Light detection device

Abstract

A light detection device disclosed herein comprises: a light-receiving layer which has a plurality of light-receiving elements and in which a plurality of pixels are arranged; a color splitter layer which has a metasurface structure and condenses incident light toward the light-receiving layer according to the wavelength of the incident light; a spacer layer that is disposed between the light-receiving layer and the color splitter layer; and a separation wall that is disposed between the light-receiving layer and the color splitter layer and blocks the incident light. When the distance between the color splitter layer and the light-receiving surface of the light-receiving layer is H, the wavelength of the incident light is λ, the refractive index of the spacer layer is n, the effective diameter of a light-condensing region corresponding to one pixel by the color splitter layer is A, the pixel pitch in the light-receiving layer is P, the height of the separation wall is h, and the width of the separation wall is w, the condition H ≤ h + (1 / 2.44) (n / λ)A x (A-P + w) (1) is satisfied.

Description

Photodetector

[0001] The present disclosure relates to a light detection device.

[0002] In photodetection devices applicable to imaging devices and the like, there is a color splitter, a structure with a function equivalent to that of a color filter (see Patent Document 1). A color splitter can perform color separation by changing the direction of light for each wavelength and splitting it. The color splitter has a structure using a metasurface element (metamaterial structure). The color splitter collects light including the surrounding light, thereby improving QE (Quantum Efficiency).

[0003] Japanese Patent Application Laid-Open No. 2022-74063

[0004] In the above-described photodetector, a spacer layer is disposed between the light receiving layer and the color splitter layer. If the height of this spacer layer is increased, the oblique incidence characteristics deteriorate and manufacturing becomes difficult.

[0005] Therefore, it is desirable to provide a photodetector that can improve oblique incidence characteristics and manufacturability.

[0006] According to an embodiment of the present disclosure, a photodetector device includes: a light receiving layer having a plurality of light receiving elements and a plurality of pixels arranged thereon; a color splitter layer having a metasurface structure and concentrating incident light toward the light receiving layer according to its wavelength; a spacer layer disposed between the light receiving layer and the color splitter layer; and a separation wall disposed between the light receiving layer and the color splitter layer and blocking the incident light. When H is the distance between the color splitter layer and a light receiving surface of the light receiving layer, λ is the wavelength of the incident light, n is the refractive index of the spacer layer, A is the effective diameter of a light-concentrating region corresponding to one pixel in the color splitter layer, P is the pixel pitch in the light receiving layer, h is the height of the separation wall, and w is the width of the separation wall, the photodetector device satisfies the following condition: H≦h+(1 / 2.44)(n / λ)A×(A−P+w) … (1).

[0007] Furthermore, an optical detection device according to an embodiment of the present disclosure includes a light receiving layer having a plurality of light receiving elements and a plurality of pixels arranged thereon, a color splitter layer having a metasurface structure and focusing incident light toward the light receiving layer according to its wavelength, and a spacer layer disposed between the light receiving layer and the color splitter layer, where H is the distance between the color splitter layer and a light receiving surface of the light receiving layer, λ is the wavelength of the incident light, n is the refractive index of the spacer layer, A is the effective diameter of a light focusing area corresponding to one pixel of the color splitter layer, and P is the pixel pitch of the light receiving layer, and the following condition is satisfied: H≦(1 / 2.44)(n / λ)A×(A−P) … (3)

[0008] In a photodetector according to an embodiment of the present disclosure, the distance between the color splitter layer and the light-receiving surface of the light-receiving layer is optimized so that oblique incidence characteristics and manufacturability can be improved.

[0009] FIG. 1 is a cross-sectional view schematically illustrating an example of a configuration of a photodetector according to a comparative example. FIG. 2 is a cross-sectional view schematically illustrating an example of a light-collecting state when obliquely incident light is incident in a photodetector according to a comparative example. FIG. 3 is a cross-sectional view schematically illustrating an example of a configuration of a photodetector according to an embodiment of the present disclosure. FIG. 4 is an explanatory diagram illustrating an example of a relationship between the height of a spacer layer and transmittance. FIG. 5 is a cross-sectional view schematically illustrating an example of a light-collecting state when obliquely incident light is incident in a photodetector according to an embodiment. FIG. 6 is an explanatory diagram illustrating an example of a relationship between the height of a spacer layer and the amount of shift in the light-collecting position on the light-receiving surface when obliquely incident light is incident. FIG. 7 is a cross-sectional view schematically illustrating an example of a light-collecting state when obliquely incident light is incident when the pupil correction amount is small. FIG. 8 is a cross-sectional view schematically illustrating an example of a light-collecting state when obliquely incident light is incident when the pupil correction amount is large. FIG. 9 is a cross-sectional view schematically illustrating an example of a configuration of a photodetector according to an embodiment. FIG. 10 is an explanatory diagram illustrating an example of a relationship between the height of a spacer layer and transmittance. FIG. 11 is a cross-sectional view schematically showing an example of a configuration of a photodetector according to a first modification of an embodiment. FIG. 12 is a plan view schematically showing an example of a configuration of a color filter. FIG. 13 is a plan view schematically showing an example of a configuration of a color filter. FIG. 14 is a plan view schematically showing an example of a configuration of a color filter. FIG. 15 is a plan view schematically showing an example of a configuration of a color filter. FIG. 16 is a plan view showing an example of a correspondence relationship between the shape of a light-collecting region and the shape (arrangement) of pixels (color filters). FIG. 17 is a plan view showing an example of a correspondence relationship between the shape of a light-collecting region and the shape (arrangement) of pixels (color filters). FIG. 18 is a cross-sectional view schematically showing an example of a configuration of a photodetector according to a third modification of an embodiment. FIG. 19 is a cross-sectional view schematically showing an example of a configuration of a photodetector according to a fourth modification of an embodiment. FIG. 20 is a cross-sectional view schematically showing an example of a configuration of a photodetector according to a fourth modification of an embodiment. FIG. 21 is a cross-sectional view schematically showing an example of a configuration of a photodetector according to a fifth modification of an embodiment. 22 is a cross-sectional view schematically illustrating a configuration example of a photodetector according to a sixth modification of an embodiment. FIG. 23 is a cross-sectional view schematically illustrating a configuration example of a photodetector according to a seventh modification of an embodiment.

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order: 0. Comparative Example 1. One Embodiment 1.1 Configuration and Function 1.2 Modification 1.3 Effects 2. Other Embodiments

[0011] <0. Comparative Example> Fig. 1 is a cross-sectional view schematically showing an example of the configuration of a photodetector according to a comparative example. Fig. 2 is a cross-sectional view schematically showing an example of a light-condensing state when obliquely incident light is incident on the photodetector according to the comparative example.

[0012] The photodetector according to the comparative example includes a light receiving layer 10 , a color splitter layer 20 , and a spacer layer 30 .

[0013] The light receiving layer 10 is made of, for example, a semiconductor substrate, has a plurality of light receiving elements 11, and has a structure in which a plurality of pixels 120 are arranged. The surface on which the plurality of light receiving elements 11 are formed forms a light receiving surface 100. When applied to an imaging device or the like, the structure has a plurality of pixels 120 arranged two-dimensionally. The light receiving elements 11 are made of, for example, PDs (photodiodes). The light receiving elements 11 output pixel signals corresponding to incident light. The plurality of light receiving elements 11 are separated into pixels by pixel separation sections 12.

[0014] The color splitter layer 20 has a metasurface structure and focuses incident light toward the light receiving layer 10 according to its wavelength. The color splitter layer 20 includes a plurality of pillars 21, e.g., cylindrical microstructures, and a medium 22. The pillars 21 and the medium 22 are made of materials with different refractive indices. For example, the pillars 21, e.g., made of a high refractive index material, are provided in the medium 22, e.g., made of a low refractive index material. The metasurface has a plurality of pillars 21, which are microstructures smaller than the wavelength of light, arranged in the medium 22, which delay the phase of the incident light according to its wavelength and deflect the incident light according to its wavelength. This allows the color splitter layer 20 to perform color separation by changing the direction of light and splitting it according to its wavelength. Note that while FIGS. 1 and 2 show an example in which the color splitter layer 20 has a two-stage metasurface structure, the metasurface structure is not limited to a two-stage structure.

[0015] The spacer layer 30 is disposed between the light receiving layer 10 and the color splitter layer 20. Between the light receiving layer 10 and the color splitter layer 20, a plurality of separation walls 31 are disposed to block incident light.

[0016] Here, Patent Document 1 (JP 2022-74063 A) proposes a structure in which the distance H between the color splitter layer 20 and the light-receiving surface 100 (which corresponds to the height of the spacer layer 30 in the configuration example of FIG. 1 ) satisfies the condition of the following formula (X): In formula (X), λ is the wavelength of the incident light, n is the refractive index of the spacer layer 30, and P is the pixel pitch in the light-receiving layer 10.

[0017] H1-P>H>H1+P...(X) H1=(n・P ２ / λ) - (λ / 4n)

[0018] When the spacer layer 30 is designed under the condition of the above formula (X), it is possible to condense light directly above the light-receiving surface 100 as shown in Fig. 1. However, in this case, as the pixel pitch P increases, the height of the spacer layer 30 increases, which leads to a deterioration in the oblique incidence characteristics as shown in Fig. 2. Furthermore, the increased height of the spacer layer 30 makes manufacturing difficult.

[0019] 1. One Embodiment> [1.1 Configuration and Operation] FIG. 3 is a cross-sectional view that schematically illustrates one configuration example of a photodetector according to one embodiment of the present disclosure.

[0020] In contrast to the configuration of the photodetector according to the comparative example, which satisfies the condition of formula (X) above, the photodetector according to one embodiment is configured to satisfy the condition of the following formula (1). Note that the configuration of the photodetector according to one embodiment may be substantially similar to that of the photodetector according to the comparative example, except for the condition of formula (1). Incident light can be focused by satisfying the condition that the diffraction angle θ of the color splitter layer 20 is θ≧diffraction limit. For this reason, the condition of formula (1) must be satisfied.

[0021] H≦h+(1 / 2.44)(n / λ)A×(AP+w)...(1)

[0022] Here, the distance between color splitter layer 20 and light-receiving surface 100 of light-receiving layer 10 is defined as H (corresponding to the height of spacer layer 30 in the configuration example of FIG. 3 ), the wavelength of incident light is defined as λ, and the refractive index of spacer layer 30 is defined as n. Also, the effective diameter of light-collecting region 110 corresponding to one pixel by color splitter layer 20 is defined as A, the pixel pitch in light-receiving layer 10 is defined as P, the height of separation wall 31 is defined as h, and the width of separation wall 31 is defined as w.

[0023] By satisfying the condition of formula (1), the photodetector according to one embodiment can focus incident light onto the light receiving layer 10, subject to the constraint of the height of the spacer layer 30 required for focusing light by the color splitter layer 20.

[0024] FIG. 4 is an explanatory diagram showing an example of the relationship between the height of the spacer layer 30 and the transmittance.

[0025] FIG. 4 illustrates the range of heights of the spacer layer 30 in a photodetector according to a comparative example that satisfies the condition of formula (X) above and a photodetector according to an embodiment that satisfies the condition of formula (1). As shown in FIG. 4, even if the spacer layer 30 is provided above a certain height, the transmittance does not increase any further. In the photodetector according to an embodiment, the condition of formula (1) is satisfied and incident light is concentrated inside the light-receiving layer 10. As a result, compared to the photodetector according to the comparative example, by reducing the height of the spacer layer 30, oblique incidence characteristics can be improved and manufacturability can be improved. Furthermore, within the condition of formula (1), it is possible to suppress a decrease in sensitivity when incident light is perpendicularly incident on the light-receiving layer 10.

[0026] FIG. 5 is a cross-sectional view schematically showing an example of a light-collecting state when obliquely incident light is incident in a photodetector according to an embodiment. FIG. 6 shows an example of the relationship between the height of the spacer layer 30 and the shift amount Δx of the light-collecting position on the light-receiving surface 100 when obliquely incident light is incident. FIG. 7 is a cross-sectional view schematically showing an example of a light-collecting state when obliquely incident light is incident when the pupil correction amount is small. FIG. 8 is a cross-sectional view schematically showing an example of a light-collecting state when obliquely incident light is incident when the pupil correction amount is large. Note that FIGS. 5 to 8 assume a pixel pitch P of 5000 nm and an incident light angle of 15°.

[0027] When considering obliquely incident light, the size of the entrance pupil changes compared to when light is perpendicularly incident. In this case, it is possible to correct the incidence characteristics (pupil correction) in the case of oblique incidence by, for example, changing the position of the separation wall 31. Here, the amount of deviation of the incidence position of light on the light-receiving surface 100 relative to the separation wall 31 is denoted by Δx. When considering obliquely incident light, by reducing the height of the spacer layer 30, the incident light is more likely to enter the light-receiving layer 10 in the photodetector according to the embodiment compared to the photodetector according to the comparative example. This makes it possible to reduce the amount of pupil correction. By reducing the amount of pupil correction, light vignetting and wraparound color mixing caused by the separation wall 31 are improved, leading to improved optical characteristics.

[0028] Fig. 9 is a cross-sectional view showing a schematic configuration example of a photodetector according to an embodiment. Fig. 10 shows an example of the relationship between the height of the spacer layer 30 and the transmittance.

[0029] If it is necessary to further shorten the spacer layer 30, the lower limit can be set as follows: In the photodetector according to one embodiment, by satisfying the condition (Equation (2)) that θ≧(desired diffraction angle), it becomes possible to focus incident light on the light receiving layer 10. Fig. 10 shows an example of the relationship between the height of the spacer layer 30 and the transmittance when Equations (1) and (2) are satisfied.

[0030] In equation (2), d is the center-to-center distance between adjacent pillars 21 (pillar 21 pitch) (see FIG. 9 ). Equation (2) is a condition that is satisfied when the metasurface that constitutes the color splitter layer 20 has a structure in which the center-to-center distance d between adjacent pillars 21 is constant regardless of position (a structure in which the pillars 21 are arranged at constant intervals).

[0031] h+(1 / 2)(n / λ)d×(AP+w)≦H……(2)

[0032] [1.2 Modifications] (Modification 1) FIG. 11 is a cross-sectional view schematically showing an example of the configuration of a photodetector according to Modification 1 of the embodiment.

[0033] 11, a photodetector according to one embodiment can be configured to include a filter layer 40 disposed between the light receiving layer 10 and the spacer layer 30. The filter layer 40 has a plurality of color filters that transmit light of different colors.

[0034] 12 to 15 are plan views each showing a schematic example of the configuration of a color filter.

[0035] In the photodetector according to the embodiment, the color and arrangement of the color filters are not limited. Fig. 12 shows a configuration in which an R filter that transmits red light, a G filter that transmits green (G) light, a B filter that transmits blue (B) light, and an IR filter that transmits infrared (IR) light are arranged. Fig. 13 shows a Bayer array configuration in which the R filters, G filters, and B filters are arranged.

[0036] In the photodetector according to one embodiment, a pixel 120 of one color may be divided into a plurality of pixels (or a plurality of adjacent pixels 120 may form a pixel block of one color). Fig. 14 shows an example of a filter configuration in which a pixel 120 of one color is divided into four pixels (or a pixel block of one color may be formed by four adjacent pixels 120).

[0037] Furthermore, the photodetector according to one embodiment may be configured to include a plurality of pixels of different sizes as the plurality of pixels 120. Fig. 15 shows an example of a filter configuration in which the pixel 120 of one color includes two pixels, one large and one small.

[0038] The other configurations may be substantially the same as those of the photodetector according to the embodiment shown in FIG.

[0039] (Modification 2) FIGS. 16 and 17 are plan views showing an example of the correspondence between the shape of the light collecting region 110 and the shape (arrangement) of the pixel 120 (color filter).

[0040] In the photodetector according to one embodiment, various shapes of light-collecting regions 110 may compete with each other. For example, the light-collecting regions 110 for each of the plurality of pixels 120 formed by the light-receiving layer 10 may include light-collecting regions 110 whose planar shapes are rotated relative to each of the plurality of pixels 120.

[0041] Fig. 16 shows an example in which the planar shape of the light-collecting region 110 is not rotated with respect to the planar shape (arrangement) of the pixels 120 (color filters). Fig. 17 shows an example in which the planar shape of the light-collecting region 110 is rotated (by 45°) with respect to the planar shape (arrangement) of the pixels 120 (color filters).

[0042] The other configurations may be substantially the same as those of the photodetector according to the embodiment shown in FIG.

[0043] (Modification 3) FIG. 18 is a cross-sectional view schematically showing an example of the configuration of a photodetector according to Modification 3 of the embodiment.

[0044] The photodetector according to one embodiment may be configured without the separation wall 31. In such a configuration, the condition of the following formula (3) may be satisfied instead of the condition of formula (1). By ensuring that the height of the spacer layer 30 satisfies the condition of formula (3), the incident light can be focused on the light receiving layer 10.

[0045] H≦(1 / 2.44)(n / λ)A×(AP)……(3)

[0046] Furthermore, instead of the condition of the above formula (2), the condition of the following formula (4) may be satisfied.

[0047] (1 / 2)(n / λ)d×(AP)≦H……(4)

[0048] It should be noted that a configuration in which the separation wall 31 is omitted may be combined with a configuration according to another modified example (such as modified example 1).

[0049] The other configurations may be substantially the same as those of the photodetector according to the embodiment shown in FIG.

[0050] (Modification 4) FIGS. 19 and 20 are cross-sectional views schematically showing an example of the configuration of a photodetector according to Modification 4 of the embodiment.

[0051] In the photodetector according to one embodiment, the separation wall 31 may have a structure including a first wall portion 32 made of a metal material and a second wall portion 33 made of a material other than a metal material and laminated on the first wall portion 32. The material other than a metal material may be a low refractive index material. In this case, the height h of the separation wall 31 in the above formula (1) may be the height of the first wall portion 32 or the height including the first wall portion 32 and the second wall portion 33. That is, the height h of the separation wall 31 may be the height of the entire separation wall 31 (FIG. 19) or only the metal portion (first wall portion 32) with high absorption (FIG. 20). The low refractive index material constituting the second wall portion 33 may be, for example, a low refractive index resin material, SiO ２ (silicon oxide), SiN (silicon nitride), etc. The metal material constituting the first wall portion 32 may be, for example, W (tungsten), TiN (titanium nitride), Ti (titanium), Al (aluminum), etc.

[0052] The other configurations may be substantially the same as those of the photodetector according to the embodiment shown in FIG.

[0053] (Modification 5) FIG. 21 is a cross-sectional view schematically showing an example of the configuration of a photodetector according to Modification 5 of the embodiment.

[0054] In the photodetector according to one embodiment, the separation wall 31 may have a stepped cross-sectional shape as shown in Fig. 21. This allows efficient collection of even obliquely incident light.

[0055] The other configurations may be substantially the same as those of the photodetector according to the embodiment shown in FIG.

[0056] (Modification 6) FIG. 22 is a cross-sectional view schematically showing an example of the configuration of a photodetector according to Modification 6 of the embodiment.

[0057] In the photodetector according to one embodiment, the light receiving layer 10 may have a structure including a plurality of regions of different heights corresponding to the plurality of light receiving elements 11. Fig. 22 shows an example including a first region 51 and a second region 52 of different heights. In this case, the distance H in each of the above conditional expressions may be the distance between the light receiving surface 100 and the color splitter layer 20 at the shortest point.

[0058] The other configurations may be substantially the same as those of the photodetector according to the embodiment shown in FIG.

[0059] (Seventh Modification) FIG. 23 is a cross-sectional view schematically showing an example of the configuration of a photodetector according to a seventh modification of the embodiment.

[0060] In the photodetector according to one embodiment, the light receiving layer 10 may have a stacked sensor structure including a plurality of regions with different light receiving sensitivities in the vertical direction for each of the plurality of pixels 120. For example, as shown in Fig. 23, the light receiving layer 10 may have a structure including a first region 61 and a second region 62 that absorb light of different wavelengths.

[0061] The other configurations may be substantially the same as those of the photodetector according to the embodiment shown in FIG.

[0062] [1.3 Effects] As described above, according to the photodetector device of one embodiment, the distance H between the color splitter layer 20 and the light-receiving surface 100 of the light-receiving layer 10 is optimized, which makes it possible to improve oblique incidence characteristics and manufacturability.

[0063] The effects described in this specification are merely examples and are not limiting, and other effects may also be achieved. The same applies to the effects of other embodiments described below.

[0064] 2. Other Embodiments The technology according to the present disclosure is not limited to the description of the above embodiment, and various modifications are possible.

[0065] For example, the present technology can be configured as follows: According to the present technology configured as follows, the distance between the color splitter layer and the light receiving surface of the light receiving layer is optimized, so that it is possible to provide a photodetector device that can improve oblique incidence characteristics and manufacturability.

[0066] (1) A photodetector comprising: a light receiving layer having a plurality of light receiving elements and in which a plurality of pixels are arranged; a color splitter layer having a metasurface structure and focusing incident light toward the light receiving layer according to wavelength; a spacer layer arranged between the light receiving layer and the color splitter layer; and a separation wall arranged between the light receiving layer and the color splitter layer and blocking the incident light, wherein the photodetector satisfies the condition: H≦h+(1 / 2.44)(n / λ)A×(A−P+w) ... (1), where H is the distance between the color splitter layer and the light receiving surface of the light receiving layer, λ is the wavelength of the incident light, n is the refractive index of the spacer layer, A is the effective diameter of the light focusing area corresponding to one pixel by the color splitter layer, P is the pixel pitch in the light receiving layer, h is the height of the separation wall, and w is the width of the separation wall. (2) The photodetector according to (1), wherein the color splitter layer has a plurality of pillars as the metasurface structure, and satisfies the condition: h + (½) (n / λ) d × (A − P + w) ≦ H (2), where d is the center-to-center distance between adjacent pillars in the plurality of pillars. (3) The photodetector according to (1) or (2), further comprising: a filter layer disposed between the light receiving layer and the spacer layer, the filter layer having a plurality of color filters that transmit light of different colors. (4) The photodetector according to any one of (1) to (3), wherein the plurality of pixels include a plurality of pixels of different sizes. (5) The photodetector according to any one of (1) to (4), wherein the light receiving layer includes, as a light collecting region for each of the plurality of pixels, a light collecting region whose planar shape is rotated with respect to each of the plurality of pixels. (6) The photodetector according to any one of (1) to (5) above, wherein the separation wall has a first wall portion made of a metal material and a second wall portion made of a material other than a metal material and laminated on the first wall portion, and a height h of the separation wall is the height of the first wall portion or a height including the height of the first wall portion and the second wall portion. (7) The photodetector according to any one of (1) to (6) above, wherein the separation wall has a stepped cross-sectional shape.(8) The photodetector according to any one of (1) to (7), wherein the light receiving layer includes a plurality of regions having different heights as the plurality of regions corresponding to the plurality of light receiving elements. (9) The photodetector according to any one of (1) to (8), wherein the light receiving layer includes a plurality of regions having different light receiving sensitivities in the vertical direction for each of the plurality of pixels. (10) A photodetector comprising: a light receiving layer having a plurality of light receiving elements and in which a plurality of pixels are arranged; a color splitter layer having a metasurface structure and focusing incident light toward the light receiving layer according to the wavelength; and a spacer layer disposed between the light receiving layer and the color splitter layer, wherein when H is the distance between the color splitter layer and the light receiving surface of the light receiving layer, λ is the wavelength of the incident light, n is the refractive index of the spacer layer, A is the effective diameter of the light focusing area corresponding to one pixel by the color splitter layer, and P is the pixel pitch in the light receiving layer, the photodetector satisfies the condition: H≦(1 / 2.44)(n / λ)A×(A−P) … (3). (11) The photodetector according to (10), wherein the color splitter layer has a plurality of pillars as the metasurface structure, and satisfies the condition (1 / 2)(n / λ)d×(A−P)≦H (4), where d is the center-to-center distance between adjacent pillars in the plurality of pillars. (12) The photodetector according to (10) or (11), further comprising a filter layer disposed between the light receiving layer and the spacer layer, the filter layer having a plurality of color filters that transmit light of different colors. (13) The photodetector according to any one of (10) to (12), wherein the plurality of pixels include a plurality of pixels of different sizes. (14) The photodetector according to any one of (10) to (13), wherein the light receiving layer includes, as a light collecting region for each of the plurality of pixels, a light collecting region whose planar shape is rotated with respect to each of the plurality of pixels. (15) The photodetector according to any one of (10) to (14) above, wherein the light receiving layer includes a plurality of regions having different heights as a plurality of regions corresponding to the plurality of light receiving elements.(16) The photodetector according to any one of (10) to (15) above, wherein the light receiving layer includes a plurality of regions with different light receiving sensitivities in the vertical direction for each of the plurality of pixels.

[0067] This application claims priority based on Japanese Patent Application No. 2024-123526, filed on July 30, 2024, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0068] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur depending on design requirements and other factors, and are intended to be within the scope of the appended claims and their equivalents.

Claims

1. A photodetector comprising: a light receiving layer having a plurality of light receiving elements and in which a plurality of pixels are arranged; a color splitter layer having a metasurface structure and focusing incident light toward the light receiving layer according to wavelength; a spacer layer arranged between the light receiving layer and the color splitter layer; and a separation wall arranged between the light receiving layer and the color splitter layer and blocking the incident light, wherein the photodetector satisfies the condition: H≦h+(1 / 2.44)(n / λ)A×(A-P+w) ... (1), where H is the distance between the color splitter layer and the light receiving surface of the light receiving layer, λ is the wavelength of the incident light, n is the refractive index of the spacer layer, A is the effective diameter of the light focusing area corresponding to one pixel by the color splitter layer, P is the pixel pitch in the light receiving layer, h is the height of the separation wall, and w is the width of the separation wall.

2. The photodetector device of claim 1, wherein the color splitter layer has a plurality of pillars as the metasurface structure, and the following condition is satisfied when the center-to-center distance between adjacent pillars in the plurality of pillars is d: h+(1 / 2)(n / λ)d×(A-P+w)≦H … (2).

3. The photodetector device according to claim 1, further comprising a filter layer disposed between said light receiving layer and said spacer layer and having a plurality of color filters that transmit light of different colors.

4. The photodetector according to claim 1, wherein said plurality of pixels includes a plurality of pixels of different sizes.

5. The photodetector according to claim 1, wherein the light-collecting region for each of the plurality of pixels formed by the light-receiving layer includes a light-collecting region whose planar shape is rotated relative to each of the plurality of pixels.

6. The photodetector device according to claim 1, wherein the separation wall has a first wall portion made of a metal material and a second wall portion made of a material other than a metal material and laminated on the first wall portion, and the height h of the separation wall is the height of the first wall portion or the height including the height of the first wall portion and the second wall portion.

7. The photodetector according to claim 1, wherein the separation wall has a stepped cross section.

8. The photodetector according to claim 1, wherein the light receiving layer includes a plurality of regions having different heights as a plurality of regions corresponding to the plurality of light receiving elements.

9. The photodetector according to claim 1, wherein the light receiving layer includes a plurality of regions with different light receiving sensitivities in the vertical direction for each of the plurality of pixels.

10. A photodetector comprising: a light receiving layer having a plurality of light receiving elements and in which a plurality of pixels are arranged; a color splitter layer having a metasurface structure and focusing incident light toward the light receiving layer according to wavelength; and a spacer layer arranged between the light receiving layer and the color splitter layer, wherein when H is the distance between the color splitter layer and the light receiving surface of the light receiving layer, λ is the wavelength of the incident light, n is the refractive index of the spacer layer, A is the effective diameter of the light focusing area corresponding to one pixel by the color splitter layer, and P is the pixel pitch in the light receiving layer, the device satisfies the condition: H≦(1 / 2.44)(n / λ)A×(A-P) ... (3).

11. The photodetector device according to claim 10, wherein the color splitter layer has a plurality of pillars as the metasurface structure, and when the center-to-center distance between adjacent pillars in the plurality of pillars is d, the following condition is satisfied: (1 / 2)(n / λ)d×(A-P)≦H … (4).

12. The light detection device according to claim 10, further comprising a filter layer disposed between said light receiving layer and said spacer layer and having a plurality of color filters that transmit light of different colors.

13. The photodetector according to claim 10, wherein the plurality of pixels includes a plurality of pixels of different sizes.

14. The photodetector according to claim 10, wherein the light-collecting region for each of the plurality of pixels formed by the light-receiving layer includes a light-collecting region whose planar shape is rotated relative to each of the plurality of pixels.

15. The photodetector according to claim 10, wherein the light-receiving layer includes a plurality of regions having different heights as a plurality of regions corresponding to the plurality of light-receiving elements.

16. The photodetector according to claim 10, wherein the light receiving layer includes a plurality of regions with different light receiving sensitivities in the vertical direction for each of the plurality of pixels.

Images