JP5169072B2 - Manufacturing method of color filter for liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a color filter for a liquid crystal display device by which an exposure defective pattern due to interference of light is hardly caused and satisfactory height difference can be easily obtained in a region where a translucent region and a transmission region are adjacent to each other in a gradation mask. <P>SOLUTION: The gradation mask is used to solve the problem. The gradation mask has a transparent substrate, and a light shielding film and a translucent film formed in a pattern shape on the transparent substrate, has a transmission region where the transparent substrate is exposed, a light shielding region where the light shielding film is provided on the transparent substrate and a translucent region where only the translucent film is provided on the transparent substrate and has a pattern where the transmission region and the translucent region are adjacent to each other; wherein light intensity is monotonously reduced from the transmission region toward the translucent region and no inflection point exists in light intensity distribution in a region within 5 &mu;m distance from the boundary between the transmission region and the translucent region when simulation of the light intensity distribution when exposure is performed using the gradation mask is performed. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a method for manufacturing a color filter for a liquid crystal display device, in which spacers and alignment control protrusions having different heights are formed.

  In recent years, with the development of personal computers, especially portable personal computers, the demand for liquid crystal displays, particularly color liquid crystal displays, has been increasing.

  In a vertical alignment (VA) type liquid crystal display device, alignment control protrusions for controlling the alignment of liquid crystal molecules and spacers for holding a gap between substrates are provided. In recent years, attempts have been made to provide spacers having different heights in order to suppress the occurrence of low-temperature foaming in a liquid crystal display device and to improve resistance to local loads.

  Conventionally, when forming alignment control protrusions and spacers, the height, physical properties, and the like of the alignment control protrusions and spacers are different, and thus it is necessary to perform the photolithography process twice. Further, when forming the alignment control protrusions and the spacers having different heights, it is necessary to perform the photolithography process three times. However, this has a problem that productivity is lowered.

  Therefore, for the purpose of improving the manufacturing efficiency of the color filter, for example, the alignment control protrusion and the spacer are formed using a gradation mask in which a pattern of a translucent film that transmits exposure light at a desired transmittance is formed. A method of forming in a lump, a method of forming spacers having different heights in a lump, and the like have been proposed (for example, see Patent Documents 1 to 4).

  As the gradation mask, for example, as shown in FIG. 14, a transparent substrate 102, a semitransparent film 103 formed on the transparent substrate 102 and transmitting exposure light with a desired transmittance, and the semitransparent film 103 And the light-shielding film 104 that substantially shields the exposure light formed on the substrate. Such a gradation mask includes a transparent region 113 through which the transparent substrate 102 is exposed and transmitting light, a light-blocking region 111 that does not substantially transmit light through the light-blocking film 104, and the amount of light transmitted through the semi-transparent film 103. And a semi-transparent region 112 adjusted, and gradation can be obtained by the difference in transmittance. As a result, it is possible to form the alignment control protrusions and the spacers at once, or to form spacers having different heights at the same time.

  For the purpose of improving the production efficiency of the color filter, for example, the alignment control projection, the first photo spacer, and the pattern of the light shielding film respectively corresponding to the second photo spacer having a height lower than the first photo spacer are provided. There has been proposed a method of forming alignment control protrusions and spacers having different heights at once using the formed photomask (see, for example, Patent Document 5).

  In the photomask, for example, as shown in FIG. 13, a light-shielding film 104 is formed in a pattern on a transparent substrate 102, and the width of each light-shielding film has a pattern 121> first corresponding to the first photospacer. The pattern 122 decreases in the order of the pattern 122 corresponding to the two photo spacers> the pattern 123 corresponding to the alignment control protrusion. In this photomask, it is possible to collectively form alignment control protrusions and spacers having different heights by utilizing the fact that the diffracted light increases as the pattern width decreases.

JP 2007-171623 A JP 2007-178649 A JP 2007-178662 A JP 2007-178688 A JP 2007-94064 A

  However, in the case where the alignment control protrusions and spacers, or spacers having different heights are formed at the same time using the gradation masks described in Patent Documents 1 to 4, the semitransparent region and the transmissive region are adjacent to each other. Interference waves are likely to occur due to the phase shift of the light passing through each region. For this reason, it may be difficult to form alignment control protrusions or spacers in a target pattern in a region corresponding to the translucent region.

  For example, as shown in FIG. 4, when the above-mentioned gradation mask is used to expose the positive photosensitive resin and the alignment control projections 53 and the spacers (the high spacer 51 and the low spacer 52) are collectively formed, Interference occurs due to the influence of the phase shift, and the film thickness of the alignment control projection 53 becomes a thin film near the boundary between the translucent region and the transmissive region, which may result in a poor exposure pattern. For this reason, when the color filter and the liquid crystal drive side substrate are opposed to each other to form a liquid crystal display device, the above-mentioned exposure defect pattern causes a liquid crystal alignment defect, and high-quality display becomes difficult.

  Further, when the photomask described in Patent Document 5 is used, the alignment control protrusion, the first photospacer, and the second photospacer having different heights are formed only by the light diffraction effect due to the difference in pattern width. Depending on the size of the photomask or color filter, it may be difficult to increase the difference in pattern width, and the difference in height may not be sufficient.

  The present invention has been made in view of the above problems, and it is difficult for an exposure failure pattern due to light interference to occur in an area where a semi-transparent area and a transmission area of a gradation mask are adjacent to each other, and the height is easily high. It is a main object of the present invention to provide a method for manufacturing a color filter for a liquid crystal display device capable of providing a difference.

  In order to achieve the above object, the present invention comprises a photosensitive resin layer forming step of forming a photosensitive resin layer made of a positive photosensitive resin on a substrate on which a colored layer is formed, and the photosensitive resin layer, Manufacturing of a color filter for a liquid crystal display device having an exposure / development process in which a high spacer, a low spacer, and an alignment control protrusion made of the positive photosensitive resin are simultaneously formed by exposing and developing using a gradation mask The gradation mask includes a transparent substrate, a light-shielding film and a semi-transparent film formed in a pattern on the transparent substrate, and a transparent region where the transparent substrate is exposed, on the transparent substrate. A light-shielding region provided with the light-shielding film and a semi-transparent region provided only with the semi-transparent film on the transparent substrate, and the transmission region and the semi-transparent region have adjacent patterns. Use tone mask When the light intensity distribution at the time of exposure is simulated, the light intensity is monotonically from the transmissive area toward the semi-transparent area in the area within 5 μm from the boundary between the transmissive area and the semi-transparent area. The present invention provides a method for manufacturing a color filter for a liquid crystal display device, characterized in that the light intensity distribution has no inflection point.

  According to the present invention, when the gradation mask performs the above simulation, the light intensity is monotonously from the transmission region to the semitransparent region in a region at a predetermined distance from the boundary between the transmission region and the semitransparent region. Since the light intensity distribution does not have an inflection point, the influence of the interference of diffracted light can be reduced in a region where the transmission region and the semitransparent region are adjacent to each other. Therefore, it is possible to form the alignment control protrusions in a target pattern. In the semi-transparent region, the film thickness of the photosensitive resin layer after exposure can be controlled by the transmittance of the semi-transparent film, so that the difference in height between the high spacer and the alignment control protrusion is made relatively large. Etc. are easily possible.

  In the above invention, in the gradation mask, the light shielding region includes a first light shielding region corresponding to the high spacer and a second light shielding region corresponding to the low spacer, and the width of the first light shielding region. May be larger than the width of the second light shielding region. In this case, a high spacer is formed using the first light shielding region of the gradation mask, a low spacer is formed using the second light shielding region, and an alignment control protrusion is formed using the translucent region. In addition, the high spacer, the low spacer, and the alignment control protrusion can be formed at the same time.

  In the above invention, in the gradation mask, the translucent region includes a first translucent region corresponding to the low spacer and a second translucent region corresponding to the alignment control protrusion, The transmittance of the first translucent region may be lower than the transmittance of the second translucent region. In this case, a high spacer is formed using the light shielding region of the gradation mask, a low spacer is formed using the first semi-transparent region, and an alignment control protrusion is formed using the second semi-transparent region. The high spacer, the low spacer, and the alignment control protrusion can be formed at the same time.

  Further, in the present invention, the gradation mask has a transmittance of T (%) at a wavelength of 365 nm of the semi-transparent region, and the phase of the exposure light that has passed through the semi-transparent region with respect to the exposure light that has passed through the transmissive region. When the delay is δ (rad), −δ / ln (T / 100) is preferably 0.4 or less. Since −δ / ln (T / 100) is in the above range, as described above, in the region where the transmission region and the semitransparent region of the gradation mask are adjacent to each other, the influence of light interference is reduced. Because it can.

  In the present invention, it is preferable that the translucent film in the gradation mask contains at least one metal selected from the group consisting of chromium, titanium, nickel, nickel alloy and tantalum. This is because with such a semi-transparent film, the phase delay of the exposure light that has passed through the semi-transparent region relative to the exposure light that has passed through the transmission region can be made relatively small.

  Furthermore, the present invention provides a color filter manufactured using the above-described method for manufacturing a color filter for a liquid crystal display device.

  In the present invention, the influence of the interference wave due to the phase shift of the light passing through each region can be reduced, and the difference in height between the high spacer and the alignment control protrusion can be made relatively large. The high spacer, the low spacer, and the alignment control protrusion can be formed with high definition.

  Hereinafter, a method for producing a color filter for a liquid crystal display device and a color filter of the present invention will be described in detail.

A. Method for Manufacturing Color Filter for Liquid Crystal Display Device First, a method for manufacturing a color filter for a liquid crystal display device of the present invention will be described.
The method for producing a color filter for a liquid crystal display device according to the present invention includes a photosensitive resin layer forming step of forming a photosensitive resin layer made of a positive photosensitive resin on a substrate on which a colored layer is formed, and the photosensitive resin layer. A color filter for a liquid crystal display device, which comprises exposing and developing the same using a gradation mask, and simultaneously forming a high spacer, a low spacer and an alignment control protrusion made of the positive photosensitive resin. The gradation mask has a transparent substrate, a light-shielding film and a semi-transparent film formed in a pattern on the transparent substrate, and a transparent region where the transparent substrate is exposed, the transparent Having a light-shielding region in which the light-shielding film is provided on the substrate and a semi-transparent region in which only the semi-transparent film is provided on the transparent substrate, and having a pattern in which the transmission region and the semi-transparent region are adjacent, this When a light intensity distribution during exposure using a tone mask is simulated, the distance from the transmission region to the semitransparent region is within a range of 5 μm from the boundary between the transmission region and the semitransparent region. The light intensity is monotonously decreased and the light intensity distribution has no inflection point.

  The high spacer and the low spacer mean spacers having different heights. The high spacer is higher than the low spacer.

The manufacturing method of the color filter for liquid crystal display devices of this invention is demonstrated referring drawings.
FIG. 1 is a schematic diagram showing an example of a gradation mask used in the present invention. FIG. 1 (a) is a cross-sectional view taken along the line AA of FIG. 1 (b). As illustrated in FIG. 1A, the gradation mask 1 is obtained by forming a translucent film 3 and a light shielding film 4 in a pattern on a transparent substrate 2. In addition, as illustrated in FIG. 1B, the gradation mask 1 includes only the light-shielding regions 11a and 11b in which the light-shielding film 4 is provided on the transparent substrate 2 and the semi-transparent film 3 on the transparent substrate 2. The translucent area 12 and the transmissive area 13 where the transparent substrate 2 is exposed are formed, and the translucent area 12 and the transmissive area 13 have adjacent patterns.

  The gradation mask illustrated in FIG. 1 has a transmission area in a predetermined distance from the boundary between the transmission area and the semi-transparent area when a light intensity distribution is simulated using the gradation mask. The light intensity decreases monotonously toward the translucent region from the light source, and the light intensity distribution has no inflection point.

In the simulation, the light amplitude E _P at the point P on the substrate is calculated from each point of the opening (transmission region) of the corresponding gradation mask by the following formula (1) based on general Fresnel diffraction. The integral value of the spherical wave is obtained by calculation, and the light intensity I at the point P can be obtained by calculation according to the following mathematical formula (2).
FIG. 2 is a diagram for explaining the calculation of the light intensity distribution at the point P on the substrate 31 by the following formula (1), and an arbitrary point Q in the opening (transmission region 13) of the gradation mask 1. FIG. 6 is a schematic diagram showing a positional relationship with an arbitrary point P on the substrate 31. In FIG. 2, a point S is a position on the substrate 31 when the exposure light 32 that has passed the point Q travels straight.

Here, in Equation (1), k = 2π / λ, E _P is the amplitude of light at point P on the substrate, A is a constant determined by the intensity of incident light, λ is the wavelength of incident light, and δ is a line The angle formed by the minute QS and the line QP, r is the distance from the point Q to the point P, and i is an imaginary unit.

I = E _P × E _P ^* (2)
Here, in Equation (2), E _P ^* is a conjugate complex number of E _P.

  The above calculation is performed by a computer by dividing the opening (transmission region) of the gradation mask and the substrate into finite minute sections.

  FIG. 3 shows the result of the light intensity distribution obtained by simulation using the gradation mask shown in FIG. Note that FIG. 3 corresponds to the BB line portion of FIG. Simulation conditions are: exposure gap: 150 μm, Collimation: 1.5 °, exposure wavelength: 365 nm, transmissivity of translucent area: 30% (365 nm), exposure light passing through translucent area relative to exposure light passing through transmissive area Phase delay (phase difference): 0.02 rad or 1.22 rad, line width of translucent region: 15 μm, exposure method: proximity exposure method.

  In the case of FIG. 3 (a), the light intensity monotonously decreases from the transmissive area to the semi-transparent area at a predetermined distance from the boundary between the transmissive area and the semi-transparent area, and the inflection point in the light intensity distribution. Does not have On the other hand, in the case of FIG. 3B, there is a portion where the light intensity increases without decreasing monotonously from the transmissive region to the semi-transparent region in a region at a predetermined distance from the boundary between the transmissive region and the semi-transparent region.

When exposure is performed using a gradation mask showing a light intensity distribution as shown in FIG. 3B, the film thickness of the region corresponding to the translucent region tends to become a thin film near the boundary with the transmission region due to light interference. .
FIG. 4 shows an example in which alignment control protrusions and spacers having different heights (low spacers / high spacers) are formed using a gradation mask having a light intensity distribution as shown in FIG. First, as illustrated in FIG. 4A, a light shielding portion 22 and a colored layer 23 are formed on a substrate 21, a transparent electrode layer 24 is formed on the colored layer 23, and a positive type is formed on the transparent electrode layer 24. A photosensitive resin layer 25 made of a photosensitive resin is formed. Next, as illustrated in FIG. 4B, when the photosensitive resin layer 25 made of a positive photosensitive resin is irradiated with light 50 through the gradation mask 1, interference occurs due to the influence of a phase shift of the light. As a result, the film thickness of the alignment control projection 53 becomes a thin film in the vicinity of the boundary between the translucent region 12 and the transmissive region 13, and an exposure failure pattern occurs. In this case, it can be said that the actually obtained pattern matches the simulation result.

On the other hand, when exposure is performed using a gradation mask having a light intensity distribution as shown in FIG. 3A, the occurrence of an exposure failure pattern due to light interference can be suppressed.
FIG. 5 shows an example of forming alignment control protrusions and spacers having different heights (low spacer / high spacer) using a gradation mask having a light intensity distribution as shown in FIG. First, as illustrated in FIG. 5A, a light shielding portion 22 and a colored layer 23 are formed on a substrate 21, a transparent electrode layer 24 is formed on the colored layer 23, and a positive type is formed on the transparent electrode layer 24. A photosensitive resin layer 25 made of a photosensitive resin is formed. Next, as illustrated in FIG. 5B, when the photosensitive resin layer 25 made of a positive photosensitive resin is irradiated with light 50 through the gradation mask 1, an exposure failure pattern due to light interference is generated. First, as illustrated in FIG. 5C, the high spacer 51, the low spacer 52, and the alignment control protrusion 53 can be formed in a desired pattern. Also in this case, it can be said that the actually obtained pattern and the simulation result coincide.

  When the predetermined gradation mask is used in this way, the gradation mask is semi-transparent from the transmissive area at a predetermined distance from the boundary between the transmissive area and the semi-transparent area when the above simulation is performed. Since the light intensity decreases monotonously toward the area and the light intensity distribution does not have an inflection point, it is possible to suppress the occurrence of a defective exposure pattern due to interference and improve the resolution. Is possible.

  In the present invention, since a positive photosensitive resin is used, the highest spacer is formed using the light shielding region of the gradation mask, and the highest height is formed using the translucent region of the gradation mask. Low alignment control protrusions are formed.

  Therefore, in the present invention, since it is possible to suppress the occurrence of an exposure failure pattern due to interference in a region where the transmissive region and the semi-transparent region are adjacent to each other, the photosensitive resin layer is patterned into a target pattern, and the alignment control protrusion Can be formed with high definition.

  Further, since the semitransparent film is provided in the semitransparent region, the transmittance can be controlled by adjusting the material, film thickness, and the like of the semitransparent film. Therefore, by setting the translucent region to a predetermined transmittance, it is possible to form the alignment control protrusion having a desired height. Therefore, in the present invention, in order to adjust the height of the high spacer and the alignment control protrusion, it is necessary to consider the width of the light-shielding region corresponding to the high spacer and the width of the translucent region corresponding to the alignment control protrusion. There is no. On the other hand, in the past, the height of the high spacer and the alignment control protrusion was controlled by adjusting the width of the light shielding film pattern (light shielding region). The width of the light-shielding film pattern (light-shielding region) corresponding to the high spacer relative to the width of the light-shielding film pattern (light-shielding region) corresponding to the protrusion may be limited, and the difference in height between the high spacer and the alignment control protrusion It was difficult to attach enough. On the other hand, in the present invention, as described above, the height of the alignment control protrusion is adjusted not by the width of the light shielding area but by the transmissivity of the translucent area. It is possible to make the difference in height relatively large.

  In the present invention, as described above, the high spacer is formed using the light shielding region of the gradation mask, and the alignment control protrusion is formed using the translucent region of the gradation mask. The spacer may be formed using the light shielding region of the gradation mask or may be formed using the translucent region of the gradation mask.

  In the case where the low spacer is formed using the semi-transparent region of the gradation mask, for example, as shown in FIG. 6, the high spacer 51 is formed using the light shielding region 11 of the gradation mask 1, and the first half is formed. The low spacer 52 can be formed using the transparent region 12a, and the alignment control protrusion 53 can be formed using the second semitransparent region 12b having a higher transmittance than the first semitransparent region 12a. In this case, as described above, in the present invention, it is possible to suppress the occurrence of an exposure failure pattern due to interference in a region where the transmissive region and the semitransparent region are adjacent to each other. Then, the alignment control projection and the low spacer can be formed with high definition. In addition, the height of the alignment control protrusion and the low spacer can be easily reduced relative to the height of the high spacer.

  On the other hand, when the low spacer is formed using the light shielding region of the gradation mask, the high spacer 51 is formed using the first light shielding region 11a of the gradation mask 1, for example, as shown in FIG. The low spacer 52 can be formed using the second light shielding region 11b having a smaller width than the first light shielding region 11a, and the alignment control projection 53 can be formed using the translucent region 12. In this case, it is possible to make the height of the alignment control protrusion relatively low with respect to the height of the high spacer and the low spacer.

The adjustment of the heights of the high spacer and the low spacer when the high spacer and the low spacer are formed using the light shielding region of the gradation mask will be described.
The gradation mask 1 illustrated in FIG. 5B includes a first light shielding region 11 a corresponding to the high spacer 51 and a second light shielding region 11 b corresponding to the low spacer 52 as light shielding regions. As shown in FIG. 5C, the height h1 of the high spacer and the height h2 of the low spacer are in a relationship of h1> h2, and the width w1 of the high spacer and the width w2 of the low spacer are w1> w2. There is a relationship. As shown in FIG. 5B, the width d1 of the first light shielding region 11a and the width d2 of the second light shielding region 11b of the gradation mask 1 correspond to the width w1 of the high spacer and the width w2 of the low spacer, respectively. And d1> d2.

  In FIG. 5B, light 50 from above the gradation mask 1 is irradiated to the photosensitive resin layer 25 through the transmission region 13 of the gradation mask 1, but if the gap G of the proximity exposure is sufficiently large. The irradiated light 50 reaches not only the portion of the photosensitive resin layer 25 below the transmission region 13 but also the portion of the photosensitive resin layer 25 below the light shielding regions 11a and 11b due to diffraction of the irradiated light. . As a result, the positive photosensitive resin is photodegraded into one that is soluble in the developer.

  The diffracted light is small below the first light-shielding region 11a having a large width d1 corresponding to the high spacer 51 having a large width w1 and corresponds to the low spacer 52 having a narrow width w2, as shown in FIG. It increases below the second light-shielding region 11b having a small width d2.

  Therefore, the amount of photolysis is small in the portion of the photosensitive resin layer 25 below the first light shielding region 11a corresponding to the high spacer 51 having the wide width w1, and the second light shielding region corresponding to the low spacer 52 having the narrow width w2. The amount of photodecomposition increases in the portion of the photosensitive resin layer 25 below 11b. Therefore, as illustrated in FIG. 5C, a high spacer having a high height and a wide width and a low spacer having a low height and a small width can be obtained at the same time.

When the simulation is performed as described above, the gradation mask used in the present invention has a monotonous light intensity from the transmissive region to the semi-transparent region at a predetermined distance from the boundary between the transmissive region and the semi-transparent region. And the light intensity distribution has no inflection point in a region at a predetermined distance from the boundary between the transmission region and the translucent region.
Since the light intensity distribution obtained by the simulation varies depending on the exposure gap, the exposure wavelength, the exposure method, and the like, the simulation conditions may be the same as the exposure conditions when the gradation mask is actually used.

Note that “an area within a distance of 5 μm from the boundary between the transmissive area and the semi-transparent area” means an area within 5 μm from the boundary between the transmissive area and the semi-transparent area, and the transmissive area and the semi-transparent area. An area within 5 μm from the boundary to the transmission area.
In addition, “having no inflection point” means that there is no point that changes from an upward convex state to a concave upward state, or a point that changes from an upward concave state to an upward convex state. Say.
The simulation results show that the light intensity decreases monotonously from the transmissive area to the semitransparent area and has no inflection point in the light intensity distribution in the area at a predetermined distance from the boundary between the transmissive area and the translucent area. Shall be confirmed. At this time, assuming that the relative intensity of the exposure light before passing through the gradation mask, that is, the relative intensity of the exposure light passing through the transmission region is 1, a change within ± 0.001 is regarded as an error.

  Hereafter, the manufacturing method of the color filter for liquid crystal display devices of this invention is demonstrated in detail for every process.

1. Photosensitive resin layer formation process The photosensitive resin layer formation process in this invention is a process of forming the photosensitive resin layer which consists of positive photosensitive resin on the board | substrate with which the colored layer was formed.

  The positive photosensitive resin used in the present invention is not particularly limited, and those generally used can be used. Specifically, a photosensitive resin using a novolac resin as a base resin can be used.

  As a coating method of the photosensitive resin composition containing the positive photosensitive resin, for example, spin coating method, casting method, dipping method, bar coating method, blade coating method, roll coating method, gravure coating method, flexographic printing method, A spray coating method or the like can be used.

  The thickness of the photosensitive resin layer after coating is appropriately adjusted according to the high spacer, low spacer, and alignment control protrusion to be formed. For example, as shown in FIG. 5, the thickness of the photosensitive resin layer is adjusted to match the height of the highest spacer 51.

  After application of the photosensitive resin composition, the photosensitive resin layer may be subjected to heat treatment (pre-baking).

  As a substrate used in the present invention, for example, a non-flexible transparent rigid material such as quartz glass, Pyrex (registered trademark) glass, synthetic quartz plate, or a flexible resin material such as a transparent resin film or an optical resin plate is used. A transparent flexible material can be used. Among these, Corning 1737 glass is a material having a small coefficient of thermal expansion, excellent dimensional stability and characteristics in high-temperature heat treatment, and is an alkali-free glass containing no alkali component in the active matrix. Suitable for color filters for liquid crystal display devices.

Moreover, the colored layer in this invention is comprised from a red pattern, a green pattern, and a blue pattern, for example. The colored layer can be formed by, for example, a photolithography method using a photosensitive resin composition containing a desired colorant. Furthermore, as a method for forming the colored layer, a general method such as a printing method, an electrodeposition method, a transfer method, or an ink jet method can be used.
The thickness of the colored layer can be set, for example, in the range of 0.5 to 3.0 μm.

In the present invention, a light shielding portion may be formed on the substrate.
The light shielding portion can be formed by forming a metal thin film such as chromium by sputtering, vacuum deposition, or the like and patterning the metal thin film. In this case, the thickness of the light-shielding part can be about 200 to 5000 mm.
The light shielding part is formed by forming a resin layer using a polyimide resin composition, an acrylic resin composition, an epoxy resin composition, or the like containing light shielding particles such as carbon fine particles, and patterning the resin layer. You can also Furthermore, the light shielding part can also be formed by forming a resin layer using a photosensitive resin composition containing light shielding particles such as carbon fine particles and metal oxide, and patterning the resin layer.

A transparent electrode layer may be formed on the substrate.
Examples of the material for forming the transparent electrode layer include indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO), and alloys thereof.
As a film forming method of the transparent electrode layer, for example, a general film forming method such as a sputtering method, a vacuum evaporation method, a CVD method, or the like can be used.
The thickness of the transparent electrode layer can be, for example, about 200 to 5000 mm.

2. Exposure / development process In the exposure / development process of the present invention, the photosensitive resin layer is exposed and developed using a gradation mask, and high spacers, low spacers, and alignment control protrusions made of a positive photosensitive resin are formed. It is a process of forming simultaneously.
Hereinafter, a method for forming a gradation mask and high spacers, low spacers, and alignment control protrusions will be described.

(1) Gradation mask The gradation mask used in the present invention has a transparent substrate, a light-shielding film and a semitransparent film formed in a pattern on the transparent substrate, and a transparent region where the transparent substrate is exposed. A pattern having a light-shielding region in which the light-shielding film is provided on the transparent substrate and a semi-transparent region in which only the semi-transparent film is provided on the transparent substrate, and the transmission region and the semi-transparent region are adjacent to each other. When a light intensity distribution is simulated when exposure is performed using the gradation mask, the above-described gradation mask has a region within a distance of 5 μm from the boundary between the transmission region and the semi-transparent region. The light intensity monotonously decreases from the transmission area toward the translucent area, and the light intensity distribution has no inflection point.
Hereinafter, each configuration of the gradation mask will be described.

(I) Transmission region and translucent region The transmission region in the gradation mask used in the present invention is a region where the transparent substrate is exposed.
Further, the semitransparent region in the gradation mask used in the present invention is a region in which only the semitransparent film is provided on the transparent substrate.

  Here, the occurrence of an exposure failure pattern due to light interference is caused by a delay in the phase of the exposure light that has passed through the semi-transparent region with respect to the exposure light that has passed through the transmission region. When the phase delay of the exposure light that has passed through the semi-transparent area with respect to the exposure light that has passed through the transmission area is relatively large, an exposure failure pattern due to light interference is likely to occur, and the translucent area for the exposure light that has passed through the transmission area When the phase delay of the exposure light that has passed through is relatively small, it becomes difficult to produce a defective exposure pattern due to light interference.

  Therefore, it is preferable to reduce the phase delay of the exposure light that has passed through the translucent region with respect to the exposure light that has passed through the transmission region to such an extent that no interference wave is generated. This phase difference limit varies depending on the transmissivity of the translucent region. Specifically, when the transmissivity of the translucent region at a wavelength of 365 nm is T (%) and the phase delay of the exposure light that has passed through the translucent region with respect to the exposure light that has passed through the transmissive region is δ (rad). , −δ / ln (T / 100) is desirably small enough not to generate an interference wave. More specifically, −δ / ln (T / 100) is preferably 0.4 or less. This is because by setting −δ / ln (T / 100) in the above range, the influence of interference can be reduced and a desired pattern can be formed. On the other hand, when -δ / ln (T / 100) exceeds the above range, the influence of interference due to light wraparound becomes large, and there is a possibility that a poorly exposed pattern may occur when the photosensitive resin is exposed.

In addition, the phase of the exposure light which passed each said area | region can be measured by brand name MPM-100 (made by Lasertec Corporation). As a result, the phase delay δ of the exposure light that has passed through the translucent region relative to the exposure light that has passed through the transmission region can be obtained.
The transmissivity T at a wavelength of 365 nm in the translucent region can be calculated by measuring the transmissivity of the translucent region with the transmissivity of the transparent substrate of the gradation mask as a reference (100%). As a device for measuring the transmittance, an ultraviolet / visible spectrophotometer (for example, Hitachi U-4000) or a device having a photodiode array as a detector (for example, Otsuka Electronics MCPD) can be used.

  Examples of the method of setting −δ / ln (T / 100) within the above range include a method of controlling the refractive index of the material of the semitransparent film and the film thickness of the semitransparent film, as will be described later.

  The gradation mask used in the present invention may have two types of translucent areas (a first translucent area and a second translucent area) having different transmittance characteristics. In this case, as illustrated in FIG. 6, the first semitransparent region is used to form a low spacer, and the second semitransparent region having a higher transmittance than the first semitransparent region is used to control the alignment control. Can be formed.

As the transmittance of the first translucent area corresponding to the low spacer and the transmissivity of the second translucent area corresponding to the alignment control protrusion, the transmittance of the first translucent area is greater than the transmittance of the second translucent area. However, there is no particular limitation as long as a desired difference in height between the low spacer and the alignment control protrusion can be realized.
In addition, the transmittance | permeability of a 1st translucent area | region and the transmittance | permeability of a 2nd translucent area | region say the transmittance | permeability in wavelength 365nm. The transmittance can be calculated by the method described above.

  Specifically, the transmittance of the first translucent region at a wavelength of 365 nm differs depending on the height of the target low spacer, the type of the positive photosensitive resin used, and cannot be specified unconditionally. However, it can be about 5% to 40%. Similarly, the transmittance of the second translucent region at a wavelength of 365 nm varies depending on the height of the target alignment control protrusion, the type of positive photosensitive resin used, and the like. Although not possible, it can be about 20% to 60%.

  Examples of a method of providing two types of semi-transparent regions having different transmittance characteristics include a method in which a plurality of semi-transparent films are laminated as described later, a film thickness of a semi-transparent film, and a semi-transparent film. And a method of adjusting the material.

  The shape of the transmissive region and the semi-transparent region is not particularly limited as long as the transmissive region and the semi-transparent region become an adjacent pattern. The shape of the target high spacer, low spacer, and alignment control protrusion It is appropriately selected depending on. Examples of the shape of the translucent region corresponding to the orientation control protrusion include a linear shape and a wedge shape. Further, examples of the shape of the translucent region corresponding to the low spacer include a circle, a rectangle, and a polygon.

(Ii) Light shielding area The light shielding area in the gradation mask used in the present invention is an area where a light shielding film is provided on a transparent substrate.

  The light shielding region may be a region where a light shielding film is formed on the transparent substrate, and only the light shielding film may be formed on the transparent substrate, and the light shielding film and the semitransparent film are formed on the transparent substrate. Also good. When the light-shielding film and the semi-transparent film are formed on the transparent substrate, the order of lamination of the transparent substrate, the light-shielding film and the semi-transparent film is not particularly limited. For example, as shown in FIG. The order may be substrate 2 / semi-transparent film 3 / light-shielding film 4, or the order of transparent substrate 2 / light-shielding film 4 / semi-transparent film 3 as shown in FIG.

  The gradation mask used in the present invention may have two types of light shielding regions (a first light shielding region and a second light shielding region) having different widths. In this case, as illustrated in FIG. 5, the high spacer can be formed using the first light shielding region, and the low spacer can be formed using the second light shielding region having a smaller width than the first light shielding region. .

  As the width of the first light-shielding region corresponding to the high spacer and the width of the second light-shielding region corresponding to the low spacer, the width of the first light-shielding region is larger than the width of the second light-shielding region. There is no particular limitation as long as the difference in height can be realized. Specifically, the width of the first light shielding region is appropriately set according to the size of the target high spacer, and can be about 15 μm to 60 μm. In addition, the width of the second light shielding region is appropriately set according to the size of the target low spacer, and can be about 10 μm to 30 μm.

  The shape of the light-shielding region is not particularly limited as long as the transmissive region and the semi-transparent region are adjacent to each other, and is appropriately selected according to the shapes of the intended high spacer and low spacer. Examples of the shape of the light shielding region corresponding to the high spacer and the low spacer include a circle, a rectangle, and a polygon.

(Iii) Translucent film The translucent film in the gradation mask used in the present invention is formed in a pattern on a transparent substrate and has a transmittance adjusting function.

As described above, it is preferable that the phase delay of the exposure light that has passed through the semi-transparent region with respect to the exposure light that has passed through the transmission region is relatively small, and the exposure light that has passed through the semi-transparent region with respect to the exposure light that has passed through the transmission region. It is preferable that the phase delay is not more than a predetermined value.
Examples of the material of the translucent film capable of realizing such a light phase difference include metals such as chromium, titanium, nickel, nickel alloy, molybdenum silicide, tantalum, aluminum, silicon, cobalt, and cobalt alloy. Among these, chromium, titanium, nickel, nickel alloy, and tantalum are preferable from the viewpoint of patternability. That is, it is preferable that the translucent film contains at least one metal selected from the group consisting of chromium, titanium, nickel, nickel alloy and tantalum.

  The semi-transparent region is a region where only a semi-transparent film is provided on the transparent substrate, and the transmissive region is a region where the transparent substrate is exposed. Therefore, when the phase difference of the semitransparent film is relatively small, the phase delay of the exposure light that has passed through the semitransparent region with respect to the exposure light that has passed through the transmission region can be made relatively small.

The phase difference of the translucent film is indicated by the product of the refractive index of the material constituting the translucent film and the film thickness of the translucent film. Therefore, the material constituting the translucent film preferably has a relatively low refractive index.
Examples of such a material having a relatively low refractive index include metals such as chromium, tantalum, and titanium, and compounds containing these metals.

  Here, when a metal is formed as a semitransparent film by a general method, a trace amount of oxygen and nitrogen are usually contained in the film. In order to realize the effect of the present invention, the content of the metal in the translucent film formed using a metal is preferably 97% or more, and more preferably 99% or more. Further, the content of nitrogen in the translucent film formed using a metal is preferably 3% or less, and more preferably 2% or less. Furthermore, the oxygen content in the translucent film formed using a metal is preferably 3% or less, and more preferably 2% or less.

  Further, the transmissivity of the translucent film is not particularly limited as long as a desired height difference between the high spacer, the low spacer, and the alignment control protrusion can be realized.

  The translucent film may be a single layer, or may be a film in which a plurality of films made of the above materials are laminated. In addition, when the translucent film | membrane consists of the film | membrane which consists of the material mentioned above in multiple layers, it is preferable that the number of laminated | stacked films | membranes shall be about 2 to 3 layers normally, and it shall be especially 2 layers. This is preferable from the viewpoint of controlling the phase difference.

  Further, since the transmissivity of the semitransparent film varies depending on the film thickness, the film thickness of the translucent film is appropriately selected according to the target transmissivity.

As a method for forming the translucent film, for example, a physical vapor deposition method (PVD) such as a sputtering method, an ion plating method, or a vacuum vapor deposition method is used.
For example, when forming a translucent film using chromium by sputtering, a carrier gas such as Ar gas is introduced into the reaction apparatus, and the translucent film is formed by reactive sputtering using a Cr target. can do. At this time, in addition to the carrier gas such as Ar gas, nitrogen gas or the like may be introduced into the reactor, but the composition of the translucent film is controlled by controlling the ratio of the flow rate of each gas. Therefore, when the flow rate of Ar gas is 1, the flow rate ratio of nitrogen gas is preferably 0.2 or less.

  The translucent film is formed in a pattern on the transparent substrate according to the shape of the translucent region.

(Iv) Light Shielding Film The light shielding film in the gradation mask used in the present invention is formed in a pattern on a transparent substrate.
The light-shielding film does not substantially transmit exposure light, and preferably has an average transmittance of 0.1% or less at the exposure wavelength. As such a light shielding film, a light shielding film generally used for a photomask can be used. For example, a metal film such as chromium, molybdenum silicide, tantalum, aluminum, silicon, titanium, or chromium oxide, chromium nitride, Examples thereof include films of oxides and nitrides of metals such as chromium oxynitride, silicon oxide, and silicon oxynitride. In addition, a nickel alloy, a cobalt alloy, a nickel-cobalt alloy, and films of these oxides, nitrides, oxynitrides, oxynitride carbides, and the like can also be used.

  Among them, examples of the light-shielding film include chromium-based films such as chromium, chromium oxide, chromium nitride, and chromium oxynitride; Ni—Cu—Ti and Ni—Ta—Cu—Ti mainly composed of nickel, and oxides thereof. Nickel alloy films such as nitride, oxynitride, oxynitride carbide, etc .; Co—Cu—Ti and Co—Ta—Cu—Ti mainly composed of cobalt, and oxides, nitrides, oxynitrides thereof, Cobalt alloy films such as oxynitride carbides; Ni—Co—Cu—Ti mainly composed of nickel and cobalt, and nickel-cobalt alloy films such as oxides, nitrides, oxynitrides and oxynitride carbides thereof Preferably used. The chromium film may be a single layer or may be a laminate of two or more layers.

  Further, the light shielding film may have a low reflection function. Since the low reflection function can prevent irregular reflection of exposure light, a clearer pattern can be formed. In order to add a low reflection function to the light shielding film, for example, a chromium compound such as chromium oxide for preventing reflection of exposure light may be contained on the surface of the light shielding film. In this case, the light shielding film may be formed by an inclined interface in which the content component gradually changes toward the surface.

  The thickness of the light shielding film is not particularly limited, and is appropriately selected depending on the type of the light shielding film. For example, in the case of a chromium film, the thickness is preferably about 50 nm to 150 nm.

  In addition, as a method for forming the light shielding film, for example, a physical vapor deposition method (PVD) such as a sputtering method, an ion plating method, or a vacuum vapor deposition method is used.

  The light shielding film is formed in a pattern on the transparent substrate according to the shape of the light shielding region.

(V) Transparent substrate As the transparent substrate in the gradation mask used in the present invention, a substrate generally used for a photomask can be used. For example, optically polished low expansion glass such as borosilicate glass and aluminoborosilicate glass, quartz glass, synthetic quartz glass, Pyrex (registered trademark) glass, soda lime glass, white sapphire and other non-flexible transparent rigid materials Alternatively, a flexible transparent material having flexibility such as a transparent resin film and an optical resin film can be used. Among them, quartz glass is a material having a small coefficient of thermal expansion, and is excellent in dimensional stability and characteristics in high-temperature heat treatment.

(Vi) Gradation mask The gradation mask used in the present invention is not particularly limited as long as the transmissive region, the translucent region, and the light-shielding region are formed. An area for use may be formed.

  The size of the gradation mask is appropriately adjusted according to the application, but can be, for example, about 300 mm × 400 mm to 1,600 mm × 1,800 mm.

  The method for manufacturing a gradation mask used in the present invention is such that a translucent film and a light-shielding film are formed in a pattern on a transparent substrate so that the transmissive area and the semitransparent area have adjacent patterns. The method is not particularly limited as long as the transmissive region, the translucent region, and the light shielding region can be arranged.

  In particular, the gradation mask manufacturing method uses the transmission region and the semitransparent film as a material for forming a translucent film when a light intensity distribution is simulated when exposure is performed using the gradation mask. In a region within a distance of 5 μm from the boundary of the region, select a material whose light intensity monotonously decreases from the transmissive region toward the semi-transparent region and has no inflection point in the light intensity distribution, It is preferable to have a translucent film forming step of forming the translucent film using the material.

  In addition, when a light intensity distribution during exposure using a gradation mask is simulated, the light intensity from the transmissive area to the semi-transparent area at a predetermined distance from the boundary between the transmissive area and the semi-transparent area. Is monotonously decreasing and has no inflection point in the light intensity distribution, as described above, and thus will not be described here.

  Further, as a material for forming the translucent film, the transmittance at a wavelength of 365 nm of the translucent region is T (%), and the phase delay of the exposure light that has passed through the translucent region with respect to the exposure light that has passed through the transmissive region. It is preferable to select a material having −δ / ln (T / 100) of 0.4 or less when δ (rad).

  When the transmissivity of the translucent region at a wavelength of 365 nm is T (%) and the phase delay of the exposure light that has passed through the translucent region with respect to the exposure light that has passed through the transmissive region is δ (rad). , −δ / ln (T / 100) is 0.4 or less, as described above, and thus the description thereof is omitted here.

  Further, a general method can be applied as a method for manufacturing a gradation mask, which is described in detail in, for example, Japanese Patent Application Laid-Open No. 2007-178649.

(2) Method for Forming High Spacer, Low Spacer, and Orientation Control Projection In the present invention, a high spacer, a low spacer, and an orientation control projection made of a positive photosensitive resin can be formed simultaneously.

  In this step, first, the photosensitive resin layer is exposed through a gradation mask. As the exposure method, when the simulation is performed as described above, the light intensity is monotonously decreased from the transmissive region to the semi-transparent region at a predetermined distance from the boundary between the transmissive region and the semi-transparent region. The intensity distribution is not particularly limited as long as it does not have an inflection point, and examples thereof include a proximity exposure method and a mirror projection exposure method. This exposure causes an acid generation reaction in the irradiated area.

  After the exposure, development is performed. The photosensitive resin layer is partially removed by development. Since a positive photosensitive resin is used as the photosensitive resin, the portion decomposed by exposure is selectively removed, and the other portions remain. This development can be performed according to a general development method.

  Further, after the exposure and development, the formed high spacer, low spacer and alignment control protrusion may be subjected to heat treatment (post-bake). This heat treatment can be appropriately set, for example, at a temperature of 100 to 250 ° C. and a treatment time of about 10 to 60 minutes.

3. Other Steps In the present invention, a step of forming various members in the color filter can be performed as necessary before the photosensitive resin layer forming step or after the exposure / development step.

For example, an alignment film forming step of forming an alignment film so as to cover the high spacer, the low spacer, and the alignment control protrusion can be performed. The alignment film can be formed, for example, by applying an organic compound such as soluble polyimide, polyamic acid type polyimide, or modified polyimide by a general printing method or application method, and then baking.
The thickness of the alignment film can be about 500 to 1000 mm.

4). Applications The method for producing a color filter for a liquid crystal display device according to the present invention uses a predetermined gradation mask, and therefore is particularly suitable for producing a color filter for a large liquid crystal display device.
Moreover, the manufacturing method of the color filter for liquid crystal display devices of this invention can also be applied to manufacture of the board | substrate for monochrome liquid crystal display devices.

B. Color Filter The color filter of the present invention is manufactured using the above-described method for manufacturing a color filter for a liquid crystal display device.
The color filter of the present invention has a high spacer, a low spacer and an alignment control protrusion made of a positive photosensitive resin, and the positive photosensitive resin constituting the high spacer, the low spacer and the alignment control protrusion is a It is the same.
Further, other configurations of the color filter can be the same as those of a general color filter.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

Hereinafter, the present invention will be specifically described with reference to examples.
[Reference Example 1]
(Production of gradation mask)
A commercially available photoresist (ip-3500, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is placed on a conventional mask blank in which a chromium film (light-shielding film) is formed to a thickness of 100 nm on an optically polished 390 mm × 610 mm synthetic quartz substrate. After coating with a thickness of 600 nm and baking on a hot plate heated to 120 ° C. for 15 minutes, a desired light-shielding film intermediate pattern was drawn with a photomask laser drawing apparatus (LRS11000-TFT3 manufactured by Micronic Co., Ltd.).
Next, development was performed with a dedicated developer (NMD3 manufactured by Tokyo Ohka Kogyo Co., Ltd.) to obtain a resist pattern for a light shielding film.
Next, the resist pattern was used as an etching mask, the chromium film was etched, and the remaining resist pattern was stripped to obtain a desired light-shielding film intermediate pattern. A commercially available cerium nitrate wet etchant (MR-ES manufactured by The Inktec Co., Ltd.) was used for etching the chromium film. The etching time for the chromium film was 60 seconds.

Next, the substrate on which the light-shielding film intermediate pattern is formed is subjected to pattern dimension inspection, pattern defect inspection, pattern correction as necessary, and after being washed well, the chromium film (translucent film) is sputtered under the following conditions. To form a film. At this time, the thickness of the semitransparent film was 10 nm.
<Film formation conditions>
・ Gas flow ratio Ar: N ₂ = 5: 1
・ Power: 1.3kW
・ Gas pressure: 3.5mTorr
Next, a commercially available photoresist (ip-3500 manufactured by Tokyo Ohka Kogyo Co., Ltd.) was again applied on the semitransparent film at a thickness of 600 nm and baked on a hot plate heated to 120 ° C. for 15 minutes.
Subsequently, an image to be a translucent film pattern was drawn again with a laser drawing device (LRS11000-TFT3 manufactured by Micronic Co., Ltd.) and developed with a dedicated developer (NMD3 manufactured by Tokyo Ohka Kogyo Co., Ltd.) to obtain a resist pattern.
Next, using the resist pattern as a mask, the semitransparent film and the light shielding film were etched with a commercially available cerium nitrate wet etchant (MR-ES manufactured by The Inktec Co., Ltd.) to obtain a semitransparent film pattern and a light shielding film pattern. Etching was performed on the translucent film and the light shielding film.
Finally, the remaining resist was peeled off, and after undergoing inspection processes such as pattern dimension inspection and pattern defect inspection, pattern correction was performed as necessary to obtain a gradation mask.

(Production of color filter)
A glass substrate (Corning 1737 glass) having a size of 100 mm × 100 mm and a thickness of 0.7 mm was prepared as a substrate. After this substrate was washed according to a conventional method, a chromium thin film (thickness: 1000 mm) was formed on the entire surface of one side of the substrate by sputtering. A positive-type photosensitive resist (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied onto the chromium thin film, and exposed and developed through a predetermined mask to form a resist pattern. Next, using this resist pattern as a mask, the chromium thin film was etched to form a black matrix having a line width of 20 μm and a pitch of 100 μm.

  Next, a negative photosensitive resin composition for a red pattern, a negative photosensitive resin composition for a green pattern, and a negative photosensitive resin composition for a blue pattern having the following compositions were prepared.

<Negative photosensitive resin composition for red pattern>
Red pigment (Ciba Specialty Chemicals chromophthal red A2B) 4.8 parts by weight Yellow pigment (BASF Pariotor Yellow D1819) 1.2 parts by weight Dispersant (Dispervic 161 manufactured by BYK Chemie) 3 1.0 part by weight / monomer (SR399 manufactured by Sartomer) 4.0 parts by weight Polymer I 5.0 parts by weight initiator (Irgacure 907 manufactured by Ciba Specialty Chemicals) 1.4 parts by weight initiator (2, 2′-bis (o-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole) 0.6 part by weight / solvent (propylene glycol monomethyl ether acetate) 80.0 parts by weight

<Negative photosensitive resin composition for green pattern>
Green pigment (Avisia Monastral Green 9Y-C) 4.2 parts by weight Yellow pigment (BASF Paliotor Yellow D1819) 1.8 parts by weight Dispersant (Bicchemy Disperbic 161) 3.0 Parts by weight / monomer (SR399, manufactured by Sartomer) 4.0 parts by weight, polymer I 5.0 parts by weight, initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals) 1.4 parts by weight, initiator (2,2 ′ -Bis (o-chlorophenyl) -4,5,4 ', 5'-tetraphenyl-1,2'-biimidazole) 0.6 parts by weight / solvent (propylene glycol monomethyl ether acetate) 80.0 parts by weight

<Negative photosensitive resin composition for blue pattern>
Blue pigment (BASF Heliogen Blue L6700F) 6.0 parts by weight Pigment derivative (Abyssia Solsperse 5000) 0.6 parts by weight Dispersant (Bic Chemie Dispersic 161) 2.4 parts by weight Monomer (SR399, manufactured by Sartomer) 4.0 parts by weight, Polymer I, 5.0 parts by weight, initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals) 1.4 parts by weight, initiator (2,2'-bis (o -Chlorophenyl) -4,5,4 ', 5'-tetraphenyl-1,2'-biimidazole) 0.6 parts by weight / solvent (propylene glycol monomethyl ether acetate) 80.0 parts by weight

  The polymer I is based on 100 mol% of a copolymer of benzyl methacrylate: styrene: acrylic acid: 2-hydroxyethyl methacrylate = 15.6: 37.0: 30.5: 16.9 (molar ratio). 2-methacryloyloxyethyl isocyanate was added at 16.9 mol%, and the weight average molecular weight was 42500.

Next, a negative photosensitive resin composition for red pattern is applied by spin coating so as to cover the black matrix on the glass substrate, exposed and developed through a photomask for red pattern, and the red pattern is formed. Formed. The red pattern was rectangular (100 μm × 300 μm).
Then, the green pattern and the blue pattern were formed by the same operation using the negative photosensitive resin composition for the green pattern and the negative photosensitive resin composition for the blue pattern. As a result, a colored layer in which a red pattern, a green pattern, and a blue pattern were arranged was formed.

  Next, a transparent electrode layer (thickness 1500 mm) made of indium tin oxide (ITO) was formed by sputtering so as to cover the black matrix and the colored layer.

Next, a positive photosensitive resin composition (LC100VL, manufactured by Rohm and Haas, solid content 15%) was applied on the transparent electrode layer by spin coating, dried under reduced pressure, and prebaked at 100 ° C. for 3 minutes. Then, it exposed on the following conditions through said gradation mask.
<Exposure conditions>
・ Exposure dose: 50 mJ / cm ² (I-line conversion)
・ Exposure gap: 150μm
Next, development was performed using an aqueous potassium hydroxide solution, and then heat treatment was performed at 230 ° C. for 30 minutes to form spacers and alignment control protrusions simultaneously.

[Reference Example 2]
(Production of gradation mask)
A gradation mask was prepared in the same manner as in Reference Example 1 except that a semitransparent film was formed as described below.
The substrate on which the light-shielding film intermediate pattern is formed is subjected to pattern dimension inspection, pattern defect inspection, pattern correction as necessary, and after cleaning, a chromium oxynitride carbide film (translucent film) is sputtered under the following conditions The film was formed. At this time, the thickness of the chromium oxynitride carbide film was 33 nm.
<Film formation conditions>
Gas flow ratio Ar: CO ₂ : N ₂ = 1: 0.5: 0.5
・ Power: 1.5kW
・ Gas pressure: 3mTorr

(Production of color filter)
A color filter was produced in the same manner as in Reference Example 1.

[Evaluation of Reference Examples 1 and 2]
For the gradation masks of Reference Examples 1 and 2, the light intensity distribution was obtained by simulation. The simulation conditions are: exposure gap: 150 μm, Collimation: 1.5 °, exposure wavelength: 365 nm, transmissivity of translucent area T: 30% (365 nm), exposure passing through translucent area with respect to exposure light passing through transmissive area The phase delay of light (phase difference) δ: 0.02 rad or 1.22 rad, the line width of the translucent region: 15 μm, the exposure method: the proximity exposure method. The simulation result is shown in FIG.
In the gradation mask of Reference Example 1 (FIG. 3 (a)), the light intensity monotonously decreases from the transmissive region to the semi-transparent region in a region within a distance of 5 μm from the boundary between the transmissive region and the semi-transparent region. It was found that the light intensity distribution has no inflection point. On the other hand, in the gradation mask of Reference Example 2 (FIG. 3B), the light intensity decreases monotonously from the transmissive region to the semi-transparent region in a region within 5 μm from the boundary between the transmissive region and the semi-transparent region. Without having an inflection point in the light intensity distribution.

  The cross-sectional shapes of the spacers and alignment control protrusions formed using the gradation masks of Reference Examples 1 and 2 were observed with a scanning electron microscope, and the dimensions were measured. In addition, the cross-sectional shape of the spacer is a circle with a truncated cone, the cross-sectional shape of the alignment control protrusion is a circle with a kamaboko shape, and the unintentional pattern remains around the protrusion is x. did. The evaluation results are shown in Table 1.

  By using the gradation mask of Reference Example 1 for the exposure process, it was possible to form a pattern having the optimum shape and dimensions as the spacer and the alignment control protrusion.

[Reference Example 3]
(Production of gradation mask)
As shown in FIG. 8, it has a translucent region 12 in which the translucent film 3 is provided on the transparent substrate 2 and a transmissive region 13 from which the transparent substrate 2 is exposed. For the gradation mask 1 having an adjacent pattern, the light intensity distribution was obtained by simulation. FIG. 8A is a cross-sectional view taken along the line CC of FIG.

  The simulation conditions are: exposure gap: 150 μm, Collimation: 1.5 °, exposure wavelength: 365 nm, transmissivity of translucent area T: 10% to 90% (365 nm), translucent area for exposure light passing through the transmissive area The phase delay (phase difference) δ of the passed exposure light δ: 0.01 rad to 1.28 rad, the line width of the translucent region: 15 μm, the exposure method: the proximity exposure method.

  From the simulation results, the shape of the light intensity distribution was evaluated. Here, in a region within a distance of 5 μm from the boundary between the transmission region and the translucent region, the light intensity monotonously decreases from the transmission region to the semitransparent region, and the light intensity distribution has no inflection point. And the others were marked with x. Table 2 shows the evaluation of the shape of the light intensity distribution and the value of −δ / ln (T / 100).

  In the simulation, when −δ / ln (T / 100) is 0.4 or less, the region is within a distance of 5 μm from the boundary between the transmissive region and the semitransparent region, and is directed from the transmissive region to the semitransparent region. It was found that the light intensity decreased monotonously and had no inflection point in the light intensity distribution.

[Reference Example 4]
(Production of gradation mask)
The film thickness of the semi-transparent film is 16 nm, except that the light-shielding film and the semi-transparent film are patterned so as to have a light-shielding region for forming a high spacer and a semi-transparent region for forming a low spacer. A gradation mask was produced in the same manner as in Reference Example 1.

(Production of color filter)
A color filter was produced in the same manner as in Reference Example 1 except that instead of forming the spacer and the alignment control protrusion, the above-described gradation mask was used to form spacers having different heights (high spacer / low spacer). .

[Reference Example 5]
(Production of gradation mask)
The film thickness of the semi-transparent film is 52 nm, except that the light-shielding film and the semi-transparent film are patterned so as to have a light-shielding region for forming a high spacer and a semi-transparent region for forming a low spacer. A gradation mask was produced in the same manner as in Reference Example 2.

(Production of color filter)
A color filter was produced in the same manner as in Reference Example 1 except that instead of forming the spacer and the alignment control protrusion, the above-described gradation mask was used to form spacers having different heights (high spacer / low spacer). .

[Evaluation of Reference Examples 4 and 5]
For the gradation masks of Reference Examples 4 and 5, the light intensity distribution was obtained by simulation. The simulation conditions are: exposure gap: 150 μm, Collimation: 1.5 °, exposure wavelength: 365 nm, transmissivity of translucent area T: 15% (365 nm), exposure through the translucent area with respect to the exposure light that has passed through the transmissive area. Light phase delay (phase difference) δ: 0.03 rad or 1.93 rad, diameter of translucent region: 30 μm, exposure method: proximity exposure method. The simulation result is shown in FIG.
In the gradation mask of Reference Example 4 (FIG. 9A), the light intensity monotonously decreases from the transmissive region to the semi-transparent region in a region within a distance of 5 μm from the boundary between the transmissive region and the semi-transparent region. It was found that the light intensity distribution has no inflection point. On the other hand, in the gradation mask of Reference Example 5 (FIG. 9B), the light intensity monotonously decreases from the transmissive region to the semi-transparent region in a region within 5 μm from the boundary between the transmissive region and the semi-transparent region. Without having an inflection point in the light intensity distribution.

  The cross-sectional shape of spacers having different heights formed using the gradation masks of Reference Examples 4 and 5 was observed with a scanning electron microscope, and the dimensions were measured. In addition, as for the cross-sectional shape of the spacer, a circle having a truncated cone is indicated by ◯, and a spacer having an unintended pattern remaining around the protrusion is indicated by ×. The evaluation results are shown in Table 3.

  By using the gradation mask of Reference Example 4, it was possible to form a pattern having an optimum shape and size as spacers having different heights.

[Example 1]
(Production of gradation mask)
10, the light shielding film 4 is provided on the transparent substrate 2 as shown in FIG. 10, the first light shielding region 11 a corresponding to the high spacer, and the light shielding film 4 is provided on the transparent substrate 2. A second light-shielding region 11b corresponding to the low spacer, a translucent region 12 corresponding to the alignment control protrusions provided only on the translucent film 3 on the transparent substrate 2, and a transmissive region 13 where the transparent substrate 2 is exposed. The gradation mask 1 having a pattern in which the semitransparent region 12 and the transmissive region 13 are adjacent to each other was produced. FIG. 10 (a) is a cross-sectional view taken along the line DD of FIG. 10 (b).
The width (diameter) d1 of the first light shielding region was 30 μm, the width (diameter) d2 of the second light shielding region was 15 μm, and the width d3 of the translucent region was 15 μm. As for the transmissivity characteristics of the translucent film, the transmissivity at a wavelength of 365 nm was 30%, the transmissivity at a wavelength of 406 nm was 30%, and the transmissivity at a wavelength of 436 nm was 30%.

  Further, with respect to this gradation mask, when the light intensity distribution was obtained by simulation in the same manner as in Reference Example 1, the simulation result was the same as that of the gradation mask in Reference Example 1.

(Production of color filter)
In the same manner as in Reference Example 1, a black matrix and a colored layer were formed on the substrate, and a transparent electrode layer was further formed.

Next, a positive photosensitive resin composition (LC100VL, manufactured by Rohm and Haas, solid content 15%) was applied on the transparent electrode layer by spin coating, dried under reduced pressure, and prebaked at 100 ° C. for 3 minutes. Then, it exposed on the following conditions through said gradation mask.
<Exposure conditions>
・ Exposure dose: 50 mJ / cm ² (I-line conversion)
・ Exposure gap: 150μm
Next, development was performed using an aqueous potassium hydroxide solution, and then heat treatment was performed at 230 ° C. for 30 minutes to simultaneously form a high spacer, a low spacer, and an alignment control protrusion. As a result, as shown in FIG. 11, a light shielding portion (black matrix) 22, a colored layer (red pattern 23R, green pattern 23G, blue pattern 23B) and a transparent electrode layer 24 are formed on the substrate 2, and a high level is formed thereon. A color filter in which the spacer 51, the low spacer 52, and the alignment control protrusion 53 were formed was obtained. FIG. 11A is a cross-sectional view taken along line EE of FIG.
The cross-sectional shapes of the obtained high spacer, low spacer and alignment control protrusion were observed with a scanning electron microscope, and the dimensions were measured.

  By using the above-described gradation mask in the exposure process, two types of spacers having different heights (a high spacer and a low spacer) and an alignment control projection could be formed simultaneously at a desired height.

[Example 2]
(Production of gradation mask)
As in Reference Example 1, as shown in FIG. 12, the light shielding film 4 is provided on the transparent substrate 2, and the light shielding region 11 corresponding to the high spacer and only the semitransparent film 3 are provided on the transparent substrate 2. The first semitransparent region 12a corresponding to the low spacer, the second translucent region 12b corresponding to the alignment control protrusion, and the transparent substrate 2 exposed, wherein only the semitransparent film 3 is provided on the transparent substrate 2 A gradation mask 1 having a region 13 and having a pattern in which the translucent regions 12a and 12b and the transmissive region 13 are adjacent to each other was manufactured. FIG. 12A is a cross-sectional view taken along line FF in FIG.
The width (diameter) d4 of the light shielding region was 30 μm, the width (diameter) d5 of the first translucent region was 30 μm, and the width d6 of the second translucent region was 15 μm. The transmittance of the first translucent region at a wavelength of 365 nm was 15%, and the transmittance of the second translucent region at a wavelength of 365 nm was 30%.

  Further, when the light intensity distribution of this gradation mask was obtained by simulation in the same manner as in Reference Example 4, the simulation result was the same as that of the gradation mask in Reference Example 4.

(Production of color filter)
In the same manner as in Example 1, a black matrix and a colored layer were formed on a substrate, a transparent electrode layer was further formed, and a high spacer, a low spacer, and an alignment control protrusion were simultaneously formed.
The cross-sectional shapes of the obtained high spacer, low spacer and alignment control protrusion were observed with a scanning electron microscope, and the dimensions were measured.

  By using the above-described gradation mask in the exposure process, two types of spacers having different heights (a high spacer and a low spacer) and an alignment control projection could be formed simultaneously at a desired height.

[Comparative example]
(Production of gradation mask)
The light shielding film is patterned in the same manner as in Reference Example 1, and a pattern 121 corresponding to a high spacer, a pattern 122 corresponding to a low spacer, and a light shielding film 104 provided on a transparent substrate 102 as shown in FIG. Then, the gradation mask 101 having the pattern 123 corresponding to the alignment control protrusion was produced. FIG. 13 (a) is a cross-sectional view taken along the line GG of FIG. 13 (b).
The width (diameter) d7 of the pattern 121 was 30 μm, the width (diameter) d8 of the pattern 122 was 15 μm, and the width d9 of the pattern 123 was 7 μm.

(Production of color filter)
In the same manner as in Example 1, a black matrix and a colored layer were formed on a substrate, a transparent electrode layer was further formed, and a high spacer, a low spacer, and an alignment control protrusion were simultaneously formed.
The cross-sectional shapes of the obtained high spacer, low spacer and alignment control protrusion were observed with a scanning electron microscope, and the dimensions were measured.

When the above-described gradation mask was used in the exposure process, the alignment control protrusion could not be achieved at the target height (1.5 μm). In this case, if the line width is reduced, the height approaches the target value, but the line width becomes too thin. Therefore, it can be seen that the target height and line width cannot be realized simultaneously with the gradation mask as described above.
Further, the alignment control protrusions are easily affected by process variations, and have a large variation in height of 1.3 to 2.4 μm and line width of 7 to 12 μm.

It is a schematic diagram which shows an example of the gradation mask used for this invention. It is a figure for demonstrating the simulation of light intensity distribution. It is a graph which shows a simulation result. It is process drawing which shows an example of the manufacturing method of the conventional color filter for liquid crystal display devices. It is process drawing which shows an example of the manufacturing method of the color filter for liquid crystal display devices of this invention. It is process drawing which shows the other example of the manufacturing method of the color filter for liquid crystal display devices of this invention. It is a schematic diagram which shows the other example of the gradation mask used for this invention. It is a schematic diagram which shows the gradation mask in the reference example 3. It is a graph which shows the simulation result of the gradation mask in the reference examples 4 and 5. FIG. 6 is a schematic diagram illustrating a gradation mask in Example 1. FIG. 4 is a schematic diagram illustrating a color filter for a liquid crystal display device in Example 1. FIG. 6 is a schematic diagram illustrating a gradation mask in Example 2. FIG. It is a schematic diagram which shows the gradation mask in a comparative example. It is a schematic diagram which shows an example of the conventional gradation mask.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Tone mask 2 ... Transparent substrate 3 ... Semi-transparent film 4 ... Light-shielding film 11 ... Light-shielding region 12 ... Semi-transparent region 13 ... Transmission region 21 ... Substrate 23 ... Colored layer 25 ... Photosensitive resin layer 51 ... High spacer 52 ... Low spacer 53 ... Orientation control protrusion

Claims (5)

A photosensitive resin layer forming step of forming a photosensitive resin layer made of a positive photosensitive resin on the substrate on which the colored layer is formed, and exposing and developing the photosensitive resin layer using a gradation mask; And a method for producing a color filter for a liquid crystal display device, which comprises an exposure / development step for simultaneously forming a high spacer, a low spacer and an alignment control protrusion made of the positive photosensitive resin,
The gradation mask has a transparent substrate, a light-shielding film and a semi-transparent film formed in a pattern on the transparent substrate, the transmission region where the transparent substrate is exposed, and the light-shielding film on the transparent substrate Having a light-shielding region provided and a semi-transparent region in which only the semi-transparent film is provided on the transparent substrate, and having a pattern in which the transmissive region and the semi-transparent region are adjacent,
The gradation mask has a transmittance of T (%) at a wavelength of 365 nm of the exposure light in the semi-transparent region, and a phase delay of the exposure light that has passed through the semi-transparent region with respect to the exposure light that has passed through the transmission region. (Rad) , at least one of the refractive index of the material of the translucent film and the film thickness of the translucent film is adjusted so that −Δ / ln (T / 100) is 0.4 or less. It has been
When a simulation of the light intensity distribution at the time of exposure using the gradation mask is performed, the region from the transmission region to the semi-transparent region is within a distance of 5 μm from the boundary between the transmission region and the semi-transparent region. A method for producing a color filter for a liquid crystal display device, characterized in that the light intensity decreases monotonously and has no inflection point in the light intensity distribution.   In the gradation mask, the light shielding region includes a first light shielding region corresponding to the high spacer and a second light shielding region corresponding to the low spacer, and the width of the first light shielding region is the second light shielding region. 2. The method for producing a color filter for a liquid crystal display device according to claim 1, wherein the color filter is larger than the width of the region.   In the gradation mask, the translucent region includes a first translucent region corresponding to the low spacer and a second translucent region corresponding to the alignment control protrusion, and the first translucent region The method for manufacturing a color filter for a liquid crystal display device according to claim 1, wherein the transmittance is lower than the transmittance of the second translucent region.   The translucent film in the gradation mask contains at least one metal selected from the group consisting of chromium, titanium, nickel, nickel alloy and tantalum. The manufacturing method of the color filter for liquid crystal display devices of description.   A color filter manufactured using the method for manufacturing a color filter for a liquid crystal display device according to any one of claims 1 to 4.

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