial component ΔX and a Z-axis component ΔZ. The latter inclination of the work stage surface is caused by yawing (rotation about the Z axis), pitching (rotation about the X axis), rolling (rotation about the Y axis), and the like when the work stage 2 moves. In yawing, the work stage is swung to the left or right while the work stage surface is horizontal, and is shifted by an angle θ with respect to the Y axis. In pitching, the work stage surface is inclined at a predetermined angle before and after in the traveling direction. Further, in rolling, the work stage surface is inclined left and right by a predetermined angle with respect to the horizontal. These errors occur due to, for example, the accuracy of a linear guide as a guide device.

Among these feed errors, errors in the X-axis direction component ΔX of yaw and straightness and the position in the Y-axis direction are as follows:
It can be obtained by the alignment camera 16. In addition, the straightness Z-axis direction component ΔZ, pitching, and rolling can be known by three gap sensors 15. Further, in the divided sequential proximity exposure apparatus of the present embodiment, the detection of the amount of plane deviation between the work stage side alignment mark 75 and the mask side alignment mark 76, and furthermore, the alignment of both marks 75 are performed by the alignment mark detection described above. The alignment camera 16 which is a means is used to perform the operation with high precision and ease.

That is, as shown in FIG. 4, an alignment camera 1 for optically detecting a mask-side alignment mark 76 provided on the front surface of a mask M from the back surface of the mask.
6 is moved toward and away from the mask M by the focus adjustment mechanism 161 to adjust the focus. Specifically, the focus adjustment mechanism 161 is connected to the linear guide 162,
A guide rail 162r of the linear guide is vertically long attached to the mask stage 1 (specifically, the holding frame 171 of the moving mechanism 17), and a table 162t is attached to the slider 162s. The alignment camera 161 is fixed through the intermediary. The nut screwed to the screw shaft of the ball screw 163 is connected to the table 162t, and the screw shaft is driven to rotate by the motor 164.

In this embodiment, as shown in FIG. 5, a work stage side alignment mark 75 is provided below a work chuck 8 provided on the work stage 2.
An optical system 78 that projects light from below has a light source 781 and a condenser lens 782 and
6 is arranged integrally with the Z-axis fine movement stage 64 in accordance with the optical axis. The work stage 2 and the Y-axis feed base 72 are provided with through holes corresponding to the optical path of the optical system 78.

Further, in the present embodiment, as shown in FIG. 6, the position of the surface of the mask M on which the alignment mark 76 is provided (mask-side alignment mark surface M _m ) is detected and the focus of the alignment camera 16 is adjusted. An alignment image best focus adjustment mechanism 9 for preventing misalignment is provided. The best focus adjustment mechanism 9 uses the gap sensor 15 as a focus deviation detecting means for the alignment camera 16 and the focus adjustment mechanism 161, and a mask lower surface position measurement value measured by the gap sensor 15 is calculated by a computer 92. A difference is obtained by comparing with a preset focus position, a change amount of a relative focus position from the set focus position is calculated from the difference, and the focus adjustment mechanism 1 is configured to adjust the focus of the alignment camera 16 by that amount.
61 moves the alignment camera 16.

By using the best focus adjustment mechanism 9, it is possible to adjust the focus of the alignment image with high accuracy irrespective of a change in the thickness of the mask M or a variation in the thickness. Note that the focus adjustment mechanism 161, the table mark projection optical system 78, and the focus adjustment mechanism 161 as shown in FIGS.
Various configurations such as the best focus adjustment mechanism 9 not only correspond to high precision of alignment of the first layer division pattern, but also contribute to high precision of alignment of the second and subsequent layers. In addition, the present invention is not necessarily limited to only the sequential exposure, and can be effectively applied to other exposures. If the thickness of the mask M is known, the best focus adjustment mechanism 9 in FIG. 6 may be omitted, and the focus adjustment mechanism may be moved according to the thickness.

Next, the operation of the present embodiment will be described. For example, RGB for color filter type large liquid crystal display
When a predetermined pattern is formed on the color filter, first, a pattern of a black matrix for partitioning between pixels is formed on a work W made of a glass substrate through respective steps of resist coating, oxygen blocking film coating, exposure, and development. On the substrate on which the pattern of the black matrix has been formed in this manner, individual patterns of the three primary colors R (red), G (green), and B (blue) are formed for each color by repeating the same steps as in the above-described pattern formation of the black matrix. To form. Here, the pattern to be formed first, that is, the pattern of the black matrix is the “first layer”, then any one of the three primary colors formed thereon is the “second layer”, and the other three primary colors are formed. Are referred to as “third layer”.

Now, a case where a glass substrate of a color filter for a large liquid crystal display is used as a work W and a pattern of a first black matrix is formed thereon by two-division sequential proximity exposure will be described as an example. On the lower surface of the mask stage 1 of the apparatus, a mask M on which a first-layer pattern is drawn is mounted in advance by vacuum suction. Further, the work stage 2 is located near the forward limit in the Y-axis direction and is lowered to the lowermost limit. (1) Gap Adjustment for Alignment First, the upper / lower coarse movement upper limit target position (for example, a mask) in which the work stage 2 is set in advance by driving the vertical coarse and coarse movement device 61 of the Z-axis feed base 6 which is a gap adjustment means. (Several mm from the surface of M). At the time of this coarse movement, the upper surface of the work chuck 8 by the gap sensor 15 (specifically, the glass test portion 8 fixed thereon)
The measurement of the gap (gap) between the (m upper surface) and the mask is not performed. Next, the vertical fine movement device including the three movable wedge mechanisms 63 of the Z-axis feed base 6 is driven. At the time of this fine movement, as shown in FIG.
The gap between the surface of the mask M provided with the workpiece 6 and the surface of the work chuck 8 provided with the work stage side alignment mark 75 is measured by the gap sensor 15, and the measurement result is fed back to the movable wedge mechanism 63. The work stage 2 is accurately raised to a preset target gap amount during alignment.

As described above, according to the present embodiment, the vertical movement speed of the gap adjusting means is divided into two speeds, most of which is moved at high speed by the vertical movement device 61, and finally, the movable wedge mechanism is moved. Since the movement is performed with high precision at 63, it is possible to simultaneously achieve the contradictory functions of speeding up the gap adjustment work and increasing the precision in the divided sequential proximity exposure. It should be noted that the gap adjusting means of the present embodiment can be applied not only to sequential exposure but also to other types of exposure. (2) Alignment Adjustment When the work stage 2 and the mask M are brought close to each other, and the feed direction (Y-axis direction) of the work W is not correctly aligned with the relative position and orientation of the mask M, for example, FIG. As shown in (a), when a mask M having a pattern is inclined with respect to the work stage 2 by an angle θ (assuming that the direction of the work stage 2 and the direction of the Y-axis direction match), The alignment mark 75 on the stage 2 side and the alignment mark 76 on the mask M side are not aligned and are shifted. If the mask pattern is exposed and printed as it is, a deviation from the division pattern that is to be formed on the same work stage 2 thereafter occurs, and a black matrix pattern with high accuracy cannot be obtained after all.

Therefore, it is necessary to align the work stage side alignment mark 75 and the mask side alignment mark 76 (alignment).
First, the alignment is performed using the alignment camera 16 as the alignment mark detecting means.
Focus on both sides. In the first-layer division exposure according to the present embodiment, as described in (1), as described in (1), the work stage side alignment mark 75 is irradiated from below with the projection optical system 78 as shown in FIG. Gap sensor 1 originally used during exposure
Use 5. That is, a gap is set between the surface (test portion) 8m of the work chuck 8 provided with the work stage side alignment mark 75 and the surface of the mask M provided with the mask side alignment mark 76 (mask side alignment mark surface M _m ). Thereby, the two cameras 75 and 76 are almost focused on the alignment camera 16 serving as an alignment mark detecting means, and the deviation between the two marks 75 and 76 is detected.

Usually, the thickness of the mask M is standardized, and is determined to be 5 mm, 8 mm, 10 mm, or the like.
The conventional alignment camera is not provided with the continuous focus adjustment mechanism 161 as in the present embodiment, and has only one fixed focal point. There is a problem that the mark detection accuracy is reduced. However, in the case of the present embodiment, the focus adjustment mechanism 161 is previously provided with the alignment camera 1 corresponding to the various mask plate thicknesses as described above.
6, the focus position of the alignment camera 16 is adjusted to the best focus position on the mask side alignment mark surface M in response to a large change in the mask thickness due to the replacement of the mask M.
_m can be positioned.

In the present embodiment, the gap sensor 15 is used to detect the defocus, as described above. With this, the actual lower limit position of the mask is measured, and the measured value is output to the computer 92. The computer 92 calculates a relative focus position change amount from a focus position (target position) set in advance on the lower surface of the mask (mask side alignment mark surface M _m ) and controls the focus adjusting mechanism 161 according to the position change amount. The drive of the motor 164 is controlled to correct the position of the alignment camera 16, thereby adjusting, for example, a focus shift due to a variation in the mask thickness to ensure the best focus on the mask-side alignment mark 76.

When the alignment camera 16 whose focus has been properly adjusted as described above detects a plane shift amount between the work stage side alignment mark 75 and the upper mask side alignment mark 76 in FIG. 7A. An X-direction driving device 14x and two Y-directions of the mask position adjusting means 14 are controlled by a control means (not shown) in accordance with the detected plane shift amount so that the centers of the work stage side alignment mark 75 and the mask side alignment mark 76 coincide with each other. The driving of the driving device 14y is controlled, whereby
The posture of the mask holding frame 13 is corrected and both marks 75 and 76 are corrected.
Are correctly aligned as shown in FIG. (3) Work Insertion and First Exposure After the above alignment is completed, the work stage 2 is once lowered by the gap adjusting means 6 as needed. In this state, an interval between the mask stage 1 (for example, 60 m)
(approximately m), the work W is loaded by a work automatic supply device (not shown), and is held by the work chuck 8 on the work stage 2. After that, the gap adjusting means 6
Thereby, the clearance between the lower surface of the mask M and the upper surface of the work W is adjusted to a predetermined value required for exposure. The procedure is the same as the above (1) except that the gap sensor 15 measures the gap between the lower surface of the mask and the upper surface of the work.

Next, exposure is performed by operating the exposure control shutter of the exposure means 3, and the mask pattern is printed on a predetermined position of the work W to obtain a first divided pattern. (4) Movement of Work Stage to Next Exposure Position Subsequently, in order to perform a joint exposure of the second divided pattern, the work drive 2 of the work stage feed mechanism 7 is operated to move the work stage 2 in the feed direction ( The workpiece W is moved in the feed direction relative to the mask M by feeding by the connecting pitch in the Y-axis direction). At this time, in order to avoid interference with the work W, the work stage 2 may be lowered by a necessary amount in the Z-axis direction as needed. (5) Gap Adjustment and Alignment Adjustment In the above-described feed in the Y-axis direction, a feed error occurs due to the above-mentioned factors. Therefore, if the next exposure is performed as it is, the second divided pattern is displaced. Therefore, before the exposure of the second divided pattern, the worktable side alignment mark 75 and the upper mask side alignment mark 76 in FIG. Is detected, the control means (not shown) adjusts the mask position adjusting means 14 in accordance with the detected plane deviation amount so that the centers of the work stage side alignment mark 75 and the mask side alignment mark 76 coincide with each other. Of the X-direction driving device 14x and the two Y-direction driving devices 14y, thereby correcting the attitude of the mask holding frame 13 to adjust both marks 7
5 and 76 are correctly aligned as shown in FIG. (6) Second Exposure After that, if the bridge exposure is performed, the second
Is obtained.

As described above, according to the first embodiment of the present invention, it is possible to obtain the effect that it is possible to realize the divisional sequential exposure of the first layer with higher accuracy than ever before. Further, the first layer exposure of the divided sequential exposure can be performed with the same accuracy as the second layer exposure using the global alignment of the conventional divided sequential exposure apparatus. Further, correction of a plane shift between the mask M and the work W due to a feed error generated when the work stage 2 is fed by the work stage feed mechanism 7 is performed by using an average shift amount between the work stage side alignment mark 75 and the mask side alignment mark 76. Is detected by the alignment camera 16 which is an alignment detecting means, so that when an expensive laser interferometer is used to detect a plane deviation between the mask M and the work W and correct the deviation. In comparison, it is possible to achieve a significant cost reduction of the divided sequential exposure apparatus.

Next, a divided sequential proximity exposure apparatus according to a second embodiment of the present invention will be described with reference to FIG. Since the basic configuration of the apparatus is the same as that of the first embodiment, the same parts are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, a mask-side alignment mark 76 is provided at least in a pair in the X-axis direction on a lower surface of a mask M, while an upper surface of a work stage 2 (specifically, a work chuck installed on the stage) is provided on the upper surface. An interval equal to the connecting pitch of the pair of work-stage-side alignment marks 75 corresponding to the position of the mask-side alignment mark 76, for example (in this embodiment, the interval A in the Y-axis direction of the work-stage-side alignment mark pair = In the step amount S), a plurality of pairs are provided in the Y-axis direction (two pairs in this embodiment because of the two-division sequential exposure, and n pairs in the case of the n-division sequential exposure).

Before the exposure of the first shot, an alignment camera as an alignment mark detecting means is used to determine the plane shift amount between the mask side alignment mark 76 and the lower work stage side alignment mark 75 in FIG. The control unit 16 controls the driving of the mask holding frame X-axis direction driving device 14x and the two Y-axis direction driving devices 14y as the mask position adjusting unit 14 in accordance with the detected plane deviation amount. The position adjustment of the mask holding frame 13 is performed so that the centers of the work stage side alignment mark 75 and the mask side alignment mark 76 substantially coincide in the XY plane (FIG. 8).
Also, before the exposure of the second shot, that is, when the work stage 2 is relatively moved by the connecting pitch in the Y-axis direction by the work stage feed mechanism 7, the work stage side alignment is performed. The mark 75 and the upper mask-side alignment mark 7 in FIG.
6 is detected by an alignment camera 16 as an alignment mark detecting means, and a mask holding frame X-axis direction driving device 14x as a mask position adjusting means 14 is controlled by a control means (not shown) in accordance with the detected plane shift amount.
And controlling the driving of the two Y-axis direction driving devices 14y so that the centers of the work stage side alignment mark 75 and the mask side alignment mark 76 substantially coincide in the XY plane. 13 is adjusted (see FIG. 8D). Note that the other configuration, operation, and effect are the same as those of the first embodiment, and thus description thereof is omitted.

Next, a divided sequential proximity exposure apparatus according to a third embodiment of the present invention will be described with reference to FIG. Since the basic configuration of the apparatus is the same as that of the first embodiment, the same parts are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, for example, a pair of work-stage-side alignment marks 75 in the form of a cross, which are arranged in the X-axis direction and are spaced apart from each other on the upper surface of a work stage 2 (specifically, a work chuck provided on the stage), are arranged in a Y direction.
Two pairs of mask-side alignment marks 76 corresponding to the pair of work stage-side alignment marks 75 are provided on the mask M at predetermined intervals H in the Y-axis direction. ing. At the exposure position of the first shot, the upper mask side alignment mark pair 76 in FIG. 9 is located at the lower work stage side alignment mark pair 75 in FIG. It is a step amount.

Before the exposure of the first shot, the plane shift amount between the lower work stage side alignment mark 75 and the upper mask side alignment mark 76 in FIG. 9A is used as alignment mark detection means. The detection is performed by the alignment camera 16, and the driving of the mask holding frame X-axis direction driving device 14x and the two Y-axis direction driving devices 14y as the mask position adjusting device 14 is controlled by control means (not shown) according to the detected plane shift amount. Then, the position of the mask holding frame 13 is adjusted so that the centers of the work stage side alignment mark 75 and the mask side alignment mark 76 substantially coincide in the XY plane (see FIG. 9B). Further, before the exposure of the second shot, that is, the work stage 2 is moved by the work stage feed mechanism 7 in the Y-axis direction. In the case of relative movement by the distance A + the distance H, the plane shift amount between the upper work stage side alignment mark 75 and the lower mask side alignment mark 76 in FIG. The mask holding frame X-axis direction drive device 14x and the two Y-axis direction drive devices 1 serving as the mask position adjusting means 14 are detected by an alignment camera 16 as a mask position adjusting means 14 in accordance with the detected plane deviation amount.
4y is controlled to adjust the position of the mask holding frame 13 such that the centers of the work stage side alignment mark 75 and the mask side alignment mark 76 substantially coincide in the XY plane (FIG. 9). (D)).

According to the third embodiment, the distance (step amount) from the pattern exposure position of the first shot to the pattern exposure position of the second shot is changed by changing the interval H. Therefore, it is possible to cope with, for example, exposure of liquid crystal displays having different sizes. The other configuration and operation and effect are the same as those of the first embodiment, and the description thereof is omitted.

In each of the above embodiments, the case where the first-layer pattern is divided into two exposures is described.
Of course, the present invention can be applied to a case where the operation is performed three or more times. In this case, at the time of the first exposure, adjustment of the gap between the mask M and the work W → correction of the relative displacement between the work W and the mask M →
The procedure of exposure is performed, and then the work stage feed, the correction of the feed error, and the procedure of exposure may be repeated as many times as necessary. Furthermore, the division may be combined with the division in the X-axis direction instead of the division only in the Y-axis direction. In that case, an X-axis direction feed work stage may be added.

In each of the above embodiments, only one mask M having the same pattern is used.
The present invention is not limited to the case of repeating the same pattern as described above.
It is also possible to cope with a case where both end patterns as shown by 51 are provided. Further, in each of the above-described embodiments, the structure has been described in which the mask stage 1 is fixedly attached to the apparatus base 4 with the mask stage support 12 and only the work stage 2 is moved up and down by the gap adjusting means 6. For example, the mask stage support table 12 may be formed of a cylinder so that the mask stage 1 is moved up and down. In this case, the Z-axis coarse movement stage 62 having the vertical coarse movement device can be omitted.

In each of the above embodiments, the work stage is configured to be movable in the Y-axis direction. Alternatively, the mask stage and the exposure unit may be configured to be movable in the Y-axis direction.

[0043]

As described above, according to the present invention,
It is possible to provide a divided sequential proximity exposure apparatus at a low cost, which can realize the divided sequential proximity exposure with higher accuracy than ever before and can prevent an increase in mask cost due to an increase in the size of the pattern.

[Brief description of the drawings]

FIG. 1 is a partially exploded perspective view illustrating a divided sequential proximity exposure apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a mask stage portion.

3A is a cross-sectional view taken along line III-III of FIG. 2, and FIG. 3B is a plan view of FIG.

FIG. 4 is a side view showing a basic structure of an alignment camera and a focus adjustment mechanism of the alignment camera.

FIG. 5 is an explanatory diagram for describing an irradiation optical system for a work stage side alignment mark.

FIG. 6 is an explanatory diagram for explaining a focus adjustment mechanism of an alignment image.

FIG. 7 is an explanatory diagram for explaining an operation of the first embodiment.

FIG. 8 is an explanatory diagram for explaining a divided sequential proximity exposure apparatus according to a second embodiment of the present invention.

FIG. 9 is an explanatory diagram illustrating a divided sequential proximity exposure apparatus according to a third embodiment of the present invention.

FIG. 10 is a schematic diagram showing a shift between an exposure pattern of a first shot and an exposure pattern of a second shot when pattern formation of a first layer is performed by sequential exposure in two without an alignment function; (A) is the first shot exposure in a state where the mask M is inclined by the horizontal angle θ with respect to the workpiece W, and (b) is the second shot exposure performed after the workpiece and the mask are relatively moved next. FIGS. 4C and 4C are views showing the state of misalignment of the divided patterns P ₁ and P ₂ due to the first and second shots formed on the work W by exposure.

[Description of Signs] W Workpiece (material to be exposed) M Mask 1 Mask stage 2 Work stage 3 Exposure means 6 Gap adjustment means 7 Work stage feed mechanism (stage feed mechanism) 14 Mask position adjustment means 16 Alignment mark detection means 75 Work stage Side alignment mark 76 Mask side alignment mark

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H097 GA45 KA02 KA12 KA13 KA15 KA28 LA12 LA17 5F046 AA04 BA02 EA04 EB01 EB02 ED01 FC06

Claims (1)

[Claims] An exposure unit having an illumination optical system for pattern exposure for irradiating the exposure target material with parallel light; a work stage for mounting the exposure target material; a mask stage for mounting a mask; A stage feed mechanism for relatively positioning the work stage and the mask stage so that the mask faces the connecting exposure position on the material to be exposed, and a gap adjustment for adjusting a gap between the opposing surfaces of the mask and the material to be exposed. Means, a pair of alignment marks spaced apart from each other in a direction intersecting a connecting direction to the mask and the work stage, and an alignment mark detection for detecting a plane shift amount between the mask side alignment mark pair and the work stage side alignment mark pair Means for adjusting the direction of the mask in the pattern plane based on the feed direction by the stage feed mechanism Mask position adjusting means, and control means for driving and controlling the mask position adjusting means in accordance with the plane shift amount detected by the alignment mark detecting means to align the mask side alignment mark and the work stage side alignment mark. Wherein a plurality of pairs of at least one of the mask side alignment mark pair and the work stage side alignment mark pair are provided at predetermined intervals in a connecting direction. .