Production method of photosensitive resin pattern and production method of gray scale mask

Abstract

To solve problems that parallel ray which transmitted in a pattern is bent in an oblique direction on a surface of an arc-shape in a cross section of a pattern upper end part, and is diffused, and by diffusion of the light, a contour of the pattern end part becomes dim and the light is mixed with diffusion light of adjacent color pixels having different colors and therefore color purity is deteriorated.SOLUTION: A cross sectional shape of a pattern end part is formed in a set shape, and the cross sectional shape of the pattern upper end part is formed in a shape which is similar to a right angle shape as much as possible, for solving problems. A photosensitive resin pattern film having a less variation of a thickness in a peripheral area of the pattern end part is formed, and when the pattern film is used for a coloring pixel of a color filter, color mixing of transmission light is reduced, and color purity in an image can be enhanced.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a photosensitive resin pattern film and a method for manufacturing a grayscale mask. In particular, it is assumed to be used in fields such as pixel patterns of color filters.

Background Art

[0002] Conventionally, pixel patterns of color filters have been formed using a photolithography process. However, in the exposure process, there is a problem of insufficient exposure depth in the film thickness direction, and a defective phenomenon called undercut occurs in which the lower end of the pattern is greatly scooped out due to overdevelopment in the subsequent development process. And there is also a problem that a defective phenomenon called edge curl occurs in which the upper end of the pattern warps upward in the subsequent baking process.

[0003] As an invention having an effect of easily forming a functional pattern without these undercut and edge curl defective phenomena, the invention of Patent Document 1 is disclosed. The invention of Patent Document 1 is a photosensitive resin composition for forming a functional pattern in which a pattern obtained by pattern exposure and development after being applied on a glass substrate is baked to form a functional pattern. After development, the relationship between the length A (bottom length) of the substrate adhesion side and the length B of the upper part of the pattern of the cross-sectional shape of the development pattern is A < B, and after baking the development pattern at a temperature lower than the melting point of the inorganic powder, the cross-sectional shape self-forms into a shape that narrows from the substrate adhesion part toward the upper surface.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the invention of Patent Document 1 is characterized in that the developed pattern, which has an undercut shape due to firing, self-forms into a cross-sectional shape that narrows from the substrate contact portion toward the upper surface, so that the cross-sectional shape of the entire obtained functional pattern becomes kamaboko-shaped or hilly, and the cross-sectional shape of the upper end of the pattern becomes arc-shaped.

[0006] If a pattern film in which the upper end section of such a pattern is arc-shaped is applied to the pixel pattern of a color filter, parallel light rays incident from the backlight and transmitted through the pixel pattern are bent diagonally by the arc-shaped surface and scattered. This light scattering causes the outline of the pattern end to become blurred and the scattered light from adjacent pixels of different colors to mix with each other, resulting in a problem of reduced color purity.

[0007] The object of the present invention is to solve the above-mentioned problems by forming the cross-sectional shape of the upper end of the pattern to be as close to a right angle as possible, preferably a rectangular shape, and to form a photosensitive resin pattern film having less variation in thickness in the area around the end of the pattern than conventionally, so that even when the pattern film is used for the colored pixels of a color filter, there is less mixing of transmitted light and an image with high color purity can be obtained. [Means for solving the problem]

[0008] In order to achieve the above object, the method for producing a photosensitive resin patterned film of the present invention has the following configuration. That is, the present invention is a method for producing a photosensitive resin patterned film by exposing and developing a photosensitive resin film, preparing a test photosensitive resin pattern film using a test photosensitive resin film having the same composition as the photosensitive resin film and a test photomask; examining a cross-sectional shape of an upper end of a test photosensitive resin pattern film; setting a pseudo curve of a test photosensitive resin pattern film that is approximate to the cross-sectional shape; calculating a mask pseudo-curve symmetrical to the test photosensitive resin pattern film pseudo-curve, the mask pseudo-curve being symmetrical to the width direction of the test photosensitive resin pattern film; determining a grayscale mask having a light-shielding portion and an opening, the light-shielding portion and a semi-transmitting portion having a density gradient corresponding to the mask pseudo curve from a boundary between the light-shielding portion and the opening toward a center of the opening; exposing a photosensitive resin film using the grayscale mask; developing the exposed photosensitive resin film to form a pattern; The present invention relates to a method for producing a photosensitive resin pattern film comprising the steps of:

[0009] The present invention also provides a method for producing a photosensitive resin film using a test photomask, comprising the steps of: examining a cross-sectional shape of an upper end of a test photosensitive resin pattern film; setting a pseudo curve of a test photosensitive resin pattern film that is approximate to the cross-sectional shape; calculating a mask pseudo-curve symmetrical to the test photosensitive resin pattern film pseudo-curve, the mask pseudo-curve being symmetrical to the width direction of the test photosensitive resin pattern film; forming a semi-transmitting portion having a light-shielding portion and an opening, the semi-transmitting portion having a concentration gradient corresponding to the mask pseudo curve from a boundary between the light-shielding portion and the opening toward a center of the opening; The method for producing a grayscale mask comprises the steps of: Effect of the Invention

[0010] The method for manufacturing a photosensitive resin pattern film of the present invention is characterized by comprising the steps of: examining the cross-sectional shape of the upper end of a test photosensitive resin pattern film; setting a pseudo-curve approximating the cross-sectional shape; calculating a mask pseudo-curve symmetrical to the pseudo-curve with the width direction of the test photosensitive resin pattern film as an axis of symmetry; and determining a grayscale mask having a light-shielding portion and an opening, and a semi-transmitting portion having a concentration gradient equivalent to the mask pseudo-curve from the boundary between the light-shielding portion and the opening toward the center of the opening. Therefore, it is possible to determine an optimal grayscale mask that is suitable for the cross-sectional shape of the photosensitive resin pattern film of the present invention to be applied.

[0011] A method for manufacturing a grayscale mask according to the present invention includes the steps of: forming a test photosensitive resin pattern film using a photosensitive resin film and a test photomask; examining a cross-sectional shape of an upper end of a test photosensitive resin pattern film; setting a pseudo curve of a test photosensitive resin pattern film that is approximate to the cross-sectional shape; calculating a mask pseudo-curve symmetrical to the test photosensitive resin pattern film pseudo-curve, the mask pseudo-curve being symmetrical to the width direction of the test photosensitive resin pattern film; forming a semi-transmitting portion having a light-shielding portion and an opening, the semi-transmitting portion having a concentration gradient corresponding to the mask pseudo curve from a boundary between the light-shielding portion and the opening toward a center of the opening; Therefore, there is an effect that it is possible to manufacture a grayscale mask capable of manufacturing a photosensitive resin pattern film in which the cross-sectional shape of the pattern end is rectangular and the cross-sectional shape of the upper end of the pattern is nearly right-angled, which was previously difficult to achieve.

[0012] The photosensitive resin pattern film of the present invention is also characterized in that its cross-sectional shape satisfies formula (2). Therefore, the photosensitive resin pattern film has less variation in thickness around the pattern end than the conventional pattern film, which has the effect of significantly suppressing scattering of light transmitted through the pattern film. As a result, when used for colored pixels of a color filter, it has the effect of producing an image with clear contours at the pattern end, less color mixing of transmitted light, and high color purity. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a flow chart showing the steps of the method for producing a photosensitive resin pattern film of the present invention. [Diagram 2] 1 is a schematic diagram showing an example of a grayscale mask used in the manufacturing process of the photosensitive resin pattern film manufacturing method of the present invention, which has a semi-transmitting portion with a concentration gradient from the boundary between the light-shielding portion and the opening toward the center of the opening. [Diagram 3]FIG. 2 is a schematic cross-sectional view showing an example of a test photomask used in producing a test photosensitive resin pattern film of the present invention. [Figure 4] 1 is a cross-sectional photograph showing an example of a test photosensitive resin pattern film of the present invention. [Diagram 5] 1 is a graph showing a pseudo curve of the cross-sectional upper end shape of a test photosensitive resin pattern film of the present invention and a function approximating the pseudo curve. [Figure 6] 6 is a graph showing a pseudo curve and a function approximating the pseudo curve in FIG. 5 , which are inverted with respect to the x-axis as an axis of symmetry, and a function approximating the pseudo curve. [Figure 7] FIG. 2 is a schematic cross-sectional view showing an example of a photosensitive resin pattern film of the present invention obtained by exposing and developing a photosensitive resin film using the grayscale mask of the present invention, and then baking the same. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention will be described in detail below with reference to the drawings. Fig. 1 is a flow chart showing the manufacturing steps of the method for manufacturing a photosensitive resin patterned film of the present invention. Fig. 2 is a schematic top view and a schematic cross-sectional view of a grayscale mask used in the manufacturing steps of the method for manufacturing a photosensitive resin patterned film of the present invention, where (a) is a schematic top view with circular openings, (b) is a schematic cross-sectional view with gradations in the thickness of the semi-transmitting parts, and (c) is a schematic cross-sectional view with gradations in the halftone dot density of the pattern of the semi-transmitting parts.

[0015] Fig. 3 is a schematic cross-sectional view of a test photomask used for producing a test photosensitive resin pattern film. Fig. 4 is a cross-sectional photograph of the test photosensitive resin pattern film. Fig. 5 is a graph showing a pseudo curve of the cross-sectional upper end shape of the test photosensitive resin pattern film and a function approximating the pseudo curve. Fig. 6 is a graph showing a pseudo curve and an approximating function obtained by inverting the pseudo curve and the approximating function with respect to the x-axis as an axis of symmetry. Fig. 7 is a schematic cross-sectional view showing an example of the photosensitive resin pattern film of the present invention obtained by exposing and developing a photosensitive resin film using the grayscale mask of the present invention.

[0016] FIG. 1 shows that the manufacturing method of the photosensitive resin pattern film of the present invention comprises at least the steps shown in FIG. 4: (a) examining the cross-sectional shape of the upper end 6 of the test photosensitive resin pattern film 101; (b) setting a test photosensitive resin pattern film pseudo-curve 20 approximating the cross-sectional shape; (c) calculating a mask pseudo-curve 30 symmetrical to the test photosensitive resin pattern film pseudo-curve 20 with the width direction of the test photosensitive resin pattern film 101 as the axis of symmetry; (d) determining a grayscale mask 10 having a light-shielding portion 11 and an opening 12, and in which a semi-transmitting portion 13 having a concentration gradient equivalent to the mask pseudo-curve 30 is formed from the boundary between the light-shielding portion 11 and the opening 12 toward the center 14 of the opening; (e) exposing a photosensitive resin film using the grayscale mask 10; and (f) developing the exposed photosensitive resin film to form a pattern. In addition to this, a step (g) of baking the developed photosensitive resin pattern film 100 may be added.

[0017] The test photosensitive resin pattern film 101 in Fig. 4 is a test photosensitive resin pattern film obtained by applying a test photosensitive resin composition having the same composition as the photosensitive resin composition used in manufacturing the photosensitive resin pattern film 100 of the present invention onto a substrate 102, preparing a test photosensitive resin film having the same composition as the photosensitive resin film of the present invention, and patterning the test photosensitive resin film by exposure and development under conditions that minimize the occurrence of defects such as film residue and undercuts using a test photomask 15 in Fig. 3 consisting of a light-shielding portion 11 and an opening 12. When a step of baking the developed photosensitive resin pattern film 100 in (g) above is added, it is preferable to bake the test photosensitive resin pattern film 101 under the same conditions.

[0018] Here, the residual film refers to a defect phenomenon in which a thin, amorphous photosensitive resin film that should be completely removed remains in the development area. Also, the undercut refers to a defect phenomenon in which the cross-sectional shape of the pattern end 5 has a taper angle θ with respect to the surface of the substrate 1 that significantly exceeds 90°, resulting in the upper end 6 of the pattern being formed in a significantly protruding shape.

[0019] Exposure is performed by irradiating the test photomask 15 with a predetermined exposure dose of exposure light from a light source (not shown) such as a mercury lamp, excimer laser, or extreme ultraviolet (EUV) light source located above the test photomask 15. In particular, for color filter pixels, an i-line mercury lamp with a wavelength of 365 nm is often used. The exposure device is not particularly limited, but examples include a stepper and a mask aligner. Specific examples include the "UX4 Series" manufactured by Ushio Inc. and the AP200 / 300 lithography system manufactured by Veeco Ultratech.

[0020] The exposure dose during exposure is appropriately set depending on the type of photosensitive resin composition, the type of exposure light, and the type of exposure device. Generally, it is 10 mJ / cm 2 More than 500mJ / cm 2 It is preferable that the concentration is less than 20 mJ / cm 2 More than 200mJ / cm 2 More preferably, it is 30 mJ / cm or less. 2 More than 100mJ / cm 2 The following is even more preferred:

[0021] The development may be performed by removing the photosensitive resin film in the non-exposed region with an alkaline developer made of a dilute alkaline aqueous solution. Examples of the dilute alkaline aqueous solution include a 0.01% by mass to 5% by mass aqueous solution of sodium carbonate, a tetramethylammonium hydroxide aqueous solution, and a potassium hydroxide aqueous solution. Examples of the method for removing the photosensitive resin film include a spray method and a shower method.

[0022] 1(a), the cross-sectional shape of the obtained test photosensitive resin pattern film 101 is examined. A method for examining the cross-sectional shape of the test photosensitive resin pattern film 101 includes, for example, cutting the film with a cutter or the like to expose a cross-section of the test photosensitive resin pattern film 101, fixing the film so that the cross-sectional shape faces upward, and taking a cross-sectional photograph with a scanning electron microscope (SEM) or the like as shown in FIG.

[0023] From the image data of the cross-sectional photograph, a pseudo curve 20 of the test photosensitive resin pattern film is set that is approximative to the cross-sectional shape of the pattern upper end 6 of the test photosensitive resin pattern film 101. It is preferable that the cross-sectional shape is a rectangular shape for the pattern end 5, but the more one tries to make it such a rectangular shape, the more likely the pattern upper end 6 will become an arc shape as shown in Fig. 4. If this arc shape is left as it is, the parallel light rays that travel from below the paper and reach the surface of the arc-shaped pattern upper end 6 will be bent obliquely and scattered, the outline of the pattern end 5 will become blurred, and the color will easily mix with the adjacent scattered transmitted light.

[0024] In the present invention, the rectangular shape includes not only a case where the cross-sectional shape of the pattern end 5 is completely rectangular, but also a case where it is approximately rectangular. That is, in Fig. 4, it includes not only a right-angle shape where the taper angle θ at the pattern lower end 7 with respect to the surface of the substrate 102 is 90°, but also a shape where the taper angle θ before and after the right-angle shape is 70° to 100°.

[0025] Then, in the step of FIG. 1(b), a pseudo curve 20 of the photosensitive resin pattern film for testing at the pattern upper end 6 showing a circular arc-shaped locus as shown in FIG. 5, in which the scales of the vertical and horizontal axes are set to the same, is obtained from the image data of the cross-sectional photograph as shown in FIG. 4, and a Y=X 1 / 1,5 However, this test photosensitive resin pattern film pseudo curve 20 and the curve of the function approximating it may change due to the components of the photosensitive resin and fluctuations in the exposure conditions, and some variation may occur depending on the location where the measurement is performed.

[0026] For this reason, it is difficult to obtain a sufficient fit with only one operation, and it is preferable to take this fluctuation into consideration, change some of the measurement points, repeat the steps of FIG. 1(a) and FIG. 1(b) several times, and set the average locus of the pseudo-curves obtained from each operation as the test photosensitive resin pattern film pseudo-curve 20.

[0027] Next, based on the test photosensitive resin pattern film pseudo-curve 20 thus set, the step of FIG. 1(c) is performed, that is, the operation of calculating a mask pseudo-curve 30 that is symmetrical to the test photosensitive resin pattern film pseudo-curve 20 and has the width direction of the test photosensitive resin pattern film 101 (i.e., the x-axis in FIG. 5 or FIG. 6) as the axis of symmetry.

[0028] For example, the pseudo curve 20 of the test photosensitive resin pattern film is Y=m·X 1 / n If the function is approximated as Y=-(m·X 1 / n ) is a function that approximates the mask pseudo curve 30 (m and n are proportional constants). Specifically, the test photosensitive resin pattern film pseudo curve 20 is a function of y=X where m=1 and n=1.5 as shown in FIG. 1 / 1.5 If the function is approximated as Y=-(X 1 / 1.5 ) is a function that approximates the mask pseudo curve 30 as shown in FIG.

[0029] The "approximation" mentioned above refers to the curves compared in Figs. 5 and 6 (for example, in Fig. 5, the test photosensitive resin pattern film pseudo curve 20 and Y = m X 1 / n In FIG. 6, the mask pseudo curve 30 and Y=-(m·X 1 / n )) means that the difference between the Y values ​​in each of the above is an average of 20% or less, and this also includes cases where there is no difference at all and they are a perfect match.

[0030] Next, in the step of Fig. 1(d), a grayscale mask 10 is determined that has a light-shielding portion 11 and an opening 12, and has a semi-transmitting portion 13 having a concentration gradient corresponding to the mask pseudo curve 30 from the boundary between the light-shielding portion 11 and the opening 12 toward the center 14 of the opening, and a new grayscale mask 10 as shown in Fig. 2 is produced. Alternatively, if there is a stock of grayscale masks 10 and an existing grayscale mask 10 that matches the concentration gradient is included among them, it may be selected and used as a substitute.

[0031] The grayscale mask 10 has a light-shielding portion 11 that is the same as that of the test photomask 15 in Figure 3, but as shown in Figure 2(a), a semi-transparent portion 13 having a concentration gradient corresponding to the mask pseudo-curve 30 is formed on the mask substrate 2 within the opening 12 from the boundary between the light-shielding portion 11 and the opening 12 toward the center 14 of the opening.

[0032] This grayscale mask 10 may be formed from the same material as the test photomask 15, for example, by forming a pattern of a mask pattern film 1 made of a material such as chromium, chromium oxide, molybdenum silicide, or silver halide on a mask substrate 2 made of glass, synthetic quartz, Pyrex (registered trademark), or polyester film by photolithography or the like to form a light-shielding portion 11 and an opening 12.

[0033] The semi-transmitting portion 13 of the grayscale mask 10 has a gradation region where the light transmittance changes stepwise, and examples of this include a case where the semi-transmitting portion 13 is relatively thin and has a gradational change in thickness, formed by sputtering the material constituting the light-shielding portion 11 for different times (FIG. 2(b)), or a case where the semi-transmitting portion 13 is formed by forming the halftone dot density (density of the number of halftone dots) of the light-shielding film 2 into a gradational pattern while keeping the thickness approximately the same as that of the light-shielding portion 11 (FIG. 2(c)). In the latter case, it is efficient and preferable to form the semi-transmitting portion 13 at the same time as forming the openings 12 by forming a pattern of the mask pattern film 1 by photolithography or the like.

[0034] The tendency of these gradations to change is adjusted so as to match as closely as possible with the concentration gradient corresponding to the mask pseudo curve 30. Specifically, the concentration gradient corresponding to the mask pseudo curve 30 is expressed as Y=-m·X 1 / n In this case, it is preferable to adjust the light transmittance of the semi-transmitting portion 13 of the grayscale mask 10 using the mask substrate 2 as a reference so as to obtain a concentration gradient as shown in the following formula 1.

[0035] T(%)=100-m·X 1 / n …(1) In this formula 1, X is the distance (μm) from the boundary between the light-shielding portion 11 and the opening 12 toward the center of the opening 12, and T is the average light transmittance (%) of only the semi-transmitting portion 13 at the distance X (μm) from the boundary between the light-shielding portion 11 and the opening 12 toward the center 14 of the opening 12, which is a value measured using the mask substrate 2 as a reference. The light transmittance is a value measured by scanning a wavelength range of 350 to 380 nm at intervals of 1 nm using a high-definition CF substrate optical inspection device (LCF-100MA 2480C; manufactured by Otsuka Electronics Co., Ltd.).

[0036] That is, the average light transmittance T of only the semi-transmitting portion 13 at a distance X (μm) from the boundary between the light-shielding portion 11 and the opening 12 toward the center 14 of the opening 12 is expressed as a concentration gradient Y=-(X 1 / 1.5 ) then 100-X 1 / 1.5 A grayscale mask 10 adjusted to have a density gradient of Y=-(X 1 / 3 ) then 100-X 1 / 3 It is recommended to use a grayscale mask 10 adjusted to be (%).

[0037] The proportional constants m and n are proportional constants determined by the arc-shaped cross-sectional shape of the upper end 6 of the test photosensitive resin pattern film 101, and have values ​​of 1.1≦n≦5 and 0.1≦m≦10. If the value of n is less than 1.1, the light transmittance near the center 14 of the semi-transmitting portion 13 becomes excessively low, and the photosensitive resin pattern film 100 is likely to have a thin film thickness near the center due to insufficient exposure at the center 14, resulting in a concave cross-sectional shape. If the value of n exceeds 5.0, the effects of the present invention are hardly exhibited.

[0038] Furthermore, when the value of m is less than 0.1, the effects of the present invention are hardly exhibited, and when the value of m exceeds 10, the light transmittance of the semi-transmitting portion 13 becomes excessively low overall, and unless the exposure amount is significantly increased, undercut defects are likely to occur.

[0039] By using the above grayscale mask 10 to expose a photosensitive resin film under the same exposure conditions as those used for the test photosensitive resin pattern film 101, and then developing and patterning the exposed photosensitive resin film under the same development conditions as those used for the test photosensitive resin pattern film 101, it is possible to produce a photosensitive resin pattern film 100 with little occurrence of defects such as film residue and undercuts, in which the cross-sectional shape of the pattern end 5 is rectangular and the cross-sectional shape of the pattern upper end 6 is not an arc, or if it is an arc, is extremely close to a straight line, as shown in Figure 7.

[0040] As a result, the photosensitive resin pattern film 100 of the present invention is a photosensitive resin pattern film with little variation in thickness in the pattern end peripheral region 8, whose cross-sectional shape satisfies the following formula (2) as shown in Fig. 7. This photosensitive resin pattern film 100 is a photosensitive resin pattern film having a completely new cross-sectional shape that has not existed in the prior art, at least in the pixel pattern of a color filter, and has the effect of greatly suppressing scattering of light that is incident from below the paper surface and transmits through the photosensitive resin pattern film.

[0041] As a result, when used for color pixels of a color filter, an image with high color purity can be obtained with little color mixing of transmitted light. Note that the pattern end peripheral region 8 in Fig. 7 refers to the widthwise region that was an arc shape at the pattern upper end 6 in the test photosensitive resin pattern film 101 in Fig. 4.

[0042] t0-W 1 / n ≦t≦t0+W 1 / n …(2) In the above formula 2, t (μm) is the film thickness at an arbitrary point 9 in the pattern end peripheral region 8 of the photosensitive resin pattern film 100, t0 (μm) is the film thickness at the photosensitive resin pattern end 5, W (μm) is the distance in the width direction from the photosensitive resin pattern end 6 to the arbitrary point 9, and 4≦n. The higher the value of n, the better. 1 / n The closer to zero the value of is, the closer t is to t0, which is preferable.

[0043] The method for producing a photosensitive resin pattern film of the present invention, the grayscale mask used therein, and the photosensitive resin pattern film have been described above. However, embodiments other than those described above are also included in the scope of the present invention as long as they are in line with the spirit of the present invention.

[0044] For example, an embodiment can be mentioned in which the photosensitive resin pattern film 100 produced by the processes (a) to (f) is regarded as the next new test photosensitive resin pattern film 101, and the processes (a) to (f) are repeated again to produce a brushed-up photosensitive resin pattern film 100 in which t is closer to t0.

[0045] In addition, an embodiment can be mentioned in which a grayscale mask that has been predicted to be suitable in the initial process (a) is regarded as a test photomask 15, and processes (a) to (f) are carried out to produce a brushed-up photosensitive resin pattern film 100 in which t is closer to t0 than when the test photomask 15 of Figure 3 is used.

[0046] Next, the material of the photosensitive resin pattern film 100 will be described in detail. The photosensitive resin pattern film 100 is formed from a composition containing, for example, an alkali-soluble resin, a coloring material, a photopolymerization initiator, a polymerizable compound, a reactive diluent, and the like. The alkali-soluble resin is not particularly limited as long as it has the performance of being developable with an alkali developer, and examples thereof include photosensitive carboxyl group-containing resins having one or more photosensitive unsaturated double bonds in one molecule.

[0047] Examples of the carboxyl group-containing photosensitive resin include polybasic acid-modified radically polymerizable unsaturated monocarboxylated epoxy resins such as polybasic acid-modified epoxy (meth)acrylates. For example, the resin can be obtained by reacting at least a portion of the epoxy groups of a polyfunctional epoxy resin having two or more epoxy groups with a radically polymerizable unsaturated monocarboxylic acid such as acrylic acid or methacrylic acid to obtain a radically polymerizable unsaturated monocarboxylated epoxy resin such as epoxy (meth)acrylate, and then reacting the resulting hydroxyl groups with a polybasic acid or anhydride thereof.

[0048] The acid value of the carboxyl group-containing photosensitive resin is not particularly limited, but is preferably 30 mgKOH / g or more from the viewpoint of reliable alkaline development, and is preferably 200 mgKOH / g or less from the viewpoint of preventing dissolution of the exposed area by the alkaline developer. The mass average molecular weight of the carboxyl group-containing photosensitive resin is not particularly limited, but is preferably 3000 or more from the viewpoint of toughness and dryness to touch of the cured product, and is preferably 200000 or less from the viewpoint of smooth alkaline development.

[0049] Examples of commercially available carboxyl group-containing photosensitive resins include Cyclomer (ACA) Z-251 (manufactured by Daicel Allnex Corporation), ZCR-1601H, ZAR-2000, ZFR-1122, and FLX-2089 (all manufactured by Nippon Kayaku Co., Ltd.), and Lipoxy SP-4621 (manufactured by Showa Denko Co., Ltd.). These resins may be used alone or in combination of two or more.

[0050] Examples of the coloring material include pigments and dyes, and any of them can be used. However, if a coloring material with low light transmittance at the wavelength of the exposure light is contained in a high proportion, the exposure light does not reach deep into the photosensitive resin, and the insufficiently exposed areas are gouged out during development, making it difficult to form the pattern end 5 in a rectangular shape. Therefore, for example, when exposure is performed using I-rays (mercury lamps) with a wavelength of 365 nm as a light source, it is preferable to use a coloring material with a light transmittance of 5% or more at a wavelength of 365 nm through the photosensitive resin film.

[0051] Examples of red colorants include CI Pigment Red (hereinafter referred to as "PR") 9 (hereinafter, all numbers are Color Index Nos.), PR48, PR97, PR122, PR123, PR144, PR149, PR166, PR168, PR177, PR179, PR180, PR192, PR209, PR215, PR216, PR217, PR220, PR223, PR224, PR226, PR227, PR228, PR240, PR254, and diketopyrrolopyrrole colorants having a bromine group.

[0052] Examples of yellow colorants include CI Pigment Yellow (hereinafter referred to as "PY") 12, PY13, PY17, PY20, PY24, PY83, PY86, PY93, PY95, PY109, PY110, PY117, PY125, PY129, PY137, PY139, PY147, PY148, PY150, PY153, PY154, PY166, and PY168 (all numbers are Color Index Nos.).

[0053] Examples of green colorants include CI Pigment Green (hereinafter referred to as "PG") PG1, PG2, PG4, PG7, PG8, PG10, PG13, PG14, PG15, PG17, PG18, PG19, PG26, PG36, PG38, PG39, PG45, PG48, PG50, PG51, PG54, PG55, PG58, PG59 (all numbers are color index numbers), etc.

[0054] Examples of blue colorants include CI Pigment Blue (hereinafter, "PB") 15, PB15:3, PB15:4, PB15:6, PB21, PB22, PB60, PB64, etc. Examples of purple colorants include CI Pigment Violet (hereinafter, "PV") 19, PV23, PV29, PV30, PV32, PV37, PV40, PV50, etc.

[0055] Examples of the dye include oil-soluble dyes, acid dyes, direct dyes, basic dyes, and acid mordant dyes. The dyes may be laked or may be salt-formed compounds of dyes and nitrogen-containing compounds. Specific examples of the dye include azo dyes, benzoquinone dyes, naphthoquinone dyes, anthraquinone dyes, xanthene dyes, cyanine dyes, squarylium dyes, croconium dyes, merocyanine dyes, stilbene dyes, diarylmethane dyes, triarylmethane dyes, fluoran dyes, spiropyran dyes, phthalocyanine dyes, indigo dyes, fulgide dyes, nickel complex dyes, and azulene dyes.

[0056] These may be used alone or in combination of two or more. As a result of verification, it was found that dyes and pigments such as red, blue, and yellow pigments used in transmitted light pixels have a light transmittance of 5% or more at a wavelength of 365 nm and can provide sufficient coloring in the visible light wavelength region, but in the case of green pigments in some transmitted light pixels and black pigments such as carbon black used for blocking in the visible light wavelength region as in black matrices, the light transmittance at a wavelength of 365 nm may not reach 5%. In such cases, it is advisable to compensate by selecting a polymerizable compound or photopolymerization initiator, which will be described later.

[0057] The polymerizable compound is a compound having at least one polymerizable double bond in one molecule, and examples thereof include trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc. These may be used alone or in combination of two or more.

[0058] The amount of the polymerizable compound is not particularly limited, and is preferably 2 parts by mass or more and 500 parts by mass or less per 100 parts by mass of the alkali-soluble resin. When a coloring material with a low light transmittance at the wavelength of the exposure light is contained in a high proportion, it is preferable to contain a polymerizable compound with a high proportion of polymerizable double bonds in a high amount. For example, when carbon black is used for a green pigment for some transmitted light pixels or a black matrix, it is preferable to contain 100 parts by mass or more of a polymerizable compound with a double bond equivalent of 500 or less per 100 parts by mass of the alkali-soluble resin.

[0059] The photopolymerization initiator is not particularly limited, and any known photopolymerization initiator can be used. For example, an oxime ester photopolymerization initiator having two or more carbazole skeletons in one molecule can be used. Examples of the oxime ester photopolymerization initiator include 1,8-octanedione, 1,8-bis[9-ethyl-6-nitro-9H-carbazol-3-yl]-, 1,8-bis(O-acetyloxime), and 1,8-octanedione, 1,8-bis[9-(2-ethylhexyl)-6-nitro-9H-carbazol-3-yl]-, 1,8-bis(O-acetyloxime).

[0060] The amount of the photopolymerization initiator is not particularly limited, but from the viewpoint of reliably improving the photosensitivity and resolution even when a coloring material is contained, it is preferably 0.2 parts by mass or more relative to 100 parts by mass of the alkali-soluble resin, and from the viewpoint of reducing outgassing, it is preferably 4.0 parts by mass or less. When a coloring material with a low light transmittance at the wavelength of the exposure light is contained in a high proportion, it is preferable to contain a plurality of photopolymerization initiators with different maximum absorption wavelengths in high amounts.

[0061] For example, when carbon black is used for the green pigment of some of the transmitted light pixels or the black matrix, it is preferable to contain 1 part by mass or more of a photopolymerization initiator having a maximum absorption wavelength of less than 365 nm and 1 part by mass or more of a photopolymerization initiator having a maximum absorption wavelength of 365 nm or more per 100 parts by mass of the alkali-soluble resin, so that the energy of exposure light with a wavelength of about 365 nm can also be absorbed.

[0062] In addition to the above-mentioned components, the photosensitive resin composition may contain a solvent to adjust the viscosity or drying property, if necessary. Examples of the solvent include ketones (e.g., methyl ethyl ketone, cyclohexanone), aromatic hydrocarbons (e.g., toluene, xylene), alcohols (e.g., methanol, isopropanol, cyclohexanol), alicyclic hydrocarbons (e.g., cyclohexane, methylcyclohexane), petroleum solvents (e.g., petroleum ether, petroleum naphtha), cellosolves (e.g., cellosolve, butyl cellosolve, carbitol, butyl carbitol), and esters (e.g., ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, ethyl diglycol acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate).

[0063] These may be used alone or in combination of two or more. The amount of the solvent is preferably 1 part by mass or more and 200 parts by mass or less per 100 parts by mass of the carboxyl group-containing photosensitive resin.

[0064] The photosensitive resin composition may also contain a filler if necessary. Examples of fillers include barium sulfate, silica, alumina, talc, and mica. These may be used alone or in combination of two or more. The amount of the filler is preferably 1 part by mass or more and 100 parts by mass or less per 100 parts by mass of the carboxyl group-containing photosensitive resin. In addition, the photosensitive resin composition may also contain various additives, such as a defoamer, a latent curing agent, an antioxidant, and a coupling agent, if necessary.

[0065] Examples of methods for forming a photosensitive resin film by applying a photosensitive resin composition include methods using a spin coater, a bar coater, a blade coater, a roll coater, a die coater, inkjet printing, screen printing, dipping, spraying, etc. The thickness of the photosensitive resin film is preferably 0.5 μm or more from the viewpoint of preventing pinholes, and is preferably 5 μm or less from the viewpoints of surface smoothness and suppressing insufficient exposure.

[0066] The method for producing a photosensitive resin pattern film of the present invention, the grayscale mask used therein, and the photosensitive resin pattern film have been described above assuming use in pixels of a color filter. However, the present invention is not limited to use in pixels of a color filter, but can be used in any use where it is meaningful to form the cross-sectional shape of the pattern end 5 into a composite shape and the cross-sectional shape of the pattern upper end 6 into a shape close to a right angle. [Explanation of symbols]

[0067] 1. Mask pattern film 2. Mask substrate 5 Pattern end 6: Pattern top 7: Pattern bottom end 8. Area around the pattern edge 9. Any point in the area surrounding the pattern edge 10. Grayscale mask 11....Mask light shielding part 12 Mask opening 13....Mask semi-transparent part 14...Center area of ​​mask opening 15 Test photomask 20. Test photosensitive resin pattern film pseudo curve 30. Pseudo curve for mask 100 Photosensitive resin pattern film 101: Photosensitive resin pattern film for testing 102: Photosensitive resin pattern film substrate W: Distance in the width direction from the end of the photosensitive resin pattern to any point t: Film thickness at any point within the area surrounding the pattern edge of the photosensitive resin pattern film t0: Film thickness at the end of the photosensitive resin pattern

Claims

1. A method for producing a photosensitive resin pattern film by exposing and developing a photosensitive resin film, comprising the steps of: preparing a test photosensitive resin pattern film using a test photosensitive resin film having the same composition as the photosensitive resin film and a test photomask; examining a cross-sectional shape of an upper end of a test photosensitive resin pattern film; setting a pseudo curve of a test photosensitive resin pattern film that is approximate to the cross-sectional shape; calculating a mask pseudo-curve symmetrical to the test photosensitive resin pattern film pseudo-curve, the mask pseudo-curve being symmetrical to the width direction of the test photosensitive resin pattern film; determining a grayscale mask having a light-shielding portion and an opening, the light-shielding portion and a semi-transmitting portion having a density gradient corresponding to the mask pseudo curve from a boundary between the light-shielding portion and the opening toward a center of the opening; exposing a photosensitive resin film using the grayscale mask; developing the exposed photosensitive resin film to form a pattern; The method for producing a photosensitive resin pattern film comprising the steps of:

2. 2. The method for producing a photosensitive resin pattern film according to claim 1, wherein the grayscale mask has a semi-transmitting portion formed therein having a concentration gradient represented by the following formula (1) from the boundary between the light-shielding portion and the opening toward the center of the opening: T(%)=100-m・X １／ｎ …(1) In the above formula 1, X is the distance (μm) from the boundary between the light-shielding portion and the opening toward the center of the opening, T is the average light transmittance (%) of only the semi-transmitting portion at the distance X (μm) from the boundary between the light-shielding portion and the opening toward the center of the opening, using the mask substrate as a reference, and m and n are proportionality constants with values ​​of 1.1≦n≦5 and 0.1≦m≦10.

3. A step of preparing a test photosensitive resin pattern film using a photosensitive resin film and a test photomask; examining a cross-sectional shape of an upper end of a test photosensitive resin pattern film; setting a pseudo curve of a test photosensitive resin pattern film that is approximate to the cross-sectional shape; calculating a mask pseudo-curve symmetrical to the test photosensitive resin pattern film pseudo-curve, the mask pseudo-curve being symmetrical to the width direction of the test photosensitive resin pattern film; forming a semi-transmitting portion having a light-shielding portion and an opening, the semi-transmitting portion having a concentration gradient corresponding to the mask pseudo curve from a boundary between the light-shielding portion and the opening toward a center of the opening; A method for manufacturing a grayscale mask comprising the steps of:

4. 3. The method for producing a photosensitive resin pattern film according to claim 1, wherein the cross-sectional shape of the photosensitive resin pattern film is represented by the following formula (2): t ０ -W １／ｎ ≦t≦t ０ +W １／ｎ …(2) In the above formula 2, t (μm) is the film thickness at an arbitrary point in the peripheral region of the pattern end, t ０ (μm) is the film thickness at the end of the photosensitive resin pattern, W (μm) is the distance in the width direction from the end of the pattern to an arbitrary point in the peripheral region of the end of the pattern, and 4≦n.

5. 3. The method for producing a photosensitive resin patterned film according to claim 1, wherein the cross-sectional shape of the pattern end of the photosensitive resin patterned film is rectangular.

6. 3. The method for producing a photosensitive resin pattern film according to claim 1, wherein the photosensitive resin film has a light transmittance of 5% or more at a wavelength of 365 nm.

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