JP6801230B2 - Solid-state image sensor and electronic equipment - Google Patents

Description

The present invention relates to a solid-state image sensor and an electronic device.

In recent years, the number of pixels of imaging devices mounted on video cameras, digital cameras, and camera-equipped mobile phones has been increased, that is, the number of pixels has been reduced. However, with the miniaturization of pixels of solid-state image pickup devices such as CCDs and CMOS sensors incorporated in image pickup devices, there is a problem that sensitivity is lowered due to a decrease in the amount of light incident on each pixel.

In a general CCD or CMOS sensor, a color filter for transmitting light having a specific wavelength is formed for each pixel. In the most common configuration, three types of filters, an R filter that allows red light to pass through, a B filter that allows blue light to pass through, and a G filter that allows green light to pass through, are arranged in a checkered pattern. The light incident on the solid-state image sensor is sorted into a specific color for each pixel by a color filter, and the light is detected by a light receiving element.

Each microlens arranged so as to face the color filter on a one-to-one basis guides the incident light to the center of the pixel and contributes to the improvement of the light receiving sensitivity. In the microlens group, the sensitivity of the sensor can be efficiently increased by arranging a plurality of substantially spherical microlenses for each pixel without a gap (see Patent Document 1). Here, when a flat surface on which a microlens is not formed exists in the pixel, the light incident from the flat surface passes near the boundary surface with the adjacent pixel of the color filter, so that the diffracted light due to the difference in the refractive index of the color filter May occur, resulting in reduced sensitivity or color mixing. Therefore, when arranging the microlenses, it is desirable to arrange them without gaps in the pixels.

In order to increase the sensitivity of the sensor, for example, there is a method of improving the light collection property by reducing the radius of curvature of the microlens. When reducing the radius of curvature, a method of reducing the area of the bottom surface of the lens or increasing the lens height without changing the area of the bottom surface of the lens is generally adopted. However, if the area of the bottom surface of the lens is reduced, a flat surface is formed on the pixels, so that sensitivity is likely to decrease and color mixing is likely to occur. On the other hand, when the height of the lens is increased, the focusing property on the photodiode deteriorates due to the deviation of the focal position, which may reduce the sensitivity and cause color mixing.

JP-A-2000-332226

The present invention has been made in view of the above problems, and an object of the present invention is to provide a solid-state image sensor and an electronic device capable of improving the sensitivity per pixel.

The solid-state imaging device according to the present invention for solving the above problems is divided into a plurality of pixels, and a photoelectric conversion region is arranged in each pixel, and the solid-state imaging device according to the present invention is located on the light incident surface side of the photoelectric conversion region. It is provided between a microlens group in which a plurality of microlenses are arranged to collect incident light in each of the photoelectric conversion regions, and between the semiconductor substrate and the microlens group, and correspond to each pixel. The microlens group includes an R filter that transmits red light, a B filter that transmits blue light, and a color filter in which G filters that transmit green light are arranged in a Bayer arrangement. the cross section of the lens boundary is between is a concave-concave on the color filter side, and each microlens, the cross section of the lens central portion is a convex shape projecting in a direction away from the color filter, the The refractive index of all wavelengths of the microlens is 1.4 or more and 1.7 or less, and the refractive indices of the R filter, G filter, and B filter at wavelengths of 450 nm are Nr, Ng, and Nb, respectively, and the height of the microlens is high. When the value is H, the radius of curvature above the pixel boundary at the lens boundary is r, and the pixel pitch is P, the following equation (1) is satisfied , and in the microlens group, two pixel arrays orthogonal to each other are arranged. When the radius of curvature r of the lens boundary when cut in the direction is r1 and r2, respectively, r1 and r2 have different values, and the lens boundary is vertically above the boundary between the R filter and the G filter. When the radius of curvature of the lens is defined as rgr and the radius of curvature of the lens boundary vertically above the boundary between the B filter and the G filter is defined as rgb, the microlens group is | Ng-Nr |> | Ng-Nb. When |, rgr <rgb is satisfied, and when | Ng-Nr | << Ng-Nb |, rgr> rgb is satisfied .
0.05 <r / P <0.24 and 0.36 <H / P <0.5 ... (1)

According to the aspect of the present invention, it is possible to improve the sensitivity per pixel by devising the lens shape of the microlens group.

An example of a solid-state image sensor provided with a color filter according to an embodiment of the present invention is shown, (a) is a plan view, and (b) and (c) are schematics in which (a) is cut by V1 or V2. It is a figure which illustrates the cross section. This is an example of a three-dimensional diagram of a microlens. It is a figure explaining the optical action of a microlens. It is a figure explaining the optical action of a microlens.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
However, in each of the figures described below, the parts corresponding to each other are designated by the same reference numerals, and the description of the overlapping parts will be omitted as appropriate. Further, the embodiment of the present invention exemplifies a configuration for embodying the technical idea of the present invention, and specifies the material, shape, structure, arrangement, dimensions, etc. of each part as follows. Not. The technical idea of the present invention may be modified in various ways within the technical scope specified by the claims stated in the claims.

<Composition>
As shown in FIG. 1, the solid-state image sensor 10 of the present embodiment has a first flattening layer 3a, a color filter 4, a second flattening layer 3b, and a microlens group 5 on the semiconductor substrate 1. It is constructed by stacking in order. In FIG. 1, a light-shielding film 2 is erected at the boundary portion of each pixel.
The surface of the semiconductor substrate 1 on the light incident side is divided into a plurality of pixels, and a photoelectric conversion region 1a is arranged in each of the pixels. For example, a photoelectric element is arranged in the photoelectric conversion region 1a. In the present embodiment, as shown in FIG. 1A, a case where each pixel is rectangular and the pixels are arranged along two orthogonal directions is illustrated. The two-dimensional arrangement directions of the pixels do not have to be orthogonal to each other.

The microlens group 5 is provided on the light incident surface side of the photoelectric conversion region 1a, and is configured by arranging a plurality of microlenses 5A for condensing the incident light on each of the photoelectric conversion regions 1a. That is, each microlens 5A is arranged directly above the pixel in pixel units.
The color filter 4 is arranged between the semiconductor substrate 1 and the microlens group 5, and a plurality of colors are arranged in a preset regular pattern corresponding to each of the plurality of photoelectric conversion regions 1a. The color filter 4 of the present embodiment is configured by arranging an R filter that transmits red light, a B filter that transmits blue light, and a G filter that transmits green light in a preset regular pattern.

That is, as shown in FIG. 1, the color filter 4 of the solid-state imaging device 10 of the present embodiment is provided on the light incident surface side (upper surface in FIGS. 1B and 1C) of the photoelectric conversion region 1a. R filter that transmits red light (described as "R" in FIG. 1 (a)), B filter that transmits blue light (described as "B" in FIG. 1 (a)), G filter that transmits green light (described as "B" in FIG. 1 (a)) A color filter 4 having (described as “G” in FIG. 1 (a)), a second flattening layer 3b provided on the light incident surface side of the color filter 4 and flattening the surface of the color filter, and A microlens group 5 provided on the light incident surface side of the color filter 4 via a second flattening layer 3b and having a plurality of microlenses 5A facing the R filter, the B filter, and the G filter on a one-to-one basis. ..

Further, the microlens group 5 has a valley-shaped concave shape in which the cross section of the lens boundary portion 5a between adjacent microlenses 5A is curved concavely toward the color filter 4, and each microlens 5A is a lens. The cross section of the central portion has a convex shape that is convex in the direction away from the color filter 4. When the height of the microlens 5A is H, the radius of curvature above the pixel boundary at the lens boundary 5a is r, and the pixel pitch is P, the microlens group 5 has 0.05 <r / P <0.24. Moreover, it is formed so as to satisfy 0.36 <H / P <0.5.

That is, the microlens group 5 has a shape in which the cross section of the lens boundary portion 5a located directly above the pixel boundary portion is smoothly curved so as to form a valley. Here, V1 and V2 shown in FIG. 1A represent pixel arrangement directions orthogonal to each other. When the microlens group 5 is cut along the cross sections V1 and V2, as shown in FIGS. 1B and 1C, when the valley of the lens boundary 5a just above the pixel boundary is fitted with a circle, the circle is formed. Let it be C1 and C2. Let the radius of curvature r of each circle C1 and C2 be r1 and r2. r1 and r2 may be equal or different.
Here, the position of the microlens group 5 in contact with the circles C1 and C2 is the lens boundary portion 5a.

When r1 and r2 are different, the focusing characteristics of the microlens 5A differ between the V1 direction and the V2 direction due to the difference in the radius of curvature of the central portion of the lens of the microlens 5A in the cross section V1 direction and the cross section V2 direction. .. Therefore, for example, when the photodiode has an asymmetrical shape having different dimensions in the V1 direction and the V2 direction, light can be focused according to the shape of the photodiode, and the sensitivity can be efficiently increased.
An example of the three-dimensional shape of each microlens 5A is shown in FIG. FIG. 2A shows an example of the shape of the microlens 5A based on the present invention, and FIG. 2B shows an example of the shape of the conventional microlens 5A in which the portion forming the valley of the lens boundary portion 5a is not rounded.
The pixel pitch is defined as P, and the height of the microlens 5A is defined as H. At this time, in order to improve the light-collecting property of each microlens 5A of the microlens group 5, 0.05 <ri / P <0.24 (i = 1, 2) and 0.36 <H / P <0. It is desirable to set the range to satisfy .5.

Next, with reference to FIG. 3, the reason for setting the radius of curvature ri in the range of 0.05 <ri / P <0.24 (i = 1, 2) will be described.
3 (a) shows when ri / P is greater than 0.24, FIG. 3 (b) shows when ri / P is less than 0.05, and FIG. 3 (c) shows 0.05 <ri. The behavior of each incident light when / P <0.24 is satisfied is schematically shown.
In FIG. 3A, since the microlens 5A near the lens boundary portion 5a is close to flat, the light traveling straight on the flat surface penetrates into the vicinity of the boundary portion of the color filter. Since the color filter is formed of a different refractive index material for each color, light is diffracted by the difference in refractive index at the boundary portion of the color filter, and some light is scattered to adjacent pixels. Therefore, it causes color mixing and a decrease in sensitivity of the sensor. Further, in FIG. 3B, since the microlens 5A near the lens boundary portion 5a is inclined, the light is refracted by the microlens 5A and the light is collected at the center of the pixel. In this case, since less light penetrates into the vicinity of the boundary of the color filter, color mixing and sensitivity reduction due to diffracted light are unlikely to occur. However, in this case, since the radius of curvature of the top (center) of the microlens 5A is larger than that in FIG. 3A, the ability to collect light inside the photoelectric conversion region 1a is inferior. On the other hand, in FIG. 3C, since the microlens 5A near the lens boundary portion 5a is inclined, the light is refracted by the microlens 5A and the light is collected at the center of the pixel. In addition, since less light penetrates into the vicinity of the boundary of the color filter, color mixing and sensitivity reduction due to diffracted light are unlikely to occur. Further, in FIG. 3 (c), since the radius of curvature of the top (center portion) of the microlens 5A is smaller than that in FIG. 3 (b), the ability to collect light inside the photoelectric conversion region 1a is shown in FIG. 3 (c). It is improved compared to. In this way, by setting the radius of curvature ri of the lens boundary portion 5a to a range satisfying 0.05 <ri / P <0.24, color mixing and sensitivity reduction can be achieved without sacrificing the light-collecting property of the microlens 5A. It can be suppressed. The details will be described in Examples.

Next, the reason why it is desirable to set the lens height H in the range satisfying 0.36 <H / P <0.5 will be described with reference to FIG.
4 (a) shows the case where the H / P is larger than 0.5, FIG. 4 (b) shows the case where the H / P is smaller than 0.36, and FIG. 4 (c) shows 0.36 <H / P <. The behavior of each incident light when 0.5 is satisfied is schematically shown.
In the case of FIG. 4A, the radius of curvature of the top of the lens is smaller than that of FIGS. 4B and 4C, so that the collection of microlenses 5A is smaller than that of FIGS. 4B and 4C. High lightness. However, as the height of the microlens 5A increases, the focal position of the microlens 5A shifts to the light incident side, so that the light spread in the photoelectric conversion region 1a is incident, and the color mixing and sensitivity due to the light incident on the adjacent pixels A drop occurs. Further, in the case of FIG. 4 (b), since the radius of curvature of the lens top (lens center portion) is larger than that of FIGS. 4 (a) and 4 (c), it is compared with FIGS. 4 (a) and 4 (c). And the light-collecting property of the microlens 5A becomes low. Therefore, light that cannot be focused is generated in the photoelectric conversion region 1a, which causes a decrease in sensitivity. By setting the lens height H in the range as shown in FIG. 4C, light can be effectively collected in the photoelectric conversion region 1a.

The light incident on the solid-state image sensor 10 is refracted by each microlens 5A of the microlens group 5, further transmitted through the color filter 4, and the light corresponding to the color of each pixel is focused on the photoelectric conversion region 1a. .. The photoelectric conversion region 1a is separated for each pixel, and the electric charge generated by irradiating the photoelectric conversion region 1a with light flows through the electronic circuit and is read out as a signal.

The substrate 1 and the photoelectric conversion region 1a are made of, for example, silicon. In order to prevent color mixing between pixels, the light-shielding film 2 is formed of a metal such as aluminum, silver, chromium, or tungsten, if necessary. The first flattening layer 3a is formed on the substrate 1 and covers the photoelectric conversion region 1a and the light-shielding film 2. The surface of the first flattening layer 3a is a flat surface parallel to the surface of the substrate 1. The first flattening layer 3a and the second flattening layer 3b are formed of silicon oxide, silicon nitride, or the like.

The color filter 4 is formed on the first flattening layer 3a. The color filter 4 is composed of, for example, an organic material containing a pigment or dye that selectively transmits wavelengths corresponding to the colors G (green), B (blue), and R (red). Each microlens 5A of the microlens group 5 is made of, for example, a transparent resin having a refractive index of 1.4 or more and 1.7 or less.

A typical arrangement method of the color filter 4 is a green checkered pattern (Bayer arrangement) as shown in FIG. 1A. It has high color reproducibility and is an array method that is widely used mainly in digital cameras.

The refractive indexes of the R, G, and B filters at wavelengths of 450 nm are Nr, Ng, and Nb, respectively, and the radius of curvature r of the lens boundary 5a at the boundary between the R pixel and the G pixel is rgr, and the radius of curvature r of the B pixel and the G pixel. Let rgb be the radius of curvature r of the lens boundary 5a at the boundary.
When | Ng-Nr |> | Ng-Nb |, rgr <rgb is satisfied, and
When | Ng-Nr | << Ng-Nb |, it is preferable to form each microlens 5A of the microlens group 5 so as to satisfy rgr> rgb.
In this way, the radius of curvature ri at the lens boundary portion 5a of the microlens group 5 may be set to a different value at the boundary surface according to the difference in the refractive index of the color filter 4. Since diffracted light is likely to be generated at the boundary surface where the refractive index difference of the color filter 4 is large, the radius of curvature ri at the lens boundary portion 5a forming the valley portion of the microlens group 5 has a large refractive index difference of the color filter 4. It is preferable to design the lens to be small at the pixel boundary.

Here, the reason why the refractive index is specified at a wavelength of 450 nm is to suppress color mixing in the direction from the BLUE pixel to the GREEN pixel. As a general characteristic of a photodiode, the sensitivity of short-wavelength light tends to decrease due to the recombination of electrons and holes on the outermost surface of the silicon photodiode. Therefore, when light flows from the BLUE pixel toward the GREEN pixel due to color mixing, the sensitivity of the BLUE pixel, which originally tends to be low, is further lowered, which is not preferable.
The microlens 5A is, for example, a part of a curved surface in which the shape of the central portion of the lens located directly above the central portion of the pixel is a spherical surface, an ellipsoid, or a curved surface similar thereto. With such a shape, the focal aberration of the microlens 5A can be reduced as compared with other shapes, and light can be efficiently focused on the photoelectric conversion region 1a. Alternatively, it may be a part of a parabolic shape or a curved surface similar thereto. When it is used as a part of a parabolic shape, the radius of curvature of the top of the microlens 5A is smaller than that of a part of a spherical surface or an ellipsoid, so that light is efficiently photoelectric when the height of the microlens 5A is low. Light can be focused on the conversion region 1a.

The light L incident on the solid-state image sensor 10 is focused by the microlens 5A and incident on the color filter 4. In the color filter 4, light having a required wavelength is transmitted according to the pixels, and light having an unnecessary wavelength is absorbed.
The light that has passed through the color filter 4 passes through the first flattening layer 3a and is focused on the photoelectric conversion region 1a. When the photoelectric conversion region 1a is irradiated with light, an electric charge is generated in proportion to the light intensity, and the generated electric charge is transferred to an electronic circuit to read a signal.

<Manufacturing method>
An example of a method for producing the microlens group 5 is as follows.
The microlens group 5 described above can be manufactured by using optical lithography. As a method of using optical lithography, a method of using a heat flow and a method of using a grayscale mask are known. In the former method, a three-dimensional rectangular pattern is produced by exposing and developing a photosensitive resist coated on a substrate using a photomask in which a pattern corresponding to the microlens group 5 is formed. After that, the resist is deformed into a curved surface shape by heat flow to form the microlens group 5. Further, if necessary, the resist is etched together with the base material to transfer the pattern of the microlens group 5 to the base material.
In the latter method, the resist is exposed and developed using a mask whose light transmittance changes stepwise to obtain a three-dimensional resist pattern. Further, if necessary, the resist pattern is transferred to the base material to produce a microlens pattern of the base material. Since each microlens 5A of the microlens group 5 in the present invention has a complicated shape, it is ideal to use the latter method.

<Effect of embodiment>
In the microlens group 5 according to the embodiment of the present invention, the cross section of the lens boundary portion 5a between the lenses is concave, and the cross section of the central portion of the lens is convex. When the height of each microlens 5A is H, the radius of curvature of the lens boundary portion 5a of the microlens group 5 is ri, and the pixel pitch is P, 0.05 <ri / P <0.2 (i = 1). 2) And 0.36 <H / P <0.5.
According to this configuration, it is possible to suppress scattering due to the difference in refractive index of the color filter 4 while improving the light-collecting property of the microlens 5A. As a result, the sensitivity of the sensor can be increased as compared with the case where the conventional microlens 5A is used.

As described above, according to the embodiment of the present invention, it is possible to improve the sensitivity per pixel of the solid-state image sensor. By applying this solid-state image sensor to electronic devices such as digital cameras, video cameras, and camera-equipped mobile phones, it is possible to improve the sensitivity and uniformity of image quality of these electronic devices.

Next, Examples and Comparative Examples of the present invention will be described.
Each microlens 5A of the microlens group 5 has a concave roundness formed at a valley portion of a lens boundary portion 5a between lenses with a predetermined radius of curvature r based on a parabolic shape. The shape of each microlens 5A was designed. The color filter 4 has a Bayer array. The sensitivity simulation was carried out using the time domain difference method (FDTD method) generally used in the optical analysis of wavelength-order structures.
The calculation conditions are as follows.

〔Calculation condition〕
-Pixel pitch: 1200 nm (1.2 μm)
-Height of microlens 5A: 350 nm to 600 nm (in 50 nm increments)
・ Refractive index of microlens 5A: 1.6 (all wavelengths)
・ Color filter 4: 700 nm thickness, Bayer arrangement of 3 RGB colors ・ Refractive index of R filter: 1.75 (wavelength 450 nm)
-Refractive index of G filter: 1.74 (wavelength 450 nm)
-Refractive index of B filter: 1.45 (wavelength 450 nm)
-Light-shielding film 2: None-Thickness of the first flattening layer 3a: 500 nm
-Thickness of the second flattening layer 3b: 100 nm
-Incident wavelength: 400 nm to 700 nm (in 10 nm increments)
・ Incident angle: 0 °, 15 °
-Polarized light: TE wave, TM wave-Light receiving surface: Set at the interface between the flattening layer 3 and the photoelectric conversion region 1a (the light receiving surface is set to 80% of the pixel area)

The radius of curvature ri (i = 1, 2) of the lens boundary portion 5a of the microlens group 5 was set as follows (the value of ri was r1 = r2 regardless of the height of the microlens 5A).
(Example 1) 88 nm (ri / P = 0.07)
(Example 2) 135 nm (ri / P = 0.11)
(Example 3) 185 nm (ri / P = 0.15)
(Comparative Example 1) 60 nm (ri / P = 0.05)
(Comparative Example 2) 240 nm (ri / P = 0.20)
(Comparative Example 3) 293 nm (ri / P = 0.24)
(Comparative Example 4) 377 nm (ri / P = 0.31)

Under the conditions of the above Examples and Comparative Examples, sensitivity simulations of R pixels, G pixels, and B pixels were performed.
Here, the sensitivity of the R pixel was calculated with an average value of a wavelength of 600 nm to 700 nm, the sensitivity of the G pixel was calculated with an average value of a wavelength of 510 nm to 570 nm, and the sensitivity of the B pixel was calculated with an average value of a wavelength of 420 nm to 470 nm. In the simulation, the average of the TE wave and the TM wave of the amount of light incident on the photoelectric conversion region 1a with respect to the amount of incident light is calculated, and the ratio of the amount of light of the reference (parabolic shape / height 450 nm) shown in FIG. 2B is calculated. Calculated.
The results are shown in Tables 1 and 2.
Table 1 shows the sensitivity values of (a) GREEN pixel, (b) BLUE pixel, and (c) RED pixel in vertical incidence. Table 2 shows the sensitivity values of (a) GREEN pixel, (b) BLUE pixel, and (c) RED pixel at an oblique angle of 15 °.

The cells painted in gray in Tables 1 and 2 represent the condition in which the sensitivity is reduced by 1% or more with respect to the reference. When the height of the microlens 5A is 400 nm or less, or when the ri / P is 0.24 or more, the sensitivity of the BLUE pixel is significantly reduced as compared with the reference. On the other hand, when the height of the microlens 5A is 550 nm or more, the sensitivity of the RED pixel is significantly lowered under the condition of an oblique angle of 15 °. When ri / P was 0.05 or less, the sensitivity difference from the reference was as small as less than ± 1% even if the height of the microlens 5A was changed, and a significant increase in sensitivity beyond the simulation error was not obtained. .. In order to obtain a significant sensitivity difference of 1% or more from the reference, the ri / P is preferably larger than 0.05 and less than 0.24. Further, the H / P is more than 0.36 and preferably less than 0.5.

When the ri / P is 0.24 or more, the sensitivity of the BLUE pixel decreases significantly because the refractive index of the BLUE filter has a large difference from the refractive index of the GREEN filter, so that the diffraction is performed from the BLUE pixel direction to the GREEN pixel direction. This is because light is generated and the amount of light incident on the photoelectric conversion region 1a of the BLUE pixel is reduced. On the other hand, since the difference between the refractive indexes of the RED filter and the GREEN filter is small, diffracted light is not generated, and the sensitivity decrease as seen in BLUE pixels does not occur. Therefore, even if the valley radius of curvature rgr of the lens boundary 5a at the boundary between the GREEN pixel and the RED pixel is set to be smaller than the valley curvature radius rgb at the boundary between the GREEN pixel and the BLUE pixel, there is a problem. There is no.

1 Substrate 1a Photoelectric conversion region 2 Light-shielding film 3a First flattening layer 3b Second flattening layer 4 Color filter 5 Microlens group 5A Microlens 5a Lens boundary 10 Solid-state image sensor

Claims (8)

A semiconductor substrate divided into a plurality of pixels and a photoelectric conversion region is arranged in each pixel.
A group of microlenses provided on the light incident surface side of the photoelectric conversion region and having a plurality of microlenses arranged to collect the incident light in each of the photoelectric conversion regions.
A Bayer arrangement of an R filter that is arranged between the semiconductor substrate and the microlens group and transmits red light corresponding to each pixel, a B filter that transmits blue light, and a G filter that transmits green light. With the color filter placed in
With
In the microlens group, the cross section of the lens boundary between adjacent microlenses is concave on the color filter side, and in each microlens, the cross section of the central part of the lens is separated from the color filter. It has a convex shape that is convex in the direction,
The refractive index of all wavelengths of the microlens is 1.4 or more and 1.7 or less.
The refractive indexes of the R filter, G filter, and B filter at a wavelength of 450 nm are defined as Nr, Ng, and Nb, respectively.
When the height of the microlens is H, the radius of curvature above the pixel boundary at the lens boundary is r, and the pixel pitch is P, the following equation (1) is satisfied and the result is satisfied .
In the microlens group, when the radius of curvature r of the lens boundary portion when cut in the directions of two pixel arrangements orthogonal to each other is r1 and r2, respectively, r1 and r2 are different values.
The radius of curvature of the lens boundary on the vertical boundary between the R filter and the G filter is defined as rgr, and the radius of curvature of the lens boundary on the vertical boundary between the B filter and the G filter is defined as rgb. If
The above microlens group
When | Ng-Nr |> | Ng-Nb |, rgr <rgb is satisfied, and
When | Ng-Nr | << | Ng-Nb |, the solid-state image sensor is characterized in that rgr> rgb is satisfied .
0.05 <r / P <0.24 and 0.36 <H / P <0.5 ... (1) The solid-state image sensor according to claim 1, wherein the length between the semiconductor substrate and the microlens group is 1300 nm . A first flattening layer arranged between the semiconductor substrate and the color filter,
A second flattening layer arranged between the color filter and the microlens group,
With
The solid-state image sensor according to claim 2, wherein the thickness of the color filter is 700 nm, the thickness of the first flattening layer is 500 nm, and the thickness of the second flattening layer is 100 nm . The refractive index Nr of the R filter at a wavelength of 450 nm is 1.75, the refractive index Ng of the G filter at a wavelength of 450 nm is 1.74, and the refractive index Nb of the B filter at a wavelength of 450 nm is 1.45.
The solid-state image sensor according to any one of claims 1 to 3, characterized in that. The refractive index of all wavelengths of the microlens is 1.6.
The solid-state image sensor according to any one of claims 1 to 4, characterized in that. The solid-state image sensor according to any one of claims 1 to 5 , wherein the shape of the central portion of the lens is a part of an ellipsoidal shape. The solid-state image sensor according to any one of claims 1 to 5 , wherein the shape of the central portion of the lens is a part of the parabolic shape. An electronic device comprising the solid-state image sensor according to any one of claims 1 to 7 .

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