JP7155359B2 - Imaging device and display device - Google Patents

Description

The present invention relates to color filter arrays.

2. Description of the Related Art Electronic devices such as imaging devices and display devices use color filter arrays in which color filters of a plurality of colors are arranged. Hereinafter, a color filter array including color filters of a plurality of colors will be referred to as a multi-color filter array, abbreviated as MCFA (Multi Color Filter Array). By using MCFA, a color image can be captured or displayed.

Patent Document 1 discloses a solid-state imaging device in which the color arrangement of color filter elements is a Bayer arrangement.

JP 2009-43899 A

One of the challenges in MCFA is color shading. Color shading is color unevenness caused by different white balances for different regions within an image.

An object of the present invention is to provide a technique useful in reducing color shading.

A first aspect of the means for solving the problem is an imaging device having a substrate having a plurality of photoelectric conversion units, and a color filter array arranged on the surface of the substrate, wherein the color filter The array is positioned between a first color filter and a second color filter each overlapping at least one of the plurality of photoelectric conversion units, and the first color filter and the second color filter. and a third color filter, wherein the first color filter and the second color filter are color filters of a first color, and the third color filter is different from the first color a color filter of a different second color, said third color filter having a first end and a second end, wherein at least a portion of said first color filter end extends from said substrate; is disposed between the base and the first end in the normal direction of the surface of the base, and at least part of the end of the second color filter is arranged in the normal direction of the surface of the base A direction in which the first color filter and the second color filter are arranged between the substrate and the second end is defined as a first direction, and a direction orthogonal to the first direction is defined as a second direction. , the second color filter extends in the second direction so as to overlap at least two photoelectric conversion units arranged in the second direction among the plurality of photoelectric conversion units, The width of the second color filter in the second direction is larger than the width of the first color filter in the second direction .

The present invention can provide techniques useful in reducing color shading.

FIG. 2 is a schematic cross-sectional view for explaining an electronic device; Schematic plan view and schematic cross-sectional view for explaining an electronic device. Schematic plan view and schematic cross-sectional view for explaining an electronic device. Schematic plan view for explaining a method of forming MCFA. FIG. 4 is a schematic cross-sectional view for explaining a method of forming MCFA. FIG. 4 is a schematic cross-sectional view for explaining a method of forming MCFA. FIG. 4 is a schematic cross-sectional view for explaining a method of forming MCFA. FIG. 4 is a schematic cross-sectional view for explaining a method of forming MCFA. The schematic diagram for demonstrating the formation method of MCFA. FIG. 4 is a schematic cross-sectional view for explaining a method of forming MCFA. FIG. 4 is a schematic cross-sectional view for explaining a method of forming MCFA. FIG. 4 is a schematic cross-sectional view for explaining a method of forming MCFA.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In addition, in the following description and drawings, common reference numerals are attached to structures common to a plurality of drawings. Therefore, common configurations will be described with reference to a plurality of drawings, and descriptions of configurations with common reference numerals will be omitted as appropriate.

As an example of an electronic device having a multi-color filter array, FIG. 1(a) shows an imaging device IS and FIG. 1(b) shows a display device DP. The MCFA 50 is arranged on the substrate 400 .

The structure of an imaging device IS as an example of an electronic device will be described with reference to FIG. The substrate 400 includes a semiconductor substrate 100 having a photoelectric conversion portion 101 such as a photodiode, and a multilayer wiring structure on the semiconductor substrate 100 . The multilayer wiring structure includes wiring layers 210, 220 and 230 stacked with an interlayer insulating film 200 interposed therebetween. A passivation film 310 and a planarizing film 320 are arranged on the multilayer wiring structure. In this embodiment, the wiring layers 210, 220, and 230 are aluminum wiring, and the interlayer insulating film 200 is a silicon oxide film. A passivation film 310 on the wiring layer has a three-layer structure of SiON/SiN/SiON. An MCFA 50 is arranged on the planarization film 320 . A microlens array 340 is provided on the MCFA 50 with a planarization film 330 interposed therebetween.

The structure of a display device DP as an example of an electronic device will be described with reference to FIG. 1(b). The substrate 400 includes a semiconductor substrate 100 having a transistor 102 and a multilayer wiring structure on the semiconductor substrate 100 . The multilayer wiring structure includes wiring layers 210 and 220 stacked with an interlayer insulating film 200 interposed therebetween. A plurality of pixel electrodes 130 functioning as one of an anode and a cathode, and a counter electrode 150 facing the plurality of pixel electrodes 130 and functioning as the other of the anode and the cathode are arranged on the multilayer wiring structure. A light-emitting layer 140 made of an organic semiconductor material is arranged between the pixel electrode 130 and the counter electrode 150 . An insulating member 135 for separation is arranged between the pixel electrodes 130 . The counter electrode 150 may be a transparent conductive film. A passivation film 310 and a planarization film 320 are arranged on the counter electrode 150 . An MCFA 50 is arranged on the planarization film 320 . A protective film 350 is provided on the MCFA 50 .

An imaging apparatus including an imaging device and a display apparatus including a display device can further include a container (package) that accommodates these electronic devices. The package can include a lid facing the electronic device, and connection members for exchanging signals between the electronic device and the outside.

An imaging system can be constructed using the imaging device. An imaging system is an information terminal having a camera and an imaging function. An imaging system can include a signal processing device that processes signals obtained from an imaging device, and a display device that displays an image captured by the imaging device.

A display system can be constructed using the display device. A display system is an information terminal having a display and a display function. The display system can include a signal processing device that processes signals input to the display device, and an imaging device that captures an image to be displayed on the display device.

Although the present disclosure includes multiple embodiments, first, items common to the multiple embodiments will be described.

FIG. 2A is a schematic plan view of the imaging device IS. This imaging device IS is used as a line sensor of a scanner, and the MCFA 50 is arranged on the substrate 400 . The substrate 400 has a surface extending in an X direction and a Y direction intersecting (perpendicular to) the X direction. Thickness and height refer to positions in the Z direction that intersects (perpendicularly) with the X and Y directions.

MCFA 50 is composed of color filter arrays of a plurality of colors including color filter array 10 , color filter array 20 and color filter array 30 . The arrangement area of the MCFA 50 is the imaging area of the imaging device. Each color filter array 10, 20, 30, 40 includes a plurality of color filters arranged one-dimensionally or two-dimensionally in an arrangement area. Each of the plurality of color filters included in color filter arrays 10, 20, 30 corresponds to at least one pixel. A plurality of color filters forming color filter arrays 10, 20, and 30 are arranged discontinuously in a certain direction. However, the plurality of color filters forming the color filter array may be partially continuous at corners or the like. A plurality of color filters forming color filter arrays 10, 20, and 30 are arranged periodically in a certain direction. As for the arrangement of each color, a Bayer type, a honeycomb type, and a stripe type can be adopted in addition to the arrangement shown in this example.

The color filter arrays 10, 20, and 30 have different dominant wavelengths for transmitting visible light (wavelengths at which the transmittance of visible light is maximized) for each color. For example, the color filter array 10 is composed of color filters (green filters) that mainly transmit green (G). The color filter array 20 is composed of color filters (blue filters) that mainly transmit blue (B). The color filter array 30 is composed of color filters (red filters) that mainly transmit red (R). MCFA 50 can be configured by combining color filter arrays 10 , 20 , 30 . The combination of colors is not limited to the RGB system, and the CMY system may be employed, or these may be combined. MCFA 50 may be configured to partially transmit white light (W). In this example, the color filter array 10 has dominant wavelengths in the green wavelength region, the color filter array 20 in the blue wavelength region, and the color filter array 30 in the red wavelength region.

Color filter array 10 includes color filters 11 , 12 , 13 , 14 and 15 . Color filter array 20 includes color filters 21 , 22 , 23 , and 24 . Color filter 21 is positioned between color filters 11 and 12 , and color filter 22 is positioned between color filters 11 and 13 . Color filter array 30 includes color filters 31 , 32 , 33 , and 34 .

As understood from FIG. 2(a), the color filters of the color filter arrays 10, 20, 30 are arranged in the X direction and the Y direction. Four rows of color filters are arranged, with each row of color filters arranged in the X direction. R pixels, G pixels, and B pixels are repeatedly arranged in the upper three rows. Color filters 11, 12, 13, and 14 are included in the second line, and color filter 15 is included in the first line. 100 to 10,000 rows of color filters are arranged, with the color filters aligned in the Y direction below being one row. Each column includes R pixels, G pixels, and B pixels included in the upper three rows and G pixels included in the lower row. A color image can be captured by the upper three rows, and a monochrome image can be captured by the lower row.

FIG. 2B shows how the color filters are arranged in the Y direction, and FIGS. 3A, 3B, and 3C show how the color filters are arranged in the X direction. FIG. 2(b) is a cross-sectional view taken along line A shown in FIG. 2(a). 3(a) is a cross-sectional view of the central portion of the imaging device IS on line B shown in FIG. 2(a), and FIG. 3(b) is a line B shown in FIG. 3 is a cross-sectional view of the peripheral portion of the imaging device IS; FIG. FIG. 3(c) is a cross-sectional view taken along line C shown in FIG. 2(a).

As shown in FIG. 3A, in the central portion of the imaging device IS, light (indicated by chain lines in FIG. 3A) enters the pixels at an angle close to perpendicular. Therefore, the center of the photoelectric conversion unit 101 and the center of the color filter approximately match in the X and Y directions. In other words, the center of the photoelectric conversion unit 101 and the center of the color filter overlap in the normal direction (Z direction) to the light receiving surface of the photoelectric conversion unit 101 . On the other hand, as shown in FIG. 3B, in the peripheral portion of the imaging device IS, light (indicated by chain lines in FIG. 3B) is obliquely incident on the pixels. Therefore, the center of the color filter is shifted in the X direction with respect to the center of the photoelectric conversion unit 101 . Since this example has only four pixel rows in the Y direction, the center of the color filter is not shifted from the center of the photoelectric conversion unit 101 in the Y direction. However, when 100 to 10000 pixel rows are provided in the Y direction, it is preferable that the center of the color filter is shifted from the center of the photoelectric conversion unit 101 also in the Y direction.

Further, around the MCFA 50, a color filter 29 is arranged in the peripheral area so as to cover the CMOS circuit for the purpose of preventing reflection and shielding the CMOS circuit of the peripheral circuit of the base 400 from light. A color filter 29 is provided so as to surround the color filter array 10 . Note that since no photoelectric conversion unit for generating signal charges for image formation by light reception is provided under the color filter 29, the color filter 29 is not a color filter constituting a pixel, but the color filter array 20. not included in

In this example, the color filter 29 is composed of a color filter (blue filter) that is the same color as the color filter array 20 and mainly transmits blue (B). In FIG. 2A, the boundary between the color filter 29 and other color filters included in the color filter 20 is indicated by a dotted line. As the color filter 29, a green filter and a red filter may be arranged, or a configuration in which the color filter 12 is not arranged may be used.

2 and 3 show widths of representative color filters. The width Wx11 is the width of the color filter 11 in the X direction, and the width Wy11 is the width of the color filter 11 in the Y direction. The width Wx12 is the width of the color filter 12 in the X direction, and the width Wy12 is the width of the color filter 12 in the Y direction. A width Wx14 is the width of the color filter 14 in the X direction.

In at least one of the Y direction in which the color filters 11 and 12 are arranged and the X direction perpendicular to the Y direction, the width of the color filters 11 and the width of the color filters 12 are different from each other. That is, in the Y direction, the width Wy12 of the color filter 12 is larger than the width Wy11 of the color filter 11 (Wy11<Wy12). In the X direction, the width Wx12 of the color filter 12 is larger than the width Wx11 of the color filter 11 (Wx11<Wx12). The width Wx12 of the color filter 12 in the X direction is larger than the width Wy12 of the color filter 12 in the Y direction (Wx12>Wy12). In the X direction, the width Wx12 of the color filter 12 is four times or more the width Wx11 of the color filter 11 (4×Wx11≦Wx12). Color filters 22 and 32 are positioned between the color filters 11 and the color filters 13 aligned in the X direction. A width Wx12 of the color filter 12 in the X direction is larger than the distance between the color filter 11 and the color filter 13 . The width Wx12 of the color filter 12 in the X direction is greater than the sum of the width Wx11 of the color filter 11 in the X direction and the width Wx22 of the color filter 22 in the X direction (Wx12>Wx11+Wx22).

In the X direction, the difference between the maximum width (Wx12) and the minimum width (Wx11) of all color filter widths included in the color filter array 10 is defined as width distribution Wdxg (Wdxg=Wx12-Wx11). In the X direction, the difference between the maximum width and the minimum width among widths of all color filters included in the color filter array 20 is defined as width distribution Wdxb. In the X direction, the difference between the maximum width and the minimum width among widths of all color filters included in the color filter array 30 is defined as a width distribution Wdxr. The width distribution Wdxb and the width distribution Wdxr are smaller than the width distribution Wdxg (Wdxb<Wdxg, Wdxr<Wdxg).

In the Y direction, the difference between the maximum width (Wy12) and the minimum width (Wy11) of all color filter widths included in the color filter array 10 is defined as width distribution Wdyg (Wdyg=Wy12-Wy11). In the Y direction, the difference between the maximum width and the minimum width among widths of all color filters included in the color filter array 20 is defined as a width distribution Wdyb. In the Y direction, the width distribution Wdyr is the difference between the maximum width and the minimum width among the widths of all color filters included in the color filter array 30 . The width distribution Wdyb and the width distribution Wdyr are smaller than the width distribution Wdyg (Wdyb<Wdyg, Wdyr<Wdyg).

Thus, the color filters included in the color filter array 20 have smaller variations in width in the X direction and/or the Y direction than the color filters included in the color filter array 10 . In addition, the color filters included in the color filter array 30 have smaller variations in width in the X direction and/or the Y direction than the color filters included in the color filter array 10 .

Among all the color filters included in the color filter array 10 and excluding the color filter 12, the color filter located at one end (left end) in the X direction is called the left end color filter. Among all the color filters included in the color filter array 10 and excluding the color filter 12, the color filter positioned at the other end (right end) in the X direction is referred to as the right end color filter.

The color filters included in the color filter array 20 and/or the color filters included in the color filter array 30 are positioned between the left end color filter, the right end color filter, and the color filter 12 . That is, in the third row adjacent to the fourth row of color filters 12 , color filters of different colors, not the same color as the color filters 12 , are arranged at the left and right ends. By doing so, the shape of the color filter array 10 can be well controlled.

2 and 3 show the thickness of typical color filters. The difference between the thickness T11 of the color filter 11 and the thickness T12 of the color filter 12 is preferably small, and there may be no difference between the thickness T11 and the thickness T12 (T11=T12). The thickness T11 is preferably about 92% to 108% of the thickness T12. The film thickness difference between color filters of the same color is preferably smaller than the film thickness difference between color filters of different colors. The difference (T12-T11) between the thicknesses T11 and T12 is preferably smaller than the difference (T21-T11) between the thicknesses T11 and T21 (T12-T11<T21-T11).

The difference between the thickness T11 of the color filter 11 and the thickness T15 (not shown) of the color filter 15 is preferably small, and there may be no difference between the thickness T11 and the thickness T15 (T11=T15). The thickness T11 is preferably about 92% to 108% of the thickness T15. Moreover, it is preferable that the difference (T15-T11) between the thickness T11 and the thickness T15 is smaller than the difference (T21-T11) between the thickness T11 and the thickness T21 (T15-T11<T21-T11).

In this way, by reducing the difference in thickness between color filters of the same color, it is possible to reduce variations in sensitivity of pixels having color filters of the same color. As a result, it is possible to reduce color unevenness in the captured image. In particular, when capturing a color image using the outputs of the pixels in the upper three rows, color shading occurs in the image if the sensitivity of the pixels of the same color varies from column to column. Therefore, it is preferable that the difference between the thickness T11 of the color filter T11 and the thickness T15 of the color filter 15 is as small as possible. In particular, the difference (T15-T11) between the thicknesses T11 and T15 is preferably smaller than the difference (T12-T11) between the thicknesses T11 and T12 (T15-T11<T12-T11).

(First embodiment)
The configuration and formation method of the MCFA 50 will be described with reference to FIGS. 4, 5, and 6. FIG. FIG. 4 shows a plan view of the MCFA 50, and FIGS. 4(a) and 4(b) show a state in the process of reaching the state of FIG. 4(c) in the formation of the MCFA 50. FIG. First, in step G shown in FIG. 4(a), the color filter array 10 is formed, then in step B shown in FIG. 4(b), the color filter array 20 is formed, and then in FIG. 4(c). 2, a color filter array 30 is formed. In this way, the color filter array 10 including color filters with different widths is formed before the other color filter arrays 20 and 30 are formed. By doing so, the difference in thickness between the color filters 11 to 15 of the same color in the color filter array 10 including the color filters 11 to 15 having different widths can be reduced.

5 and 6 illustrate, as cross-sectional views taken along line A of FIG.

FIG. 4(a) shows a process G for forming the color filter array 10, and cross-sectional states of each stage included in the process G are shown in FIGS. 5(a) and 5(b).

At stage Ga shown in FIG. 5A, a substrate 400 formed by a semiconductor process or the like is prepared, and a color filter film 600 is formed on the substrate 400 using a coating method. The film thickness of the color filter film 600 is preferably about 800-1200 nm. A typical coating method is a spin coating method, but a dipping method, a spray method, or the like may also be used.

At stage Gb shown in FIG. 5B, the color filter film 600 is patterned by photolithography (exposure and development). Color filter film 600 is exposed with a suitable photomask. Although the color filter film 600 in this example is a negative-type photosensitive resin, the color filter film 600 may be a positive-type photosensitive resin. The exposed color filter film 600 is developed. The exposed portion of the negative-type photosensitive resin color filter film 600 remains after development. A portion left after the patterning of the color filter film 600 becomes the color filter array 10 . At this time, color filter 11 has width Wy11 (and width Wx11), and color filter 12 has width Wy12 (and width Wx12). The width Wy11 is narrower than the width Wy12, and the width Wx11 is narrower than the width Wx12. However, since the color filter film 600 is uniformly formed on the surface of the substrate 400 with little unevenness, the difference between the thickness T11 of the color filter 11 and the thickness T12 of the color filter 12 can be reduced.

FIG. 4(b) shows a process B for forming the color filter array 20, and cross-sectional states of each stage included in the process B are shown in FIGS. 5(c) and 6(d).

At step Bc shown in FIG. 5C, a color filter film 700 is formed on the substrate 400 so as to cover the color filter array 10 using a coating method. The film thickness of the color filter film 700 is preferably about 800-1200 nm. A typical coating method is a spin coating method, but a dipping method, a spray method, or the like may also be used.

At step Bd shown in FIG. 6D, the color filter film 700 is patterned by photolithography (exposure and development). Color filter film 700 is exposed with a suitable photomask. Although the color filter film 700 in this example is a negative-type photosensitive resin, the color filter film 700 may be a positive-type photosensitive resin. The exposed color filter film 700 is developed. The exposed portion of the negative-type photosensitive resin color filter film 700 remains after development. A portion left after the patterning of the color filter film 700 becomes the color filter array 20 .

FIG. 4(c) shows a process R for forming the color filter array 30, and cross-sectional states of each stage included in the process R are shown in FIGS. 6(e) and 6(f).

At stage Re shown in FIG. 6(e), a color filter film 800 is formed on the substrate 400 so as to cover the color filter arrays 10 and 20 using a coating method. The film thickness of the color filter film 800 is preferably about 800-1200 nm. A typical coating method is a spin coating method, but a dipping method, a spray method, or the like may also be used.

At step Rf shown in FIG. 6F, the color filter film 800 is patterned by photolithography (exposure and development). Color filter film 800 is exposed with a suitable photomask. Although the color filter film 800 in this example is a negative-type photosensitive resin, the color filter film 800 may be a positive-type photosensitive resin. The exposed color filter film 800 is developed. The exposed portion of the negative-type photosensitive resin color filter film 800 remains after development. A portion left after the patterning of the color filter film 800 becomes the color filter array 20 .

(comparative form)
In the comparative embodiment, first, step R for forming the color filter array 30 shown in FIG. 4C is performed, then step B for forming the color filter array 20 shown in FIG. Then, the step G of forming the color filter array 10 shown in FIG. 4A is performed. Thus, in the comparative embodiment, the color filter array 10 including color filters with different widths is formed after the other color filter arrays 20 and 30 are formed. As a result, the difference in thickness between the color filters 11 to 15 of the same color in the color filter array 10 including the color filters 11 to 15 having different widths becomes large.

7 and 8 illustrate, as cross-sectional views taken along line A of FIG.

7(a) and 7(b) show cross-sectional views of steps included in the process R of forming the color filter array 30. FIG.

At stage Ra shown in FIG. 7A, a substrate 400 formed by a semiconductor process or the like is prepared, and a color filter film 800 is formed on the substrate 400 using a coating method.

At stage Rb shown in FIG. 4B, next, the color filter film 800 is patterned by photolithography (exposure and development). Color filter film 800 is exposed with a suitable photomask. The exposed color filter film 800 is developed. The exposed portion of the negative-type photosensitive resin color filter film 800 remains after development. A portion left after the patterning of the color filter film 800 becomes the color filter array 30 .

7(c) and 7(d) show cross-sectional views of steps included in the process B of forming the color filter array 20. FIG.

At step Bc shown in FIG. 7C, a color filter film 700 is formed on the substrate 400 using a coating method so as to cover the color filter array 30 .

At step Bd shown in FIG. 8D, the color filter film 700 is patterned by photolithography (exposure and development). Color filter film 700 is exposed with a suitable photomask. The exposed color filter film 700 is developed. The exposed portion of the negative-type photosensitive resin color filter film 700 remains after development. A portion left after the patterning of the color filter film 700 becomes the color filter array 20 . At this time, a gap 3 having a width Wy120 is formed between the color filters 21 included in the color filter array 20 and 31 included in the color filter array 30, and a gap 3 having a width Wy110 is formed between the color filters 21 and 29. A gap 4 is formed. Width Wy110 of gap 4 is smaller than width Wy120 of gap 3 .

8(e) and 8(f) show cross-sectional views of steps included in the process G of forming the color filter array 10. FIG.

At the stage Ge shown in FIG. 8E, a color filter film 600 is formed on the substrate 400 so as to cover the color filter arrays 20 and 30 using a coating method. At this time, the thickness of the color filter film 600 at the gap 4 between the color filters 21 and 31 is greater than the thickness at the gap 3 between the color filters 21 and 29 . This is because when a color filter film is formed using a coating method, the narrower the gap in which the color filter film is formed, the thicker the color filter film formed in the gap tends to be.

At stage Gf shown in FIG. 8F, the color filter film 600 is patterned by photolithography (exposure and development). Color filter film 600 is exposed with a suitable photomask. The exposed color filter film 600 is developed. The exposed portion of the negative-type photosensitive resin color filter film 600 remains after development. A portion left after the patterning of the color filter film 600 becomes the color filter array 10 . Specifically, a color filter 11 with a width of Wy11 is formed in the gap 4 with a width of Wy110, and a color filter 12 with a width of Wy12 is formed in the gap 3 with a width of Wy120. As shown in stage Ge, there was a film thickness difference between the color filter film 600 in the gap 3 and the color filter film 600 in the gap 4 . Therefore, the thickness T11 of the color filter 11 formed in the gap 4 is thicker than the thickness T12 of the color filter 12 formed in the gap 3 (T12<T11).

Although the case where the widths of the gaps 3 and 4 and the widths of the color filters 11 and 12 in the Y direction are different has been described here, the case where the widths of the gaps 3 and 4 and the widths of the color filters 11 and 12 in the X direction are different is also described. It is the same.

When the comparative form is employed, the thickness of the color filter 15 (see FIG. 2A) tends to be greater than that of the color filter 11 . One reason for this is that the color filter 15 is located farther from the color filter 12 than the color filter 11 is. Another reason is that the color filter 29 is located near the color filter 15 . Therefore, although the thicknesses of the color filters 11 and 12 are compared in the above description, a difference in thickness between the color filters 11 and 15 is likely to occur in the comparison mode.

Therefore, if a formation method like this comparative example is adopted, a difference in sensitivity tends to occur between pixels having respective color filters of the color filter array 10 . Therefore, in order to reduce color shading caused by the difference in color filter thickness, it is possible to form the color filter array 10 before the other color filter arrays 20 and 30 as in the first embodiment. It is valid.

(Second embodiment)
In the second embodiment, attention is focused on the case where the color filter arrays 10, 20, and 30 are shifted from the photoelectric conversion unit 101 as shown in FIGS. 3(a) and 3(b). As shown in FIG. 3A, in the central portion of the imaging device IS, a wiring layer 230, which is the uppermost layer of the multilayer wiring, is positioned directly below the boundary between the color filters. On the other hand, as shown in FIG. 3B, in the peripheral portion of the imaging device IS, the wiring layer 230 is not located directly under the boundary between the color filters. Thus, the shape of the region of the color filter 11 overlapping the wiring layer 230 is different from the shape of the region of the color filter 14 overlapping the wiring layer 230 . In this case, when patterning color filters of the same color, the width of the color filters of the same color may differ depending on whether or not the wiring layer 230 reflects the exposure light and how strong it is. A line P in FIG. 9A indicates that the width of the color filter is larger in the peripheral portion of the imaging device IS than in the central portion.

10, 11 and 12 show a method of forming the MCFA 50 according to the second embodiment.

10(a) and 10(b) are detailed explanatory diagrams of the stage Gb shown in FIG. 5(b). At the stage of FIG. 10(a), a color filter film 600 made of a negative type photosensitive material is applied, and then i-line exposure using a photomask 510 is performed to form a latent image of the pattern on the photomask 510 onto the color filter film 600. formed in At the stage of FIG. 10(b), the color filter film 600 is developed to remove the unexposed portions and form the color filter array 10. In FIG.

An opening of a photomask 510 for exposing a portion of the color filter film 600 that will become the color filter 11 located in the central portion of the imaging device IS has a width OPga. An opening of a photomask 510 for exposing a portion of the color filter film 600 that will become the color filter 14 located in the peripheral portion of the imaging device IS has a width OPgb. Color filter 11 has a width Wga corresponding to width OPga, and color filter 14 has a width Wgb corresponding to width OPgb.

11(c) and 11(d) are detailed explanatory diagrams of the step Bd shown in FIG. 6(d). At the stage of FIG. 11(c), a color filter film 700 made of a negative photosensitive material is applied, and then i-line exposure using a photomask 520 is performed to form a latent image of the pattern on the photomask 520 onto the color filter film 700. formed in At the stage of FIG. 11(d), the color filter film 700 is developed to remove the unexposed portions and form the color filter array 20. In FIG.

An opening of a photomask 520 for exposing a portion of the color filter film 700 that becomes the color filter 22 located in the central portion of the imaging device IS has a width OPba. An opening of a photomask 520 for exposing a portion of the color filter film 700 that will become the color filter 23 located in the peripheral portion of the imaging device IS has a width OPbb. The color filter 22 has a width Wba corresponding to the width OPba, and the color filter 23 has a width Wrb corresponding to the width OPrb.

FIGS. 12(e) and 12(f) are detailed explanatory diagrams of the stage Rf shown in FIG. 6(f). At the stage of FIG. 12(e), a color filter film 800 made of a negative photosensitive material is applied, and then i-line exposure using a photomask 530 is performed to form a latent image of the pattern on the photomask 530 onto the color filter film 800. formed in At the stage of FIG. 12( f ), the color filter film 800 is developed to remove the unexposed portions and form the color filter array 30 .

An opening of a photomask 520 for exposing a portion of the color filter film 800 that becomes the color filter 32 located in the central portion of the imaging device IS has a width OPra. An opening of a photomask 530 for exposing a portion of the color filter film 800 that will become the color filter 34 located in the peripheral portion of the imaging device IS has a width OPrb. The color filter 32 has a width Wra corresponding to the width OPra, and the color filter 34 has a width Wrb corresponding to the width OPrb.

A photomask 500 shown in FIG. 9B corresponds to a photomask 510 for forming the color filter array 10 . The opening OPXL is an opening for forming the color filter 12 in the first embodiment. Aperture OPL is an aperture for forming all color filters included in color filter array 10 except for color filter 12 . In the second embodiment, as shown in FIG. 9B, a photomask 500 is used which is designed such that the widths of the openings other than the openings OPXL having a large pattern opening width are all the same width OPL. Therefore, the widths of the openings are OPga=OPgb, OPba=OPbb, and OPra=OPrb. However, the widths of the color filters obtained by development are Wga<Wgb, Wba<Wbb, and Wra<Wrb. Wga<Wgb, Wba<Wbb, and Wra<Wrb fall within the ranges of the relationships Wdxb<Wdxg, Wdxr<Wdxg, Wdyb<Wdyg, and Wdyr<Wdyg described in the first embodiment.

This will be explained. Although the photomask 500 in FIG. 9B is applied to the photomask 510 as an example, it may be applied to the photomasks 520 and 530 in the same manner.

As shown in FIG. 10A, in the central portion where the wiring layer 230 is located under the boundary of the color filters, the barrier metal forming the upper surface of the wiring layer 230 prevents reflection of the exposure light.

The wiring layer 230 is provided with titanium nitride (TiN) as a barrier metal on aluminum, and the upper surface of the wiring layer 230 is made of the barrier metal. The barrier metal absorbs ultraviolet light (i-line), which is the exposure light, thereby suppressing reflection of the exposure light on the wiring layer 230 . For example, titanium nitride has an i-line reflectance of 20-30% and silicon has an i-line reflectance of 50-70%. Therefore, in the central portion where the wiring layer 230 is located under the boundary of the color filters, halation during exposure of the color filter film, which may be caused by reflection of the exposure light, is suppressed. On the other hand, in the peripheral portion where there is no wiring layer 230 (or there is little wiring layer 230) under the boundary of the color filter, the barrier metal forming the upper surface of the wiring layer 230 does not prevent the reflection of the exposure light (the degree is reduced to some extent). Therefore, the exposure light is reflected on the surface of the substrate 100, and the reflected light overexposes the color filter film at the edge of the color filter, which can cause halation. As a result, when the negative type color filter film is developed, the width of the color filter becomes large in the peripheral portion where the degree of halation is large. When a positive photosensitive material is used as the color filter film, the width of the color filter becomes smaller in the peripheral portion where the degree of halation is greater, contrary to the above. Further, when the upper surface of the wiring layer 230 has a higher reflectance of the exposure light than the substrate 100, the degree of halation increases toward the central portion where the ends of the color filters overlap the wiring layer 230, contrary to the above. . In this way, when the positional relationship between the wiring layer 230 and the end portions of the color filters is different between the central portion and the peripheral portion of the imaging device IS, the width of the color filters will differ depending on how halation occurs. As described above in the first embodiment, the color filter array including color filters with different widths is preferably formed first. Therefore, even if the positional relationship between the previously formed color filter array 10 and the wiring layer 230 differs between the positions (central part and peripheral part) in the imaging device IS, the MCFA 50 that suppresses the occurrence of color shading is obtained. be able to.

(Third embodiment)
In the third embodiment, as shown in FIG. 9C, the width of the openings other than the opening OPXL having a large pattern opening width is set to the width OPL in the central portion, the width OPS in the peripheral portion, and the width between the central portion and the peripheral portion. A photomask 500 designed to have a width of OPM is used in the middle portion of . Therefore, the widths of the openings are OPga>OPgb, OPba>OPbb, and OPra>OPrb. Thus, the photomask 500 has an opening having a width OPga for exposing a portion of the color filter film 600 that will become the color filter 11 and an opening that has a width OPga for exposing a portion of the color filter film 600 that will become the color filter 14 . an opening having a width OPgb. The width OPga and the width OPgb are different from each other in the direction in which the opening having the width OPga and the opening having the width OPgb are arranged (corresponding to the X direction). As a result, the influence of halation is compensated for, and the widths of the color filters obtained by development can achieve Wga=Wgb, Wba=Wbb, Wra=Wrb, or similar relationships.

FIG. 9(c) simulates a photomask for forming a color filter array, and shows a state in which openings for forming a color filter array are arranged over the entire photomask. FIG. 9(c) shows a method of suppressing the line width variation due to the difference in reflectance shown in FIG. 9(a). It shows how the entire surface of the photomask is corrected to offset the dimensional change of the patterned color filter array with respect to the openings corresponding to the color filter array on the photomask 500 . The correction of the photomask 500 is adjusted so that the dimension of the color filter array at the time of patterning becomes uniform according to the increase in line width. In FIG. 9C, the adjustment is performed in the direction of decreasing the color filter array dimension on the photomask 510 from the center of the pixel to the periphery of the pixel. Although the photomask 510 is described as an example in FIG. 9C, the photomasks 520 and 530 may be similarly applied. By adjusting the array dimension on the photomask 500 in accordance with the reflectance immediately below the array in this way, it is possible to suppress the variation in the array dimension within the pixel that becomes apparent in an electronic device to which a shrink structure is applied. becomes possible.

(Fourth embodiment)
In the fourth embodiment, the substrate 400 can be configured to have a light absorption film positioned between the wiring layer 230 and the color filter films 600, 700, 800 in order to suppress the halation itself described above. Here, the light-absorbing film refers to a film having an absorptivity of 10% or more for exposure light (for example, i-line) used for patterning the color filter films 600, 700, and 800. FIG. In this example, the planarization film 320 is used as a light absorption film. Note that the i-line absorption rate of a general resin planarization film is 2 to 3%. The absorptance of the exposure light is preferably 20% or more. may be 60% or less. Even if the exposure light transmitted through the light absorbing film is reflected by the substrate 100, it is absorbed again by the light absorbing film. By arranging the light absorbing film having an absorptance of 10% or more on the wiring layer 230 in this way, the difference in the degree of halation due to the difference in the positional relationship between the wiring layer 230 and the color filter film is less likely to occur. .

In the above-described third and fourth embodiments, as indicated by line Q in FIG. 9A, the width of the color filter differs between the central portion and the peripheral portion of the imaging device IS due to the influence of halation during exposure. This indicates that it is possible to suppress

The embodiments described above can be modified as appropriate without departing from the spirit of the present invention.

50 multi-color filter array 600, 700 color filter film 10, 20 color filter array 1, 2 gap 11, 12, 21 color filter Wx11, Wy11, Wx12, Wy12 width

Claims (12)

An imaging device comprising a substrate having a plurality of photoelectric conversion units and a color filter array arranged on the surface of the substrate,
The color filter array includes a first color filter and a second color filter each overlapping at least one of the plurality of photoelectric conversion units, and between the first color filter and the second color filter. a third color filter located at
the first color filter and the second color filter are color filters of a first color;
the third color filter is a color filter of a second color different from the first color,
the third color filter has a first end and a second end;
at least part of the end of the first color filter is arranged between the base and the first end in the normal direction of the surface of the base;
at least part of the end of the second color filter is arranged between the base and the second end in the normal direction of the surface of the base;
When the direction in which the first color filters and the second color filters are arranged is defined as a first direction, and the direction orthogonal to the first direction is defined as a second direction, the second color filters are arranged in the plurality of extends in the second direction so as to overlap with at least two photoelectric conversion units arranged in the second direction among the photoelectric conversion units of the
The imaging device, wherein the width of the second color filter in the second direction is larger than the width of the first color filter in the second direction. 2. The method according to claim 1, wherein the difference between the thickness of said first color filter and the thickness of said second color filter is smaller than the difference between the thickness of said first color filter and the thickness of said third color filter. Imaging device as described. The width of the second color filter in the second direction is larger than the width of the second color filter in the first direction,
3. The imaging device according to claim 1, wherein the width of said second color filter in said first direction is greater than the width of said first color filter in said first direction. further comprising a fourth color filter being a color filter of the first color, aligned with the first color filter in the second direction;
The width of the second color filter in the second direction is larger than the distance between the first color filter and the fourth color filter according to any one of claims 1 to 3. imaging device. the width of the second color filter in the second direction is greater than the sum of the width of the first color filter in the second direction and the width of the third color filter in the second direction; The imaging device according to any one of claims 1-4. The color filter array has a first color filter array composed of a plurality of color filters of the first color and a second color filter array composed of a plurality of color filters of the second color. death,
a color filter located at one end in the second direction and a color filter located at the other end in the second direction among all the color filters included in the first color filter array and excluding the second color filter; 6. The imaging device according to any one of claims 1 to 5, wherein a color filter having a color different from the first color is arranged between the second color filter and the second color filter. 7. The imaging device according to claim 1, wherein said first color filter overlaps only a single photoelectric conversion unit among said plurality of photoelectric conversion units. the width of the second color filter in the second direction is greater than the sum of the width of the first color filter in the second direction and the width of the third color filter in the second direction; The imaging device according to any one of claims 1-7. The substrate has a wiring layer,
9. The region according to claim 1, wherein a shape of a region of said first color filter that overlaps said wiring layer is different from a shape of a region of said second color filter that overlaps said wiring layer. imaging device. 7. The imaging device of claim 6 , wherein the plurality of color filters included in said first color filter array are partially continuous. The imaging according to any one of claims 1 to 10, wherein the first color filter is located in the central part of the color filter array and the second color filter is located in the peripheral part of the color filter array. device. A display device comprising a substrate having a plurality of photoelectric conversion units and a color filter array disposed on the surface of the substrate,
The color filter array includes a first color filter and a second color filter each overlapping at least one of the plurality of photoelectric conversion units, and between the first color filter and the second color filter. a third color filter located at
the first color filter and the second color filter are color filters of a first color;
the third color filter is a color filter of a second color different from the first color,
the third color filter has a first end and a second end;
at least part of the end of the first color filter is arranged between the base and the first end in the normal direction of the surface of the base;
at least part of the end of the second color filter is arranged between the base and the second end in the normal direction of the surface of the base;
When the direction in which the first color filters and the second color filters are arranged is defined as a first direction, and the direction orthogonal to the first direction is defined as a second direction, the second color filters are arranged in the plurality of extends in the second direction so as to overlap with at least two photoelectric conversion units arranged in the second direction among the photoelectric conversion units of the
A display device, wherein the width of the second color filter in the second direction is larger than the width of the first color filter in the second direction.

Images