WO2007029561A1

WO2007029561A1 - Aligner

Info

Publication number: WO2007029561A1
Application number: PCT/JP2006/316956
Authority: WO
Inventors: Koichi Kajiyama; Yoshio Watanabe
Original assignee: V Technology Co., Ltd.
Priority date: 2005-09-09
Filing date: 2006-08-29
Publication date: 2007-03-15
Also published as: CN101258447A; JP2007072371A; KR20080059558A; TW200710603A; CN101258447B

Abstract

An aligner comprising a stage (13) having an upper surface (13a) for mounting a color filter substrate (11), a mask stage (6) arranged above the stage (13) such that a stripe photomask (5) can be held on the upper surface of the stage (13) in parallel therewith, and a light source (2) for irradiating the photomask (5) held on the mask stage (6) with exposure light, and forming a predetermined exposure pattern at a predetermined position by irradiating the color filter substrate (11) with exposure light radiated from the light source (2) through the photomask (5). A cylindrical lens (14) for shaping the cross-sectional profile of the beams of exposure light radiated from the light source (2) in accordance with the profile of the stripe photomask (5) is arranged on the optical path between the light source (2) and the mask stage (6). Consequently, utilization efficiency of exposure light radiated for the stripe photomask is enhanced.

Description

Specification

Exposure equipment

Technical field

The present invention relates to an exposure apparatus that irradiates an object to be exposed with exposure light through a photomask to form an exposure pattern, and more specifically, uses of exposure light to irradiate a strip-shaped photomask. The present invention relates to an exposure apparatus that attempts to improve efficiency.

Background art

As shown in FIG. 7, a conventional exposure apparatus includes a light source 2 whose exposure optical system 1 is for ultraviolet irradiation, for example, an ultra-high pressure mercury lamp force, a concave mirror 3 that collects irradiation light from the light source 2, Located near the focal point of the concave mirror 3 and arranged between the cylindrical optical integrator 4 that uniformizes the luminance distribution of the light beam L on the exposure surface, and the mask stage 6 that holds the optical integrator 4 and the photomask 5 It consists of a curved mirror 7 that guides the incident exposure light as a parallel light beam to the exposure surface, and a set of flat mirrors 8 and 8 that reverse the optical path. The exposure light having the light beams parallel to each other is irradiated perpendicularly to the photomask 5 held on the mask stage 6 (see, for example, Patent Document 1). In the figure, reference numeral 9 denotes a workpiece stage on which the object to be exposed is placed, upper reference numeral 10 denotes an object to be exposed such as a color filter substrate cover, and reference numeral 11 denotes an opening / closing control of the optical path of the exposure light. Show the exposure control shutter! /

Patent Document 1: Japanese Patent Laid-Open No. 2004-347883 (FIG. 7)

Disclosure of the invention

Problems to be solved by the invention

However, in such a conventional exposure apparatus, since the cross-sectional shape of the light beam 12 emitted from the curved mirror 7 is circular as shown in FIG. 8, for example, the photomask 5 is formed in a strip shape. In this case, the light beam L shown by hatching in the figure does not contribute to the exposure and is wasted, and the use efficiency of the exposure light applied to the strip-shaped photomask 5 is low. I helped. Therefore, the energy density of exposure light for irradiating the object to be exposed is low, the exposure processing time is long, and the outside is low. Accordingly, an object of the present invention is to provide an exposure apparatus that addresses such problems and attempts to improve the use efficiency of exposure light that irradiates a strip-shaped photomask. Means for solving the problem

In order to achieve the above object, an exposure apparatus according to the present invention has a stage on which an object to be exposed is placed on an upper surface, a strip-like shape disposed above the stage and parallel to the upper surface of the stage. A mask stage capable of holding a photomask; and a light source that irradiates exposure light to the photomask held on the mask stage. The exposure light emitted from the light source is transmitted through the photomask. An exposure apparatus for irradiating the object to be exposed to form a predetermined exposure pattern at a predetermined position, wherein a cross section of a light beam of exposure light emitted from the light source on an optical path between the light source and a mask stage Light beam cross-sectional shape shaping means for shaping the shape according to the shape of the strip-shaped photomask is provided.

With such a configuration, exposure light is emitted from the light source, and the cross-sectional shape of the exposure light beam emitted from the light source is shaped according to the shape of the strip-shaped photomask by the light beam cross-sectional shape shaping unit. The shaped exposure light is irradiated onto a photomask held on a mask stage, and the exposure light is further irradiated onto an object to be exposed placed on the upper surface of the stage via the photomask. The exposure pattern is formed.

[0007] Further, the light beam cross-sectional shape shaping means is a cylindrical lens that forms a linear beam at the focal position by refracting in only one direction of two axes perpendicular to the incidence of parallel rays. As a result, the cross-sectional shape of the light beam is shaped by a cylindrical lens that refracts the parallel incident light only in one axial direction and forms a linear beam at the focal position.

[0008] Further, the light beam cross-sectional shape shaping means is a fly-eye lens that forms a plurality of linear beams at the focal position by refracting only in the direction of two axes perpendicular to the incidence of parallel rays. . As a result, the cross-sectional shape of the light beam is shaped by a fly-eye lens that refracts only in one axial direction with respect to parallel incident light and forms a plurality of linear beams at the focal position.

[0009] Then, a kaleidoscope is provided on the optical path between the light source and the light beam cross-sectional shape shaping means to make the luminance distribution of the exposure light irradiated to the photomask uniform. . As a result, the color disposed on the optical path between the light source and the light beam cross-sectional shape shaping means. The brightness distribution of the exposure light irradiated on the photomask with the idscope is made uniform.

[0010] Further, a condensing lens that emits incident exposure light as parallel light is disposed on the optical path between the beam cross-sectional shape shaping means and the mask stage. As a result, the exposure light incident on the condenser lens disposed on the optical path between the light beam cross-sectional shape shaping means and the mask stage is emitted as parallel light.

[0011] Furthermore, the stage is configured so that the object to be exposed is placed on the surface of the strip-shaped photomask when exposure is performed by irradiating the object to be exposed placed on the upper surface with exposure light. It is transported in a direction parallel to the longitudinal direction. Thus, when exposure is performed by irradiating an exposure object placed on the upper surface of the stage with exposure light, the exposure object is parallel to the surface of the strip-shaped photomask and its longitudinal direction. Transport in the orthogonal direction.

[0012] The strip-shaped photomask has a plurality of mask patterns arranged in a line along the longitudinal direction. Thereby, a predetermined exposure pattern is formed with a strip-shaped photomask in which a plurality of mask patterns are arranged in a line along the longitudinal direction.

The invention's effect

[0013] According to the invention of claim 1, since the exposure light can be collected on the strip-shaped photomask, the utilization efficiency of the exposure light irradiated to the strip-shaped photomask can be improved. it can. Therefore, it is possible to increase the energy density of the exposure light that irradiates the object to be exposed. Thereby, the exposure processing time of the object to be exposed is shortened, and the tact can be increased.

[0014] According to the invention according to claim 2, the cross-sectional shape of the light beam of the exposure light can be easily shaped into a flat shape by reducing the cross-sectional shape to one of the two orthogonal axes.

[0015] Further, according to the invention of claim 3, it is possible to easily shape the cross-sectional shape of the light beam of the exposure light into a flat shape by reducing the cross-sectional shape in one of the two orthogonal axes. Further, it is possible to uniformly irradiate the photomask with exposure light.

[0016] According to the invention of claim 4, it is possible to uniformly irradiate the photomask with exposure light. Accordingly, the object to be exposed can be uniformly exposed.

[0017] According to the invention of claim 5, particularly, the light rays in the direction along the long axis of the photomask can be made parallel to each other. Therefore, along the longitudinal direction of the strip-shaped photomask. Thus, the resolution of the exposure pattern formed can be improved.

[0018] Further, according to the invention of claim 6, it is possible to form an exposure pattern while conveying the object to be exposed. Therefore, the exposure processing time can be further shortened.

[0019] According to the invention of claim 7, a plurality of exposure patterns can be formed along the longitudinal direction of the strip-shaped photomask.

Brief Description of Drawings

FIG. 1 is a front view showing a first embodiment of an exposure apparatus according to the present invention.

2 is a side view showing the main part of FIG.

FIG. 3 is a plan view showing a color filter substrate used in the exposure apparatus.

FIG. 4 is an explanatory view showing an irradiation state of exposure light having an elliptical light beam cross section with respect to a strip-shaped photomask in the exposure apparatus.

FIG. 5 is a front view showing a second embodiment of the exposure apparatus according to the present invention.

FIG. 6 is a diagram showing a configuration example of a fly-eye lens used in the second embodiment.

(a) is a front view, (b) is a right side view, and (c) is a plan view.

FIG. 7 is a front view showing a conventional exposure apparatus.

FIG. 8 is an explanatory view showing an irradiation state of exposure light having a circular light beam cross section with respect to a strip-shaped photomask in a conventional exposure apparatus.

Explanation of symbols

[0021] 2 ... Light source

5 ··· Photomask

6. Mask stage

10. Color filter substrate (exposed object)

12 ... Flux

13 · “Stage

13a… Top of stage

14 · · · Cylindrical lens (light beam cross-sectional shape shaping means)

15 ... Callide scope

16 ··· Condenser lens (Condenser lens;) 19 ... Mask no turn

23 ... exposure pattern

24 ··· Fly eye lens (light beam cross-sectional shape shaping means)

L ... light

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a front view showing a first embodiment of an exposure apparatus according to the present invention, and FIG. 2 is a side view showing the main part of FIG. This exposure apparatus forms an exposure pattern by irradiating an object to be exposed with exposure light through a photomask. A stage 13, a mask stage 6, a light source 2, a cylindrical lens 14, and a callide are formed. It consists of a scope 15 and a condenser lens 16. Here, the case where the exposure apparatus is a proximity exposure apparatus that exposes a photomask and an object to be exposed will be described, and the case where the object to be exposed is a color filter substrate will be described.

[0023] The stage 13 is for placing the color filter substrate 10 coated with a predetermined color resist on the upper surface 13a, and exposing the color filter substrate 10 placed on the upper surface 13a by exposing it to exposure light. When the color filter substrate 10 is driven by the conveying means 27, the color filter substrate 10 is parallel to the surface of a strip-shaped photomask 5 to be described later and is orthogonal to the longitudinal direction (the direction of arrow A shown in FIG. 1). ) Is transported at a constant speed.

As shown in FIG. 3, the color filter substrate 10 is formed with a black matrix 18 in which a large number of pixels 17 are provided corresponding to the pixels in the exposure region 28. Of the many pixels 17, the upper left corner of the pixel 17a at the left end in FIG. 3 serves as a reference position S1 for alignment with a reference position S2 (see FIG. 4) of the photomask 5 described later. It is set in advance.

A mask stage 6 is disposed above the stage 13 in close proximity. This mask stage 6 is capable of holding a strip-shaped photomask 5 parallel to the upper surface 13a of the stage 13, and is orthogonal to the direction of arrow A in a plane parallel to the upper surface 13a of the stage 13. It can be moved in the direction and can be rotated (Θ) about the central axis of the surface of the photomask 5 (see FIG. 4). Here, the strip-shaped photomask 5 has a plurality of long and rectangular mask patterns 19 arranged in a line along the longitudinal direction in the conveying direction indicated by an arrow A as shown in FIG. As shown in FIG. 2, it is formed by etching a non-transparent film 21 of, for example, Cr deposited on a transparent glass substrate 20, and the surface on which the opaque film 21 is formed faces downward. It is held by the mask stage 6 described above. For example, among the plurality of mask patterns 19, the left edge of the mask pattern 19a at the left end shown in FIG. 4 is set in advance as a reference position S2 for aligning with the reference position S1 of the color filter substrate 10. Yes.

A light source 2 is provided so that exposure light can be irradiated onto the photomask 5 held on the mask stage 6. The light source 2 emits ultraviolet rays, and is, for example, an ultrahigh pressure mercury lamp, a xenon lamp, an ultraviolet light emitting laser, or the like. Then, a convex lens 22 is disposed in front of the exposure light in the radial direction reflected by the concave mirror 3 so that the exposure light can be condensed.

A cylindrical lens 14 is disposed on the optical path between the light source 2 and the mask stage 6. This cylindrical lens 14 forms a linear beam at the focal position by refracting only in two uniaxial directions perpendicular to the incidence of parallel rays. The cylindrical surface is parallel to its central axis. The cross section of the luminous flux 12 of the exposure light emitted from the light source 2 (hereinafter simply referred to as “cross section”) is matched to the shape of the strip-shaped photomask 5. For example, as shown in FIG. 4, it becomes a beam cross-sectional shape shaping means for shaping from a circle (shown by a broken line in the figure) to an ellipse (shown by a solid line in the figure). Then, as shown in the figure, the central axis of the cylinder is photo-aligned so that the long axis of the shaped elliptical light beam 12 substantially coincides with the central axis in the longitudinal direction of the strip-shaped photomask 5. The mask 5 is arranged so as to substantially coincide with the central axis.

A kaleidoscope 15 is disposed on the optical path between the light source 2 and the cylindrical lens 14. The kaleidoscope 15 makes the brightness distribution of the exposure light irradiated to the photomask 5 uniform, is formed to a predetermined length, and has multiple sides parallel to its central axis. Each is a reflective surface. Then, the end 15a on the light source 2 side is substantially coincident with the focal point of the convex lens 22, and the end 15b on the cylindrical lens 14 side is It is made to substantially coincide with the focal point of a condenser lens 16 described later.

A condenser lens 16 is disposed on the optical path between the cylindrical lens 14 and the mask stage 6. The condenser lens 16 serves as a condenser lens that emits the light beam L of the exposure light incident thereon as parallel light beams parallel to each other. Thereby, the exposure light emitted from the condenser lens 16 irradiates the photomask 5 vertically. The exposure light passes through the photomask 5 in the vertical direction and vertically exposes the color resist on the color filter substrate 10. Therefore, the resolving power of the exposure pattern 23 (see FIG. 3) formed on the color filter substrate 10 is improved, and the exposure pattern 23 is sharply formed.

Next, the operation of the exposure apparatus configured as described above will be described.

First, with the color filter substrate 10 coated with a color resist being placed on the stage 13, the stage 13 is moved at a constant speed by the conveying means 27, and the color filter substrate 10 is indicated by an arrow A in FIG. Transport in the direction.

At this time, the mask stage 6 is controlled based on the image of the pixel 17 of the black trimmer 18 of the color filter substrate 10 imaged by an imaging camera (not shown), and the surface parallel to the upper surface of the stage 13 1 is moved in a direction perpendicular to the direction of arrow A shown in FIG. 1 and rotated (0) around the center axis of the surface of the photomask 5 to set a reference position preset on the color filter substrate 10. The reference position S2 (see FIG. 4) of the photomask 5 held on the mask stage 6 is positioned with respect to S1 (see FIG. 3).

At the same time, the light source 2 is turned on and exposure light is emitted from the light source 2, and the photomask 5 held on the mask stage 6 is irradiated by the exposure light. Then, the mask pattern 19 formed on the photomask 5 is transferred onto the color filter substrate 10 being conveyed in the direction of arrow A shown in FIG. As a result, as shown in FIG. 3, a striped exposure pattern 23 is formed on a predetermined pixel 17 of the black matrix 18 on the color filter substrate 10.

In this case, the exposure light emitted from the light source 2 is reflected forward by the concave mirror 3 and condensed at the focal point by the convex lens 22 provided in front of the light source 2. The condensed exposure light is incident on the light source 2 side end 15 a of the scope scope 15. And this callide scope 15 The light is mixed by multiple reflection at the side surface 15c parallel to the central axis in the longitudinal direction, and emitted from the end 15b on the cylindrical lens 14 side.

The exposure light emitted from the kaleidoscope 15 is incident on the cylindrical lens 14. At this time, of the exposure light emitted from the kaleidoscope 15, as shown in FIG. 1, in the surface 14a of the cylindrical lens 14, the direction perpendicular to the central axis of the cylinder (the left-right direction in the figure) The emitted light beam L is refracted inward so as to be narrowed and exits the cylindrical lens 14.

On the other hand, of the exposure light emitted from the kaleidoscope 15, as shown in FIG. 2, in the surface 14a of the cylindrical lens 14 in the direction along the central axis of the cylinder (the left-right direction in the figure). The emitted light beam L exits the cylindrical lens 14 without changing the radiation angle. Therefore, as shown by the broken line in FIG. 4, the exposure light of the light beam 12 having a polygonal cross section (shown as a circle in the figure) emitted from the kaleidoscope 15 is shown as a solid line in the figure. A cylindrical lens 14 shapes the light beam 12 into a flat shape (shown as an ellipse in the figure) with the long axis as the axis parallel to the central axis of the cylinder and the short axis as the axis perpendicular to the central axis. Is done.

In this way, the exposure light whose sectional shape of the light beam 12 is shaped into, for example, an elliptical circular force is incident on the condenser lens 16. In this case, the light beam L in the direction along the major axis of the elliptical cross section, that is, the light beam L radiated in the direction along the central axis of the cylindrical lens 14 is, as shown in FIG. It is emitted as parallel light parallel to the optical axis. On the other hand, the light beam L in the direction along the minor axis having an elliptical cross section is further focused by the condenser lens 16 as shown in FIG.

[0038] Here, the cylindrical lens 14 is arranged so that the central axis of the cylinder substantially coincides with the central axis in the longitudinal direction of the strip-shaped photomask 5 held by the mask stage 6, so that the condenser lens As shown in FIG. 4, the exposure light having an elliptical cross section emitted from 16 irradiates the photomask 5 with its long axis aligned with the central axis in the longitudinal direction of the strip-shaped photomask 5. . In this case, since the exposure light emitted from the light source 2 is collected on the photomask 5, the energy density of the exposure light that irradiates the photomask 5 is improved. Thereafter, the light beam L in the direction along the long axis of the exposure light having an elliptical cross section hangs down the photomask 5. Passing directly, the color resist on the color filter substrate 10 is exposed vertically. Therefore, among the exposure patterns 23 formed on the color filter substrate 10, the resolving power along the longitudinal direction of the strip-shaped photomask 5 is improved, and the exposure pattern 23 in the direction orthogonal to the arrow A shown in FIG. Edge 23a, 23b force S Sharp.

On the other hand, the light beam L in the direction along the short axis of the exposure light having an elliptical cross section passes obliquely through the photomask 5 and wraps around the lower side of the photomask 5, so that the color layer on the color filter substrate 10 is reflected. Expose the dies diagonally. Therefore, the resolving power in the direction orthogonal to the longitudinal direction of the strip-shaped photomask 5 in the exposure pattern 23 formed on the color filter substrate 10 is reduced, and the edge of the exposure pattern 23 in the direction of arrow A shown in FIG. Part 23c, 23d lose power. However, in this case, the exposure pattern 23 has a stripe shape extending in the direction of arrow A as shown in FIG. 3, and the blurs of the edge portions 23c and 23d in the direction of arrow A of the exposure pattern 23 are adjacent to each other. It has no effect on the color filter of the color. Therefore, blurring of the edge portions 23c and 23d in the direction of arrow A of the exposure pattern 23 is allowed.

In the above description, the force described in the case where the light beam cross-sectional shape of the exposure light radiated from the kaleidoscope 15 is circular is not limited to this, and the cross-sectional shape of the kaleidoscope 15 is rectangular. The light beam cross-sectional shape of the exposure light that is formed and emitted may be substantially rectangular. In addition, a light pipe may be used instead of the kaleidoscope 15.

FIG. 5 is a front view showing a second embodiment of the exposure apparatus according to the present invention. This exposure apparatus focuses on the optical path between the light source 2 and the mask stage 6 as a beam cross-sectional shape shaping means by performing a refracting action only in one of the two axes perpendicular to the incidence of the parallel light beam. A fly-eye lens 24 that forms a plurality of linear beams at a position is disposed, and a strip-like lens is provided together with a condenser lens 16 disposed on the optical path between the fly-eye lens 24 and the mask stage 6. The brightness distribution can be made uniform at the same time as the exposure light is collected on the photomask 5. Therefore, in the second embodiment, the kaleidoscope 15 provided in the first embodiment can be omitted.

[0042] As shown in Fig. 6 (a), a specific configuration example of the fly-eye lens 24 includes a minute convex cylindrical lens 25a on the end surface 24b on the condenser lens 16 side, and Fig. 6 (c). As shown by the broken line, the central axis of the cylinder is parallel to the Y axis in the XY plane. A first cylindrical lens array 25 arranged in four is formed. As shown in the figure, a second cylindrical lens array 26 is formed in which the central axis of the cylinder is parallel to the X axis and, for example, four are arranged in the Y axis direction.

Next, the path of the light beam in the direction along the X axis and the Y axis will be described. Of the exposure light beam L incident on the end surface 24a on the light source 2 side of the fly eye lens 24, the light beam L radiating in the X-axis direction and entering the second cylindrical lens array 26 shown in FIG. Without being refracted by the second cylindrical lens array 26 (actually, it is refracted so as to spread slightly outward), the first lens formed on the end surface 24b on the condenser lens 16 side. Is incident on the cylindrical lens array 25. Then, the light beam L is refracted inwardly so as to be narrowed down by the first cylindrical lens array 25 and is emitted from the end surface 24b on the condenser lens 16 side through the fly-eye lens 24.

[0044] On the other hand, out of the exposure light ray L incident on the end surface 24a on the light source 2 side of the fly-eye lens 24, it radiates in the Y-axis direction shown in Fig. 6 (c) and enters the second cylindrical lens array 26. The light beam L is refracted so as to be broadly spread by the second cylindrical lens array 26 and further spreads outward to be incident on the first cylindrical lens array 25 formed on the end surface 24b on the condenser lens 16 side. . The light beam L is not refracted by the first cylindrical lens array 25 (actually, it is refracted so as to be slightly squeezed inward), and the fly-eye lens 24 passes through the end surface 24b on the condenser lens 16 side. Eject. Therefore, the cross-sectional shape of the light beam of the exposure light emitted from the fly-eye lens 24 is a flat shape with the major axis in the Y-axis direction and the minor axis in the X-axis direction shown in FIG. Further, since the exposure light emitted from each of the minute cylindrical lenses 25a of the first cylindrical lens array 25 is superimposed on the photomask 5 to irradiate the photomask 5, the exposure light on the photomask 5 is irradiated. The luminance distribution becomes uniform.

Note that although the case where the exposure apparatus is a proximity exposure apparatus that exposes the photomask 5 and the object to be exposed in proximity has been described in the above embodiment, the present invention is not limited to this. However, the present invention can be applied to any exposure apparatus that uses a strip-shaped photomask 5. In the above description, the case where the object to be exposed is the color filter substrate 10 is described. As described above, any substrate may be used as long as the striped exposure pattern 23 is formed.

Claims

The scope of the claims

[1] a stage for placing an object to be exposed on the upper surface;

A mask stage disposed above the stage and capable of holding a strip-shaped photomask parallel to the upper surface of the stage;

A light source that emits exposure light to the photomask held on the mask stage, and the exposure light emitted from the light source cover is irradiated onto the object to be exposed through the photomask. An exposure apparatus for forming a predetermined exposure pattern at a position, wherein a cross-sectional shape of a light beam of exposure light emitted from the light source is formed on the optical path between the light source and the mask stage, and the shape of the strip-shaped photomask. An exposure apparatus comprising a light beam cross-sectional shape shaping means for shaping in accordance with the above.

[2] The light beam cross-sectional shape shaping means is a cylindrical lens that forms a linear beam at the focal position by refracting in only one of the two axes perpendicular to the incidence of parallel rays. The exposure apparatus according to claim 1.

[3] The beam cross-sectional shape shaping means is a fly-eye lens that forms a plurality of linear beams at a focal position by performing a refracting action only in one axial direction of two axes orthogonal to the incidence of parallel rays. The exposure apparatus according to claim 1, wherein:

[4] A kaleidoscope is provided on the optical path between the light source and the light beam cross-sectional shape shaping means to make the luminance distribution of the exposure light irradiated to the photomask uniform. The exposure apparatus according to claim 1.

5. The exposure according to claim 1, wherein a condensing lens that emits incident exposure light as parallel light is disposed on an optical path between the beam cross-sectional shape shaping means and the mask stage. apparatus.

[6] The stage is configured so that the object to be exposed is parallel to the surface of the strip-shaped photomask when exposure is performed by irradiating the object to be exposed placed on the upper surface with exposure light. 2. The exposure apparatus according to claim 1, wherein the exposure apparatus transports in a direction orthogonal to the longitudinal direction.

7. The exposure apparatus according to claim 1, wherein the strip-shaped photomask has a plurality of mask patterns arranged in a line along a longitudinal direction thereof.