JP2010092079A - Method for manufacturing liquid crystal display and exposure apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a liquid crystal display element having an improved viewing angle and a response speed. <P>SOLUTION: The method for manufacturing a liquid crystal display element includes: mounting a mask having two periodical patterns arranged in a first direction and a second direction different from each other; and transferring the mask pattern through a partial projection optical system onto a substrate by controlling the distribution of luminous energy of the exposure light on an pupil plane IPP of a partial illumination system in such a manner that on the pupil plane of the partial illumination system, the luminous energy increases in four regions (first to fourth regions) having a predetermined positional relation and an angular relation with the two periodical patterns. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a liquid crystal display element and an exposure apparatus that can be used to carry out this manufacturing method.

  In recent years, with the widespread use of various information display devices and information processing devices such as flat panel televisions, laptop computers and mobile phones, there has been a demand for higher performance display panels. In order to meet such demands, liquid crystal display elements (liquid crystal display) such as IPS (In Plane Switching) method and VA (Vertical Alignment: vertical alignment) method, etc., in which fine lattice patterns are formed on the electrodes of the display pixels Equipment) has been developed. In particular, in the VA liquid crystal display element, the pitch of the fine lattice pattern formed on the electrode or the electrode is as fine as about 6 μm in order to increase the display response speed, widen the viewing angle, and further improve the transmittance. (For example, refer to Patent Document 1).

In addition, in the MVA (Multi-domain Vertical Alignment) type liquid crystal display element in which each pixel is divided into a plurality of domains in order to further improve the viewing angle, the above-described fine lattice pattern is formed in each divided domain. Changing the periodic direction is performed (for example, refer to Patent Document 2).
By the way, a fine lattice pattern of a liquid crystal display element is formed by a lithography process, and in order to expose the entire surface of a large substrate such as a liquid crystal display element, an exposure apparatus equipped with a large-field projection optical system is required. It is. Therefore, a multi-lens type exposure apparatus has been developed in which the projection optical system is composed of a plurality of partial projection optical systems each having a numerical aperture of less than about 0.1 (for example, see Patent Document 3).

JP 2002-107730 A JP 2001-235748 A JP 2001-330964 A

  In a conventional liquid crystal display element in which a fine lattice pattern is formed on an electrode of a display pixel or the electrode, in order to further improve the response speed, it is necessary to further refine the pitch of the lattice pattern. However, in a conventional exposure apparatus for a liquid crystal display element such as a multi-lens method, the projection optical system (or partial projection optical system) requires a large field of view of 100 mm or more, so that the numerical aperture is increased (large NA). Therefore, it is difficult to form a lattice pattern with a finer pitch.

  In view of such circumstances, it is an object of an aspect of the present invention to provide a method for manufacturing a liquid crystal display element with an improved viewing angle and response speed, and an exposure apparatus that can be used to implement the method.

  According to the first aspect of the present invention, an element pattern including a first pattern and a second pattern, which are periodic patterns having a predetermined pitch and are arranged in different first and second directions, respectively, is formed. The mask is disposed on the object plane side of the projection optical system of the exposure apparatus, and the light quantity distribution of the exposure light on the pupil plane of the illumination system that illuminates the mask with the exposure light of the exposure apparatus or in the vicinity thereof, It is on a first straight line that passes through the optical axis of the illumination system and extends in a direction corresponding to the intermediate direction between the first direction and the second direction, and is in the opposite direction from the optical axis and with the optical axis. The first region and the second region including the first point and the second point that are equal to each other, and the second straight line that is orthogonal to the first straight line and in the opposite direction from the optical axis, the optical axis The third point that is equal to each other And the third region and the fourth region including the fourth point, and the light amount in the other region is larger than the light amount in the other region, and the element pattern of the mask is transferred to the liquid crystal display element through the projection optical system. There is provided a method of manufacturing a liquid crystal display element, including transferring the substrate to the substrate and processing the substrate on which the pattern is transferred.

  According to the second aspect of the present invention, in an exposure apparatus that exposes a substrate with exposure light through a mask pattern, an illumination system that illuminates the mask pattern with the exposure light, and a pupil of the illumination system The light quantity distribution of the exposure light on the surface or a surface in the vicinity thereof extends in a direction corresponding to an intermediate direction between the first direction and the second direction intersecting each other on the pattern surface of the mask through the optical axis of the illumination system. A first area and a second area that are on the first straight line and that are in opposite directions from the optical axis and that have the same distance from the optical axis; The amount of light in the third area and the fourth area on the second straight line orthogonal to each other and in the opposite directions from the optical axis and including the third point and the fourth point, which are equal to each other, is equal to the optical axis. Greater than the light intensity in other areas A light quantity distribution setting device which can be set in such a manner, a projection optical system comprising a plurality of partial projection optical systems for forming an image of the mask pattern on the surface of the substrate, and the plurality of partial projection optical systems for the mask An exposure apparatus is provided that includes a stage system that synchronizes movement in a predetermined direction and movement of the substrate in a direction corresponding to the predetermined direction.

  According to the method for manufacturing a liquid crystal display element of the present invention, light fluxes from the first region to the fourth region on the pupil plane of the illumination system or a surface in the vicinity thereof are illuminated onto the first pattern or the second pattern of the mask. Then, on the pupil plane of the projection optical system, the 0th-order light from the first pattern or the second pattern passes through a position conjugate with the region (a position away from the optical axis), and the first pattern or the second pattern. The 1st-order diffracted light from the pattern passes through a position away from the 0th-order light in a direction corresponding to the first direction or the second direction. Accordingly, since the images of the first pattern and the second pattern are formed on the substrate with high contrast, the pitch of the first pattern and the second pattern (fine lattice pattern) can be further miniaturized.

  In addition, according to the present invention, even when the same projection optical system is used, the projection optical system can be compared with a case where a normal illumination system in which zero-order light passes through a region centered on the optical axis of the projection optical system is used. Since the distance between the 0th order light and the 1st order diffracted light from the first pattern and the second pattern can be increased on the pupil plane, the pitch of the first pattern and the second pattern that can be transferred can be miniaturized. Therefore, since the pitch of the lattice pattern formed on the substrate can be reduced, a liquid crystal display element with improved response speed can be easily manufactured.

  Moreover, the manufacturing method of the liquid crystal display element of this invention can be implemented using the exposure apparatus of this invention.

(A) is expanded sectional view which shows schematic structure of the liquid crystal display element manufactured by an example of embodiment, (B) is sectional drawing of the BB 'part of FIG. 1 (A), (C) is embodiment of embodiment. It is an expanded sectional view showing a schematic structure of a liquid crystal display element of a modification. It is a perspective view which shows schematic structure of the exposure apparatus of an example of embodiment. It is a figure which shows the principal part of the illumination system of FIG. It is sectional drawing which shows one partial projection optical system of FIG. (A) is a diagram showing a part of the illumination system of FIG. 2, (B) is a side view showing the intensity distribution setting device 14b of FIG. 5 (A), and (C) is the aperture stop plate 12b of FIG. 5 (A). FIG. It is an enlarged view which shows a part of pattern of a 1st mask. (A) is a diagram showing a light amount distribution on the pupil plane of the illumination system that illuminates the first mask pattern, and (B) shows a distribution of diffracted light from the first mask pattern on the pupil plane of the projection optical system. FIG. FIG. 4 is an enlarged view showing a part of a TFT pattern forming surface of a glass substrate TG on the TFT side of a liquid crystal display element being manufactured in an example of an embodiment. It is an enlarged view which shows a part of pattern formation surface of glass substrate TG by the side of TFT in the state where formation of the fine lattice pattern was completed in an example of an embodiment. FIG. 10 is an enlarged view showing a change in a pattern formed on the glass substrate TG of FIG. 9, wherein (A), (C), (E), and (G) are enlarged views showing circuit patterns near the transistor TR5 in FIG. FIGS. 9B, 9D and 9H are enlarged cross-sectional views of the vicinity of the transistor TR5 in the AA ′ portion of FIG. FIG. 10 is an enlarged cross-sectional view of a B-B ′ portion of FIG. 9 showing a part of a liquid crystal display element completed in an example of an embodiment. It is a flowchart which shows the manufacturing process of the liquid crystal display element of an example of embodiment. It is an enlarged view which shows a part of pattern of the 2nd mask used in the modification of embodiment.

An example of an embodiment of the present invention will be described with reference to FIGS.
FIG. 1A is an enlarged view showing a schematic configuration in one display pixel of a liquid crystal display element (liquid crystal display device) 20 of an active matrix drive type by a VA (Vertical Alignment) method manufactured in this embodiment. FIG. 1B is a cross-sectional view of the BB ′ portion of FIG. 1A. 1A, a liquid crystal display element 20 basically includes a liquid crystal layer 22 containing liquid crystal molecules 22a, a TFT (Thin Film Transistor) side glass substrate 21A that sandwiches the liquid crystal layer 22, and a color filter side glass substrate. 21B, a transparent pixel electrode 23A formed on the upper surface of the glass substrate 21A, and a transparent counter electrode 23B formed on the bottom surface of the glass substrate 21B so as to face the pixel electrode 23A. The pixel electrode 23A and the counter electrode 23B are made of ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), respectively.

  Further, the liquid crystal display element 20 has a fine period formed in a predetermined direction at a predetermined pitch so as to deform the electric field pattern formed between the electrodes 23A and 23B on the surface of the pixel electrode 23A formed on the glass substrate 21A. As a fine periodic structure, the first lattice pattern 24A as a typical structure and the surface of the counter electrode 23B formed on the glass substrate 21B are formed so that the phase of the lattice pattern 24A differs from that of the lattice pattern 24A by approximately 180 °, for example. The third lattice pattern 24C is provided. The lattice patterns 24A and 24C are periodic convex patterns. Note that, within one display pixel of the liquid crystal display element 20, for example, it is finely connected to or adjacent to the lattice patterns 24A and 24C and different in the periodic direction at the same pitch as the lattice patterns 24A and 24C. Second and fourth lattice patterns (not shown) as periodic structures are also formed. These first to fourth lattice patterns 24A, 24C and the like are formed of a dielectric (insulating material) or a conductive material. The lattice patterns 24A, 24C and the like are preferably formed of a material transparent to visible light, for example, so that the light beam introduced into the liquid crystal display element 20 can pass through.

In the present embodiment, the pitch of the lattice patterns 24A, 24C and the like is preferably 3 to 5 μm as an example. Within that range, as an example, the line widths of the lattice patterns 24A, 24C, etc. are about 2 μm and the pitch is about 4 μm. However, the pitch of the lattice patterns 24A, 24C, etc. can be 3 μm or less or 5 μm or more.
Furthermore, the liquid crystal display element 20 includes a molecular alignment film 25A formed on the surface of the pixel electrode 23A so as to cover the lattice pattern 24A, and a molecular alignment film 25B formed on the surface of the counter electrode 23B so as to cover the lattice pattern 24C. And a polarizing film (polarizer) 26A formed on the lower surface of the glass substrate 21A and having a first light absorption axis P (see FIG. 1B), and a first light absorption formed on the upper surface of the glass substrate 21B. And a polarizing film (analyzer) 26B having a second light absorption axis A orthogonal to the axis P. The molecular alignment films 25A and 25B are in contact with the liquid crystal layer 22, and the liquid crystal molecules 22a in the liquid crystal layer 22 are in a non-driven state where no electric field is applied between the pixel electrode 23A and the counter electrode 23B. Restrict in a direction substantially perpendicular to the surface. Therefore, in the non-driven state, the light beam incident on the liquid crystal display element 20 is substantially shielded.

  As an example, the liquid crystal layer 22 can be a liquid crystal having negative dielectric anisotropy commercially available from Merck, and the molecular alignment films 25A and 25B are vertical alignment films provided by JSR. Can be used. In a typical example, the glass substrates 21A and 21B are assembled using appropriate spacers so that the liquid crystal layer 22 has a thickness of about 4 μm. Further, as an example, the lattice patterns 24A, 24C and the like (fine periodic structure) can be formed from a positive photoresist which is a transparent dielectric, and as such a photoresist, a positive resist PC403 manufactured by JSR Corporation. Etc. can be used. The grid patterns 24A and 24C are preferably formed to a thickness of about 0.4 μm, for example.

  FIG. 1B shows an alignment state of the liquid crystal molecules 22a on the surface of the glass substrate 21A in a driving state of the liquid crystal display element 20 in which a driving voltage is applied between the pixel electrode 23A and the counter electrode 23B. In FIG. 1B, the extending direction (direction orthogonal to the periodic direction) of each line pattern of the lattice pattern 24A intersects the light absorption axes P and A by the polarizing films 26A and 26B at 45 °. . Further, the liquid crystal molecules 22a are aligned in a state of being tilted in the extending direction of the lattice pattern 24A due to the effect of the locally deformed electric field formed by the lattice pattern 24A. Therefore, the transmittance of the liquid crystal display element 20 in the display pixel with respect to the incident light flux is increased. Actually, a second lattice pattern (not shown) having a periodic direction different from that of the first lattice pattern 24A is formed in each display pixel. The liquid crystal molecules 22a are tilted in the first and second lattice patterns. Due to the difference, the liquid crystal display element 20 exhibits a wide viewing angle characteristic.

  Further, when such a driving electric field is formed, the individual liquid crystal molecules 22a are tilted in the extending direction of the lattice pattern 24A and the like, so that the tilt of the liquid crystal molecules need not propagate from one region to another region. The response speed will be very fast. Furthermore, in this embodiment, since the pitch of the lattice pattern 24A and the like is 3 to 5 μm, which is finer than the conventional one, a higher response speed can be obtained.

  As a modification of the present embodiment, as shown by the liquid crystal display element 20A in FIG. 1C, a fine periodic structure is formed by a periodic concave pattern formed on the pixel electrode 23A of the glass substrate 21A. The first lattice pattern 24E and the third lattice pattern 24G made of a periodic concave pattern formed on the counter electrode 23B of the glass substrate 21B may be used. The grid patterns 24E and 24G are cut-out patterns formed on the pixel electrode 23A and the counter electrode 23B. Also in this configuration example, the second grating pattern (not shown) and the fourth grating pattern are connected to or close to the grating patterns 24E and 24G, and the periodic directions are different at the same pitch as the grating patterns 24E and 24G. A lattice pattern (not shown) is formed. Also in this configuration example, the pitch of the lattice patterns 24E and 24G is preferably 3 to 5 μm.

  Further, a molecular alignment film 25A is formed on the surface of the pixel electrode 23A of the glass substrate 21A so as to cover the lattice pattern 24E, and a molecular alignment film 25B is formed on the surface of the counter electrode 23B of the glass substrate 21B so as to cover the lattice pattern 24G. Has been. Also in the liquid crystal display element 20A, since the lattice patterns 24E, 24G and the like are provided, a wide viewing angle characteristic can be obtained and a high response speed can be obtained.

  Next, a manufacturing method of the liquid crystal display element 20 in the present embodiment will be described. In the liquid crystal display element 20, the portions other than the lattice patterns 24A and 24C can be manufactured by a well-known technique, and the lattice pattern 24C can be manufactured in the same manner as the lattice pattern 24A. A method for manufacturing adjacent lattice patterns will be described.

First, the configuration of an exposure apparatus used in a lithography process for manufacturing the liquid crystal display element 20 will be described with reference to FIGS.
2 is a perspective view schematically showing the overall configuration of the exposure apparatus EX according to the present embodiment, FIG. 3 is a diagram schematically showing the configuration of the illumination system ILS in FIG. 2, and FIG. 4 is a diagram in FIG. It is a figure which shows schematically the structure of each partial projection optical system (projection optical unit) which comprises the projection optical system PL. The exposure apparatus EX moves the mask M and the substrate PT with respect to the projection optical system PL composed of a plurality of catadioptric partial projection optical systems, and the pattern of the mask M is applied to the surface of the substrate PT coated with a photoresist. This is a multi-lens scanning exposure apparatus that performs projection exposure.

  Note that the pattern surface of the mask M and the surface of the substrate PT are substantially parallel during exposure. 2 to 4 and the like, the X axis is set along the moving direction (scanning direction) of the mask M and the substrate PT at the time of scanning exposure in a plane parallel to the pattern surface of the mask M (substantially horizontal plane in the present embodiment). A description will be given by setting, setting the Y axis along the direction orthogonal to the X axis (non-scanning direction), and setting the Z axis in the direction orthogonal to the X axis and the Y axis.

  2 and 3, the exposure apparatus EX includes a light source 1 including, for example, an ultra-high pressure mercury lamp that generates illumination light (exposure light) for exposure, and a predetermined plurality of pattern surfaces of the mask M using the exposure illumination light. An illumination system ILS that illuminates the illumination area with a uniform illuminance distribution, a mask stage MS that moves the mask M in parallel with the XY plane via a mask holder (not shown), and an image of the pattern of the mask M A projection optical system PL formed on the surface of the substrate PT and a substrate stage PS (see FIG. 4) that holds and moves the substrate PT are provided. The illumination light emitted from the light source 1 at the first focal position of the elliptical mirror 2 forms a light source image at the second focal position of the elliptical mirror 2 via the elliptical mirror 2 and the mirror 3. A shutter (not shown) is disposed in the vicinity of the second focal position.

  The illumination light that has passed through the open shutter enters the first relay lens system 5 including the wavelength selection filter 6 that transmits only the light flux in a desired wavelength range along the optical axis AX0. The wavelength selection filter 6 selects i-line (wavelength 365 nm) as an example of illumination light (exposure light) for exposure. Note that the wavelength selection filter 6 may simultaneously select g-line (wavelength 436 nm), h-line (wavelength 405 nm), and i-line as exposure light. Further, in the wavelength selection filter 6, for example, the g-line and the h-line may be selected simultaneously, or the h-line and the i-line may be selected simultaneously.

As described above, when the pitch of the lattice patterns 24A, 24C and the like formed on the liquid crystal display element 20 is set to 3 to 5 μm using the exposure apparatus EX, the wavelength of the exposure light is 365 to 486 nm (0.365 to 0. (486 μm) is preferable.
The illumination light that has passed through the first relay lens system 5 enters the incident end 8 a of the light guide 8 via the second relay lens system 7. The light guide 8 is a random light guide fiber formed by bundling a large number of optical fiber strands at random, and has the same number of incident ends 8a as the number of light sources 1 (one in FIG. 2) and the projection optical system PL. The number of exit ends 8b to 8f (only the exit end 8b is shown in FIG. 3) is the same as the number of partial projection optical systems (5 in FIG. 2). In this way, the illumination light incident on the incident end 8a of the light guide 8 propagates through the inside thereof and then exits from the five exit ends 8b to 8f. The illumination system ILS has a plurality (here, five) partial illumination systems arranged between the emission ends 8b to 8f and the mask M.

  In FIG. 3, the divergent light beam emitted from the exit end 8b of the light guide 8 is converted into a substantially parallel light beam by the collimator lens 10b in the partial illumination system 81, and then enters the fly eye integrator (optical integrator) 11b. . The fly's eye integrator 11b is formed by arranging a large number of lens elements having positive refractive powers vertically and horizontally and densely so that the central axis extends along the optical axis AXI. The light beam incident on the fly eye integrator 11b is wavefront divided by a large number of lens elements, and the pupil plane of the partial illumination system 81 (hereinafter referred to as the illumination pupil plane) IPP, which is the rear focal plane (surface in the vicinity of the exit plane). A surface light source comprising a number of secondary light sources is formed.

  A slidable aperture stop plate 12b having a plurality of aperture stops is disposed on the illumination pupil plane IPP (or a surface in the vicinity thereof). Illumination light emitted from the fly eye integrator 11b and passing through one aperture stop in the aperture stop plate 12b passes through the condenser lens system 13b in the Y direction of the pattern surface of the mask M in the shape of each element of the fly eye integrator. Illuminates a long, roughly rectangular illumination area similar to. The illumination pupil plane IPP is optically Fourier-transformed with respect to the pattern surface of the mask M. That is, the illumination light emitted from an arbitrary point on the illumination pupil plane IPP becomes substantially parallel light and enters the pattern surface of the mask M with an incident angle corresponding to the position of the arbitrary point. In other words, the illumination light applied to an arbitrary point on the pattern surface of the mask M is applied to the pattern surface of the mask M at an incident angle corresponding to the position of the illumination light on the illumination pupil plane IPP. By the aperture stop in the aperture stop plate 12b, the projection optical system corresponding to the shape of the secondary light source and the maximum numerical aperture NAIL of the light beam incident on the mask M from the partial illumination system 81 (in this embodiment, the partial projection optical system PL1). ) Is determined as a coherence factor (σ value) (= NAIL / NAin), which is a ratio of the numerical aperture NAin to the numerical aperture NAin on the incident side.

A partial illumination system 81 is configured including optical members from the collimating lens 10b to the condenser lens system 13b. Similarly, a partial illumination system having the same configuration as the partial illumination system 81 (only the condenser lens system is shown in FIG. 2) is arranged between the emission ends 8c to 8f and the mask M in FIG. Yes.
FIG. 5A shows a more detailed configuration of the partial illumination system 81 and the partial illumination system 83 downstream of the exit end 8d in FIG. In FIG. 5A, an intensity distribution setting device 14b is arranged between the collimating lens 10b and the fly eye integrator 11b. FIG. 5B is a side view of the intensity distribution setting device 14b viewed from the + Y direction. In FIG. 5B, the intensity distribution setting device 14b has a configuration in which two prisms 15A and 15B each having a concave and convex pyramidal cross-sectional shape in the XZ plane are arranged along an axis parallel to the optical axis AXI. The first distribution setting unit 15, the flat plate-like second distribution setting unit 16 for aligning the optical path length, and the first distribution setting unit 15 and the second distribution setting unit 16 are alternately installed in the optical path of the illumination light IL. And a slide type drive unit 17. When the first distribution setting unit 15 is installed in the optical path of the illumination light IL, the illumination light IL includes four light beams ILA and ILB separated in the X direction and two light beams (not shown) separated in the Y direction. Since it becomes a light beam and enters the fly eye integrator 11b, high illumination efficiency is obtained when performing quadrupole illumination (details will be described later) along an axis parallel to the X axis and the Y axis. The second distribution setting unit 16 is installed in the optical path of the illumination light IL when a normal illumination method is used.

Further, an interval adjusting unit that adjusts the interval between the two prisms 15A and 15B of the first distribution setting unit 15 may be further provided. In this case, higher illumination efficiency can be obtained by adjusting the distance between the prisms 15A and 15B in accordance with the distance between the quadrupole secondary light sources along the axis parallel to the X axis and the Y axis.
Further, as shown in FIG. 5C, the aperture stop plate 12b has four circular openings 18Aa, 18Ab, 18Ac, and 18Ad arranged on axes parallel to the X-axis and Y-axis, respectively. A stop 18A and an aperture stop 18B for normal illumination having a circular opening are formed. By moving the aperture stop plate 12b in the X direction by a slide-type drive unit (not shown), one of the aperture stops 18A and 18B is set on the illumination pupil plane IPP of the exit surface of the fly eye integrator 11b. it can. The detailed shapes of the aperture stops 18A and 18B will be described later. The aperture stop plate 12b may be exchanged according to the pattern formed on the mask to be exposed.

Further, when the shape of the secondary light source on the illumination pupil plane IPP can be set to a required shape with high accuracy by the distribution setting units 15 and 16, etc., it is not always necessary to set an aperture stop on the illumination pupil plane IPP. .
Similarly to the partial illumination system 81, the partial illumination system 83 on the exit end 8d side is the same as the intensity distribution setting device 14d, the fly eye integrator 11d, and the aperture stop plate 12b having the same configuration as the collimating lens 10d and the intensity distribution setting device 14b. The aperture stop plate 12d and the condenser lens system 13d are configured. The partial illumination system 83 having the optical axis AXId also sets the shape of the secondary light source on the illumination pupil plane IPPd on the exit surface of the fly eye integrator 11d in the same manner as the partial illumination system 81. The same applies to other partial illumination systems.

Note that by providing a condensing lens for condensing each of the four illumination light beams divided by the prisms 15A and 15B between the prism 15B and the fly-eye lens 11b, the utilization efficiency of the illumination light IL is further increased. You can also. For example, the condenser lens has four positive refractive power lenses whose centers coincide with the centers of the two light beams ILA and ILB in FIG. 5B and the two light beams (not shown) separated in the Y direction. And it is sufficient.
In the above embodiment, the center positions of the four illumination light beams ILA, ILB, etc. on the illumination pupil plane IPP are all equidistant from the optical axis AXI, but it is not necessary that all the distances are equal. . For example, the distance from the optical axis of each light beam can be changed by making the inclination angles of the four inclined surfaces of the two pyramid prisms 15A and 15B as the first distribution setting unit 15 different.

In the above embodiment, the shape of the secondary light source on the illumination pupil plane IPP is such that the illumination light is in the vicinity of a total of four points, two points separated from the optical axis AXI in the X direction and two points separated in the Y direction. Although the intensity distribution is assumed to increase, this direction is not limited to the X direction and the Y direction, and may be an intermediate direction between the X direction and the Y direction. Furthermore, it can be set in any direction according to the pattern formed on the mask to be exposed.
The five partial illumination systems in FIG. 2 illuminate five generally rectangular regions arranged in two rows in the Y direction on the pattern surface (lower surface) of the mask M. In the above example, in the illumination system ILS, the illumination light from the light source 1 is equally divided into five illumination lights through the light guide 8, but the number of divisions is arbitrary.

Illumination light from each illumination area of the mask M is received from a plurality of (a total of five in FIG. 1) partial projection optical systems PL1 to PL5 arranged in two rows along the Y direction so as to correspond to each illumination area. Is incident on the projection optical system PL. The configurations of the partial projection optical systems PL1 to PL5 are the same. The numerical apertures of the partial projection optical systems PL1 to PL5 are, for example, between 0.1 and 0.07. Hereinafter, the configuration of each partial projection optical system will be described with reference to FIG.
The partial projection optical system shown in FIG. 4 is arranged in the vicinity of the first imaging optical system K1 that forms a primary image of the mask pattern based on the light from the mask M and the primary image, and the partial projection optical system in the mask M A field stop FS that defines a trapezoidal shape of the field area (illumination area) and the projection area (exposure area) of the partial projection optical system on the substrate PT, and an erect image (2) of the mask pattern based on the light from the primary image And a second imaging optical system K2 for forming a next image) on the substrate PT.

  The first imaging optical system K1 includes a first right-angle prism PR1 having a first reflection surface that reflects light incident in the −Z direction from the mask M in the −X direction, and the −X direction in order from the first right-angle prism PR1 side. And a first refractive optical system G1P having a positive refractive power and a first concave reflecting mirror MI1. The light incident on the first right-angle prism PR1 in the + X direction from the first concave reflecting mirror MI1 is reflected in the −Z direction by the second reflection surface of the first right-angle prism PR1.

  On the other hand, the second imaging optical system K2 sequentially includes a second right-angle prism PR2 having a first reflection surface that reflects light incident in the −Z direction from the field stop FS in the −X direction and the second right-angle prism PR2 side. A second refractive optical system G2P having a positive refractive power and a second concave reflecting mirror MI2 disposed in the −X direction; The light incident on the second right-angle prism PR2 in the + X direction from the second concave reflecting mirror MI2 is reflected in the −Z direction by the second reflection surface of the second right-angle prism PR2 and enters the substrate PT. In addition, parallel plane plates DP1 and DP2 as image shifters are disposed in the vicinity of the pattern surface of the mask M and in the vicinity of the field stop FS, respectively.

  In the partial projection optical system, the first imaging optical system K1 forms a primary image with a lateral magnification of +1 in the X direction and a lateral magnification of -1 in the Y direction, and the second imaging optical system K2 in the X direction. A primary image is formed with a lateral magnification of +1 and a lateral magnification in the Y direction of -1. Therefore, the image of the mask pattern formed on the substrate PT via each partial projection optical system is an equal-size erect image. Each partial projection optical system is a telecentric optical system on substantially both sides. The configuration of each partial projection optical system is arbitrary, and each partial projection optical system may be configured from a refractive system.

  In FIG. 2, an erect image equal to the mask pattern is formed in a plurality of trapezoidal exposure regions arranged in two rows in the Y direction so as to correspond to each illumination region on the surface of the substrate PT. Further, the mask stage MS of FIG. 3 is provided with a scanning drive system (not shown) having a long stroke for moving the stage along the X direction which is the scanning direction. Also, a pair of drive systems (not shown) are provided for moving the mask stage MS by a minute amount along the non-scanning direction (Y direction) and rotating the mask stage MS by a minute amount around an axis parallel to the Z axis. Yes. Then, the position coordinates of the mask stage MS are measured by a laser interferometer MIF using a moving mirror, and the position control of the mask stage MS is performed based on the measurement result.

  A similar stage drive system is also provided in the substrate stage PS of FIG. That is, a scanning drive system (not shown) having a long stroke for moving the substrate stage PS along the scanning direction (X direction) and the substrate stage PS is moved by a minute amount along the non-scanning direction (Y direction). And a pair of drive systems (not shown) for rotating the axis around the axis parallel to the Z axis by a minute amount. Then, the position coordinate of the substrate stage PS is measured by a laser interferometer PIF using a moving mirror, and the position control of the substrate stage PS is performed based on the measurement result.

Further, in FIG. 2, as a means for relatively aligning the mask M and the substrate PT along the XY plane, a pair of, for example, an image processing type alignment system AL is disposed above the mask M.
In this way, the mask M and the substrate PT are integrated with each other with respect to the projection optical system PL including the plurality of partial projection optical systems PL1 to PL5 by the scanning drive system on the mask stage MS side and the scanning drive system on the substrate stage PS side. By moving in the direction (X direction), the entire image of the pattern area of the mask P is sequentially transferred (scanned exposure) to the entire surface of each pattern formation area of the substrate PT. The shape and arrangement of the plurality of trapezoidal exposure areas and the shape and arrangement of the plurality of generally rectangular illumination areas are described in detail in, for example, Japanese Patent Application Laid-Open No. 7-183212.

  Next, in order to form a lattice pattern 24A or the like as a fine periodic structure on the glass substrate 21A on the TFT side of the liquid crystal display element 20 of FIG. 1A, the element pattern shown in FIG. 6 was formed. Mask M1 is arranged on the object plane (upper surface of mask stage MS) of projection optical system PL of exposure apparatus EX. In the pattern area of the mask M1, a plurality of positions P (i, j) arranged in I rows × J columns (I and J are each an integer of about several hundreds to 1,000, for example) at predetermined intervals in the X and Y directions. A pixel region 30 corresponding to each display pixel of the liquid crystal display element 20 is arranged around (i = 1 to I, j = 1 to J). The plurality of pixel areas 30 are element patterns for one liquid crystal display element (liquid crystal display panel), and the pattern area of the mask M1 includes a plurality of liquid crystal displays at predetermined intervals in the X direction and the Y direction. Element patterns for elements are formed.

  FIG. 6 shows an enlarged view of the pixel region 30 for 2 rows × 2 columns located at positions P (i, j) to P (i + 1, j−1) among the plurality of pixel regions 30. In FIG. 6, the X axis and the Y axis are respectively set in parallel to the directions corresponding to the light absorption axes P and A in FIG. 1B due to the polarizing films 26 </ b> A and 26 </ b> B of the liquid crystal display element 20. In this case, each pixel region 30 is a rectangular region elongated in the Y direction and surrounded by two sides parallel to the X axis and two sides parallel to the Y axis. In each pixel region 30, the first periodic pattern 31 </ b> S is formed on the + Y side and the second periodic pattern 31 </ b> R is formed on the −Y side with the light transmission portion as a background.

  The first periodic pattern 31S is a line-and-space pattern (hereinafter referred to as an L & S pattern) formed at a pitch P1 parallel to a direction S1 (first direction) that intersects the X axis clockwise at an angle θ. The second periodic pattern 31R is an L & S pattern formed at a pitch P1 parallel to a direction R1 (second direction) that intersects the X axis counterclockwise at an angle θ.

  In this case, the first periodic pattern 31S is a pattern constituting the first lattice pattern 24A of FIG. 1A, and the second periodic pattern 31R constitutes a second lattice pattern (not shown). Pattern. The angle formed by the periodic direction (direction S1) of the periodic pattern 31S and the periodic direction (direction R1) of the periodic pattern 31R is 2θ, and the intermediate direction between the direction S1 and the direction R1 is a direction parallel to the X axis. It is. Further, the angle θ can take any value within the range of (0 ° <θ <90 °), but in the present embodiment, the angle θ is 45 °. Therefore, the direction S1 and the direction R1 are orthogonal. Note that the angle θ1 may be different from the angle θ2, where θ1 is an angle that the direction S1 is clockwise with respect to the X axis, and θ2 is an angle that the direction R1 is clockwise with respect to the X axis. Furthermore, both the direction S1 and the direction R1 can be set to different angles clockwise (or counterclockwise) with respect to the X axis.

  Since the magnification β of the projection optical system PL of the present embodiment is equal, the pitch P1 is the same as the pitch of the lattice pattern 24A and the like, and the preferable range of the pitch P1 is 3 to 5 μm. When the magnification β of the projection optical system PL is not equal, the pitch P1 is set to 1 / β times the pitch of the lattice pattern 24A or the like.

  When the exposure apparatus EX projects the pattern of the mask M1 onto the substrate PT via the projection optical system PL, the amount of illumination light IL on the illumination pupil plane IPP of the partial illumination system 81 in FIG. 5A of the illumination system ILS. The distribution is set so that the light amount (integrated value) in the four circular regions 43A, 43B and 45A, 45B indicated by the oblique lines in FIG. 7A is larger than the light amount (integrated value) in the other regions. Is done. The light amount distribution on the illumination pupil plane of all other partial illumination systems 83 and the like is also set to the same distribution as the light amount distribution of the illumination light IL on the illumination pupil plane IPP.

  In FIG. 7A, the origins of the X axis and the Y axis are set to the optical axis AXI of the partial illumination system 81. Further, since the illumination pupil plane IPP of the partial illumination system 81 and the pattern surface of the mask are in an optical Fourier transform relationship, the light beam passing through a position away from the optical axis AXI in the predetermined direction DILS on the illumination pupil plane IPP The light is incident on the pattern surface of the mask (for example, mask M1) in a direction DM corresponding to the direction DILS. In other words, the projection of the light flux on the pattern surface is parallel to the direction DM. Hereinafter, it is said that the direction DM on the pattern surface of the mask having such a relationship and the direction DILS on the illumination pupil plane IPP are in correspondence with each other.

  In the partial illumination system 81 of FIG. 5 (A), since there is only the condenser lens system 13b between the illumination pupil plane IPP and the mask pattern plane, it is on the illumination pupil plane IPP corresponding to a predetermined direction of the mask pattern plane. The direction of is parallel to the predetermined direction. Accordingly, the direction on the illumination pupil plane IPP corresponding to the direction parallel to the X axis of the mask pattern surface is parallel to the X axis. Needless to say, when a folding mirror is arranged between the illumination pupil plane IPP and the mask, the corresponding relationship changes with respect to a simple spatial relationship due to the reversal effect of the mirror.

  In FIG. 7A, a circumference 46 centered on the optical axis AXI is an area where the numerical aperture NAin on the incident side of the corresponding partial projection optical system PL1 is the same as the numerical aperture of the emitted illumination light. Accordingly, the circumference 46 is a region where the coherence factor (σ value) is 1. In addition, the directions on the illumination pupil plane IPP corresponding to the directions S1 and R1 which are the periodic directions of the two periodic patterns 31S and 31R of the mask M1 in FIG. 6 are the directions S2 and R2, respectively. In this case, the direction on the illumination pupil plane IPP corresponding to the intermediate direction (X direction) between the directions S1 and R1 in FIG. 6 is also the X direction. Accordingly, in FIG. 7A, the direction S2 intersects the X axis clockwise at an angle θ, and the direction R2 intersects the X axis counterclockwise at an angle θ.

Then, the regions 43A and 43B on the X axis among the four circular regions 43A and 43B and 45A and 45B that are shaded, which is a region with a large light amount distribution on the illumination pupil plane IPP, are in the direction S2 from the optical axis AXI. Assuming two symmetric straight lines 40S and 40SB passing through the point of distance D1 and orthogonal to the direction S2, along the circumference of a predetermined radius r centering on the intersections 42A and 42B between the straight lines 40S and 40SB and the X axis It is an enclosed area.
In this case, the wavelength D of the illumination light is λ, the numerical aperture of the illumination light (illumination system ILS or partial illumination system 81) is used as a unit, and the distance D1 is expressed as follows using the pitch P1 of the periodic patterns 31S and 31R in FIG. Is set as follows.
D1 = λ / (2 · P1) (1)
Since the angle formed by the direction S2 and the X axis is θ, the distance D2 between the centers 42A and 42B and the optical axis AXI is as follows.
D2 = D1 / cos θ = λ / (2 · P1 · cos θ) (2)

Further, the regions 45A and 45B on the Y axis are regions surrounded by a circumference having a predetermined radius r centering on intersections 44A and 44B between the two straight lines 40S and 40SB and the Y axis.
At this time, the distance D3 between the centers 42A and 42B and the optical axis AXI is as follows.
D3 = D1 / sin θ = λ / (2 · P1 · sin θ) (3)
In this embodiment, the amount of light in the two regions 43A and 43B disposed along the X axis passing through the optical axis AXI and the two regions 45A and 45B disposed along the Y axis is large. This can be called quadrupole illumination on the XY axis. As an example, the radius r of the regions 43A and 43B and the regions 45A and 45B is preferably set to 0.2 to 0.3 as follows, with the radius of 1 as the unit.
r = 0.2-0.3 (4)

As an example, the regions 43A and 43B and the regions 45A and 45B have the same uniform light amount distribution, and the regions 43A and 43B and the regions 45A and 45B out of the amount of illumination light passing through the circumference 46 are respectively. It is preferable that the integral value of the amount of illumination light passing through the interior is about 90% or more and the integral value of the amount of illumination light passing through the other region is about 10% or less. Further, for example, the radius of the regions 43A and 43B and the radius of the regions 45A and 45B may be different within a range satisfying the expression (4).
In place of the regions 43A, 43B, 45A, 45B, illumination conditions are used in which the amount of light is large in a small oval, rectangular, or fan-shaped region having substantially the same area as the regions 43A, 43B, 45A, 45B. May be.

  When a large number of patterns (periodic patterns 31S and 31R) of the mask M1 in FIG. 6 are illuminated with illumination light having a light amount distribution on the illumination pupil plane IPP in FIG. 7A, a partial projection optical system having a corresponding numerical aperture NA. The distribution of diffracted light on the pupil plane PP of PL1 (a plane conjugate with the exit pupil) is as shown in FIG. The distribution of diffracted light on the pupil planes of the other partial projection optical systems PL2 to PL5 is also the same as that in FIG. Since the partial projection optical system PL1 has the same magnification, the numerical aperture NAin on the incident side and the numerical aperture NA on the emission side are equal. Moreover, since the pupil plane PP is optically conjugate with the illumination pupil plane IPP, the coordinate axes on the pupil plane PP corresponding to the X axis and the Y axis on the illumination pupil plane IPP are set as the X axis and the Y axis, respectively.

In the pupil plane PP of FIG. 7B, a circumference 46P is an area through which illumination light having a numerical aperture NA conjugate with the circumference 46 (σ = 1) of the illumination pupil plane IPP passes. At this time, the light beams emitted from the regions 43A, 43B, 45A, and 45B in FIG. 7A and passed without being diffracted by the periodic patterns 31S and 31R in FIG. 6 (0th-order light) Passes through the regions 47A, 47B, 48A, and 48B on the pupil plane PP, respectively.
Then, for example, one of the first-order diffracted lights emitted from the region 43A and diffracted by the periodic pattern 31S has an angle θ clockwise from the + X direction with respect to the region 47A according to the direction and pitch of the periodic pattern 31S. In the intersecting direction, the distance λ / P1, that is, the region 48A that is a position away from the expression (2) by 2 · D1 is passed. On the other hand, one of the first-order diffracted lights emitted from the region 43A and diffracted by the periodic pattern 31R intersects the region 47A counterclockwise from the + X direction at an angle θ according to the direction and pitch of the periodic pattern 31R. In this direction, the region 48B that is a position separated by the distance λ / P1 is passed.

Similarly, the first-order diffracted light generated from the periodic patterns 31S and 31R by the illumination light emitted from the region 43B of the illumination pupil plane IPP passes through the region 48B and the region 48A, respectively.
Next, regarding one of the first-order diffracted light generated from the periodic pattern 31S by the illumination light emitted from the region 45A of the illumination pupil plane IPP, −X with respect to the region 48A due to the pitch and directionality of the periodic pattern 31S. The region 47A, which is a position separated by a distance λ / P1, is passed in a direction crossing at an angle θ counterclockwise from the direction. Similarly, one of the first-order diffracted light generated from the periodic pattern 31R by the illumination light emitted from the region 45A passes through the region 47B in the same manner.

Therefore, from the first periodic pattern 31S or the second periodic pattern 31R in the multiple patterns of FIG. 6 by irradiation of illumination light beams from the four regions 43A, 43B, 45A, and 45B on the illumination pupil plane IPP. The generated 0th-order light and one first-order diffracted light both pass through the pupil plane PP, that is, pass through the partial projection optical system PL1, and enter the surface of the substrate PT. Then, interference fringes of 0th-order light and 1st-order diffracted light, that is, high-contrast images of the first periodic pattern 31S and the second periodic pattern 31R are formed on the substrate PT. Therefore, a fine periodic pattern can be exposed with high resolution.
Further, the four 0th-order lights and the four first-order diffracted lights all pass through any one of the four regions 45A, 45B, 47A, and 47B that are substantially equidistant from the optical axis AX on the pupil plane PP. That is, the light is incident on the surface of the substrate PT at substantially the same incident angle. For this reason, the images of the periodic patterns 31R and 31S have a large depth of focus.

Note that the distances from the optical axis AXI of the four regions 43A, 43B, 45A, and 45B on the illumination pupil plane IPP are not necessarily limited to the same distance, and the optical axes of the four regions 43A, 43B, 45A, and 45B are not necessarily limited. If the distances from each other are equal to each other within about −20% to + 20%, the above-described effect of improving the depth of focus can be obtained.
Next, an example of a process for manufacturing the liquid crystal display element 20 of FIG. 1A using the exposure apparatus EX of the present embodiment will be described with reference to the flowchart of FIG. The structure of the liquid crystal display element in the manufacturing process will be described with reference to FIGS. For convenience of explanation, in FIGS. 8 to 10, the TFT-side glass substrate 21A in FIG. 1A is the glass substrate TG, the lattice patterns 24A and 24C are the lattice patterns LS1 and LC1, and the color filter-side glass substrate 21B is the glass substrate. FG, the liquid crystal layer 22 will be described as the liquid crystal layer LC, the counter electrode 23B as the counter electrode CE, and the pixel electrode 23A as the pixel electrodes PE1, PE2,. Further, the description of the molecular alignment films 25A and 25B and the polarizing films 26A and 26B is omitted, and in FIGS. 8 and 9, the polarizing films 26A and 26B are parallel to the light absorption axes P and A of FIG. A description will be given by taking the X axis and the Y axis.

  FIG. 8 is an enlarged view of a main part including a plurality of pixel regions of the glass substrate TG on the TFT side of the liquid crystal display element being manufactured as viewed from the side where the TFT pattern is formed. 8, a large number of signal lines (signal electrodes) SL1, SL2, SL3,... Extend in the Y direction on the upper surface of the glass substrate TG, and a large number of selection lines (scanning electrodes) GL1, GL2,. ... is extended. Transistors TR1, TR2,... Composed of TFTs are formed at the intersections between the signal lines SL1, SL2,... And the selection lines GL1, GL2,. .. Are determined by the transistors TR1, TR2,..., And the brightness (transmittance) of each display pixel is determined.

First, in the pattern formation process 401 of FIG. 12, a glass substrate TG on the TFT side is manufactured by forming a circuit pattern on the glass substrate TG. This manufacturing process will be described with reference to FIG.
10A, 10C, 10E, and 10G are enlarged views of the vicinity of the transistor TR5 in FIG. 8, and FIGS. 10B, 10D, 10F, and 10H are shown in FIGS. FIG. 8 is a cross-sectional view taken along the line AA ′ in the vicinity of the transistor TR5 in FIG.

  First, as shown in FIGS. 10A and 10B, a metal film such as tantalum is formed on the upper surface of the glass substrate TG, and an exposure apparatus (for example, the exposure apparatus EX of FIG. 2 may be used). The selection line GL2 and the gate electrode TG5 made of the metal film are formed in predetermined portions by the lithography process. Thereafter, for example, by anodizing the metal film, a metal oxide film (not shown) is formed on the surfaces of the selection line GL2 and the gate electrode TG5.

Here, the line widths of the selection line GL2 and the gate electrode TG5 are preferably about 10 μm, respectively.
Next, as shown in FIGS. 10C and 10D, an amorphous silicon film is formed on the upper surface of the glass substrate TG, and the transistor TR5 made of the above amorphous silicon is straddled across the gate electrode TG5 by a lithography process. Form. Then, a metal such as aluminum or a highly conductive semiconductor is formed thereon, and the source electrode TS5 and the drain electrode TD5 are formed in a predetermined region over the transistor TR5 by a lithography process.

In this state, the gap between the source electrode TS5 and the drain electrode TD5 is preferably about 3 μm.
Subsequently, as shown in FIGS. 10E and 10F, a metal such as aluminum is formed on the upper surface of the glass substrate TG on the TFT side and aligned with the source electrode TS5 by a lithography process. A signal line SL2 is formed at the position. Thereafter, a transparent insulating film PV made of, for example, an organic material is formed on the upper surface of the glass substrate TG, and an opening (hole) is formed in the insulating film PV at a position aligned with the drain electrode TD5 by a lithography process. A transparent electrode made of ITO or IZO is formed thereon, and the transparent electrode is separated into transparent pixel electrodes PE5 corresponding to the respective display pixels by a lithography process.

  Next, as shown in FIGS. 10G and 10H, a fine lattice pattern LS1, which is a feature of the present embodiment, is formed on the surface of the transparent pixel electrode PE5 or the like by a lithography process. . Describing this process in detail, in step 301 of FIG. 12, a coater / developer (not shown) applies a positive photoresist as a dielectric to the surface of the glass substrate TG including the pixel electrodes PE5 and the like. In the next step 302, periodic patterns (31S, 31R) are formed on the object plane (upper surface of the mask stage) of the projection optical system PL of the exposure apparatus EX of FIG. Load the mask M1. Almost in parallel with this, in step 303, the illumination conditions of the illumination system ILS (partial illumination system 81, etc.) of the exposure apparatus EX are set, and the light quantity distribution on the illumination pupil plane IPP, etc. is in the state of FIG. Set to upper quadrupole illumination.

  In the next step 304, the exposure apparatus EX scans and exposes the pattern image of the mask M1 on the photoresist layer of the glass substrate TG. In the next step 305, a coater / developer (not shown) develops the photoresist on the glass substrate TG, thereby forming an image of the periodic pattern 31S of FIG. 6 on the surface of the pixel electrodes PE5 and the like of the plurality of display pixels. A lattice pattern LS2 (see FIG. 9) as an image of the lattice pattern LS1 and the periodic pattern 31R is formed with high accuracy.

FIG. 9 includes a plurality of pixel regions (pixel electrodes PE1, PE2,... Are formed respectively) of the glass substrate TG on the TFT side of the present embodiment in a state where the formation of the fine lattice patterns LS1, LS2 is completed. The enlarged view of the principal part is shown. As an example, the line width of the lattice patterns LS1 and LS2 is about 2 μm and the pitch is about 4 μm, but the numerical aperture NA of the partial projection optical systems PL1 to PL5 (projection optical system PL) of the exposure apparatus EX is 0. If it is larger than 1, the pitch of the lattice patterns LS1 and LS2 may be finer.
The lattice patterns LS1 and LS2 may be, for example, the photoresist itself formed by the exposure and development processes described above, and the dielectric film formed below the photoresist is etched using the photoresist as an etching mask. It may be a thing.

Next, in step 402, a glass substrate FG on the color filter side is manufactured.
FIG. 11 is an enlarged cross-sectional view showing a plurality of display pixels of the completed liquid crystal display element in the present embodiment, and FIG. 11 shows a cross-sectional view of the BB ′ portion in FIG. As shown in FIG. 11, in the completed liquid crystal display element, the glass substrate TG on the TFT side and the glass substrate FG on the color filter side are arranged to face each other, and the liquid crystal layer LC is sandwiched therebetween.

  A portion facing the pixel electrodes PE5, PE6, and PE10 of the TFT side glass substrate TG on the bottom surface of the color filter side glass substrate FG is formed by a lithography process in the same manner as a general color filter side glass substrate. The black matrix layers MB2, MB3, BM4, the red color filter CR, the green color filter CG, and the blue color filter CB are formed. A transparent insulating film PV2 and a counter electrode CE made of ITO or IZO are formed so as to cover these surfaces (lower surfaces).

Further, in the glass substrate FG on the color filter side in the present embodiment, the main surface of the counter electrode CE (the lower surface in FIG. 11) is opposed to the lattice patterns LS1 and LS2 (not shown in FIG. 11) by the lithography process. A fine first lattice pattern LC1 and a second lattice pattern (not shown), which are features of the embodiment, are formed.
In the exposure apparatus EX of FIG. 2, the lattice pattern LC1 and the like are formed with a periodic pattern whose phase with respect to the pattern period is 180 ° different from that of the mask M1 (or the periodic patterns 31S and 31R) similar to FIG. Can be formed by performing the same processes as in steps 301 to 305.

Then, after the color filter forming step 402, a cell assembly step 403 is executed. In the cell assembly step 403, liquid crystal is injected between the TFT side glass substrate TG obtained in the pattern formation step 401 and the color filter side glass substrate FG obtained in the color filter formation step 402. A liquid crystal display element (liquid crystal cell) is manufactured.
Thereafter, in a module assembling step 404, components such as an electric circuit and a backlight for performing display operation of the assembled liquid crystal cell are attached to complete a liquid crystal display element. According to the above-described method for manufacturing a liquid crystal display element, it is possible to obtain a liquid crystal display element with a very high response speed with a high throughput on which fine lattice patterns LS1, LC1, etc. are formed, using the exposure apparatus EX.

The effects and the like of this embodiment are as follows.
(1) A method for manufacturing a liquid crystal display element using the exposure apparatus EX of the present embodiment is a periodic method having a pitch P1 and arranged in different directions S1 (first direction) and R1 (second direction). Step 302 of disposing a mask M1 on which a pattern (element pattern) including a pattern 31S (first pattern) and a periodic pattern 31R (second pattern) is formed on the object plane side of the projection optical system PL of the exposure apparatus EX including. Further, the manufacturing method calculates the light amount distribution of the illumination light on the illumination pupil plane IPP (or a surface in the vicinity thereof) of the partial illumination system 81 of the illumination system ILS that illuminates the mask M1 with illumination light (exposure light) of wavelength λ. The distance between the optical axis AXI and the X axis (first straight line) extending in the direction corresponding to the intermediate direction between the direction S1 and the direction R1 and opposite to the optical axis AXI A region 43A (first region) and a region 43B (second region) including an intersection 42A (first point) and an intersection 42B (second point) where D2 are equal to each other, and a Y axis (second line) orthogonal to the X axis A region 45A (third region) including an intersection point 44A (third point) and an intersection point 44B (fourth point) which are on the opposite sides of the optical axis AXI and have the same distance D3 from the optical axis AXI. In region 45B (fourth region) Steps 303 and 304 for transferring the element pattern of the mask M1 to the glass substrate TG of the liquid crystal display element through the projection optical system PL in such a manner that the amount is larger than the amount of light in other regions, and the element pattern is And developing and processing the photoresist on the transferred glass substrate TG.

According to the manufacturing method of the present embodiment, the first periodic pattern 31S in the multiple patterns of FIG. 6 or the irradiation of the illumination light beams from the four regions 43A, 43B, 45A, 45B on the illumination pupil plane IPP or Both the 0th-order light and one of the first-order diffracted lights generated from the second periodic pattern 31R pass through the pupil plane PP, that is, pass through the partial projection optical system PL1, and enter the surface of the substrate PT. Therefore, interference fringes of 0th-order light and 1st-order diffracted light, that is, high-contrast images of the first periodic pattern 31S and the second periodic pattern 31R are formed on the substrate PT. Therefore, a fine periodic pattern can be exposed with high resolution.
Further, the four 0th-order lights and the four first-order diffracted lights all pass through any one of the four regions 45A, 45B, 47A, and 47B that are substantially equidistant from the optical axis AX on the pupil plane PP. That is, the light is incident on the surface of the substrate PT at substantially the same incident angle. For this reason, the images of the periodic patterns 31R and 31S have a greater depth of focus.

Therefore, it is possible to manufacture a liquid crystal display element that can transfer all the images of the respective patterns (31S, 31R) of the mask M1 to the glass substrate TG with high resolution and a large depth of focus, and has a wide viewing angle and improved response speed.
(2) The periodic patterns 31S and 31R of the mask M1 are patterns for patterning a photoresist as a dielectric film on the surface of the glass substrate TG. Note that a substance other than a photoresist can be used as the dielectric film.
(3) Further, the liquid crystal display element 20 manufactured in the present embodiment is a multi-domain type VA system having two domains in a pixel electrode corresponding to one TFT. The present invention can also be applied to the case of manufacturing a multi-domain VA liquid crystal display element having four or more domains in a pixel electrode corresponding to one TFT. In this case, the periodic patterns 31S and 31R of the mask M1 can be used as patterns for forming the respective domains included in the multi-domain in the display pixel. The present invention can also be applied to the case of manufacturing a multi-domain VA liquid crystal display element in which one pixel electrode is divided into two or more pixel electrodes. Furthermore, the present invention is not limited to the VA method, and can be applied to the manufacture of an IPS liquid crystal display element when a fine L & S pattern is required for the pixel electrode.

  (4) In the present embodiment, the fine lattice pattern LS1 and the pixel electrode on the TFT-side glass substrate TG constituting the liquid crystal display element and the pixel electrode on the color filter-side glass substrate FG Since LC1 is formed, the response speed of the liquid crystal display element can be further increased. Note that the fine lattice pattern LS1 or LC1 may be formed only on at least one of the pixel electrode on the TFT-side glass substrate TG and the color filter-side glass substrate FG constituting the liquid crystal display element. Even in this case, the response speed is increased.

(5) The projection optical system PL is composed of a plurality of partial projection optical systems PL1 to PL5 that respectively form partial images of the pattern of the mask M1 on the surface of the glass substrate TG or the like. Accordingly, since the exposure area can be widened by using the small projection optical system PL as a whole, the image of the pattern of the mask M1 can be exposed to the glass substrate TG having a large area by one scanning exposure.
The optical system on the exit side of the illumination system ILS is divided into a plurality of partial illumination systems 81 and the like corresponding to the plurality of partial projection optical systems PL1 to PL5. Therefore, the illumination system ILS can also be reduced in size.

Note that the method for manufacturing a liquid crystal display element of the present invention can also be applied to exposure using an exposure apparatus having a projection optical system composed of only one imaging optical system. In this case, the illumination system ILS can be composed of one optical system that illuminates one illumination area as a whole.
(6) Although the exposure apparatus EX performs scanning exposure, the method for manufacturing a liquid crystal display element of the present invention is also applicable when exposure is performed with a stepper type exposure apparatus.

  (7) The exposure apparatus EX of the present embodiment is a part that illuminates the pattern of the mask M with the illumination light IL in the exposure apparatus that exposes the substrate PT through the pattern of the mask M with the illumination light IL (exposure light). The distribution of the amount of illumination light in the illumination system ILS including the illumination system 81 and the illumination pupil plane IPP of the partial illumination system 81 (or in the vicinity thereof) passes through the optical axis AXI of the partial illumination system 81 and passes through the optical axis AXI of the mask M. The optical axis AXI is on the X axis (first straight line) extending in the direction corresponding to the intermediate direction (X direction) between the S1 direction and the R1 direction intersecting each other on the pattern surface, and is in the opposite direction from the optical axis AXI. And the regions 43A and 43B including the intersections 42A and 42B having the same distance D2, and the Y axis (second straight line) orthogonal to the X axis and in the opposite directions from the optical axis AXI, respectively. An intensity distribution setting device 14b and an aperture stop plate 12b (light amount distribution setting device) that can be set so that the amount of light in the regions 45A and 45B including the intersections 44A and 44B having the same distance D3 is larger than the amount of light in the other regions; A projection optical system PL composed of a plurality of partial projection optical systems PL1 to PL5 for forming an image of the pattern of the mask M on the surface of the substrate PT, and an X direction (predetermined direction) with respect to the plurality of partial projection optical systems PL1 to PL5 of the mask M ) And a stage system that synchronizes the movement of the substrate PT in the direction corresponding to the predetermined direction.

  According to the exposure apparatus EX, the images of the periodic patterns 31S and 31R of the mask M1 are exposed to the substrate PT with high resolution and a large depth of focus by illumination light from the regions 43A, 43B, 45A, and 45B of the illumination pupil plane IPP. it can. Therefore, by using the substrate PT as the glass substrate of the liquid crystal display element, the fine lattice patterns LC1 and LC2 can be formed on the glass substrate, and the response speed of the liquid crystal display element can be increased.

  Next, a modification of the above embodiment will be described with reference to FIG. In this modification, a cut-out pattern 24E, which is a fine periodic pattern, is formed on the pixel electrode 23A (PE1 etc.) on the glass substrate 21A (TG) on the TFT side like the liquid crystal display element 20A in FIG. (LS1) is formed. Then, a cut-out pattern 24G (LC1), which is a fine periodic pattern, is also formed on the counter electrode 23B (CE) on the bottom surface of the glass substrate 21B (FG) on the color filter side. In order to form the lattice pattern 24E, when the pixel electrode 23A is formed on the glass substrate 21A, a light shielding film 30B is formed in each pixel region 30 on the mask as shown in FIG. From the periodic pattern 31BS composed of the L & S pattern of the pitch P1 along the direction S1 and the L & S pattern of the pitch P1 along the direction R1, so that the brightness is opposite to that of the periodic patterns 31S and 31R of FIG. A mask M2 formed with a periodic pattern 31BR to be formed may be used.

  In this case, the periodic pattern 31BS (31BR) has a line pattern 31BSa (31BRa) formed of an opening pattern having a width of approximately P1 / 2 extending in a direction orthogonal to the direction S1 (R1) in the direction S1 (R1). Arranged at P1. As an illumination condition for illuminating the pattern of the mask M2, a condition in which the light quantity distribution on the illumination pupil plane IPP of each partial illumination system 81 or the like becomes four poles on the XY axes as shown in FIG. .

  In this modification, for example, when the pixel electrode 23A is formed on the glass substrate 21A of FIG. 1C or when the pixel electrode PE5 of FIG. 14F is formed, a transparent conductive film such as ITO is used. A positive photoresist is applied on the entire surface of the substrate. Thereafter, the exposure apparatus EX exposes and transfers the image of the pattern of the mask M2 in FIG. 17 to the photoresist under the illumination conditions in FIG. Etching treatment may be performed on a transparent conductive film using as an etching mask. Similarly, the lattice pattern 24G on the glass substrate 21B (FG) side can be formed.

In the above-described embodiment, an ultrahigh pressure mercury lamp is used as the light source, but the present invention is not limited to this, and other appropriate light sources can be used. That is, in the present invention, the exposure wavelength is not particularly limited to g-line, h-line, i-line and the like.
In addition, this invention is not limited to the above-mentioned embodiment, A various structure can be taken in the range which does not deviate from the summary of this invention.

  ILS ... illumination device, IPP ... illumination pupil plane, M1, M2 ... mask, PL ... projection optical system, PT ... substrate, 20, 20A ... liquid crystal display element, 21A (TG) ... TFT side glass substrate, 21B (FG) A glass substrate on the color filter side, 24A (LS1) ... lattice pattern, 24C (LC1) ... lattice pattern, 31S ... first periodic pattern, 31R ... second periodic pattern, 43A, 43B, 45A, 45B ... High light area

Claims (12)

A method of manufacturing a liquid crystal display element,
An object plane of the projection optical system of the exposure apparatus is formed by using a mask having a periodic pattern having a predetermined pitch and an element pattern including a first pattern and a second pattern arranged in different first and second directions, respectively. Placing it on the side,
The light quantity distribution of the exposure light on the pupil plane of the illumination system that illuminates the mask with the exposure light of the exposure apparatus or in the vicinity thereof, passes through the optical axis of the illumination system, and the first direction and the second direction. A first region including a first point and a second point which are on a first straight line extending in a direction corresponding to an intermediate direction of the first and second points in opposite directions from the optical axis and having the same distance from the optical axis. A third point that is on a second straight line that passes through the optical axis of the illumination system and is orthogonal to the first straight line, and is in the opposite direction from the optical axis and equal to the optical axis. And the third region including the fourth point and the fourth region have a light quantity larger than that in the other areas, and the element pattern of the mask is transferred to the liquid crystal display element via the projection optical system. Transferring to the substrate,
Processing the substrate to which the pattern has been transferred;
A method for producing a liquid crystal display element comprising: When the pitch of the first pattern and the second pattern is P1, the wavelength of the exposure light is λ, and the angle of the first direction with respect to the intermediate direction is θ,
2. The liquid crystal display element according to claim 1, wherein the position of the first point and the second point is set to a point where a distance from the optical axis is λ / (2 · P1 · cos θ). Production method. When the pitch of the first pattern and the second pattern is P1, the wavelength of the exposure light is λ, and the angle of the first direction with respect to the intermediate direction is θ,
3. The liquid crystal display according to claim 1, wherein the position of the third point and the fourth point is set to a point at which the distance from the optical axis is λ / (2 · P1 · sin θ). Device manufacturing method.   2. The first region, the second region, the third region, and the fourth region are circular regions each having a radius converted to a coherence factor of 0.2 to 0.3. The manufacturing method of the liquid crystal display element as described in any one of -3.   5. The device according to claim 1, wherein the first pattern and the second pattern of the element pattern are patterns for forming an electrode pattern of each pixel of the liquid crystal display element. 6. The manufacturing method of the liquid crystal display element of description.   The said liquid crystal display element is a liquid crystal display element of a vertical alignment system, The manufacturing method of the liquid crystal display element as described in any one of Claims 1-5 characterized by the above-mentioned.   The liquid crystal display element is a multi-domain vertical alignment type liquid crystal display element, and the first pattern and the second pattern are patterns for forming respective domains included in the multi-domain in the display pixel. It exists, The manufacturing method of the liquid crystal display element as described in any one of Claims 1-6 characterized by the above-mentioned.   The pitch of the first pattern and the second pattern is 3 μm to 5 μm, the exposure wavelength λ is between 0.365 μm and 0.486 μm, and the numerical aperture NA of the projection optical system is 0.1 to 0. It is between 0.07, The manufacturing method of the liquid crystal display element as described in any one of Claims 1-7 characterized by the above-mentioned.   The said projection optical system consists of a some partial projection optical system which forms the one part image of the pattern of the said mask on the surface of the said board | substrate, respectively. A method for manufacturing a liquid crystal display element.   The method for manufacturing a liquid crystal display element according to claim 1, wherein at least a part of the illumination system is provided in a plurality corresponding to the plurality of partial projection optical systems.   In order to transfer the element pattern of the mask to the substrate via the projection optical system, the mask moves in a predetermined direction with respect to the projection optical system, and the substrate moves in a direction corresponding to the predetermined direction. The method of manufacturing a liquid crystal display element according to claim 1, wherein the movement is performed in synchronization. In an exposure apparatus that exposes a substrate through a mask pattern with exposure light,
An illumination system for illuminating the pattern of the mask with the exposure light;
The light quantity distribution of the exposure light on the pupil plane of the illumination system or a surface in the vicinity thereof is in an intermediate direction between the first direction and the second direction passing through the optical axis of the illumination system and intersecting each other on the pattern surface of the mask. A first region and a second region including a first point and a second point which are on a first straight line extending in a corresponding direction and which are in opposite directions from the optical axis and have the same distance from the optical axis; Third and fourth points that pass through the optical axis of the illumination system and are on a second straight line that is orthogonal to the first straight line, are in opposite directions from the optical axis, and have the same distance from the optical axis. A light amount distribution setting device that can be set so that the light amount in the third region and the fourth region including
A projection optical system comprising a plurality of partial projection optical systems for forming an image of the mask pattern on the surface of the substrate;
An exposure apparatus comprising: a stage system that synchronizes movement of the mask in a predetermined direction with respect to the plurality of partial projection optical systems and movement of the substrate in a direction corresponding to the predetermined direction. .