KR102413891B1 - Exposure device using substrate unbending frame and substrate unbending frame - Google Patents

Abstract

An exposure apparatus for placing a photosensitive substrate supported by a substrate correction jig on an exposure stage and exposing a pattern image on the photosensitive substrate by a projection exposure means, wherein the substrate correction jig is thinned To obtain an exposure apparatus and a substrate calibration jig which can reduce the sizing) and prevent interference with the exposure apparatus.
The substrate calibration jig includes: an outer frame having an end having a support surface for supporting a periphery of the photosensitive surface of the photosensitive substrate and a standing surface opposite to the end face of the photosensitive substrate; an inner frame inserted into the outer frame to constrict the periphery of the photosensitive substrate between the outer frame and the supporting surface; and a mechanical pressing mechanism for pressing the inner frame toward the supporting surface of the outer frame.

Description

An exposure apparatus using a substrate correction jig, and a substrate correction jig TECHNICAL FIELD

The present invention relates to an exposure apparatus for performing exposure using a substrate correction jig for correcting a warped photosensitive substrate in a planar shape, and to the jig.

An exposure apparatus (projection exposure apparatus, stepper or scanner, direct exposure apparatus, etc.) that performs projection exposure is exposed to ultraviolet light or the like on the surface of a photosensitive substrate (hereinafter referred to as a substrate) coated with photoresist. Exposure is performed by forming a pattern image by light. In such a projection exposure apparatus, when the substrate has a warp exceeding the depth of focus of the projection optical system, the resolution accuracy on the pattern imaged on the substrate surface decreases. A board|substrate is a printed wiring board which used resin as a base material, a glass substrate for LCDs, a silicon board|substrate for semiconductors, etc., All are unavoidable the problem of warpage. When the warpage of the substrate is large, a vacuum leak occurs in the robot hand that transports the substrate or the substrate adsorption of the exposure stage, which causes an error.

Patent Document 1 proposes a conveyance jig that corrects and holds the warpage of the substrate, and conveys and exposes the substrate. In this document, processing in a state in which the warpage of the substrate is corrected is made possible by fixing the substrate W between two molds that are attracted by magnetic force. Further, Patent Document 2 proposes a holder for holding the substrate in a state with little distortion by pressing the substrate against the regulating plate with a spring.

[Patent Document 1] Japanese Patent Laid-Open No. 2002-299406 [Patent Document 2] Japanese Patent Laid-Open No. 2005-064329

In general, the distance between the projection optical system of the exposure apparatus and the substrate tends to become closer due to the high precision of exposure, and since a focus adjustment optical system, a substrate height measurement device, etc. are installed in this portion, the space margin is small. However, since the substrate calibration jig such as Patent Document 1 and Patent Document 2 is large, it is difficult to install it in an exposure apparatus with little space, or a structure is required in which the optical system or the exposure stage is largely retracted when transported to the exposure position. There was a task to do.

An object of the present invention is to obtain an exposure apparatus capable of reducing the thickness (lower height) and preventing interference with an exposure apparatus, and a substrate correction jig, based on the above problem awareness. .

The present invention provides an exposure apparatus in which a photosensitive substrate supported by a substrate calibration jig is positioned on an exposure stage, and a pattern image is exposed on the photosensitive substrate by a projection exposure means, wherein the substrate calibration jig comprises: an outer frame having an end having a support surface for supporting a periphery of the photosensitive surface of the photosensitive substrate and a standing surface opposite to the end face of the photosensitive substrate; an inner frame inserted into the outer frame to constrict a periphery of the photosensitive substrate between the outer frame and the supporting surface; and a mechanical pressing mechanism for pressing the inner frame toward the supporting surface of the outer frame.

The present invention provides an aspect of a substrate calibration jig, comprising: an outer frame having an end portion having a support surface for supporting a periphery of a photosensitive surface of a photosensitive substrate and a standing surface opposite to the end face of the photosensitive substrate; an inner frame for constricting a periphery of the photosensitive substrate between the support surface; and a mechanical pressing mechanism for pressing the inner frame toward the supporting surface of the outer frame.

The mechanical pressing mechanism is a pressing lever formed in the inner frame and positioned within the thickness of the outer frame on a recess formed in the outer frame and pressed by the pressing lever formed in the inner frame. It is preferable to constitute the to-be-pressed part to be used.

A spring-like member or cam surface for biasing the inner frame toward the support surface by operation of the pressing lever is provided on either one of the engaging portions of the pressing lever and the portion to be pressed. It is preferable to do You may provide a cam surface to a spring member.

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

It is preferable to form a hole in the outer frame by partially removing the standing surface to expose an end portion of the photosensitive substrate.

In the exposure apparatus according to the present invention, by using a thin substrate calibration jig, even in an exposure apparatus having no space between the projection optical system and the substrate, the substrate can be corrected with a high flatness and high-precision patterns can be exposed. .

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows the whole structure of the direct exposure apparatus including the board|substrate calibration jig by this invention.
2 is a plan view of an assembly state of the substrate straightening jig.
FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2 .
Fig. 4 is a partial perspective view of a single frame of the substrate straightening jig.
Fig. 5 is a partial perspective view of a state in which an outer frame and an inner frame of a substrate calibration jig are combined.
Fig. 6 is a perspective view showing the outer frame, inner frame, and substrate of the substrate calibration jig in an exploded state with the outer frame facing down.
Fig. 7 is a perspective view showing the outer frame, inner frame, and substrate of the substrate calibration jig as viewed from the opposite direction to Fig. 6 with the outer frame facing down (with the outer frame facing up).
Fig. 8 is a partially exploded perspective view of the outer frame of the substrate straightening jig.

1 : has shown an example of the exposure apparatus 1 to which this invention is applied. This exposure apparatus 1 has the illumination optical system 10, the photomask M, the projection optical system 11, and the exposure stage 20 in order from top to bottom (Z direction). A photosensitive substrate (hereinafter referred to as a substrate) W on at least one surface (upper surface) of which a photoresist is applied or laminated is held by the substrate calibration 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 on a plane and positioning it with respect to a projection optical system, and is a well-known stage provided with the function of adsorbing and fixing the back surface of the substrate W. The exposure stage 20 is supported by a movement mechanism (not shown), and is movable in, for example, the XYθZ direction. In addition, by using the above moving mechanism, it is possible to perform exposure while moving the exposure stage 20 relative to the projection optical system 11 (eg, step & repeat, or scan).

The illumination optical system 10 is equipped with 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. In addition, the illumination optical system 10 has a function of condensing the light emitted by the light source and equalizing the amount of light.

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

A substrate distance measuring means (not shown) is provided on or around the projection optical system 11 . This substrate distance measuring means measures the distance between the photosensitive surface of the substrate W and the projection optical system 11 in units of μm, and based on the measurement result, a focus adjustment means (not shown) measures the distance between the projection optical system 11 and the projection optical system 11 . Adjustment is performed so that the focus of the pattern image by the above may be matched with the surface of the board|substrate W.

The focus adjusting means is provided in the projection optical system 11 or provided at the exit of the projection optical system 11 as well known. The focus may be adjusted by moving the exposure stage 20 in the Z direction.

Between the projection optical system 11 and the substrate W, an alignment unit (imaging unit) (not shown) for aligning the photomask M and the substrate W is provided. The specific alignment means of the photomask M and the board|substrate W is well-known (for example, TTL system).

In addition, between the projection optical system 11 and the substrate W, a cover glass (not shown) for preventing sublimation from the photoresist on the surface of the substrate W from adhering to the projection lens of the projection optical system 11 . ) etc. are provided, and the space|interval between the projection optical system 11 and the board|substrate W is narrowing.

In the exposure apparatus 1 , a substrate cassette 30 accommodating a plurality of substrates W to which the substrate correction jig F is attached, and a substrate W to which the substrate correction jig F is attached among the substrate cassettes 30 are interposed between the exposure stage 20 . A transport robot (transport means) 40 for transporting in the .

The substrate W is, for example, a printed wiring board, an interposer substrate, a substrate for LCD, a substrate for semiconductors, etc., which is made of resin, glass, silicon or the like, and is shaped in a spherical shape. Before this board|substrate W receives exposure by the exposure apparatus 1, various processes are made|formed, and warpage may generate|occur|produce. Specifically, for example, bonding of a plurality of substrates, heat treatment, or polishing of one surface is performed. As a result, an internal stress may be deflected and distortion may occur. In the example of a certain resin interposer substrate (external dimension 200x250 mm), warpage of 50 mm or more occurs, and even if it is placed on the exposure stage 20 as it is and vacuum suction is performed, it is within the depth of focus of the projection optical system 11 . Since the displacement of the surface of the substrate does not enter, the resolution of the pattern is adversely affected.

The substrate correction jig F is positioned on the exposure stage 20 in a state in which the distortion of the substrate W is corrected and planarity is maintained favorably. The board|substrate calibration jig|tool F is comprised from the two frame bodies of the outer frame 50 and the inner frame 60, as shown in FIGS. 2-8.

As shown in Figs. 2, 6, and 7, the outer frame 50 has a rectangular frame shape as a whole. The outer frame 50 is, in this embodiment, as well shown in Figs. 3 and 8, a spherical continuous mounting frame 51 and discontinuous intermediate frame 52 to be laminated and bonded. and a spherical continuous cover mold 53 , and a spherical substrate exposure opening 51a is formed in the center of the mounting mold 51 . The intermediate mold 52 is a discontinuous thick member disposed biasedly on the peripheral side on the mounting mold 51 , and is in a state fixed to the mounting mold 51 , and is in the mounting mold 51 , the substrate exposure opening 51a ) along to form a spherical support surface (51b). The inner peripheral surface of the intermediate frame 52 constitutes a standing 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 the state which mounted the board|substrate correction jig F on the exposure stage 20, The standing surface 52a is parallel to the same optical axis. is the side On the inner circumferential surface of the cover frame 53, a standing surface 53a that is flush with the standing surface 52a is formed, and the support surface 51b and the standing surface 52a (and the standing surface 53a) are formed. ) forms the end 54 . The planar shape (contour) of the standing surfaces 52a (and 53a) corresponds to the planar outer shape of the substrate W, and opposes the end surface of the substrate W when the substrate W is placed on the support surface 51b.

The inner frame 60 has a spherical general cross section, and fits within the outline of the standing surfaces 52a (and 53a) corresponding to the planar shapes of the standing surfaces 52a (and 53a) of the outer frame 50 (the rising surfaces 52a and 53a). (嵌入) forms a spherical shape. The width S shown in FIG. 3 corresponds to the width s of the support surface 51b (S>s in the illustrated embodiment). In addition, the inner opening dimension of the inner frame 60 is determined by the exposure margin of the board|substrate W. As shown in FIG. When exposing the surface of the substrate in contact with the inner frame 60 , the portion of the substrate W in contact with the inner frame 60 is not exposed, so the inside of the opening of the inner frame 60 is within the exposed range. (When exposing the substrate surface in contact with the outer frame 50, the inner side of the substrate exposure opening of the outer frame 50 becomes a range capable of exposure). In addition, the thickness d of the inner frame 60 is sufficiently smaller than the depth D of the end portion 54 (the inner frame 60 is sufficiently thin compared to the outer frame 50 ), and the depth D of the end portion 54 is the inner frame 60 . is greater than the sum of the thickness d of the substrate W and the thickness x of the substrate W (D > d + x). The thickness x varies depending on the type of the substrate W, but this relationship is satisfied in any substrate W.

In the outer frame 50 (the mounting frame 51, the intermediate frame 52, and the cover frame 53) along the board|substrate exposure opening 51a, the hole 55 (FIG. 2, FIG. 3 and FIG. 5) are formed in plurality at intervals. The position of the substrate W can be detected by detecting the end face of the substrate W from the hole 55 with a detection means such as an optical sensor or a camera. In addition, on the substrate W, alignment marks for accurate positioning with the photomask M are usually formed, and cross-sectional information (position information) of the substrate W recognized through the hole 55 is pre-alignment ( can be used for pre-alignment).

Between the outer frame 50 and the inner frame 60 , a mechanical pressing mechanism (lock mechanism) 70 for pressing the inner frame 60 toward the support surface 51b is provided. As for the mechanical pressing mechanism 70, the thing of the same structure is provided in each edge part of the outer frame 50 (inner frame 60), multiple (two in the illustrated embodiment). As shown in the disassembled state in FIG. 8 , each mechanical pressing mechanism 70 is mounted on a shaft 71 between the mounting frame 51 of the outer frame 50 and the cover frame 53 . It consists of a pressing lever 72 and the to-be-pressed part 74 provided in the inner frame 60. As shown in FIG. The pressing lever 72 is provided with the holding force operation part 72a extending in the substantially opposite direction centering on the axis|shaft 71, and the pressing part 72b. Further, the shaft 71 is equipped with a torsion spring 73 that biases the pressing lever 72 in the direction in which the pressing portion 72b projects on the support surface 51b, and the pressing lever The holding operation part 72a of (72) always fits within the outline of the outer frame (50). The intermediate frame 52 is discontinuous at the mounting portion of the shaft 71, and is sandwiched between the mounting frame 51 and the cover frame 53 by means of a fixing screw 56 (FIG. 4) or the like. It is fixed to the mounting frame 51 and the cover frame 53 . 5 : has shown the state of the outer frame 50 before laminating|stacking the cover frame 53 to the mounting frame 51 and the intermediate|middle frame 52. As shown in FIG.

The pressed portion 74 is made of a plate spring body, has a slope (mountain) 74a pressed by the pressing portion 72b of the pressing lever 72, and has one end ( 74b) (FIG. 5) is fixed (eg, welded) on the inner frame 60 . When pressed by the pressing part 72b, the inclined surface 74a of the to-be-pressed part 74 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 the substrate W is supported on the substrate calibration jig F of the above configuration, the outer set-up device (or manual operation) provided separately removes the inner frame 60 from the outer frame 50, the outer frame 50 Pressing the force operation part 72a of the pressing lever 72 of each mechanical pressing mechanism 70 inward (FIG. 4 arrow A direction) is pressed, and the pressing part 72b is retracted from the support surface 51b. The mounting frame 51 is provided with a cutout portion 51c (FIG. 8) that facilitates the operation of pressing the pulling force operation portion 72a inward with a jig (or manual operation). In a state in which the pressing portion 72b is retracted from the supporting surface 51b, in the end 54 of the outer frame 50, the substrate W with the photosensitive surface facing the supporting surface 51b, and the to-be-pressed portion 74 are mounted on the substrate W Insert the inner frame 60 facing the opposite side in order. After that, when the external force to the pressing lever 72 is released while the inner frame 60 is temporarily pressed to the substrate W side (with the substrate W flat), the force of the torsion spring 73 causes the pressing lever The pressing part 72b of (72) presses the to-be-pressed part 74 of the inner frame 60, the board|substrate W will be in the state closely_contact|adhered to the support surface 51b, and the flatness of the board|substrate W is ensured.

And the board|substrate W with which the board|substrate calibration jig|tool F was attached is accommodated in the board|substrate cassette 30 attached to the exposure apparatus 1 in plurality, for example. Since the substrate straightening jig F is thin, a large number of substrates W can be accommodated in the substrate cassette 30 .

On the other hand, at the time of actual exposure operation, the board|substrate W equipped with the board|substrate calibration jig F accommodated in the board|substrate cassette 30 is taken out by the conveyance robot 40, and is conveyed on the exposure stage 20 after processes, such as pre-alignment. do. At this time (or when the substrate W on which the substrate correction jig F is mounted is accommodated in the substrate cassette 30), as shown in FIG. 50 ) is set on the exposure stage 20 , facing upward. The exposure stage 20 vacuum-sucks and fixes the back surface (surface opposite to the exposure surface) of the substrate W exposed by the outer frame 50 . Since the board|substrate W is directly adsorbed and fixed, the board|substrate whose planarity was improved with the board|substrate calibration jig|tool F is fixed with more favorable planar precision.

In this way, when the outer frame 50 is set toward the projection optical system 11 side, even if the thickness of the substrate W changes, the distance between the upper surface of the outer frame 50 and the exposure surface of the substrate W is kept constant and minimum (保持) can For this reason, the space between the substrate W and the projection optical system 11 is small due to factors such as restrictions of the focal length of the projection optical system 11, distance measuring means, focus adjusting means, imaging means, cover glass, etc., exposure apparatus ( 1) is also advantageous.

The board|substrate W which the exposure was complete|finished is accommodated in the board|substrate cassette 30 again with the board|substrate calibration jig|tool F attached by the conveyance robot 40. As shown in FIG. When the board|substrate W is delivered from the exposure apparatus 1 to the next process (development etc.) apparatus, the board|substrate calibration jig|tool F is disassembled from the board|substrate W by the external installation machine installed outside the exposure apparatus 1, and it collect|recovers.

The conveyance means for conveying a board|substrate is not limited to a robot, According to the board|substrate W, it can select and design suitably from well-known conveyance mechanisms. Alternatively, the upstream and downstream apparatus and the substrate W to which the substrate calibration jig F is mounted may be exchanged in-line by a conveyor or the like. In addition, the exposure apparatus 1 is equipped with well-known functions necessary suitably, such as a pre-aligner (not shown).

The mechanical pressing mechanism 70 in the above embodiment shows an example, and various changes are possible. Even in the form using the pressing lever 72 of the example shown in figure, for example, the installation location and number of the to-be-pressed part (plate spring body) 74 of the inner frame 60 are rigidity of the inner frame 60, a board|substrate. It is designed in a timely manner by the rigidity and elasticity of W and the elasticity of the leaf spring body. The portion to be pressed 74 may be formed of an elastic body other than a leaf spring body (eg, urethane rubber), or may be formed of a cam surface. Moreover, you may provide an elastic body or a cam surface in the engaging part with the to-be-pressed part 74 of the pressing part 72b of the pressing lever 72. In addition, the shape of the pressing lever 72 shows an example, and it is possible to shift to the state in which the pressing part 72b does not interfere with the inner frame 60, and the interference state which interferes and presses the inner frame 60 to the board|substrate W side. good to do

In the above embodiment, since the outer frame 50 has a three-layer structure of the mounting frame 51, the intermediate frame 52, and the cover frame 53, there is an advantage that machining is easy, for example, a die It can also be set as the integral structure made by the die casting.

The inner frame 60 may prepare a plurality of different (especially different thicknesses) according to the property (thickness) of the substrate W.

In the above embodiment, the present invention has been described using the projection exposure apparatus using the photomask M as an example. Instead of the photomask M, a direct exposure apparatus using a light modulation element array (eg, a liquid crystal panel or DMD, etc.), or A direct exposure apparatus by laser scanning or the like that does not use a modulation element array may be used. Moreover, you may use this board|substrate calibration frame as a proximity exposure apparatus etc. which are not equipped with a projection optical system.

1: exposure device
10: illumination optical system
11: Projection optics
20: exposure stage
30: substrate cassette
40: transport robot
50: outer frame
51: wit frame
51a: substrate exposure opening
51b: support surface
51c: cutout
52: middle frame
52a: standing surface
53: cover frame
54: end
55: hole
60: inner frame
70: mechanical pressure mechanism (lock mechanism)
71: axis
72: press lever
72a: grip control unit
72b: pressing unit
73: torsion spring
74: the to-be-pressed part
F: substrate correction jig
W: substrate

Claims (6)

An exposure apparatus using a substrate calibration jig, comprising placing a photosensitive substrate supported on a substrate calibration jig on an exposure stage and exposing a pattern image to the photosensitive substrate by a projection exposure means,
The substrate calibration jig,
an outer frame having an end having a supporting surface for supporting a periphery of the photosensitive surface of the photosensitive substrate and a standing surface opposite to the end face of the photosensitive substrate;
an inner frame inserted into the outer frame to constrict a periphery of the photosensitive substrate between the outer frame and the supporting surface of the outer frame; and
A mechanical pressing mechanism for pressing the inner frame toward the supporting surface of the outer frame
equipped with
The outer frame includes a spherical continuous placing frame, a discontinuous intermediate frame, and a spherical continuous cover frame, laminated and bonded, the placing frame having the support surface, the intermediate frame and the cover frame has the standing surface, and forming the end with the support surface and the standing surface;
the mechanical pressing mechanism is provided with a pressing lever located within the thickness of the outer frame, which is axially mounted between the mounting frame and the cover frame at a discontinuous position of the intermediate frame; and
The exposure apparatus using a substrate straightening jig, characterized in that the pressing lever is provided with an attraction operation unit extending in the opposite direction about the axis, and a pressing unit pressing the inner frame in the direction of the support surface. According to claim 1,
The exposure apparatus using the board|substrate calibration jig which the said inner frame is provided with the to-be-pressed part pressed by the pressing part of the said press lever. 3. The method of claim 2,
At least one of a cam surface and a spring member that urges the inner frame toward the support surface by rotation of the pressing lever is provided in one of the pressing portion of the pressing lever and the pressing portion of the inner frame. Exposure apparatus using a jig. 4. The method according to any one of claims 1 to 3,
An exposure apparatus using a substrate calibration jig positioned in the order of the outer frame, the photosensitive substrate, and the inner frame from the projection exposure means side. 4. The method according to any one of claims 1 to 3,
An exposure apparatus using a substrate calibration jig, wherein a hole is formed in the mounting frame, the cover frame, and the intermediate frame by partially removing the support surface and the standing surface to expose an end portion of the photosensitive substrate. an outer frame having an end having a supporting surface for supporting a periphery of the photosensitive surface of the photosensitive substrate and a standing surface opposite to the end face of the photosensitive substrate;
an inner frame inserted into the outer frame to constrict a periphery of the photosensitive substrate between the outer frame and the supporting surface of the outer frame; and
A mechanical pressing mechanism for pressing the inner frame toward the supporting surface of the outer frame
equipped with
The outer frame has a spherical continuous placing frame, a discontinuous intermediate frame, and a spherical continuous cover frame, laminated and bonded, the placing frame having the support surface, the intermediate frame and the cover frame being the standing having a surface, and forming the end portion with the support surface and the standing surface;
the mechanical pressing mechanism is provided with a pressing lever located within the thickness of the outer frame, which is axially mounted between the mounting frame and the cover frame at a discontinuous position of the intermediate frame, and
The pressing lever is provided with an attractive force operation unit extending in the opposite direction about the axis, and a pressing unit for pressing the inner frame in the direction of the support surface.

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