JP5446098B2 - Photomask for on-chip color filter - Google Patents

Description

  The present invention relates to a photomask for producing a color filter. The field in which the present invention is particularly useful is a photomask for producing an on-chip color filter used for producing a colored filter corresponding to a photoelectric conversion element of a solid-state imaging device by a photolithography method, and an on-chip color using the same. The field relates to a method of manufacturing a filter. In particular, the field relates to a photomask for manufacturing an on-chip color filter in which a correction pattern is provided at a connecting portion where four corners of a rectangular first color filter pattern arranged in a checkered pattern are in contact with each other.

  In general, colored filters such as blue, green, and red corresponding to the photoelectric conversion element of the solid-state imaging element are generally manufactured by a photolithography method from the viewpoint of pattern accuracy and pattern reproducibility. It is produced by the steps as shown in a) to (f). The color filter shown here is a configuration example of a color filter used for a color solid-state imaging device or the like, and is a case where a black matrix is not provided between individual colored filters.

  First, a green photosensitive resin solution in which a green pigment is dispersed in an acrylic photosensitive resin is applied onto a semiconductor substrate 11 on which a photoelectric conversion element and a planarizing layer are formed using a spinner or the like, thereby forming a green photosensitive layer 24. (See FIG. 1 (a)). Further, pattern exposure is performed using a predetermined photomask, and a series of patterning processes such as development and post-baking are performed to form a green filter 24G (see FIG. 1B).

  Next, a blue photosensitive resin solution in which a blue pigment is dispersed in an acrylic photosensitive resin is applied onto the semiconductor substrate 11 on which the green filter 24G is formed by using a spinner or the like to form a blue photosensitive layer 25 (FIG. 1 (c)).

  Next, pattern exposure is performed using a predetermined photomask, and a series of patterning processes such as development and post-baking are performed to form a blue filter 25B (see FIG. 1D).

  Next, a red photosensitive resin solution in which a red pigment is dispersed in an acrylic photosensitive resin is applied to the semiconductor substrate 11 on which the green filter 24G and the blue filter 25B are formed using a spinner or the like, and the red photosensitive layer 26 is applied. It forms (refer FIG.1 (e)).

  Next, pattern exposure is performed using a predetermined photomask, and a series of patterning processes such as development and post-baking are performed to form a red filter 26R (see FIG. 1F).

  The on-chip color filters of the green filter 24G, the blue filter 25B, and the red filter 26R can be manufactured on the solid-state image pickup device substrate 11 through the above steps.

  Here, an example of the color filter array in plan view of the on-chip color filter is shown in FIG. In FIG. 2, only the portion of 6 rows and 6 columns is shown for convenience, but the whole is n rows and m columns (n and m are arbitrary natural numbers). In this color filter array, for example, a square green filter G is arranged in a checkered pattern so as to be in contact with four sides of the square blue filter B. In addition, a square green filter G is arranged in a checkered pattern so as to be in contact with the four sides of the square red filter R.

Here, FIG. 3 partially shows the color filter array around the blue filter B in the second row and the third column in the color filter array of FIG. A square green filter G is arranged in a checkered pattern so as to be in contact with four sides of the square blue filter B, and a red filter R is arranged diagonally to the blue filter B.

  The on-chip color filters such as the green filter 24G, the blue filter 25B, and the red filter 26R, which are manufactured using the photomask having a simple rectangular pattern that is a checkered pattern in plan view by the manufacturing method of FIG. 4, the corner portions of each pattern of the green filter 24G are connected to each other (this connected portion is referred to as “bridge” in the present patent application), and the blue filter 25B, the red filter, and so on. Each pattern of 26R may be surrounded by a green filter 24G pattern.

  Such an on-chip color filter having a shape in which each of the four corners of the green filter 24G is connected by a bridge has a feature of being strong against peeling and having high adhesion to a base layer (for example, Patent Documents). 1). Further, when the color filter pattern becomes fine, the corners are not resolved, and the corners are scraped during development, and the corners of the pattern are easily rounded. For this reason, a gap is likely to be generated at a corner portion where the green filter 24G, the blue filter 25B, and the red filter 26R are in contact with each other. FIG. 5 schematically shows the gap. If a gap occurs at each corner, white light enters through the gap, which causes a problem of deteriorating the color reproducibility of the color solid-state imaging device. Therefore, it is desirable to form a bridge in terms of manufacturing an on-chip color filter and improving the performance of the solid-state imaging device.

However, an on-chip color filter such as a green filter 24G, a blue filter 25B, or a red filter 26R manufactured by a photomask having a simple rectangular pattern that is a checkered pattern in plan view by the manufacturing method shown in FIG. There remains a slight problem with the shape of this bridge. The photograph of FIG. 6 shows a typical example when a color filter is produced by the manufacturing method of FIG. 1 described above. The mark [G] in FIG. 6 indicates a portion corresponding to the green filter 24G. As can be seen from this photograph, when a photomask having a simple rectangular pattern is used, the bridge becomes too thick, and the finished shapes of the green filter 24G, blue filter 25B, and red filter 26R patterns are deteriorated. is there. In addition, if the patterns of the blue filter 25B and the red filter 26R are continuously formed on the green filter 24G having a thick bridge, the finished areas of the blue filter and the red filter become excessively small. Therefore, this also leads to deterioration of the color reproducibility of the color solid-state imaging device.
JP 2000-241619 A

  The present invention has been devised in view of the above problems, and when a colored filter corresponding to a photoelectric conversion element of a solid-state imaging element is produced by a photolithography method, a finished shape of a first color (for example, green) bridge is formed. The color filter photomask capable of ensuring the maximum opening (pixel) area of the second color (for example, blue) filter and the third color (for example, red) filter and manufacturing a color filter using the same It is an object to provide a method.

In the present patent application, the invention described in claim 1 is a photo that is used to fabricate a square-shaped colored filter corresponding to a photoelectric conversion element of a solid-state image sensor by a photolithography method using a negative resist. The photomask is a first color filter photomask for producing a first color filter arranged in a checkered pattern so as to be in contact with the four sides of the second color or third color filter. There, by providing the square correction pattern at the junction of the four corners of the placed rectangular first color filter forming pattern so as to correspond to the first color filter, the first color filter forming pattern the area, the compared with the case of a simple checkerboard pattern without correction pattern, Fotoma for on-chip color filter, wherein the smaller A click.

In the present patent application, the invention described in claim 2 is an etching apparatus in which the correction pattern dissolves a resolution limit of an exposure machine, a resolution limit of a developing machine, a resolution limit of a photoresist, and a first color filter material. 2. The photomask for on-chip color filter according to claim 1, wherein the photomask has a fine pattern exceeding at least one of the processing limits.

The invention according to claim 3 in the present patent application, the correction pattern is a combination of a square pattern, either overlapping or turned according to claim 1 or 2, characterized in that it consists of a combination and superimposition This is a photomask for chip color filter.

In the present patent application, the invention according to claim 4 is characterized in that the correction pattern is a combination of a square pattern having a side of 0.1 to 0.4 micrometers, a superposition, or a combination and a superposition. The on-chip color filter photomask according to claim 1, wherein the photomask is an on-chip color filter.

  When a color filter is manufactured using the photomask for on-chip color filter of the present invention, the first color filter and the second color filter are particularly opposed to each other between the first color filter and the third color filter. Since no gap is generated between the corners, it is strong against peeling and white light does not leak, so that a solid-state imaging device having excellent sensitivity characteristics can be obtained. In addition, since the bridge of the first color filter is formed in the desired accurate shape (FIG. 7), the second color filter or the third color filter becomes smaller, or conversely, the bridge is disconnected. It is also possible to prevent the occurrence of problems such as

  Hereinafter, embodiments of the present invention will be described.

  In order to solve the problem, the inventor of the present patent application first produced a green filter 24G using a green filter photomask for exposing a negative type green photosensitive resist as shown in FIG. I tried. FIG. 9 shows an example of a photomask that aims to narrow the bridge of the green filter 24G by cutting each corner portion (four corners) of each square pattern for forming the green filter. Note that GP in FIG. 9 indicates each square pattern for forming the green filter 24G.

  However, although the use of this photomask is an example of a solution, it is not the best solution. That is, even if the corner portion is cut, if the cut area is large (that is, d1 in FIG. 9 is large), the bridge is not thinned. Conversely, if the cut size is reduced, the bridge is often in a disconnected state. FIG. 8 shows a photograph of a typical example (when the corner cut is small) when a color filter is produced by using this photomask. A mark [G] in FIG. 8 indicates a portion corresponding to the green filter 24G. As can be seen in this photograph, the bridge is easily disconnected. When the bridge is disconnected, it becomes a gap, so that white light enters from the gap and prevents the color reproducibility of the color solid-state image sensor from being hindered, and the bridge as described above is strong. This is a problem because it loses its features.

  Based on this fact, the inventor of the present patent application not only cuts the corner portions (four corners) of each quadrilateral pattern of the green filter 24G but also uses a photomask having a correction portion that makes it difficult for the bridge to be disconnected. Thus, it has been found that it is best to produce the green filter 24G.

  FIG. 10 is a schematic partial plan view of a photomask having this correction unit. The on-chip color filter photomask 30 of the present invention includes a first color (for example, green) filter formation pattern 33 (opening) and a first color (for example, green) filter formation pattern 33. The correction part 32 of the connection part located in four corners and the blank pattern 31 (light-shielding part) are comprised. The blank pattern 31 is a space for forming a second color (for example, blue) or a third color (for example, red) color filter later without forming a first color (for example, green) filter. It is a pattern.

  Hereinafter, a negative type resist is used as the color resist for forming the color filter. Then, the pattern 33 for forming the first color (for example, green) filter becomes an opening (light transmission portion), and the blank pattern 31 becomes a light shielding portion. However, the present invention is not limited to the case where the resist is a negative type. If the opening portion and the light shielding portion in FIG. 10 are interchanged, it can be used in the case of a positive type resist. Further, the color filter itself is not limited to being formed of a colored resist. It may be formed of other materials such as resin that is not a resist (it is formed with a colored resist if a resist material is applied separately from above, followed by steps of exposure drawing, development, patterning, and dyeing the formed pattern. The same execution as in the following embodiment can be performed).

  Although the correction | amendment part 32 can have a various planar shape, the specific example is shown in FIG.

  Here, the size of the pattern (hereinafter sometimes referred to as “correction pattern”) formed in the correction unit 32 is the same as that exposed when the exposed resist is developed and when the exposed resist is developed. The size is made smaller than the size at which the pattern is obtained, that is, smaller than the so-called resolution limit. For this reason, even when the color resist for forming the color filter is exposed and developed, the corners are completely rounded without being developed according to the pattern (correction pattern) provided in the correction unit in order to exceed the resolution limit. Note that exceeding the resolution limit is not necessarily limited to the resolution limit of the resist. Depending on the case, the resolution limit of the exposure machine, the resolution limit of the developing machine, the resolution limit of the etching apparatus, etc. It may be determined. As a result, the shape of the color filter material after development does not have to be exactly the same as the pattern formed on the correction portion, and the corner may be rounded.

  In the following, a mask pattern for patterning a negative resist material will be described. For convenience of explanation, the light shielding portion is illustrated in white and the opening portion is illustrated in black. In other words, in the actual mask, 33 sites (black portions) in FIG. 11 are light transmitting portions, and 31 sites (white portions) are light shielding portions.

The correction unit 32 in FIG. 11 includes a light-shielding pattern with one side a = 0.2 μm square and an island-shaped opening pattern with one side b = 0.1 μm square overlapping therewith. Such a correction | amendment part 32 is arrange | positioned in the connection part of the four corners of each opening pattern 33 for 1st color (for example, green) filter formation. Thereby, the area of the light-shielding portion at the connecting portion is 0.01 μm ² larger than that in the case of a simple checkered pattern without the correcting portion 32. Therefore, by providing the correction pattern, the area of the first color filter forming pattern is smaller than that of a simple checkered pattern without the correction pattern. As a result, the correction unit 32 increases the light shielding rate of the connecting portions at the four corners for forming the first color (for example, green) filter, and the color resist for forming the color filter hardly remains. That is, the bridge becomes thinner.

However, on the other hand, the case where the correction part 32 of FIG. 11 is provided is the case of a simple corner cut (FIG. 12, a = 0.2 μm. Is larger by 0.01 μm ² ), the island-like opening pattern having one side b = 0.1 μm square is present at the center of the connecting portion, so that the bridge is less likely to be disconnected.

  Note that the values a and b in the correction unit 32 in FIG. 11 are not limited to the above-described values. According to the experiment by the inventors of the present patent application, for example, even when a = 0.4 μm and b = 0.15 μm, the color resist forming color resist currently used has a sufficient effect. It was. Thus, in practice, the range of values that each value of a and b can take is determined by the resolution limit value.

  The on-chip color filter photomask 30 can be manufactured by a photoetching method using low-reflection chrome blanks, exposing the resist to an electron beam, developing, and etching. Therefore, a pattern of 0.1 to 0.4 μm can be accurately produced in the correction unit 32.

  Hereinafter, a manufacturing method of the on-chip color filter using the on-chip color filter photomask will be described. FIGS. 13A to 13F are schematic sectional views showing one example of a method for producing an on-chip color filter using the photomask for on-chip color filter of the present invention. Here, the color filter planar arrangement of the green filter G, the blue filter B, and the red filter G is the arrangement shown in FIG.

  First, a color pigment (for example, CI Pigment Yellow 150, CI Pigment Green 36, and CI Pigment Green 36) is applied to a negative photosensitive resin on a semiconductor substrate 11 on which a photoelectric conversion element and a planarizing layer are formed. Pigment Green 7), a negative green resist prepared by kneading an organic solvent such as cyclohexanone or PGMEA, an acid-decomposable resin, a photoacid generator, and a dispersant with a roll mill or the like is applied by spin coating or the like. Then, the green photosensitive layer 21 is formed (see FIG. 13A).

Next, the on-chip color filter photomask 30 shown in FIG. 13 in which an opening pattern 33 for forming a first color (for example, green) filter and a light shielding pattern 31 are formed on a transparent substrate such as glass is used. Then, patterning processing such as pattern exposure and development is performed to form a green filter 21G at a predetermined position on the semiconductor substrate 11 (see FIGS. 13B and 14).

  Next, a negative blue resin prepared by kneading a negative photosensitive resin with a blue pigment (for example, CI Pigment Blue 15: 6, CI Pigment Violet 23) and a dispersing agent using a roll mill or the like. A resist is applied by spin coating or the like to form the blue photosensitive layer 22 (see FIG. 13C).

  Next, pattern exposure is performed using a blue filter exposure mask on which a square pattern is formed, and a series of patterning processes such as development are performed to form a blue filter 22B (see FIGS. 13D and 15). ).

  Here, the corners of the blue filter 22B are formed so as to overlap with the connecting portions 21c provided at the four corners of the green filter 21G, so that no gap is generated between the green filter 21G and the blue filter 22B. . Further, since the green filter is strongly adhered to the substrate, the green filter overlaps with the green filter, and the adhesion of the blue filter supported by the green filter to the substrate is also improved.

  Next, a red pigment (for example, CI Pigment Red 177, CI Pigment Red 48: 1 and CI Pigment Yellow 139) and a dispersing agent, etc., are added to the negative photosensitive resin with a roll mill or the like. A negative red resist prepared by kneading is applied by spin coating or the like to form a red photosensitive layer 23 (see FIG. 13E).

  Next, pattern exposure is performed using a red filter exposure mask in which a square pattern is formed, and a series of patterning processes such as development are performed to form a red filter 23R (see FIG. 5F and FIG. 21). ).

  Here, the corners of the red filter 23R are formed so as to overlap with the connecting portions 21c provided at the four corners of the green filter 21G, so that no gap is generated between the green filter 21G and the red filter 23R. . Further, as described above, the adhesion of the red filter supported by the green filter to the substrate is improved.

  Through the above steps, a solid-state imaging device color filter including the green filter 21G, the blue filter 22B, and the red filter 23R can be formed on the semiconductor substrate 11 on which the photoelectric conversion element and the planarization layer are formed.

  In the method of manufacturing a solid-state imaging device color filter using the photomask for on-chip color filter of the present invention, the first color filter arranged in a checkered pattern so as to be in contact with the four sides of the second color or the third color filter A photomask for a first color filter for manufacturing the first color filter, wherein the four corners of the square-shaped first color filter forming pattern arranged so as to correspond to the first color filter are corrected to the connecting portion. Since the first color (green) filter is produced using the photomask for the on-chip color filter provided with the pattern, the second color (blue) and the third color (red) filter dimensions can be produced uniformly. A solid having excellent sensitivity characteristics with no gap between the first color (green) filter and the second color (blue) filter, and between the first color (green) filter and the third color (red) filter. Imaging element It is possible to obtain.

In the following embodiment, another specific example of the correction unit will be given. In the following example, a negative resist is used as the color resist for forming the color filter. However, for convenience of explanation, the light shielding portion and the opening of the mask pattern are displayed in reverse color. That is, in FIG. 16 to FIG. 20, the black portion indicates the light transmission portion, and the white portion indicates the light shielding portion. When a positive type is used as the colored resist, the black and white of the 22 patterns are the same as the black and white of FIGS.

FIG. 16 is a schematic partial plan view showing a first example of another correction. (Hereinafter, “first”, “second”, etc. are numbered for convenience and are not directly related to the magnitude of the effect, etc.)
Here, the pattern formed on the correction unit 32 is not developed according to the opening pattern and is completely rounded off because the color resist forming color resist is exposed and developed to exceed the resolution limit. This is a very fine pattern. Note that exceeding the resolution limit is not necessarily limited to the resolution limit of the resist. In some cases, the resolution limit of the exposure machine, the resolution limit of the developing machine, the resolution limit of the etching apparatus, etc. Good. As a result, the shape of the color filter material after development does not have to be exactly the same as the pattern formed in the correction unit 32, and it is sufficient that the corners are rounded.

The correction unit 32 in FIG. 16 includes a light-shielding pattern with one side a = 0.3 μm square and two opening patterns with one side b = 0.1 μm square. Such a correction | amendment part 32 is arrange | positioned in the connection part of the four corners of each opening pattern for 1st color (for example, green) filter formation. Thereby, the area of the light-shielding part in the connection part is 0.03 μm ² larger than the simple checkered pattern without the correction part 32. Therefore, by providing a pattern in the correction unit, the area of the first color filter forming pattern is smaller than that of a simple checkered pattern without the correction pattern. Therefore, due to the pattern of the correction unit 32, the light shielding rate increases at the four corners of each opening pattern 31 for forming the first color (for example, green) filter, and the colored resist for forming the color filter hardly remains. That is, the bridge becomes thinner.

  However, on the other hand, in the case of the simple corner cut (FIG. 12), the value of “a” is a value that makes the area of the opening equal to that in FIG. 16 (a> 0.3 μm). )), The shortest distance between the openings is shortened and the bridge is less likely to be disconnected because there are two square opening patterns with one side b = 0.1 μm.

  Note that the values a and b in the correction unit 32 in FIG. 16 are not limited to the above-described values. According to the experiment by the inventors of the present patent application, for example, even when a = 0.6 μm and b = 0.25 μm, the color resist forming color resist currently used has a sufficient effect. It was. Thus, in practice, the range of values that each value of a and b can take is determined by the resolution limit value.

  FIG. 17 is a partial plan view schematically illustrating a second example of another correction pattern.

  Here, the pattern formed on the correction unit 32 is not developed according to the opening pattern and is completely rounded off because the color resist forming color resist is exposed and developed to exceed the resolution limit. This is a very fine pattern. Note that exceeding the resolution limit is not necessarily limited to the resolution limit of the resist. In some cases, the resolution limit of the exposure machine, the resolution limit of the developing machine, the resolution limit of the etching apparatus, etc. Good. As a result, the shape of the color filter material after development does not have to be exactly the same as the pattern formed in the correction unit 32, and it is sufficient that the corners are rounded.

17 includes a square light-shielding pattern with one side a = 0.45 μm, three squares (one side b = 0.15 μm square and two sides c = 0.15 μm square). ) Opening pattern. Such a correction | amendment part 32 is arrange | positioned in the connection part of the four corners of each opening pattern for 1st color (for example, green) filter formation. Thereby, the area of the light-shielding portion at the connecting portion is 0.015 μm ² larger than that of the simple checkered pattern without the correcting portion 32. Therefore, by providing the correction pattern, the area of the first color filter forming pattern is smaller than that of a simple checkered pattern without the correction pattern. Therefore, the correction unit 32 increases the light shielding rate at the four corners of each opening pattern 33 for forming the first color (for example, green) filter, and the color resist for forming the color filter hardly remains. That is, the bridge becomes thinner.

  However, on the other hand, in the case of the simple corner cut (FIG. 12), the value of a is equal to the value in the case of FIG. 17 (0.2 <a <0.3 μm).) Compared with 3), the opening pattern of three one-side b = 0.15 μm squares is diagonally arranged near the center of the connecting portion, so that the bridge is less likely to be disconnected. ing.

  Note that the values a and b in the correction unit 32 in FIG. 17 are not limited to the above values. Actually, the range of possible values for each of the values a, b, and c is determined by the resolution limit value. It is not always true that b = c.

  FIG. 18 is a schematic partial plan view showing a third example of another correction pattern.

  Here, the pattern formed on the correction unit 32 is not developed according to the opening pattern and is completely rounded off because the color resist forming color resist is exposed and developed to exceed the resolution limit. This is a very fine pattern. Note that exceeding the resolution limit is not necessarily limited to the resolution limit of the resist. In some cases, the resolution limit of the exposure machine, the resolution limit of the developing machine, the resolution limit of the etching apparatus, etc. Good. As a result, the shape of the color filter material after development does not have to be exactly the same as the pattern formed in the correction unit 32, and it is sufficient that the corners are rounded.

The correction unit 32 in FIG. 18 is configured by a light-shielding pattern of one side a = 0.2 μm square. Further, b = a / 2. Such a correction | amendment part 32 is arrange | positioned in the connection part of the four corners of each opening pattern for 1st color (for example, green) filter formation. Thereby, the area of the light-shielding portion at the connecting portion is 0.02 μm ² larger than that of a simple checkered pattern without the correcting portion 32. Therefore, by providing the correction pattern, the area of the first color filter forming pattern is smaller than that of a simple checkered pattern without the correction pattern. Therefore, the correction unit 32 increases the light shielding rate of the connecting portions at the four corners of each opening pattern 33 for forming the first color (for example, green) color filter, so that the color filter forming colored resist hardly remains. That is, the bridge becomes thinner.

  However, on the other hand, in the case of the simple corner cut (FIG. 12), the value of “a” is a value that makes the area of the opening equal to that in FIG. 18 (0.2 <a <0.3 μm), the shortest distance between the openings is shortened due to the difference in the shape of the light shielding pattern, and the bridge is less likely to be disconnected.

  Note that the values a and b in the correction unit 32 in FIG. 18 are not limited to the above values. In practice, the range of possible values for each of the values a and b is determined by the resolution limit value.

  FIG. 19 is a schematic partial plan view showing a fourth example of another correction pattern.

Here, the pattern formed on the correction unit 32 is not developed according to the opening pattern and is completely rounded off because the color resist forming color resist is exposed and developed to exceed the resolution limit. This is a very fine pattern. Note that exceeding the resolution limit is not necessarily limited to the resolution limit of the resist. In some cases, the resolution limit of the exposure machine, the resolution limit of the developing machine, the resolution limit of the etching apparatus, etc. Good. As a result, the shape of the color filter material after development does not have to be exactly the same as the pattern formed in the correction unit 32, and it is sufficient that the corners are rounded.

  The correction unit 32 in FIG. 19 includes a light shielding pattern with a side a = 0.3 μm square and two opening patterns with a side b = 0.1 μm square. Such a correction | amendment part 32 is arrange | positioned in the connection part of the four corners of each opening pattern for 1st color (for example, green) filter formation. Thereby, the area of the light-shielding part in the said connection part is larger than the case of the simple checkered pattern shape which does not have this correction | amendment part 32. FIG. Therefore, by providing a pattern in the correction unit, the area of the first color filter forming pattern is smaller than that of a simple checkered pattern without the correction pattern. Therefore, due to the pattern of the correction unit 32, the light shielding rate increases at the four corners of each opening pattern 33 for forming the first color (for example, green) color filter, and the color resist for forming the color filter hardly remains. That is, the bridge becomes thinner.

  However, on the other hand, the case where the correction part 32 of FIG. 19 is present is compared with the case of a simple corner cut (FIG. 12, the value of a is a value such that the area of the opening is equal to the case of FIG. 19). And since the opening pattern of two 1 side b = 0.1 micrometer square exists in the center part vicinity of a connection part, it is difficult for a bridge to be in a disconnection state.

  Note that the values a and b in the correction unit 32 in FIG. 19 are not limited to the above values. Actually, the range of possible values for each of the values a, b, and c is determined by the resolution limit value. It is not limited that b = c, and the light shielding pattern may not be square.

  FIG. 20 is a schematic partial plan view showing a fifth example of another correction pattern.

  Here, the pattern formed on the correction unit 32 is not developed according to the opening pattern and is completely rounded off because the color resist forming color resist is exposed and developed to exceed the resolution limit. This is a very fine pattern. Note that exceeding the resolution limit is not necessarily limited to the resolution limit of the resist. In some cases, the resolution limit of the exposure machine, the resolution limit of the developing machine, the resolution limit of the etching apparatus, etc. Good. As a result, the shape of the color filter material after development does not have to be exactly the same as the pattern formed in the correction unit 32, and it is sufficient that the corners are rounded.

  The correction unit 32 shown in FIG. 20 is configured by eight square light-shielding patterns with one side a = 0.1 μm. Such a correction pattern 32 is arranged at the connecting portion at the four corners of each opening pattern for forming the first color (for example, green) filter. Thereby, the area of the light-shielding part in the said connection part is larger than the case of the simple checkered pattern shape which does not have this correction | amendment part 32. FIG. Therefore, by providing the correction pattern, the area of the first color filter forming pattern is smaller than that of a simple checkered pattern without the correction pattern. Therefore, the correction unit 32 increases the light shielding rate of the connecting portions at the four corners of each opening pattern 33 for forming the first color (for example, green) filter, and the color resist for forming the color resist hardly remains. That is, the bridge becomes thinner.

  However, on the other hand, the case where the correction part 32 of FIG. 20 is present is compared with the case of a simple corner cut (FIG. 12. The value of “a” is a value such that the area of the opening is equal to that of FIG. 20). And the bridge is hard to break.

  In addition, each value of a in the correction part 32 of FIG. 20 is not necessarily restricted to the above-mentioned value. Actually, the range of possible values of each value of a is determined by the resolution limit value.

It is explanatory drawing which shows the example of the manufacturing process of a solid-state image sensor color filter. FIG. 5 is an arrangement diagram illustrating an example of a color filter array of a green filter G, a blue filter B, and a red filter R. FIG. 5 is an arrangement diagram illustrating an example of a color filter array of a green filter G, a blue filter B, and a red filter R. It is a plane schematic diagram of the color filter of the green filter 24G, the blue filter 25B, and the red filter 26R when there is a bridge at each corner. It is a plane schematic diagram of the color filter of the green filter 24G, the blue filter 25B, and the red filter 26R when there is a gap at each corner. It is a photograph of a color filter with thick bridge (according to the prior art). It is a photograph of a color filter (according to the technique of the present invention) in which the bridge is thin and has a preferable finished shape. It is a photograph of the color filter in which the bridge is in a disconnected state. FIG. 6 is a schematic plan view of a photomask in which four corners of each square-shaped first color filter forming pattern arranged in a checkered pattern are cut. FIG. 6 is a schematic plan view of the photomask of the present invention in which correction patterns are provided at the four corners of each square-shaped first color filter forming pattern arranged in a checkered pattern. It is a plane schematic diagram which shows an example of the correction | amendment part in the photomask of this invention. It is a plane schematic diagram which shows the example in case the correction | amendment part in the photomask of this invention is a simple corner cut type | mold. It is a cross-sectional schematic diagram explaining the example of the photomask manufacturing process of this invention. It is a plane schematic diagram explaining the example of the photomask manufacturing process of this invention. It is a plane schematic diagram explaining the example of the photomask manufacturing process of this invention. It is a plane schematic diagram which shows an example of the correction | amendment part in the photomask of this invention. It is a plane schematic diagram which shows an example of the correction | amendment part in the photomask of this invention. It is a plane schematic diagram which shows an example of the correction | amendment part in the photomask of this invention. It is a plane schematic diagram which shows an example of the correction | amendment part in the photomask of this invention. It is a plane schematic diagram which shows an example of the correction | amendment part in the photomask of this invention. It is a plane schematic diagram explaining the example of the photomask manufacturing process of this invention.

Explanation of symbols

11... Semiconductor substrate 21, 24... Green photosensitive layer 21 c .. Connecting portions 21 G, 24 G, G... Green filter 22, 25... Blue photosensitive layer 22 B, 25 B, B. Photosensitive layers 33R, 26R, R... Red filter 30... Green filter photomask 31... Blank pattern (for example, a light shielding portion when using a negative resist, and an opening portion when using a positive resist)
32... Corrector 33... First color filter forming pattern (for example, an opening when using a negative resist and a light-shielding portion when using a positive resist)
GP …… Green filter formation pattern

Claims (4)

A photomask used for producing colored filters each having a rectangular shape in plan view corresponding to a photoelectric conversion element of a solid-state imaging device by a photolithography method using a negative type resist , wherein the photomask is a second color Or a photomask for a first color filter for producing a first color filter arranged in a checkered pattern so as to be in contact with the four sides of the third color filter, and arranged so as to correspond to the first color filter By providing a square correction pattern at the four corners of the square-shaped first color filter forming pattern, the area of the first color filter forming pattern is a simple checkered pattern without the correction pattern. A photomask for an on-chip color filter , which is smaller than the case of the shape . The correction pattern has at least one of a resolution limit of an exposure machine, a resolution limit of a developing machine, a resolution limit of a photoresist, and a processing limit of an etching apparatus for dissolving a first color filter material. The photomask for on-chip color filter according to claim 1, wherein the photomask has a fine pattern exceeding. Said correction pattern is a combination of a square pattern, either overlapping or on-chip color photomask filter of claim 1 or 2, characterized in that it consists of a combination and superposition. 4. The correction pattern according to claim 1, wherein the correction pattern is a combination or superposition of square patterns having a side of 0.1 to 0.4 μm , or a combination and superposition . 5. The photomask for on-chip color filters described in 1.