JP6543061B2 - Exposure apparatus using substrate correction jig, and substrate correction jig - Google Patents

Description

  The present invention relates to an exposure apparatus that performs exposure using a substrate correction jig that corrects a warped photosensitive substrate into a planar shape, and a jig therefor.

  An exposure apparatus (a projection exposure apparatus, a stepper, a scanner, a direct exposure apparatus, etc.) for performing projection exposure forms a pattern image by exposure light such as ultraviolet light on the surface of a photosensitive substrate (hereinafter referred to as substrate) coated with photoresist. Let exposure to do. In such a projection exposure apparatus, when the substrate is warped beyond the focal depth of the projection optical system, the resolution accuracy of the pattern image formed on the substrate surface is lowered. The substrate is, for example, a printed wiring board using a resin as a base material, a glass substrate for LCD, a silicon substrate for semiconductor, etc., and any problem of warping can not be avoided. In the case where the warpage of the substrate is large, a vacuum leak occurs in the robot hand for transporting the substrate or the suction of the substrate of the exposure stage, which causes an error.

  Patent Document 1 proposes a transport jig that transports and exposes a substrate by correcting and holding the warp of the substrate. In this document, the substrate W is sandwiched and fixed between two frames attracted by magnetic force, thereby enabling processing in a state in which the warp of the substrate is corrected. Moreover, in patent document 2, the holder which hold | maintains a board | substrate in a state with few distortions is proposed by pressing a board | substrate on a control board with a spring.

JP 2002-299406 A JP, 2005-064329, A

  In general, the distance between the projection optical system of the exposure apparatus and the substrate tends to be short due to the high precision of exposure, and a focus adjustment optical system, a substrate height measuring device, etc. are installed in this part. There is little margin. However, since the substrate correction jig as in Patent Document 1 and Patent Document 2 is large, it is difficult to install it in an exposure apparatus with a small space margin, or when it is transported to the exposure position, an optical system or exposure There is a problem that a structure that the stage is largely retracted is required.

  An object of the present invention is to obtain an exposure apparatus and a substrate correction jig which can be thinned (reduced in height) and prevent interference with an exposure apparatus based on the above problem awareness.

In the aspect of the exposure apparatus according to the present invention, in which the photosensitive substrate supported by the substrate correction jig is positioned on the exposure stage and the pattern image is exposed on the photosensitive substrate by the projection exposure means, the substrate correction jig An outer frame comprising a support surface for supporting the peripheral surface of the photosensitive surface of the substrate and a stepped portion having an erected surface facing the end surface of the photosensitive substrate; inserted into the outer frame and between the support surface of the outer frame An inner frame sandwiching the peripheral edge of the photosensitive substrate; and a mechanical pressing mechanism pressing the inner frame toward the support surface of the outer frame ; and the outer frame is a continuous rectangular stack A mounting frame, a discontinuous intermediate frame and a rectangular continuous cover frame, wherein the setting frame has the support surface, the middle frame and the cover frame have the rising surface, and the supporting surface The step portion is formed by the rising surface, and the mechanical pressing mechanism is A pressure lever pivotally mounted between the upper frame and the cover frame at a discontinuous position of the intermediate frame, the pressure lever being positioned within the thickness of the outer frame, and the pressure lever comprising: It is characterized by comprising a force operation portion extending in a substantially opposite direction centering on the axis and a pressing portion for pressing the inner frame in the direction of the support surface .

In the aspect of the substrate correction jig according to the present invention, an outer frame provided with a support surface for supporting the photosensitive surface peripheral edge of the photosensitive substrate and a stepped portion facing the end surface of the photosensitive substrate; is, the inner frame is clamped the periphery of the photosensitive substrate between the support surface of the outer frame; mechanical pressing mechanism for pressing and the frame to the support surface of the outer frame; equipped with, the The outer frame is provided with a stacked continuous rectangular continuous mounting frame, a discontinuous intermediate frame and a continuous rectangular cover frame, and the above-mentioned mounting frame has the above-mentioned support surface, and the above-mentioned intermediate frame and the above-mentioned cover The frame has the erected surface, and the stepped portion is formed by the support surface and the erected surface, and the mechanical pressing mechanism is arranged at the discontinuous position of the intermediate frame, and the frame and the above described Providing a pressure lever pivotally mounted between the cover frames and located within the thickness of the outer frame, Fine the pressing lever has a wearing force operation section and the inner frame extending in substantially opposite directions about said axis, characterized in that it comprises a pressing portion for pressing to the support surface direction.

The inner frame, Rukoto includes a pressed portion which is pressed by the pressing lever is preferable.

The pressing portion of the pressing lever and on either pressed portion Neu deviation, by the rotation of the push lever, it is preferable to provide a spring member or a cam surface for urging the inner frame to a support surface. The springy member may be provided with a cam surface.

  It is desirable that the outer frame, the photosensitive substrate, and the inner frame are located in this order from the side of the projection exposure means.

It is desirable that the cover frame and the intermediate frame be provided with a viewing hole in the outer frame by partially removing the rising surface to expose the end of the photosensitive substrate.

  The exposure apparatus according to the present invention uses the thin substrate correction jig to correct the substrate with a high degree of flatness even in an exposure apparatus that has no space between the projection optical system and the substrate, thereby achieving a highly accurate pattern. Can be exposed.

FIG. 1 is a front view showing an overall configuration of a direct exposure apparatus including a substrate correction jig according to the present invention. It is a top view of the assembly state of a substrate correction jig. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. It is a fragmentary perspective view of the outer frame single-piece | unit of a board | substrate correction jig | tool. It is a fragmentary perspective view in the state where the outer frame and inner frame of a substrate correction jig were combined. It is a perspective view which shows the outer frame of a board | substrate correction jig, an inner frame, and a board | substrate in the disassembled state which made the outer frame down. FIG. 7 is a perspective view of a state in which the outer frame, the inner frame, and the substrate of the substrate correction jig are viewed from the opposite direction of FIG. 6 with the outer frame down (the outer frame is up). It is a partial disassembled perspective view of the outer frame of a board | substrate correction jig | tool.

  FIG. 1 shows an example of an exposure apparatus 1 to which the present invention is applied. The exposure apparatus 1 has an illumination optical system 10, a photomask M, a projection optical system 11, and an exposure stage 20 in this order from the top to the bottom (Z direction). A photosensitive substrate (hereinafter referred to as a substrate) W coated or laminated with a photoresist on at least one surface (upper surface) is held by the substrate correction jig F and positioned on the exposure stage 20. The exposure pattern light emitted from the illumination optical system 10 and transmitted through the photomask M is imaged on the surface of the substrate W by the projection optical system 11.

  The exposure stage 20 is for fixing the substrate W in a planar manner and for positioning with respect to the projection optical system, and is a known stage having a function of attracting and fixing the back surface of the substrate W. The exposure stage 20 is supported by a moving mechanism (not shown), and is movable, for example, in the XYθZ direction. Moreover, it is also possible to perform exposure while moving the exposure stage 20 relative to the projection optical system 11 (for example, step & repeat or scan) by using the above moving mechanism.

  The illumination optical system 10 includes a light source (for example, a mercury lamp) not shown. The light source emits light of a wavelength according to the photoresist on the surface of the substrate W. The illumination optical system 10 also has a function of condensing the light emitted from the light source to make the light quantity uniform.

  The projection optical system 11 is a known imaging optical system in which the photomask M and the surface (photosensitive surface) of the substrate W are in a conjugate relationship. The distance between the projection optical system 11 and the surface of the substrate W as the object to be exposed is strictly determined by the focal length of the projection optical system, but may be arranged as close as several tens mm (for example, about 30 mm).

  Substrate distance measuring means (not shown) is provided around the projection optical system 11 or the periphery thereof. The substrate distance measuring unit measures the distance between the photosensitive surface of the substrate W and the projection optical system 11 in μm units, and based on the measurement result, the focus adjusting unit (not shown) focuses the pattern image by the projection optical system 11 Adjustment is performed to fit the surface of the substrate W.

  The focus adjustment means is installed in the projection optical system 11 or installed at the exit of the projection optical system 11, as is known. Focus adjustment may be performed by moving the exposure stage 20 in the Z direction.

  Between the projection optical system 11 and the substrate W, alignment means (imaging means) (not shown) for aligning the photomask M and the substrate W are provided. A specific alignment means of the photomask M and the substrate W is known (for example, TTL method).

  In addition, a cover glass (not shown) or the like is provided between the projection optical system 11 and the substrate W to prevent the sublimate from the photoresist on the surface of the substrate W from adhering to the projection lens of the projection optical system 11. The distance between the projection optical system 11 and the substrate W is narrow.

  The exposure apparatus 1 includes a substrate cassette 30 for storing a plurality of substrates W with substrate correction jig F, and a transfer robot for transferring the substrate W with substrate correction jig F in the substrate cassette 30 with the exposure stage 20 (transfer A means 40 is provided.

  The substrate W is, for example, a printed wiring board made of resin, glass, silicon or the like as a base material, an interposer substrate, a substrate for LCD, a substrate for semiconductor, etc., and is shaped into a rectangle. Before the substrate W is exposed to light by the exposure apparatus 1, various processes are performed, which may cause warpage. Specifically, for example, processing such as bonding of a plurality of substrates, heat treatment, or polishing on one side is performed, and as a result, internal stress may be biased and distortion may occur. In an example of a resin interposer substrate (outside dimension 200 × 250 mm), warpage of 50 mm or more occurs, and even if it is mounted on the exposure stage 20 and vacuum suction is performed, within the focal depth of the projection optical system 11 Since the displacement of the substrate surface can not be accommodated, the resolution of the pattern is adversely affected.

  The substrate correction jig F is to be positioned on the exposure stage 20 in a state in which the distortion of the substrate W is corrected and the flatness is maintained well. The substrate correction jig F is comprised from two frames, the outer frame 50 and the inner frame 60, as shown to FIG. 2 thru | or FIG.

  The outer frame 50 is in the form of a square frame as a whole, as shown in FIGS. The outer frame 50 is, in this embodiment, a rectangular continuous mounting frame 51, a discontinuous intermediate frame 52, and a rectangular continuous cover frame, which are stacked and coupled, as better shown in FIGS. A rectangular substrate exposure opening 51 a is formed at the center of the mounting frame 51. The intermediate frame 52 is a discontinuous thick-walled member arranged on the mounting frame 51 so as to be biased toward the peripheral side, and fixed to the mounting frame 51 in the mounting frame 51, the substrate exposure opening 51a. Forming a rectangular support surface 51b along the The inner peripheral surface of the intermediate frame 52 constitutes a rising surface 52a orthogonal to the support surface 51b. The support surface 51b is a surface orthogonal to the optical axis of the projection optical system 11 in a state where the substrate correction jig F is mounted on the exposure stage 20, and the rising surface 52a is a surface parallel to the optical axis. On the inner peripheral surface of the cover frame 53, a rising surface 53a which is flush with the rising surface 52a is formed, and the support surface 51b and the rising surface 52a (and the rising surface 53a) form a step 54. The planar shape (contour) of the rising surface 52a (and 53a) corresponds to the planar outer shape of the substrate W, and faces the end surface of the substrate W when the substrate W is placed on the support surface 51b.

The inner frame 60 has a rectangular general cross section, and has a rectangular shape (fitted in the contour of the rising surface 52a (and 53a)) corresponding to the planar shape of the rising surface 52a (and 53a) of the outer frame 50 . The width s shown in FIG. 3 corresponds to the width S of the support surface 51b (S> s in the illustrated embodiment). The inner opening dimension of the inner frame 60 is determined by the exposure margin of the substrate W. When exposure ( exposure from the cover frame 53 side) of the substrate surface on the side in contact with the inner frame 60 is performed, the area in contact with the inner frame 60 of the substrate W is not exposed. It becomes. (When the substrate surface on the side in contact with the outer frame 50 is exposed ( exposure from the support frame 51 side) , the inside of the substrate exposure opening 51a of the outer frame 50 is the range where exposure can be performed.) The thickness d is sufficiently smaller than the depth D of the step 54 (the inner frame 60 is sufficiently thin compared to the outer frame 50), and the depth D of the step 54 is equal to the thickness d of the inner frame 60 The total thickness obtained by adding the thickness X of the substrate W is larger (D> d + X ). Although the thickness X differs depending on the type of the substrate W, this relationship is satisfied for any substrate W.

In the outer frame 50 (mounting frame 51, intermediate frame 52, cover frame 53), the observation hole 55 (FIG. 2, FIG. 2 ) in which the rising surface 52a (and 53a) and the support surface 51b are removed along the substrate exposure opening 51a. 4 and 5) are formed at intervals. The position of the substrate W can be detected by detecting the end face of the substrate W from the observation hole 55 by a detection means such as an optical sensor or a camera. In addition, on the substrate W, an alignment mark for accurate positioning with the photomask M is usually formed, and the end surface information (position information) of the substrate W recognized through the observation hole 55 is , Can be used for pre-alignment.

  Between the outer frame 50 and the inner frame 60, a mechanical pressing mechanism (locking mechanism) 70 for pressing the inner frame 60 toward the support surface 51b is provided. The mechanical pressing mechanism 70 is provided with a plurality (two in the illustrated embodiment) of the same structure at each side of the outer frame 50 (inner frame 60). Each mechanical pressing mechanism 70 is provided on the inner frame 60 and the pressing lever 72 pivotally attached by the shaft 71 between the mounting frame 51 of the outer frame 50 and the cover frame 53, as shown in a disassembled state in FIG. It consists of a pressed portion 74. The pressing lever 72 includes a force operating portion 72a and a pressing portion 72b which extend in substantially opposite directions with respect to the shaft 71. Further, a torsion spring 73 is attached to the shaft 71 for urging the pressing lever 72 in the direction in which the pressing portion 72b protrudes above the support surface 51b, and the force operating portion 72a of the pressing lever 72 is always an outer frame It is within the 50 contours. The intermediate frame 52 is discontinuous at the pivoted portion of the shaft 71 and is placed by the fixing screw 56 (FIG. 4) or the like in a state of being sandwiched between the placement frame 51 and the cover frame 53. It is fixed to the frame 51 and the cover frame 53. FIG. 5 shows the state of the outer frame 50 before the cover frame 53 is laminated and connected to the mounting frame 51 and the intermediate frame 52.

  The pressed portion 74 is formed of a leaf spring and includes a slope (a chevron surface) 74a pressed by the pressing portion 72b of the pressing lever 72, and one end 74b (FIG. 5) is fixed on the inner frame 60 For example, it is fixed by welding). When the slope 74a of the pressed portion 74 is pressed by the pressing portion 72b, it bends and presses the inner frame 60 in the direction of the support surface 51b (substrate W). The force of the torsion spring 73 is set sufficiently stronger than the force of the pressed portion 74.

When supporting the substrate W on the substrate correction jig F having the above configuration, the inner frame 60 is removed from the outer frame 50 by the separately provided outer setting machine (or a manual operation), and each mechanical pressing of the outer frame 50 is performed. The pressing force operating portion 72a of the pressing lever 72 of the mechanism 70 is pressed inward (in the direction of arrow A in FIG. 5 ) to retract the pressing portion 72b from the support surface 51b. In the mounting frame 51, a notch 51c (FIG. 8) is formed which facilitates the work of pressing the force operation portion 72a inward with a jig (or a manual operation). The pressing part 72b in a state of being retracted from the support surface 51b, the stepped portion 54 of the outer frame 50, and the substrate W with its photosensitive surface to the supporting surface 51b, toward the pressed portion 74 on the opposite side of the substrate W Insert the inner frame 60 in order. Thereafter, when the external force to the pressing lever 72 is released in a state where the inner frame 60 is temporarily pushed to the substrate W side (the substrate W is made flat), the pressing portion 72b of the pressing lever 72 The pressed portion 74 of the inner frame 60 is pressed, and the substrate W is in close contact with the support surface 51 b, whereby the planarity of the substrate W is secured.

  Then, a plurality of substrates W with the substrate correction jig F are accommodated, for example, in the substrate cassette 30 attached to the exposure apparatus 1. Since the substrate correction jig F is thin, the substrate cassette 30 can accommodate a large number of substrates W.

  On the other hand, at the time of actual exposure work, the substrate W with the substrate correction jig F stored in the substrate cassette 30 is taken out by the transfer robot 40 and transferred onto the exposure stage 20 after processes such as prealignment. At this time (or when storing the substrate W with the substrate correction jig F in the substrate cassette 30), as shown in FIG. 7, the substrate W with the substrate correction jig F is turned upside down and the outer frame 50 is directed upward. And set on the exposure stage 20. The exposure stage 20 vacuum-sucks and fixes the back surface (surface opposite to the exposure surface) of the substrate W exposed from the outer frame 50. Since the substrate W is directly fixed by suction, the substrate whose planarity has been improved by the substrate correction jig F is further fixed with high planar accuracy.

  In this manner, when the outer frame 50 is set to face the projection optical system 11, the distance between the upper surface of the outer frame 50 and the exposure surface of the substrate W is kept constant and minimal even if the thickness of the substrate W changes. can do. Therefore, in the exposure apparatus 1 in which the space between the substrate W and the projection optical system 11 is small due to factors such as restriction of the focal length of the projection optical system 11, distance measurement means, focus adjustment means, imaging means, cover glass, etc. It is also advantageous against.

  The substrate W for which the exposure has been completed is again stored in the substrate cassette 30 by the transport robot 40 while the substrate correction jig F is mounted. When the substrate W is delivered from the exposure apparatus 1 to the next process (developing or the like) apparatus, the substrate correction jig F is removed from the substrate W and collected by an external setting machine installed outside the exposure apparatus 1.

  The transfer means for transferring the substrate is not limited to the robot, and can be appropriately selected and designed from known transfer mechanisms according to the substrate W. Alternatively, the upstream / downstream apparatus and the substrate correction jig F-attached substrate W may be exchanged by a conveyor or the like in line. In addition, the exposure apparatus 1 is provided with a well-known function that is necessary as appropriate, such as a pre-aligner not shown.

  The mechanical pressing mechanism 70 in the above embodiment is an example, and various modifications are possible. Even in the embodiment using the pressing lever 72 of the illustrated example, for example, the installation location and number of the pressed portions (leaf spring) 74 of the inner frame 60 are the rigidity of the inner frame 60, the rigidity and elasticity of the substrate W, and the elasticity of the leaf spring. It is designed by timely etc. The pressed portion 74 may be an elastic body (e.g., urethane rubber) other than a leaf spring, or may be formed of a cam surface. Furthermore, an elastic body or a cam surface may be provided in the engaging portion of the pressing portion 72b of the pressing lever 72 with the pressed portion 74. Further, the shape of the pressing lever 72 is an example, and it may be possible to shift to a state in which the pressing portion 72 b does not interfere with the inner frame 60 and an interference state in which the pressing causes the interference to press the inner frame 60 toward the substrate W .

  The outer frame 50 has a three-layer structure of the mounting frame 51, the intermediate frame 52, and the cover frame 53 in the above embodiment, so that there is an advantage that machining is easy. You can also

  The inner frame 60 may have a plurality of different (particularly, different thicknesses) depending on the nature (thickness) of the substrate W.

  Although the above embodiment has described the present invention by taking a projection exposure apparatus using a photomask M as an example, direct exposure using a light modulation element array (for example, a liquid crystal panel or DMD) instead of the photomask M The apparatus may be a direct exposure apparatus by laser scanning or the like that does not use a light modulation element array. Furthermore, this substrate correction frame may be used in a proximity exposure apparatus or the like that does not have a projection optical system.

Reference Signs List 1 exposure apparatus 10 illumination optical system 11 projection optical system 20 exposure stage 30 substrate cassette 40 transport robot 50 outer frame 51 placement frame 51a substrate exposure opening 51b support surface 51c notch 52 intermediate frame 52a rising surface 53 cover frame 54 step 55 Observation hole 60 Inner frame 70 Mechanical pressing mechanism (locking mechanism)
71 shaft 72 pressing lever 72a force operating portion 72b pressing portion 73 torsion spring 74 pressed portion F substrate correction jig W substrate

Claims (6)

An exposure apparatus using a substrate correction jig, wherein a photosensitive substrate supported by a substrate correction jig is positioned on an exposure stage, and a pattern image is exposed on the photosensitive substrate by a projection exposure unit,
The above substrate correction jig
An outer frame provided with a support surface for supporting the photosensitive surface peripheral edge of the photosensitive substrate and a stepped portion having an erected surface facing the end surface of the photosensitive substrate;
An inner frame inserted into the outer frame and sandwiching the peripheral edge of the photosensitive substrate between the outer frame and the support surface; mechanical pressing the inner frame against the support surface of the outer frame Pressing mechanism;
Equipped with
The outer frame is provided with a stacked continuous rectangular continuous mounting frame, a discontinuous intermediate frame, and a continuous rectangular cover frame, and the above-mentioned setting frame has the above-mentioned supporting surface, and the above-mentioned middle frame and above The cover frame has the rising surface, and the stepped portion is formed by the support surface and the rising surface.
The mechanical pressing mechanism comprises a pressing lever located within the thickness of the outer frame pivotally mounted between the setting frame and the cover frame at discrete positions of the intermediate frame. And
An exposure apparatus using a substrate correction jig characterized in that the pressing lever includes a force operating portion extending in a substantially opposite direction about the axis and a pressing portion pressing the inner frame in the direction of the support surface. . In the exposure apparatus using the claim 1 substrate straightening jig, wherein the inner frame is an exposure apparatus that uses the substrate correcting jig is provided with a pressed portion which is pressed by the pressing portion of the pressing lever. An exposure apparatus using the substrate correction jig according to claim 2
The one or pressing lever pressing portion and the pressed portion Neu deviation of by rotation of the push pressure lever, at least one spring member and the cam surface for urging the frame to the support surface is provided Exposure apparatus using a substrate correction jig. An exposure apparatus using the substrate correction jig according to any one of claims 1 to 3.
An exposure apparatus using a substrate correction jig which is positioned in the order of the outer frame, the photosensitive substrate and the inner frame from the side of the projection exposure means. The exposure apparatus using the substrate correction jig according to any one of claims 1 to 4, wherein the support surface and the rising surface are partially removed from the support frame, the cover frame and the intermediate frame , An exposure apparatus using a substrate correction jig in which a viewing hole for exposing an end portion of the photosensitive substrate is formed. An outer frame provided with a support surface for supporting the photosensitive surface peripheral edge of the photosensitive substrate and a stepped portion having a rising surface facing the end surface of the photosensitive substrate;
An inner frame inserted into the outer frame and sandwiching the peripheral edge of the photosensitive substrate between the outer frame and the support surface; mechanical pressing the inner frame against the support surface of the outer frame Pressing mechanism;
Equipped with
The outer frame is provided with a stacked continuous rectangular continuous mounting frame, a discontinuous intermediate frame, and a continuous rectangular cover frame, and the above-mentioned setting frame has the above-mentioned supporting surface, and the above-mentioned middle frame and above The cover frame has the rising surface, and the stepped portion is formed by the support surface and the rising surface.
The mechanical pressing mechanism comprises a pressing lever located within the thickness of the outer frame pivotally mounted between the setting frame and the cover frame at discrete positions of the intermediate frame. And
A substrate correction jig characterized in that the pressing lever includes a force operating portion extending in a substantially opposite direction about the axis and a pressing portion pressing the inner frame in the direction of the support surface .

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