JP7099200B2 - A photomask and a method for manufacturing a color filter using the photomask. - Google Patents

Description

The present invention relates to a photomask for producing a color filter and a method for manufacturing a color filter using the photomask.

The liquid crystal display device is composed of a liquid crystal panel in which a liquid crystal layer is sandwiched between a pair of transparent substrates. Specifically, a color filter substrate on which colored pixels and the like are formed and a TFT array substrate on which a drive circuit such as a thin film transistor (TFT) is formed are opposed to each other and bonded to each other via a spacer that controls a gap, and a liquid crystal display is formed in the gap. Is enclosed and configured.

Recently, the size of the liquid crystal panel itself is required to be increased, and the production efficiency is also required to be improved. Therefore, in the color filter substrate, it is particularly important to increase the size of the mother glass to efficiently manufacture the multi-imposed color filter substrate. For example, in FIG. 6A, a 4 × 4 color filter substrate 40 is impositioned on one mother glass 40M. Hereinafter, in the present application, the unit of the imposition color filter substrate may be referred to as a “cell”.

The active area 46 of each cell 40 is partitioned by a frame portion 45 as shown in FIG. 6 (b). In the active area 46, as shown in FIG. 6C, an opening 44 for forming a colored pixel is partitioned by a black matrix (BM) line. After the color filter substrate is bonded to the TFT array substrate, the BM has a grid pattern formed by a thin wire called the source wiring of the TFT array and a BM thin wire 42 and a BM thick wire 43 that substantially overlap the thick wire called the gate wiring in a plan view. It is patterned in. The line width of the frame portion 45 is much thicker than that of the BM thin line 42 and the BM thick line 43.
In the present application, when the BM thin line and the BM thick line are not distinguished, they are simply referred to as a BM pattern.

In the manufacture of a color filter substrate, a BM thin wire 42, a BM thick wire 43, and a frame portion 45 are collectively formed on a transparent substrate made of a glass substrate or the like, and then R (red), G (green), B ( Blue) and other colored pixels are formed. The pattern of the BM, the frame portion, and the colored pixels is usually formed by subjecting a photosensitive resin composition (photosensitive resist) to proximity (proximity) exposure using a photomask, development, or the like by a photolithography method.

Regarding the constituent materials and methods of BM and frame pattern, in recent years, due to environmental problems and the simplicity of the manufacturing method, photolithography has been applied to photosensitive resists in which black pigments are dispersed instead of conventional Cr (chromium). Many methods have been adopted to directly form the film. The film thickness of such a resin BM and the resin frame portion for ensuring a predetermined optical density is thicker than that of the Cr pattern.

On the other hand, in recent years, the design line width of the BM pattern has also become higher in definition due to the higher definition of the liquid crystal display device (specifically, 700 ppi = pixels per inch or more) and the higher brightness, and the BM pattern in the active area 46 has become higher in definition. The difference in design line width between the frame portion 45 and the frame portion 45 is large (see FIG. 6 (c)). Therefore, in the batch development process of the BM pattern and the frame portion 45 in the manufacturing process, a local development rate difference occurs, and the BM pattern in the vicinity of the frame portion 45 in the active area 46 becomes thinner than the original design line width. The finishing phenomenon is occurring.

That is, since the BM in the active area 46 has a grid pattern, the photosensitive resist is removed and the developer becomes a consumption area, and the developer fatigues. However, since the photosensitive resist is not removed in the frame portion 45, it becomes a non-consumption area. There is no developer fatigue. Therefore, the closer to the frame portion 45, the more the active state of the developing solution is maintained, so that the line width of the BM pattern in the vicinity of the frame portion 45 becomes thinner as the development progresses as compared with the central region of the active area. This phenomenon is called the microloading effect.
Although the line width thinning of the BM pattern can occur in both the BM thin line and the BM thick line, the thinning (disappearance, unresolution) of the BM thin line, which is particularly problematic, will be described below in the present application.

FIG. 7 is a schematic plan view illustrating the line width narrowing and partial disappearance of the BM thin line due to the microloading effect. The figure in the left column of FIG. 7 shows a part of a normal photomask, and the figure in the right column uses the photomask and a photocurable negative photosensitive resist (hereinafter abbreviated as negative resist). The transferred BM pattern and the frame portion 55 are shown. As shown in FIG. 7A, the BM thin line 52p in the BM thin line area 52a closest to the translucent portion 55p of the photomask 51P which is the frame portion 55 is finely transferred like the BM thin line 52q on the right side.

FIG. 7B shows a case where the BM pattern has been further refined as compared with FIG. 7A, and the BM in the BM thin line area 62a closest to the translucent portion 65p of the photomask 61P which is the frame portion 55. Since the originally designed line width is small, the thin line 62p becomes even thinner as a result of transfer, and peeling occurs and the BM thin line disappears as in the BM thin line area 62b on the right side.

As described above, the narrowing of the line width of the BM thin line (deterioration of in-plane uniformity in the active area) due to the microloading effect becomes larger toward the position closer to the frame, and becomes more remarkable with the recent increase in the size of the mother glass. It is a cause of deterioration of the display quality of. In the present application, the case where the BM thin line area closest to the frame portion is narrowed with a certain width is mainly described, but even when viewed within the area, as shown in FIG. 8, the closer to the frame portion 55, the thinner the area.

In response to the above problem, in the photomask for forming a BM pattern, the line width of the BM in the region near the frame of the color filter is designed to be thicker in advance by the amount that is thinner than the line width in the central region of the active area in the developing process. A method of performing correction (line width correction) is disclosed (Patent Document 1).

FIG. 9 is a schematic plan view illustrating the relationship between the line width correction and the line width thinning of the BM thin line due to the microloading effect. In FIG. 9A, as a result of using the photomask 51R in which the BM thin line in the thinned area 52c is corrected to be thick in advance as in 52r, the thinning is eliminated in the developed pattern 51S as in the BM line width 52s. There is.

However, in the line width correction method, as shown in FIG. 9B, as the definition of the BM pattern further increases, the light-shielding portion becomes extremely narrow like the BM fine wire 62r in the area 62c, and as a result, the transferred area 62d Then, the resolution is lost and it cannot be formed as a BM thin line.

Further, as described above, the region near the frame portion of the color filter in which the line width of the BM becomes narrower with respect to the central region of the active area in the developing process differs depending on the shape of the BM pattern. Therefore, it is not easy to accurately grasp the region near the frame portion of the color filter in which the BM line width is actually narrowed in the developing process.

Similarly, for color filters having BM patterns of various shapes, it is extremely troublesome and difficult to accurately grasp the area near the frame and properly perform the line width correction of the photomask as described above. Have.

Furthermore, depending on the application, complex cell shapes such as circular ones have appeared, and in that respect as well, for the actual work of properly correcting the line width of the photomask as described above. It becomes a big barrier.

On the other hand, with respect to uniform development processing on a large substrate (uniform distribution of developer and uniform replacement efficiency), measures such as inclined transfer and shaking of the developer spray nozzle are taken. Although this measure contributes to the uniformity of the developing process on the entire surface of the substrate, it is considered that the effect on the uniformity of the developer between the local frame portion and the active area is small.

Furthermore, a halftone mask is used for the frame portion, the exposure amount is adjusted so that the frame portion is irradiated with less light than the BM pattern portion, the thickness of the frame portion is reduced, and the developer is physically developed. It has been proposed to change the flow of the developer and prevent the developer from staying in the vicinity of the frame portion (Patent Document 2).

However, the method of forming the frame portion with the halftone mask prevents the BM line width from narrowing or constricting, but the optical density of the frame portion is lower than the specified density, so that the BM layer is laminated on the frame portion as a correction. However, as the number of steps increases, the laminated portion may peel off.

Japanese Unexamined Patent Publication No. 2002-122856 Japanese Unexamined Patent Publication No. 2009-244523

The present disclosure has been made in order to solve the above-mentioned problems, and the purpose of the present disclosure is to suppress the thinning of the line width in the vicinity of the frame portion of the BM due to development, and to achieve the in-plane uniformity of the BM line width. It is an object of the present invention to provide a photomask for producing an excellent high-definition color filter, and a method for producing a color filter using the photomask.

In order to solve the above problems, the invention according to claim 1 is for producing a color filter for collectively forming a black matrix for forming colored pixels in an opening and a frame portion for partitioning a plurality of the openings. It ’s a photomask of
The photomask has a light-transmitting portion, a light-shielding portion, and a semi-light-shielding portion having one or more different transmittances.
The transmittance of the semi-light-shielding portion is 50% or less, which is higher than that of the light-shielding portion.
The frame portion and the black matrix are formed by the translucent portion, and the frame portion and the black matrix are formed.
The opening is formed by the light-shielding portion and the semi-light-shielding portion.
The opening closest to the frame portion is a photomask characterized in that it is formed by the semi-light-shielding portion having the highest transmittance among the semi-light-shielding portions.

The invention according to claim 2 is a photomask for producing a color filter, which collectively forms a black matrix for forming colored pixels in an opening and a frame portion for partitioning a plurality of the openings.
The photomask has a light-shielding portion, a translucent portion, and a semi-transmissive portion having one or more different transmittances.
The transmittance of the semi-transmissive portion is 50% or more, which is lower than that of the translucent film.
The frame portion and the black matrix are formed by the light-shielding portion, and the frame portion and the black matrix are formed.
The opening is formed by the translucent portion and the semi-transmissive portion.
The opening closest to the frame portion is a photomask characterized in that it is formed by the semi-translucent portion having the lowest transmittance among the semi-transmissive portions.

The invention according to claim 3 has the semi-light-shielding portion according to claim 1 or the semi-transmissive portion according to claim 2.
The photomask according to claim 1 or 2, which comprises a dot pattern of a thin film having a light-shielding property.

The invention according to claim 4 uses the photomask according to any one of claims 1 to 3.
This is a method for manufacturing a color filter, which is characterized by the above.

According to the present disclosure, there is provided a photomask for producing a high-definition color filter which suppresses the thinning of the line width in the vicinity of the frame portion of the BM due to development and has excellent in-plane uniformity of the BM line width, and uses the photomask. A method for manufacturing a color filter that has been used is provided. The photomask of the present disclosure and the method of manufacturing a color filter using the same are for a photomask for manufacturing a color filter without line width correction, but it is also effective when used in combination with line width correction as appropriate. be.

(A) Partial schematic plan view, (b) Light intensity distribution of AA'cross section, (c) Negative resist of AA' cross section during development, according to the photomask of the first embodiment of the present disclosure. FIG. 3 is a schematic plan view of a film thickness distribution and (d) a pattern after development. (A) Partial schematic plan view, (b) Light intensity distribution of CC'cross section, (c) Positive resist of CC' cross section during development, according to the second embodiment of the present disclosure. FIG. 3 is a schematic plan view of a film thickness distribution and (d) a pattern after development. (A) Partial schematic plan view, (b) Light intensity distribution of EE'cross section, (c) Negative resist of EE'cross section during development, according to the photomask of the third embodiment of the present disclosure. FIG. 3 is a schematic plan view of a film thickness distribution and (d) a pattern after development. (A) A schematic plan view of a semi-light-shielding portion (represented by portion B) closest to the frame portion in FIG. 1 (a) according to a modified example of the photomask of the first embodiment of the present disclosure, (b) the present disclosure. 2 is a schematic plan view of a translucent portion (represented by the D portion) closest to the frame portion in FIG. 2 (a) according to a modified example of the photomask of the second embodiment. (A) A schematic plan view of a semi-light-shielding portion (represented by portion B) closest to the frame portion in FIG. 1 (a), according to another modification of the photomask of the first embodiment of the present disclosure, (b). It is a schematic plan view of the translucent part (represented by D part) which is the closest to the frame part in FIG. 2A, which concerns on another modification of the photomask of 2nd Embodiment of this disclosure. It is a schematic plan view for demonstrating (a) imposition of a color filter, (b) a cell, (c) an unconsumed area and a consumed area of a developer in a development process in the conventional color filter manufacturing. It is a schematic plan view which illustrates (a) line width narrowing and (b) partial disappearance of a BM thin line by a microloading effect in the conventional color filter manufacturing. It is a schematic plan view which illustrates the case where the line width of a BM fine line becomes narrower as it gets closer to a frame part in a BM thin line area by a microloading effect in the conventional color filter manufacturing. In relation to the relationship between the line width correction and the line width thinning of the BM thin line due to the microloading effect in the conventional color filter manufacturing, when (a) the line width thinning of the BM thin line is eliminated, (b) it is not resolved as a BM thin line. It is a schematic plan view which illustrates the case.

Hereinafter, a photomask according to an embodiment of the present invention and a method for manufacturing a color filter using the same will be described with reference to the drawings. The same components are designated by the same reference numerals unless there is a reason for convenience. In each drawing, the thickness and ratio of the components may be exaggerated for the sake of readability, and the number of components may be reduced. Further, the present invention is not limited to the following embodiments as they are, and can be embodied by appropriate combinations and modifications as long as they do not deviate from the gist.

FIG. 1A relates to a photomask of the first embodiment of the present disclosure, in which a black matrix for forming colored pixels in openings and a frame portion for partitioning a plurality of openings are formed by using a negative resist. It is a partial schematic plan view of a photomask for collective formation.
In the present application, when the BM pattern is formed, the BM thin lines extend in the X direction and are parallel in the Y direction in FIG. 1, and the thick BM lines extend in the Y direction and are parallel in the X direction. Will be described as an example in the case of a rectangular shape long in the X direction. Further, the frame portion extends in both the X direction and the Y direction, but in the present application, the frame portion 15 extending in the Y direction will be described as a representative.

The photomask 10 of the first embodiment has a semi-light-shielding portion (1 of 17-1 in FIG. 1) having a transmittance of one or more different from the translucent portions 12, 13, 15 and the light-shielding portions 17-2, 17-3. The transmissivity of the semi-light-shielding portion 17-1 is 50% or less, but the transmittance is higher than that of the light-shielding portions 17-2 and 17-3 (in other words, the light-shielding ratio is low).

By performing lithography using the photomask 10 and the negative resist of the first embodiment, as shown in FIG. 1 (d), after the development is completed, the translucent portion 15 is used for the frame portion 5, and the translucent portion 13 is used for the thick BM line. 3. The translucent portion 12 forms BM fine wires 2-1, 2-2, 2-3. Further, the light-shielding portions 17-2 and 17-3 are openings 4-2 and 4-3, respectively. The opening 4-1 closest to the frame portion 5 is formed by the semi-light-shielding portion 17-1 having the highest transmittance among the semi-light-shielding portions having one or more different transmittances.

By using the photomask 10 of the first embodiment, the photomask 10 disappears in the past (FIG. 7 (b) right), or the resolution is not obtained even if the line width correction is applied (FIG. 9 (b) right). BM thin lines can be formed close to the design line width. The reason will be described below.

FIG. 1B shows the light intensity distribution of the light passing through the photomask 10 of the first embodiment of the present disclosure along the AA'cross section of the photomask 10, and is transmitted toward the upper side (direction indicated by the arrow). It means that the rate is high. The translucent portions 12, 13 and 15 have the highest transmittance, and the light-shielding portions 17-2 and 17-3 have the lowest transmittance and are shielded from light. Further, as described above, the transmittance of the semi-light-shielding portion 17-1 is 50% or less, but the transmittance is higher than that of the light-shielding portion (in other words, the light-shielding ratio is low).

FIG. 1 (c) shows the negative resist film thickness distribution along the AA'cross section during development, which means that the film thickness is thicker toward the upper side (direction indicated by the arrow). As described above, during the development of the negative resist, the portion exposed by the light passing through the translucent portions 13 and 15 has the thickest film thickness, and the portion shaded by the light-shielding portions 17-2 and 17-3 is the most film. The thickness becomes thinner. The portion exposed by the light that has passed through the semi-light-shielding portion 17-1 has an intermediate film thickness.

In other words, the portion exposed by the light that has passed through the semi-light-shielding portion 17-1 has a slower development speed than the portion shaded by the light-shielding portions 17-2 and 17-3. Therefore, in the developing process, the step d2 between the portion exposed by the light passing through the translucent portions 13 and 15 and the portion exposed by the light passing through the semi-light-shielding portion 17-1 forms the translucent portions 13 and 15. It is smaller than the step d1 between the portion exposed by the passed light and the portion shaded by the light-shielding portions 17-2 and 17-3.

That is, in the development of the negative resist exposed using the photomask 10 of the first embodiment, the developer consumption is slower in the vicinity of the frame portion than in the central region of the active area, so that the developer fatigue continues to progress. I will continue. Further, since the step d2 in the vicinity of the frame portion is smaller than the step d1 in the central region of the active area, the phenomenon that the developer stays in the vicinity of the frame portion is also reduced. From these facts, when the line width correction is not performed as in the past, the problem that the line width of the BM pattern near the frame is narrowed is suppressed, and the problem that the line width disappears in the high-definition BM thin line is solved, and the design line is used. It can be formed close to the width.

FIG. 2A relates to the photomask of the second embodiment of the present disclosure, in which a black matrix for forming colored pixels in openings and a frame portion for partitioning a plurality of openings are formed by using a positive resist. It is a partial schematic plan view of a photomask for collective formation.

The photomask 20 of the second embodiment has a semi-transmissive portion (27-1 in FIG. 2) having a transmittance of one or more different from the light-shielding portions 22, 23, 25 and the translucent portions 27-2, 27-3. The transmissive part 27-1 has a transmittance of 50% or more, but has a lower transmittance than the translucent parts 27-2 and 27-3.

By performing lithography using the photomask 20 and the positive resist of the second embodiment, after the development is completed, as shown in FIG. The light-shielding portion 22 forms BM thin lines 2-1, 2-2, 2-3. Further, the translucent portions 27-2 and 27-3 have openings 4-2 and 4-3, respectively. The opening 4-1 closest to the frame portion 5 is formed by the semi-transmissive portion 27-1 having the lowest transmittance among the semi-transmissive portions having one or more different transmittances.

By using the photomask 20 of the second embodiment, the photomask 20 disappears in the past (FIG. 7 (b) right), or is not resolved even if the line width correction is applied (FIG. 9 (b) right). BM thin lines can be formed close to the design line width. The reason will be described below.

FIG. 2B shows the light intensity distribution of the light passing through the photomask 20 of the second embodiment of the present disclosure along the CC'cross section of the photomask 20, and is transmitted toward the upper side (direction indicated by the arrow). It means that the rate is high. The light-shielding portions 22, 23, and 25 are shielded from light and have the lowest transmittance, and the light-transmitting portions 27-2, 27-3 have the highest transmittance. Further, as described above, the transmittance of the semi-transmissive portion 27-1 is 50% or more, but the transmittance is lower than that of the translucent portion.

FIG. 2 (c) shows the positive resist film thickness distribution along the CC'cross section during development, which means that the film thickness is thicker toward the upper side (direction indicated by the arrow). As described above, during the development of the positive resist, the portion shaded by the light-shielding portions 23 and 25 has the thickest film thickness, and the portion exposed by the light passing through the translucent portions 27-2 and 27-3 is the most film. The thickness becomes thinner. The portion exposed by the light that has passed through the semi-transmissive portion 27-1 has an intermediate film thickness.

In other words, the portion exposed by the light passing through the translucent portion 27-1 has a slower development speed than the portion exposed by the light passing through the translucent portions 27-2 and 27-3. Therefore, in the development process, the step d3 between the portion shaded by the light-shielding portions 23 and 25 and the portion exposed by the light passing through the semi-transmissive portion 27-1 is the portion shaded by the light-shielding portions 23 and 25. It is smaller than the step d1 with the portion exposed by the light that has passed through the translucent portions 27-2 and 27-3.

That is, in the development of the positive resist exposed using the photomask 20 of the second embodiment, the consumption of the developer is slower in the vicinity of the frame portion than in the central region of the active area, so that the fatigue of the developer continues to progress. I will continue. Further, since the step d3 in the vicinity of the frame portion is smaller than the step d1 in the central region of the active area, the phenomenon that the developer stays in the vicinity of the frame portion is also reduced. From these facts, when the line width correction is not performed as in the past, the problem that the line width of the BM pattern near the frame is narrowed is suppressed, and the problem that the line width disappears in the high-definition BM thin line is solved, and the design line is used. It can be formed close to the width.

FIG. 3A defines a black matrix that forms colored pixels in the openings and a plurality of openings, similarly to the photomask of the first embodiment of the third embodiment of the present disclosure. It is a partial schematic plan view of a photomask for collectively forming a frame portion by using a negative resist.

Comparing the photomask 30 of the third embodiment with the photomask 10 of the first embodiment, in the photomask 10 of the first embodiment, only 17-1 of the BM thin line area 12a closest to the frame portion is a semi-light-shielding portion. On the other hand, in the photomask 30 of the third embodiment, in addition to 37-1 of the BM thin line area 32a closest to the frame portion, 37-2 of the BM thin line area 32b closest to the frame portion is also a semi-light-shielding portion. ing. Further, the transmittance (light-shielding rate) of the semi-light-shielding section 37-1 is higher (lower) than the transmittance (light-shielding rate) of the semi-light-shielding section 37-2.

In the photomask of the present disclosure, when a negative resist is used, there may be a plurality of types of semi-light-shielding portions having different transmittances, and the transmittances are all 50% or less, but the BM thin line area close to the frame portion. The semi-light-shielding part has higher transmittance (lower light-shielding rate).

FIG. 3B shows the light intensity distribution of the light passing through the photomask 30 of the third embodiment of the present disclosure along the EE'cross section of the photomask 30, and is transmitted toward the upper side (direction indicated by the arrow). It means that the rate is high. The transmissive portions 32, 33, and 35 have the highest transmittance, and the semi-light-shielding portions 37-1, 37-2, and the light-shielding portions 37-3 have the lowest transmittance in this order.

FIG. 3 (c) shows the negative resist film thickness distribution along the EE'cross section during development, which means that the film thickness is thicker toward the upper side (direction indicated by the arrow). As described above, during the development of the negative resist, the portion exposed by the light passing through the translucent portions 33 and 35 has the thickest film thickness, and the portion exposed by the light passing through the semi-light-shielding portion 37-1 is half. The film thickness decreases in the order of the portion exposed by the light passing through the light-shielding portion 37-2 and the portion shaded by the light-shielding portion 37-3.

In other words, the portion exposed by the light passing through the semi-light-shielding portion 37-2 has a slower development speed than the portion shaded by the light-shielding portion 37-3, and is exposed by the light passing through the semi-light-shielding portion 37-1. The development speed of the shaded portion is further slower than that of the portion shaded by the semi-light-shielding portion 37-2. Therefore, in the development process, the step between the portion exposed by the light passing through the translucent portions 33 and 35 and the portion exposed by the light passing through the semi-light-shielding portion 37-2 is d4, and the translucent portions 33 and 35 are formed. The step between the portion exposed by the light that has passed and the portion exposed by the light that has passed through the semi-light-shielding portion 37-1 is d5, and the portion exposed by the light that has passed through the translucent portions 33 and 35 and the light-shielding portion 37- Assuming that the step d1 with the portion shaded by 3 is set, the steps decrease in the order of d1> d4> d5.

That is, in the development of the negative resist exposed using the photomask 30 of the third embodiment, the developer consumption becomes slower in the BM fine line area closer to the frame portion in the vicinity of the frame portion, so that the developer fatigue continues. And progress. Further, since the step in the vicinity of the frame portion is smaller in the BM thin line area closer to the frame portion than in the step d1 in the central region of the active area, the phenomenon that the developer stays in the vicinity of the frame portion is further reduced. From these facts, when the line width correction is not performed as in the past, the problem that the line width of the BM pattern near the frame is narrowed is suppressed, and the problem that the line width disappears in the high-definition BM thin line is solved, and the design line is used. It can be formed close to the width.

In FIG. 3, a photomask for producing a color filter using a negative resist has been described, but the same form can be applied to a photomask using a positive resist, even if there are a plurality of semi-transmissive portions having different transmittances. Well, the transmittance is 50% or more in each case, but the transmittance is lower in the semi-transmissive portion of the BM thin line area near the frame portion. In this case, the description of the light intensity after transmission through the photomask and the film thickness during development will be omitted because they can be easily inferred from the comparison between the explanations of FIGS. 1 and 2.

FIG. 4 (a) shows a semi-light-shielding portion (represented by the portion B) in the BM thin line area 12a closest to the frame portion in FIG. 1 (a) according to a modified example of the photomask of the first embodiment of the present disclosure. It is a schematic plan view of. In FIG. 1 (a), it is assumed that each of the semi-light-shielding portions has the same transmittance in the plane, but it may be divided in the frame portion direction (X direction), as shown in FIG. 4 (a). In addition, the transmittance of B-1 closest to the frame portion is the highest, and it may be lower in the order of B-2 and B-3.

FIG. 4B relates to a modified example of the photomask of the second embodiment of the present disclosure, and is represented by a semitransparent portion (represented by a D portion) in the BM thin line area 22a closest to the frame portion in FIG. ) Is a schematic plan view. In FIG. 2 (a), it is assumed that each of the semi-transmissive portions has the same transmittance in the plane, but it may be divided in the frame portion direction (X direction), and FIG. 4 (b) shows. As described above, the transmittance of D-1 closest to the frame portion may be the lowest, and the transmittance may be higher in the order of D-2 and D-3.

In FIG. 4, the semi-light-shielding portion and the semi-transmissive portion are divided within the BM thin line areas 12a and 22a closest to the frame portion and have different transmittances, but the semi-light-shielding portion and the semi-transmissive portion are not limited to the BM thin line area closest to the frame portion. , Like the BM thin line area 32b second closest to the frame portion in the photomask 30 of the third embodiment, in the photomask of the present disclosure, the semi-light-shielding portion and the semi-transmissive portion in the second and subsequent BM thin line areas are formed. It may have different transmittances divided.

When the semi-light-shielding part (semi-transmissive part) is divided, the "transmittance" is the first in which the "average transmittance" in the semi-light-shielding part (semi-transparent part) plane is the closest to the frame part. It is assumed that the highest (lowest), the second, ..., and the nth are higher (lower) in that order. In the form in which the semi-light-shielding portion and the semi-transmissive portion are divided and have different transmittances, as represented by FIG. 4, the line width becomes narrower as it is closer to the frame portion in the same BM thin line area as shown in FIG. Especially effective in some cases.

There are mainly two methods for forming a semi-light-shielding portion or a semi-transmissive portion included in the photomask of the present disclosure. The first method is a method of patterning and forming a translucent thin film usually called a halftone film represented by a metal oxide or a metal nitride. The transmittance can be appropriately selected by changing the content of oxygen or nitrogen at the time of film formation or by changing the film thickness.

The second method is a method of patterning a thin film having a light-shielding property such as Cr, which is usually used as a light-shielding film of a photomask, in a dot pattern shape. Although the dot pattern is not resolved and transferred onto the color filter substrate, the transmittance at the time of exposure can be appropriately changed by changing the shape, size, and arrangement density of the dots. Such a photomask is also referred to as a "concentration distribution mask" and is disclosed in detail in, for example, Japanese Patent Application Laid-Open No. 2002-244273.

Comparing the first method and the second method, the first method requires a film forming step and a patterning step of a halftone film, whereas the second method uses a thin film for a light-shielding portion to block light. Since the dot pattern may be formed at the same time as the portion formation, there is an advantage that it is not necessary to add a separate film forming step and patterning step.

Another advantage of the second method using the dot pattern is that changing the size and arrangement density of the dots has a higher degree of freedom than changing the elemental composition and the film thickness of the halftone film. .. Therefore, when the transmittance is changed in each semi-light-shielding portion (semi-transmissive portion) as shown in FIG. 4, the halftone film has to be stepwise, but the dot pattern changes more continuously. Can be made to.

On the other hand, the patterning of the dot pattern has a disadvantage that the data volume of the electron beam drawing machine for forming the original pattern becomes larger than the patterning of the halftone film. As one method for alleviating this, there is a method in which the dot pattern is not formed on the entire surface of each semi-light-shielding portion (semi-transmissive portion) but is formed intermittently.

That is, as shown in FIG. 5, the dot patterns B'-1 and B'are included in each semi-light-shielding portion (semi-transmissive portion) so as to include the light-shielding portion O (translucent portion T) in which the dot pattern does not exist. -2, B'-3, (D'-1, D'-2, D'-3) are arranged in the X direction. Even if they are arranged in this way, the connected state is intermittently maintained during the development of the BM thin lines vertically adjacent to each other in the Y direction (not shown), so that the BM thin lines are prevented from peeling off and disappearing. Here, even if B'-1, B'-2, B'-3, and D'-1, D'-2, and D'-3 have the same transmittance, they are the same as in FIG. The order may be different. The width of the light-shielding portion O (translucent portion T) is preferably 0.1 to 20.0 μm.

Based on the above, whether to select the first method or the second method as the method for forming the semi-light-shielding portion or the semi-transmissive portion is determined by the photomask pattern according to the application and specifications of the color filter. , The design conditions such as the line width, and the manufacturing conditions may be taken into consideration and appropriately selected.

The method for manufacturing a color filter using a photomask of the present invention can be suitably used for manufacturing a high-definition liquid crystal display device that requires high display quality, a color filter substrate constituting the high-definition liquid crystal display device, and a liquid crystal display panel.

10, 20, 30 ..... Photomask 2-1, 2-2, 2-3 ... BM thin wire 3 ............... BM thick wire 4- 1, 4-2, 4-3 ・ ・ ・ Opening 5 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Frame part 12, 13, 15, 32, 33, 35 ・ ・ ・ Translucent part 17-1 , 37-1, 37-2 ... Semi-light-shielding part 17-2, 17-3, 37-3 ..... Shading part 22, 23, 25 .....・ ・ ・ Light-shielding part 27-1 ・ ・ ・ ・ ・ Semi-transmissive part 27-2, 27-3 ・ ・ ・ ・ ・ ・ ・ ・ Translucent part 12a, 22a, 32a, 32b ... BM thin line area B ... One of the semi-light-shielding parts B-1, B-2, B-3, B'-1, B'-2, B' -3 ... Divided semi-light-shielding part D ... One of the semi-transmissive parts D-1, D-2, D-3, D'-1, D'-2, D' -3 ・ ・ ・ Divided semi-transmissive part O ・ ・ ・ ・ ・ ・ ・ Light-shielding part T ・ ・ ・ ・ ・ ・ Translucent part 40M ・ ・ ・ ・ ・ Mother glass 40 ・ ・ ・ ・ ・ ・ Cell ( Color filter)
41 ... Part of cell (color filter) 42 ... BM thin wire 43 ... BM thick wire 44 ... Opening 45 ... Frame Part (unconsumed area of developer)
46 ... Active area (developer consumption area)
51P, 61P ... Part of photomask (without line width correction) 51Q, 61Q ... Part of color filter after development by 51P, 61P 52p, 62p ... BM thin line, photo Translucent part of mask (without line width correction)
52a, 62a, 52e ... BM thin line area closest to the frame of the photomask 52q, 52t ... BM thin line after development (without line width correction)
52b, 62b ... The BM thin line area closest to the frame after development 55p, 65p ... The translucent part of the photomask (without line width correction) that becomes the frame.
51R, 61R ... Part of photomask (with line width correction) 51S, 61S ... Part of color filter after development by 51R, 61R 52r, 62r ... BM thin line of photomask ( With line width correction)
52c, 62c ... BM thin line area closest to the frame of the photomask 52s ... BM thin line after development (with line width correction)
52d, 62d ... BM thin line area closest to the frame after development ..... Frame part

Claims (4)

A photomask for producing a color filter that collectively forms a black matrix that forms colored pixels in an opening and a frame portion that partitions a plurality of the openings.
The photomask has a light-transmitting portion, a light-shielding portion, and a semi-light-shielding portion having one or more different transmittances.
The transmittance of the semi-light-shielding portion is 50% or less, which is higher than that of the light-shielding portion.
The frame portion and the black matrix are formed by the translucent portion, and the frame portion and the black matrix are formed.
The opening is formed by the light-shielding portion and the semi-light-shielding portion.
The opening closest to the frame portion is formed by the semi-light-shielding portion having the highest transmittance among the semi-light-shielding portions.
A photomask that features that. A photomask for producing a color filter that collectively forms a black matrix that forms colored pixels in an opening and a frame portion that partitions a plurality of the openings.
The photomask has a light-shielding portion, a translucent portion, and a semi-transmissive portion having one or more different transmittances.
The transmittance of the semi-transmissive portion is 50% or more, which is lower than that of the translucent film.
The frame portion and the black matrix are formed by the light-shielding portion, and the frame portion and the black matrix are formed.
The opening is formed by the translucent portion and the semi-transmissive portion.
The opening closest to the frame portion is formed by the semi-translucent portion having the lowest transmittance among the semi-transmissive portions.
A photomask that features that. The semi-light-shielding portion according to claim 1 or the semi-transmissive portion according to claim 2 is
It consists of a thin film dot pattern with light-shielding properties.
The photomask according to claim 1 or 2, wherein the photomask is characterized in that. The photomask according to any one of claims 1 to 3 is used.
A method for manufacturing a color filter, which is characterized by the fact that.

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