Light receiving element and light detection device

Abstract

The purpose of the present invention is to provide a light-receiving element capable of improving the measurement accuracy of a color mixture component included in an output signal of a light-shielding pixel located around a light-receiving pixel. The peripheral pixel region is made to have a specific pixel group including a light-receiving pixel and a light-blocking pixel surrounding the light-receiving pixel. A first conductivity type region corresponding to the light-receiving pixel and the light-shielding pixel of the specific pixel group is made to have a lower first conductivity type impurity concentration than a first conductivity type region corresponding to the effective pixel located in the effective pixel region. Accordingly, since the concentration of the first conductivity type impurity of a specific pixel group (light-receiving pixel, light-shielding pixel) is low, pn junction strength may be weakened, and dark current in the light-receiving pixel and the light-shielding pixel may be suppressed. Accordingly, noise included in the output signal of the light-shielding pixel may be reduced, and measurement accuracy of a color mixing component included in the output signal of the light-shielding pixel may be improved.

Description

Technical Field

[0001] The present disclosure relates to a light receiving element and a light detecting device. Background Art

[0002] In the related art, a light receiving element has been proposed, which includes a plurality of pixels, each pixel having a photoelectric converter including a silicon semiconductor, and pixels in an area outside an effective pixel area among the plurality of pixels include light-shielded pixels and light-receiving pixels whose adjacent pixels are all light-shielded pixels (for example, see Patent Document 1). In the light receiving element disclosed in Patent Document 1, a color mixing component included in an output signal of a light-shielded pixel is measured, and the output signal of the effective pixel is corrected based on the measurement result.

[0003] Citation list

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-66801 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] However, when the technology disclosed in Patent Document 1 is directly applied to a light receiving element having a photoelectric converter including a compound semiconductor, the measurement accuracy of the color mixing component is reduced, and there is a possibility that the image quality of the captured image cannot be improved as expected even if the output signal of the effective pixel is corrected based on the measurement result.

[0008] Therefore, an object of the present disclosure is to provide a light receiving element and a light detecting device capable of improving the measurement accuracy of a color mixture component contained in an output signal of a light-shielded pixel.

[0009] Solutions to technical problems

[0010] The light receiving element of the present disclosure includes: (a) a plurality of pixels having a common photoelectric conversion layer including a compound semiconductor; and (b) a contact layer arranged on a surface of the photoelectric conversion layer opposite to a light incident surface, wherein (c) the contact layer includes a plurality of first conductive type regions formed in a one-to-one manner relative to the plurality of pixels and a second conductive type region as a region other than the first conductive type region, and (d) a peripheral pixel region located outside an effective pixel region in a pixel region in which the pixels are arranged includes a specific pixel group, the specific pixel group includes a light receiving pixel and a light shielding pixel arranged to surround the light receiving pixel, and the concentration of the first conductive type impurities of the first conductive type region corresponding to the light receiving pixel and the light shielding pixel of the specific pixel group is lower than that of the first conductive type region corresponding to the effective pixel located in the effective pixel region.

[0011] The light detection device of the present disclosure includes: a light receiving element, which includes (a) a plurality of pixels having a common photoelectric conversion layer including a compound semiconductor, and (b) a contact layer arranged on a surface of the photoelectric conversion layer opposite to a light incident surface, (c) the contact layer includes a plurality of first conductive type regions formed in a one-to-one manner with respect to the plurality of pixels and a second conductive type region as a region other than the first conductive type region, and (d) a peripheral pixel region outside an effective pixel region in a pixel region where the pixels are arranged includes a specific pixel group, the specific pixel group includes light receiving pixels and light shielding pixels arranged to surround the light receiving pixels, and the specific pixel group includes a plurality of first conductive type regions and a second conductive type region. (e) a color mixing parameter generating unit which generates, based on the output signals of the light receiving pixels and the light shading pixels of the specific pixel group, color mixing parameters for reducing the influence of the charges moved from other effective pixels from the respective output signals of the effective pixels located in the effective pixel area of ​​the light receiving element; and (f) an output signal correction unit which corrects the respective output signals of the effective pixels according to the color mixing parameters generated by the color mixing parameter generating unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a diagram showing a schematic configuration of an image pickup device according to the first embodiment.

[0013] Figure 2 1 is a diagram showing a planar structure of a light receiving element.

[0014] Figure 3 It is shown along Figure 2 A diagram of a cross-sectional configuration of a light receiving element in an effective pixel area taken along line AA in FIG.

[0015] Figure 4 yes Figure 2 An enlarged view of area B in the middle shows the planar configuration of a specific pixel group in the peripheral pixel area.

[0016] Figure 5 It is along Figure 4 A diagram of light receiving pixels and light shielding pixels taken along line CC.

[0017] Figure 6 It is along Figure 4 Figure 2. OPB pixel image captured by the DD line.

[0018] Figure 7is a diagram showing color mixing parameters, light receiving pixels, and light shielding pixels in a superimposed manner.

[0019] Figure 8 is a diagram showing the concentration distribution of the first conductivity type impurity in the first conductivity type region.

[0020] Fig. 9 This is a diagram for explaining the internal structure of the digital signal processing unit.

[0021] Fig.10 is a diagram illustrating a method of correcting a captured image signal by using an output signal correction unit.

[0022] Fig.11 is a diagram illustrating a method of correcting a captured image signal by using an output signal correction unit.

[0023] Fig.12 : is a diagram showing a planar configuration of a specific pixel group according to a modification example.

[0024] Fig.13 : is a diagram showing a planar configuration of a specific pixel group according to a modification example.

[0025] Fig.14 : is a diagram showing a planar configuration of a light receiving element and a specific pixel group according to a modification.

[0026] Fig.15 It is a diagram for explaining the internal structure of a digital signal processing unit according to a modified example.

[0027] Fig.16 is a diagram showing a cross-sectional configuration of a light receiving element in an effective pixel region according to a modification example.

[0028] Fig.17 : is a diagram showing a cross-sectional structure of an element substrate in an effective pixel region according to a modification example.

[0029] Fig.18 is a diagram showing a cross-sectional configuration of a light-receiving pixel in a peripheral pixel area according to a modification.

[0030] Fig.19 is a diagram showing a cross-sectional configuration of a light-shielding pixel in a peripheral pixel region according to a modification. DETAILED DESCRIPTION

[0031] In the following, reference will be made to Figures 1 to 16 An example of a light receiving element and a light detecting device according to an embodiment of the present disclosure is described. The embodiment of the present disclosure will be described in the following order. Note that the present disclosure is not limited to the following examples. In addition, the effects described herein are illustrative and not restrictive, and there may be other effects.

[0032] 1. First Implementation Method

[0033] 1-1 Structure of the camera device

[0034] 1-2 Structure of the light receiving element

[0035] 1-3 Configuration of light receiving elements in peripheral pixel regions

[0036] 1-4 Structure of Digital Signal Processing Unit

[0037] 1-5 Variations

[0038] <1. First Implementation Method>

[0039] [1-1 Structure of Camera Device]

[0040] An imaging device as an example of the light detection device according to the first embodiment of the present disclosure will be described.

[0041] Figure 1 is a diagram showing a schematic configuration of an image pickup device 100 according to the first embodiment.

[0042] like Figure 1 As shown, the imaging device 100 ("light detection device" in a broad sense) includes a camera lens 101, a light receiving element 102, an analog signal processing unit 103, a digital signal processing unit 104, and a storage unit 105. For example, the imaging device 100 is applied to an infrared camera that detects wavelengths in the visible range (e.g., 380 to 780 nm) to the short infrared range (e.g., 780 to 2400 nm).

[0043] The camera lens 101 guides incident light (image light) from a subject to the light receiving element 102, and the light incident surface ( Figure 2 An image is formed on the effective pixel area 4) shown.

[0044] The light receiving element 102 converts the intensity of incident light that has formed an image on the effective pixel area 4 by the camera lens 101 into an electric signal for each pixel. The converted electric signal is supplied as an output signal to the analog signal processing unit 103. The detailed configuration of the light receiving element 102 will be described later.

[0045] The analog signal processing unit 103 performs processing such as sampling and holding and automatic gain control on the output signal supplied from the light receiving element 102, and then performs analog-to-digital (A / D) conversion. The output signal of the effective pixel area 4 obtained by the A / D conversion is supplied to the digital signal processing unit 104 as a captured image signal. In addition, the output signal of the peripheral pixel area 5 is also supplied to the digital signal processing unit 104.

[0046] The digital signal processing unit 104 performs signal processing such as white balance processing, gamma processing, and color difference signal processing on the captured image signal and the like supplied from the analog signal processing unit 103. For example, a digital signal processor (DSP) circuit may be employed.

[0047] The storage unit 105 stores various parameters and the like used in the digital signal processing unit 104. For example, a flash memory and the like can be used as the storage unit 105.

[0048] Next, the configurations of the light receiving element 102 and the digital signal processing unit 104 will be described.

[0049] [1-2 Structure of Light Receiving Element]

[0050] Next, the configuration of the light receiving element 102 will be described.

[0051] Figure 2 is a diagram showing a planar configuration of the light receiving element 102. In addition, Figure 3 It shows that along Figure 2 FIG. 2 is a diagram of a cross-sectional configuration of the light receiving element 102 in the effective pixel area 4 taken along line AA in FIG. Figure 3 The light receiving element 102 in the embodiment includes a pixel region 3 in which a plurality of pixels 2 are arranged in a two-dimensional array and has a function of photoelectrically converting light having a wavelength in a visible range to a short infrared range, for example.

[0052] like Figure 2 As shown, the pixel region 3 includes an effective pixel region 4 located in the central portion and a peripheral pixel region 5 which is a region located outside the effective pixel region 4 to surround the effective pixel region 4. The light shielding film 6 (refer to Figure 4 ) is formed on the light incident surface of the pixel region 3 (at Figure 2 , the front side of the paper). The light shielding film 6 has an opening in the region where the effective pixel region 4 and the light receiving pixel 2B are located. Examples of the material of the light shielding film 6 include alloys of titanium (Ti), tungsten (W), carbon (C), chromium oxide (Cr2O3), samarium (Sm), and silver (Ag), and organic materials.

[0053] The effective pixel area 4 corresponds to the area where the subject image is formed. Figure 3As shown, in the effective pixel area 4, the light receiving element 102 has a multilayer structure formed by stacking an element substrate 7 and a readout circuit substrate 8. Here, one surface of the element substrate 7 is used as a light incident surface (hereinafter, also referred to as "back side S1"), and the other surface is used as a bonding surface with the readout circuit substrate 8 (hereinafter, also referred to as "front side S2"). The element substrate 7 includes a wiring layer 9, a first contact layer 10 (a "contact layer" in a broad sense), a photoelectric conversion layer 11, and a second contact layer 12 in sequence from the readout circuit substrate 8. The first contact layer 10, the photoelectric conversion layer 11, and the second contact layer 12 constitute a semiconductor layer 15. In addition, the readout circuit substrate 8 is a so-called readout integrated circuit (ROIC), and is arranged to be in contact with the bonding surface (front side S2) of the element substrate 7.

[0054] The wiring layer 9 is formed to span the entire effective pixel area 4 and has a bonding surface (front side S2) with the readout circuit substrate 8. The wiring layer 9 includes an electrode 17 in an interlayer insulating film 16. The interlayer insulating film 16 includes, for example, an inorganic insulating material. Examples of inorganic insulating materials include silicon nitride (SiN), aluminum oxide (Al2O3), silicon oxide (SiO2), and hafnium oxide (HfO2). In addition, in the wiring layer 9, an opening H is formed for each pixel 2 (for each first conductive type region 19A).

[0055] In addition, the electrode 17 is embedded in the opening H of the wiring layer 9 and has an end portion adjacent to the first contact layer 10, which is connected to the first conductive type region 19A of the first contact layer 10. As the material of the electrode 17, for example, any one of titanium (Ti), tungsten (W), titanium nitride (TiN), platinum (Pt), gold (Au), germanium (Ge), palladium (Pd), zinc (Zn), nickel (Ni) or aluminum (Al), or an alloy containing at least one of them can be used. This allows the electrode 17 to be electrically connected to the top portion of the first conductive type region 19A present in the photoelectric conversion layer 11 (that is, the first conductive type region 20A of the photoelectric conversion layer 11) through the bottom portion of the first conductive type region 19A located in the first contact layer 10. Therefore, a voltage is applied to the photoelectric conversion layer 11 to read out the charges (for example, holes) generated in the photoelectric conversion layer 11.

[0056] Furthermore, an eave-shaped connection layer 18 (metal pad) extending in the radial direction of the electrode 17 is formed at the end of the electrode 17 adjacent to the readout circuit substrate 8. The connection layer 18 is a metal pad bonded to the connection layer 23 of the readout circuit substrate 8 to electrically connect the electrode 17 to the readout electrode 22 of the readout circuit substrate 8. As a material of the connection layer 18, for example, copper (Cu) can be used.

[0057] The first contact layer 10 is a layer constituting the front side of the semiconductor layer 15, and is arranged on the surface of the photoelectric conversion layer 11 opposite to the light incident surface (hereinafter, also referred to as "surface S3"). As a material of the first contact layer 10, for example, a compound semiconductor having a larger energy band gap than the photoelectric conversion layer 11 can be used. For example, when the photoelectric conversion layer 11 includes In 0.53 Ga 0.47 In the case of As (band gap 0.74 eV), the band gap is larger than that of In 0.53 Ga 0.47 Examples of compound semiconductors of As include InP (energy band gap 1.34 eV).

[0058] In addition, the first contact layer 10 includes a plurality of first conductive type regions 19A formed in a one-to-one manner relative to the pixel 2. That is, a plurality of first conductive type regions 19A are discretely formed in the first contact layer 10. As the first conductive type impurity contained in the first conductive type region 19A, for example, a p-type impurity can be used. An example of the impurity includes zinc (Zn). The first conductive type region 19A extends from the surface of the first contact layer 10 adjacent to the readout circuit substrate 8 (hereinafter, also referred to as "surface S4") into the photoelectric conversion layer 11, and the top portion of the first conductive type region 19A constitutes the first conductive type region 20A of the photoelectric conversion layer 11.

[0059] In addition, the first contact layer 10 includes a second conductive type region 19B as a region other than the first conductive type region 19A. That is, the second conductive type region 19B is formed around the first conductive type region 19A in the first contact layer 10 to contact the first conductive type region 19A. As the second conductive type impurity contained in the second conductive type region 19B, for example, an n-type impurity can be used. Through such a configuration, the first contact layer 10 can form a pn junction interface between the first conductive type region 19A and the second conductive type region 19B, and electrically isolate the adjacent pixels 2.

[0060] The photoelectric conversion layer 11 is formed as a common layer of a plurality of pixels 2. That is, one photoelectric conversion layer 11 is formed for all pixels 2. As a material for the photoelectric conversion layer 11, for example, a compound semiconductor such as a III-V semiconductor can be used. For example, indium gallium arsenide (InGaAs), indium gallium nitride (InGaN), indium aluminum nitride (InAlN), indium antimony arsenide (InAsSb), indium arsenic (InAs), indium antimony (InSb), or mercury cadmium telluride (HgCdTe) can be used. In addition, examples of InGaAs include InGaN, InGaN, InAlN, InAsSb, InAsSb, or HgCdTe. x Ga (1-x)As (0 < x ≤ 1). In particular, to achieve sensitivity in the infrared region, x ≥ 0.4 is desirable. For example, in the case where the second contact layer 12 includes InP, examples of the composition of the compound semiconductor of the photoelectric conversion layer 11 include In 0.53 Ga 0.47 As. Note that as the material of the photoelectric conversion layer 11, not only inorganic semiconductors but also organic semiconductors can be employed.

[0061] The photoelectric conversion layer 11 includes a first conductivity type region 20A formed on the surface (surface S3) opposite to the light incident surface of the photoelectric conversion layer 11 for each pixel 2, and a portion other than the first conductivity type region 20A (hereinafter, also referred to as "second conductivity type region 20B"). The first conductivity type region 20A includes the top portion of the first conductivity type region 19A of the first contact layer 10. As the first conductivity type impurity contained in the first conductivity type region 20A and the second conductivity type impurity contained in the second conductivity type region 20B, for example, the same impurities as those contained in the first conductivity type region 19A and the second conductivity type region 19B can be respectively employed. With this configuration, the photoelectric conversion layer 11 forms a photodiode using a pn junction, and photoelectrically converts light having a wavelength in the visible range to the short infrared range to generate charges (holes).

[0062] The second contact layer 12 includes, for example, a compound semiconductor such as a III-V group semiconductor containing a second conductivity type impurity. Examples of the compound semiconductor include n-type InP. With such a configuration, the second contact layer 12 serves as a blocking layer for preventing the charges generated in the photoelectric conversion layer 11 from flowing back.

[0063] The readout circuit substrate 8 is bonded to the bonding surface (front surface S2) of the element substrate 7. The readout circuit substrate 8 includes a readout electrode 22 in the interlayer insulating film 21. In addition, an eaves-shaped connection layer 23 (metal pad) extending in the radial direction of the readout electrode 22 is formed at the end portion of the readout electrode 22 adjacent to the element substrate 7. As the material of the connection layer 23, for example, copper (Cu) can be employed. The connection layer 27 is bonded to the connection layer 18 (metal pad) of the element substrate 7 by Cu-Cu to electrically connect the readout electrode 22 of the readout circuit substrate 8 to the electrode 17 of the element substrate 7. This configuration enables the readout circuit substrate 8 to read the charges (holes) generated in the photoelectric conversion layer 11 for each pixel 2.

[0064] Note that in the first embodiment, an example in which the element substrate 7 and the readout circuit substrate 8 are bonded by Cu-Cu has been described, but other configurations can also be employed. For example, bump bonding can be used.

[0065] [Structure of Light-Receiving Elements in 1-3 Peripheral Pixel Regions]

[0066] Figure 4 yes Figure 2 0 is an enlarged view of area B in FIG. 5 , which shows the planar configuration of a specific pixel group 25 in the peripheral pixel area 5 . Figure 5 and Figure 6 are diagrams each showing a cross-sectional configuration of the light receiving element 102 in the peripheral pixel region 5, Figure 5 It shows that along Figure 4 A diagram of a light receiving pixel 2B and a light shielding pixel 2C intercepted by line CC in FIG. 1 , and Figure 6 is a diagram showing an OPB pixel 2D taken along line DD.

[0067] The peripheral pixel region 5 is a region surrounding the effective pixel region 4. Figure 5 and Figure 6 As shown, in the peripheral pixel region 5 , the light receiving element 102 has layers similar to those in the effective pixel region 4 (light shielding film 6 , wiring layer 9 , first contact layer 10 , photoelectric conversion layer 11 , and second contact layer 12 ).

[0068] The peripheral pixel area 5 includes a light receiving pixel 2B and a light shielding pixel 2C arranged to surround the light receiving pixel 2B. The light receiving pixel 2B is a pixel whose surface S4 of the photoelectric conversion layer 11 is not covered by the light shielding film 6. In addition, each light shielding pixel 2C is a pixel whose back surface S1 of the second contact layer 12 is covered by the light shielding film 6. In addition, the light receiving pixel 2B and the plurality of light shielding pixels 2C surrounding the light receiving pixel 2B constitute a specific pixel group 25. Figure 4 2B and a plurality of light-shielding pixels 2C surrounding the light-receiving pixel 2B. Figure 4 , as the specific pixel group 25 , the light receiving pixels 2B and the light shielding pixels 2C are arranged in a two-dimensional array of 11×11.

[0069] As described above, with the construction of the specific pixel group 25 including the light receiving pixel 2B and the light shielding pixel 2C, when light is incident on the light receiving pixel 2B, a part of the photoelectric conversion layer 11 constituting the light receiving pixel 2B performs photoelectric conversion on the light to generate charges (holes). Most of the generated charges are read out by the readout circuit substrate 8 via the first conductive type region 19A of the light receiving pixel 2B. At the same time, some of the generated charges move in the photoelectric conversion layer 11, enter a part of the photoelectric conversion layer 11 constituting the light shielding pixel 2C, and are read out by the readout circuit substrate 8 via the first conductive type region 19A of the light shielding pixel 2C. Therefore, the output signal of the light shielding pixel 2C corresponds to a signal (hereinafter also referred to as a "color mixing component") based on the charge generated by the photoelectric conversion of the light receiving pixel 2B and moved to the light shielding pixel 2C. With such a construction, it is possible to simulate the diffusion of charges from a certain effective pixel 2A to the surrounding effective pixels 2A occurring in the effective pixel area 4 by using the light receiving pixel 2B and the light shielding pixel 2C.

[0070] Therefore, based on the output signals read from the specific pixel group 25 (light-receiving pixel 2B and light-shielding pixel 2C), the value obtained by dividing each output signal of the light-shielding pixel 2C by the output signal of the light-receiving pixel 2B can be obtained as the color mixing parameter a by the digital signal processing unit 104 or the like. 00 、a 01 、a 02 …(refer to Figure 7 ). Color mixing parameter a 00 、a 01 、a 02 ...is a parameter indicating how much charge is diffused from the central light receiving pixel 2B to the surrounding light shielding pixels 2C. In addition, the color mixing parameter a 00 、a 01 、a 02 ...is also a parameter for reducing the influence of charges moved from other effective pixels 2A on each output signal of the pixel 2 located in the effective pixel area 4 of the light receiving element 102 (hereinafter, also referred to as “effective pixel 2A”). Figure 7 The color mixing parameter a is shown 00 、a 01 、a 02 ..., the light receiving pixel 2B and the light shielding pixel 2C are shown in a superimposed manner to make their relationship clear. In addition, the color mixing parameter a 00 、a 01 、a 02 ……by Figure 7 The matrix of the array arrangement shown is referred to as the "color mixing matrix C".

[0071] Here, compound semiconductors such as InGaAs easily generate dark current, and the magnitude of the dark current tends to be large. Therefore, in the case where the photoelectric conversion layer 11 includes a compound semiconductor, the noise contained in the output signal of the light-shielded pixel 2C tends to be large. Therefore, in the case of measuring the color mixing component contained in the output signal of the light-shielded pixel 2C, there is a possibility that the measurement accuracy of the color mixing component is reduced.

[0072] On the other hand, in the first embodiment, the concentration of the first conductive type impurity of the first conductive type region 19A corresponding to the light receiving pixel 2B and the light shielding pixel 2C of the specific pixel group 25 is made lower than that of the first conductive type region 19A corresponding to the effective pixel 2A located in the effective pixel region 4. Therefore, since the concentration of the first conductive type impurity of the specific pixel group 25 (the light receiving pixel 2B and the light shielding pixel 2C) is low, the pn junction strength can be reduced, and the dark current in the light receiving pixel 2B and the light shielding pixel 2C can be suppressed. Therefore, the noise contained in the output signal of the light shielding pixel 2C can be reduced, and the measurement accuracy of the color mixing component contained in the output signal of the light shielding pixel 2C can be improved. Then, since the concentration of the first conductive type impurity of the effective pixel region 4 is kept high, the pn junction strength can be improved, the saturation charge amount of the effective pixel 2A will not decrease, and the degradation of the image quality of the captured image obtained from the light receiving element 102 can be suppressed.

[0073] Furthermore, in the first embodiment, if Figure 5 and Figure 8 As shown, the concentration distribution 26 of the first conductive type impurity in the first conductive type region 19A on the straight line L extending from the interface S4 between the first conductive type region 19A and the electrode 17 toward the light incident surface of the photoelectric conversion layer 11 has a flat region at a predetermined depth from the interface S4 to the extending direction of the straight line L. Therefore, the above-mentioned condition of the concentration of the first conductive type impurity can be rewritten as, for example, the average concentration X of the flat region of the concentration distribution 26 of the first conductive type region 19A corresponding to the light receiving pixel 2B and the light shielding pixel 2C of the specific pixel group 25 is lower than the average concentration Y of the flat region of the concentration distribution 26 of the first conductive type region 19A corresponding to the effective pixel 2A located in the effective pixel region 4 (X<Y). As the flat region, for example, a range from the interface S4 to a depth of 50 nm can be adopted.

[0074] In addition, if Figure 4 and Figure 5As shown, the peripheral pixel region 5 includes an optical black (OPB) pixel 2D, which is a pixel different from the light receiving pixel 2B and the light shielding pixel 2C. The OPB pixel 2D is a pixel in which the back side S1 of the second contact layer 12 is covered by the light shielding film 6, and is a pixel for obtaining a reference signal of an optical black level. In addition, the concentration of the first conductive type impurity in the first conductive type region 19A corresponding to the OPB pixel 2D is the same as that of the first conductive type region 19A of the effective pixel region 4. That is, the average concentration Z of the flat area of ​​the concentration distribution 26 of the first conductive type region 19A corresponding to the OPB pixel 2D (refer to Figure 8 ) is the same as the average concentration Y of the flat area of ​​the concentration distribution 26 of the first conductive type region 19A corresponding to the effective pixel 2A located in the effective pixel region 4 (Z=Y). Therefore, the difference between the dark current in the OPB pixel 2D and the dark current in the effective pixel 2A can be reduced, the black level of the output signal of the effective pixel 2A can be corrected more appropriately, and an image with higher image quality can be obtained.

[0075] [1-4 Structure of digital signal processing unit]

[0076] Fig. 9 It is a diagram for explaining the internal structure of the digital signal processing unit 104.

[0077] like Figure 1 and Fig. 9 As shown, the digital signal processing unit 104 includes a color mixing parameter generating unit 28 and an output signal correcting unit 29 .

[0078] The color mixing parameter generating unit 28 generates the color mixing parameter a based on the output signals of the light receiving pixels 2B and the light shielding pixels 2C of the specific pixel group 25. 00 、a 01 、a 02 …(refer to Figure 7 ). As the generated color mixing parameter a 00 、a 01 、a 02 For example, the following method may be used: the value obtained by dividing each output signal of the light-shielding pixel 2C by the output signal of the light-receiving pixel 2B is used as the color mixing parameter a 00 、a 01 、a 02 That is, the ratio of the output signal of the light-shielding pixel 2C to the output signal of the light-receiving pixel 2B is calculated as the color mixing parameter a. 00 、a 01 、a 02 ……. Such a configuration enables the color mixing parameter generation unit 28 to generate the color mixing parameter a in real time when capturing an image of the subject. 00 、a01 、a 02 ..., and causes the output signal correction unit 29 to use the generated color mixing parameter a 00 、a 01 、a 02 ...to correct the output signal of the effective pixel 2A.

[0079] The output signal correction unit 29 generates a signal according to the color mixing parameter a. 00 、a 01 、a 02 ...corrects each output signal (captured image signal) of the effective pixel 2A located in the effective pixel area 4 of the light receiving element 102. As a correction method, for example, the following method can be adopted: 00 、a 01 、a 02 ...generates the color mixing matrix C, and as Fig.10 As shown, using the generated color mixing matrix C, a deconvolution operation is performed on the captured image signal based on the output signal of the effective pixel area 4 (the output of the analog signal processing unit 103) to obtain a captured image signal from which the color mixing component has been removed. In addition, for example, Fig.11 As shown, the following method can be used: the color mixing parameter a 00 、a 01 、a 02 ... and a captured image signal based on the output signal of the effective pixel area 4 (the output of the analog signal processing unit 103) are input to a neural network (e.g., a convolutional neural network (CNN)) that outputs a captured image signal from which the color mixing component has been removed, thereby obtaining a captured image signal from which the color mixing component has been removed. Note that the method for correcting the captured image signal is not limited to such a method, and any method may be employed as long as the color mixing parameter a is used. 00 、a 01 、a 02 …….

[0080] As described above, in the first embodiment, the color mixing parameter generating unit 28 generates the color mixing parameter a based on the output signals of the light receiving pixels 2B and the light shielding pixels 2C of the specific pixel group 25. 00 、a 01 、a 02 ……. In addition, the output signal correction unit 29 adjusts the color mixing parameter a 00 、a 01 、a 02...corrects each output signal of the effective pixel 2A located in the effective pixel region 4 of the light receiving element 102. Therefore, for each effective pixel 2A, a color mixing component caused by the movement (crosstalk) of the electric charge from another effective pixel 2A can be reduced, and degradation of the image quality of the captured image due to the crosstalk can be suppressed.

[0081] [1-5 Modification Example]

[0082] (1) Furthermore, in the first embodiment, it has been described that the color mixing parameter generating unit 28 generates the color mixing parameter a using all pixels of the specific pixel group 25 including the light receiving pixel 2B and the light shielding pixel 2C. 00 、a 01 、a 02 ..., but other constructions are possible. For example, to generate the color mixing parameter a 00 、a 01 、a 02 The range of the light shielding pixel 2C can be set according to the use environment. As the use environment, for example, the temperature of the light receiving element 102 and the voltage applied to the photoelectric conversion layer 11 can be used. As an example, Fig.12 As shown, compared with the case where the temperature of the light receiving element 102 is lower than the predetermined threshold, when the temperature of the light receiving element 102 is greater than or equal to the predetermined threshold, the color mixing parameter a is generated. 00 、a 01 、a 02 As a method of changing the range of the light-shielded pixels 2C used to generate the color mixing parameters, for example, a method may be adopted in which, in the case of widening the range, all the light-shielded pixels 2C constituting the specific pixel group 25 are used, and in the case of narrowing the range, only the light-shielded pixels 2C near the light-receiving pixels 2B (in Fig.12 In addition, as another example, when the voltage applied to the photoelectric conversion layer 11 is less than or equal to the preset predetermined threshold, the color mixing parameter a is generated when the voltage applied to the photoelectric conversion layer 11 is less than or equal to the preset predetermined threshold, compared with the case where the voltage applied to the photoelectric conversion layer 11 is greater than the preset predetermined threshold. 00 、a 01 、a 02 By this method, a more suitable color mixing parameter a can be generated for a use environment with a wider charge mobility range (high temperature and low voltage). 00 、a 01 、a 02 ...and more appropriately improve the image quality of captured images.

[0083] (2) In addition, in the first embodiment, an example has been described in which the specific pixel group 25 includes one light receiving pixel 2B and a plurality of light shielding pixels 2C surrounding the one light receiving pixel 2B, but other configurations may also be adopted. Fig.13 As shown, a structure in which two or more light receiving pixels 2B are arranged in a two-dimensional array and a plurality of light shielding pixels 2C surround the two or more light receiving pixels 2B can be adopted. With such a structure, the total amount of charge (for example, holes) generated by the light receiving pixels 2B can be increased, the diffusion of charge from the effective pixel 2A with a higher incident light intensity to the surrounding effective pixels 2A can be simulated, and the color mixing parameter a for correcting the output signal of the effective pixel 2A with a higher incident light intensity can be obtained. 00 、a 01 、a 02 ... Therefore, the output signal of the effective pixel 2A having a higher incident light intensity can be corrected more appropriately.

[0084] (3) In addition, in the first embodiment, an example has been described in which the peripheral pixel area 5 includes only one specific pixel group 25, but other configurations may also be adopted. Fig.14 As shown, the peripheral pixel region 5 may include a plurality of specific pixel groups 25. In this case, the pattern of the area occupied by the light receiving pixels 2B included in the specific pixel group 25 may include two or more types of patterns. Fig.14 There is shown a case where 10 specific pixel groups 25 are provided in the peripheral pixel region 5 , and the pattern of the area occupied by the light-receiving pixels 2B includes three types of patterns of large, medium, and small.

[0085] With such a configuration, for example, for a specific pixel group 25 (hereinafter, also referred to as a "specific pixel group 25A") in which the area occupied by the light receiving pixel 2B is large, the total amount of charge generated by the light receiving pixel 2B can be increased, the diffusion of the charge from the effective pixel 2A having a higher incident light intensity to the surrounding effective pixels 2A can be simulated, and the color mixing parameter a for correcting the output signal of the effective pixel 2A having a higher incident light intensity can be obtained. 00 、a 01 、a 02 ……. In addition, for example, for a specific pixel group 25 (hereinafter, also referred to as a “specific pixel group 25B”) in which the area occupied by the light receiving pixel 2B is small, the total amount of charge generated by the light receiving pixel 2B can be reduced, the diffusion of the charge from the effective pixel 2A with a lower incident light intensity to the surrounding effective pixels 2A can be simulated, and the color mixing parameter a for correcting the output signal of the effective pixel 2A with a lower incident light intensity can be obtained. 00 、a 01 、a 02…. In addition, for example, for the specific pixel group 25 ranked between the specific pixel groups 25A and 25B in terms of the area occupied by the light receiving pixel 2B (hereinafter, also referred to as “specific pixel group 25C”), the color mixing parameter a for correcting the output signal of the effective pixel 2A having a medium incident light intensity can be obtained. 00 、a 01 、a 02 …….

[0086] Furthermore, in this case, the color mixing parameter generating unit 28 generates respective color mixing parameters A1=[a 00 , a 01 , a 02 …]、A2=[a 00 、a 01 , a 02 …] and A3 = [a 00 , a 01 , a 02 In addition, the output signal correction unit 29 selects a color mixing parameter A1, A2, A3, etc. for correcting the output signal from the plurality of color mixing parameters A1, A2, A3, etc. generated by the color mixing parameter generation unit 28 according to the size of each output signal to be corrected. i As an example, for each output signal to be corrected, a color mixing parameter A1, A2, A3, ... is selected for each output signal to be corrected, wherein the total value of the output signal of the light receiving pixel 2B of the specific pixel group 25 used to generate the color mixing parameter is closest to the value of the output signal to be corrected. i Therefore, each of the output signal of the effective pixel 2A having a high incident light intensity, the output signal of the effective pixel 2A having a low incident light intensity, and the output signal of the effective pixel 2A having a moderate incident light intensity can be corrected more appropriately.

[0087] (4) Furthermore, in the first embodiment, it has been described that the color mixing parameter generating unit 28 generates the color mixing parameter a in real time when an image of a subject is captured. 00 、a 01 、a 02 , but other constructions are also possible. Fig.15 As shown, the color mixing parameter generating unit 28 may generate the color mixing parameter a before capturing the image. 00 、a 01 、a 02 In this case, the color mixing parameter a generated by the color mixing parameter generating unit 28 is 00 、a 01 、a 02...are stored in the storage unit 105. In addition, the output signal correction unit 29 uses the color mixing parameter a stored in the storage unit 105 00 、a 01 、a 02 ...to correct each output signal of the effective pixel 2A.

[0088] As an example, in each of a plurality of use environments (temperature of the light receiving element 102 and intensity of light incident on the light receiving pixel 2B), a plurality of color mixing parameters A1=[a 00 , a 01 , a 02 …], A2 = [a 00 , a 01 , a 02 …], A3 = [a 00 , a 01 , a 02 …]… In addition, for each combination of temperature and light intensity, the plurality of color mixing parameters a generated by the color mixing parameter generating unit 28 are 00 、a 01 、a 02 …are stored in the storage unit 105. In addition, the output signal correction unit 29 selects, for each output signal to be corrected, a color mixing parameter A1, A2, A3, …stored in the storage unit 105, which is closest to the combination of the temperature of the light receiving element 102 during imaging and the intensity of the light incident on the effective pixel 2A to be corrected. i Then, using the selected color mixing parameter A i To correct each output signal of the effective pixel 2A. Therefore, a more appropriate color mixing parameter A can be selected according to the usage environment. i , and more appropriately improve the image quality of captured images.

[0089] (5) In addition, in the first embodiment, an example has been described in which nothing is stacked on the back surface S1 of the second contact layer 12 of the effective pixel region 4, but other configurations may also be adopted. Fig.16 As shown, one or both of the color filter 13 and the microlens 14 may be stacked on the back surface S1 of the second contact layer 12 . Fig.16 The state where the color filter 13 and the microlens 14 are stacked in this order is shown.

[0090] The color filter 13 is arranged at a position that coincides with each of the plurality of pixels 2 in a plan view. That is, one color filter 13 is formed for each pixel 2. The color filter 13 includes, for example, a red filter 13R, a green filter 13G, a blue filter 13B, and an IR filter 13I. Then, each color filter 13 transmits light having a predetermined wavelength, and causes the transmitted light to enter the photoelectric conversion layer 11. With such a configuration, light of a wavelength other than the predetermined wavelength can be prevented from entering the photoelectric conversion layer 11, and optical color mixing can be prevented.

[0091] The microlens 14 is arranged at a position that coincides with each of the plurality of pixels 2 in a plan view. That is, one microlens 14 is formed for each pixel 2. Then, each microlens 14 converges incident light (image light) from the subject, and causes the converged incident light to enter each portion of the photoelectric conversion layer 11 (the portion that coincides with the position of the microlens 14). With such a configuration, light incident on the microlens 14 of a certain pixel 2 can be prevented from entering the portion of the photoelectric conversion layer 11 corresponding to other adjacent pixels 2, and optical color mixing can be prevented.

[0092] (6) In addition, the structure of the element substrate 7 is not limited to Figure 3 The structure shown in FIG. 1 and FIG. 2 may also be used, for example Fig.17 , Fig.18 and Fig.19 The structure shown. Fig.17 4 is a diagram showing a cross-sectional structure of the element substrate 7 in the effective pixel region 4. Fig.18 is a diagram showing a cross-sectional configuration of a light receiving pixel 2B in the peripheral pixel region 5. In addition, Fig.19 2C in the peripheral pixel region 5. Fig.17 As shown, the element substrate 7 includes a photoelectric conversion layer 11, an upper electrode 31 arranged on the light incident surface of the photoelectric conversion layer 11, a first insulating film 32 arranged on the surface S3 of the photoelectric conversion layer 11, a second insulating film 33 arranged on the surface of the first insulating film 32 adjacent to the readout circuit substrate 8, and a storage electrode 34, a lower electrode 35 and a shielding electrode 36 arranged separately from each other in the second insulating film 33. In addition, the photoelectric conversion layer 11 includes an N+ layer 11a and a P layer or a non-doped layer (hereinafter, also referred to as an "i layer") 11b. Here, the N+ layer 11a is arranged to contact the upper electrode 31, and the P layer or the i layer 11b is arranged to contact the first insulating film 32. In addition, the first insulating film 32 has a potential capable of accumulating and transmitting charges (e.g., holes) obtained by photoelectric conversion of the photoelectric conversion layer 11.

[0093] In addition, in the photoelectric conversion layer 11, an impurity ion diffusion region 37 (first diffusion region 37a) covering the lower electrode 35 and an impurity ion diffusion region 37 (second diffusion region 37b) covering the shielding electrode 36 are formed. The first diffusion region 37a and the second diffusion region 37b are regions where N+ impurity ions are diffused. With such a configuration, Fig.17 In the element substrate 7 shown, when holes photoelectrically converted by the photoelectric conversion layer 11 flow into the first diffusion region 37a or the second diffusion region 37b, the holes recombine with electrons in the first diffusion region 37b or the second diffusion region 37b. Therefore, holes can be prevented from flowing from the first diffusion region 37a to the lower electrode 35.

[0094] Furthermore, in the peripheral pixel region 5, in addition to the layers similar to those in the effective pixel region 4, the element substrate 7 includes the following: Figure 4 The light shielding film 6 with openings shown in the figure is used as the outermost layer to form the light receiving pixel 2B, the light shielding pixel 2C and the specific pixel group 25. Fig.18 and Fig.19 As shown, the N-type impurity concentration of the impurity ion diffusion region 37 (the first diffusion region 37a and the second diffusion region 37b) corresponding to the light receiving pixel 2B and the light shielding pixel 2C of the specific pixel group 25 is lower than that of the impurity ion diffusion region 37 corresponding to the effective pixel 2A located in the effective pixel region 4. Here, the impurity ion diffusion region 37 and the P layer or the i layer 11b correspond to the "contact layer", the impurity ion diffusion region 37 corresponds to the "first conductivity type region", the P layer or the i layer 11b corresponds to the "second conductivity type region", the N type corresponds to the "first conductivity type", and the P type corresponds to the second conductivity type.

[0095] (7) Furthermore, the present technology can be applied not only to the above-described imaging device 100 but also to any light detection device that measures distance, such as a distance-measuring sensor also called a time-of-flight (ToF) sensor. A distance-measuring sensor is a sensor that emits irradiation light toward an object, detects reflected light (i.e., irradiation light reflected by the surface of the object), and calculates the distance to the object based on the flight time from the emission of the irradiation light to the reception of the reflected light.

[0096] Note that the present disclosure may also have the following configurations.

[0097] (1) A light receiving element comprising:

[0098] a plurality of pixels having a common photoelectric conversion layer including a compound semiconductor; and

[0099] a contact layer disposed on a surface of the photoelectric conversion layer opposite to the light incident surface, wherein

[0100] The contact layer includes a plurality of first conductive type regions formed in a one-to-one manner with respect to the plurality of pixels and a second conductive type region as a region other than the first conductive type region, and

[0101] A peripheral pixel area located outside the effective pixel area of ​​the pixel area in which the pixel is arranged includes a specific pixel group, wherein the specific pixel group includes a light receiving pixel and a light shielding pixel arranged to surround the light receiving pixel, and a concentration of first conductive type impurities in the first conductive type area corresponding to the light receiving pixel and the light shielding pixel of the specific pixel group is lower than that in the first conductive type area corresponding to the effective pixel located in the effective pixel area.

[0102] (2) The light receiving element according to (1) above further includes:

[0103] a wiring layer arranged on a surface of the contact layer opposite to a surface on the photoelectric conversion layer side, wherein

[0104] The wiring layer includes an electrode electrically connected to the first conductive type region, and

[0105] The concentration distribution of the first conductive type impurity in the first conductive type region on a straight line extending from the interface between the first conductive type region and the electrode toward the light incident surface of the photoelectric conversion layer has a flat area at a predetermined depth from the interface to the extension direction of the straight line, and the average concentration of the flat area of ​​the concentration distribution of the first conductive type region corresponding to the light receiving pixel and the light shielding pixel of the specific pixel group is lower than the average concentration of the flat area of ​​the concentration distribution of the first conductive type region corresponding to the effective pixel located in the effective pixel area.

[0106] (3) The light receiving element according to (1) or (2) above, wherein

[0107] The specific pixel group includes one light receiving pixel and a plurality of light shielding pixels surrounding the one light receiving pixel, or includes two or more light receiving pixels arranged in a two-dimensional array and a plurality of light shielding pixels surrounding the two or more light receiving pixels.

[0108] (4) The light receiving element according to (3) above, wherein

[0109] The peripheral pixel region includes a plurality of the specific pixel groups, and the patterns of areas occupied by the light receiving pixels included in the specific pixel groups are two or more.

[0110] (5) A light receiving element according to any one of (1) to (3) above, wherein the peripheral pixel area includes an OPB pixel for obtaining a reference signal of an optical black level, the OPB pixel is different from the light receiving pixel and the light shielding pixel, and the concentration of the first conductive type impurity in the first conductive type area corresponding to the OPB pixel is the same as that in the first conductive type area corresponding to the effective pixel.

[0111] (6) The light receiving element according to any one of (1) to (5) above,

[0112] The compound semiconductor includes any one of InGaAs, InGaN, InAlN, InAsSb, InAs, InSb and HgCdTe.

[0113] (7) A light detection device comprising:

[0114] A light receiving element, the light receiving element comprising a plurality of pixels, the pixels having a common photoelectric conversion layer comprising a compound semiconductor; and a contact layer arranged on a surface of the photoelectric conversion layer opposite to a light incident surface, the contact layer comprising a plurality of first conductive type regions formed in a one-to-one manner with respect to the plurality of pixels and a second conductive type region as a region other than the first conductive type region, a peripheral pixel region located outside an effective pixel region of a pixel region in which the pixels are arranged comprises a specific pixel group, the specific pixel group comprises a light receiving pixel and a light shielding pixel arranged to surround the light receiving pixel, the first conductive type regions corresponding to the light receiving pixels and the light shielding pixels of the specific pixel group have a lower concentration of first conductive type impurities than the first conductive type regions corresponding to the effective pixels located in the effective pixel region;

[0115] a color mixing parameter generating unit for generating, based on output signals of the light receiving pixel and the light shielding pixel of the specific pixel group, a color mixing parameter for reducing the influence of the charges moved from other said effective pixels from the respective output signals of the effective pixels located in the effective pixel region of the light receiving element; and

[0116] An output signal correction unit corrects each output signal of the effective pixel according to the color mixing parameter generated by the color mixing parameter generation unit.

[0117] (8) The light detection device according to (7) above,

[0118] The color mixing parameter generating unit sets the range of the light-shielding pixels for generating the color mixing parameters according to a use environment.

[0119] (9) The light detection device according to (8) above,

[0120] Compared with a case where the temperature of the light receiving element is less than a predetermined threshold, when the temperature of the light receiving element is greater than or equal to the predetermined threshold, the color mixing parameter generating unit expands the range of the shading pixels used to generate the color mixing parameters.

[0121] (10) The light detection device according to (8) or (9) above,

[0122] Among them, compared with the case where the voltage applied to the photoelectric conversion layer is greater than a predetermined threshold, when the voltage applied to the photoelectric conversion layer is less than or equal to the predetermined threshold, the color mixing parameter generation unit expands the range of the shading pixels used to generate the color mixing parameters.

[0123] (11) The light detection device according to (7) above,

[0124] wherein the peripheral pixel region includes a plurality of the specific pixel groups, and the patterns of the areas occupied by the light receiving pixels included in the specific pixel groups are two or more,

[0125] The color mixing parameter generating unit generates the color mixing parameter for each of the specific pixel groups, and

[0126] The output signal correction unit selects the color mixing parameter for correcting the output signal from the plurality of color mixing parameters generated by the color mixing parameter generation unit for each output signal to be corrected according to the size of the output signal.

[0127] (12) The light detection device according to any one of (7) to (11) above,

[0128] The color mixing parameter generating unit calculates the ratio of the magnitude of the output signal of the light shielding pixel to the magnitude of the output signal of the light receiving pixel as the color mixing parameter.

[0129] (13) The light detection device according to any one of (7) to (12) above, further comprising:

[0130] a storage unit for storing the color mixing parameters generated by the color mixing parameter generating unit,

[0131] The output signal correction unit uses the color mixing parameters stored in the storage unit to correct the output signals of the effective pixels.

[0132] Reference numerals list

[0133] 2 pixels

[0134] 2A effective pixels

[0135] 2B Light receiving pixel

[0136] 2C Light-blocking Pixels

[0137] 2D OPB Pixel

[0138] 3 pixel area

[0139] 4Effective pixel area

[0140] 5Peripheral pixel area

[0141] 6 shading film

[0142] 7-component substrate

[0143] 8Readout circuit board

[0144] 9 Wiring Layer

[0145] 10 First contact layer

[0146] 11 Photoelectric conversion layer

[0147] 12 Second contact layer

[0148] 15Semiconductor layer

[0149] 16 interlayer insulation film

[0150] 17 electrodes

[0151] 18 connection layers

[0152] 19A First conductivity type region

[0153] 19B Second conductivity type region

[0154] 20A First conductivity type region

[0155] 20B Second conductivity type region

[0156] 21Interlayer insulation film

[0157] 22 Readout electrode

[0158] 23 Connection layer

[0159] 25, 25A, 25B, 25C specific pixel group

[0160] 26 Concentration distribution

[0161] 27 Connection Layer

[0162] 28 color mixing parameter generation unit

[0163] 29 Output signal correction unit

[0164] 30 Areas

[0165] 31 Upper electrode

[0166] 32 first insulating film

[0167] 33 second insulating film

[0168] 34 Storage electrode

[0169] 35 Lower electrode

[0170] 36 shielding electrodes

[0171] 37Impurity ion diffusion region

[0172] 37a First diffusion region

[0173] 37b Second diffusion region

[0174] 100 Camera Device

[0175] 101 Camera Lens

[0176] 102 light receiving element

[0177] 103 Analog signal processing unit

[0178] 104 Digital Signal Processing Unit

[0179] 105 storage units.

Claims

1. A light receiving element, comprising: a plurality of pixels having a common photoelectric conversion layer including a compound semiconductor; and a contact layer disposed on a surface of the photoelectric conversion layer opposite to the light incident surface, wherein The contact layer includes a plurality of first conductive type regions formed corresponding to each of the plurality of pixels and a second conductive type region as a region other than the first conductive type region, and A peripheral pixel area located outside the effective pixel area of ​​the pixel area in which the pixel is arranged includes a specific pixel group, wherein the specific pixel group includes light receiving pixels and light shading pixels arranged to surround the light receiving pixels, and a concentration of first conductive type impurities in the first conductive type area corresponding to the light receiving pixels and the light shading pixels of the specific pixel group is lower than that in the first conductive type area corresponding to the effective pixels located in the effective pixel area.

2. The light receiving element according to claim 1, comprising: a wiring layer arranged on a surface side of the contact layer opposite to a surface on the photoelectric conversion layer side, wherein The wiring layer includes an electrode electrically connected to the first conductive type region, and The concentration distribution of the first conductive type impurity in the first conductive type region on a straight line extending from the interface between the first conductive type region and the electrode toward the light incident surface side of the photoelectric conversion layer has a flat area at a predetermined depth from the interface to the extension direction of the straight line, and the average concentration of the flat area of ​​the concentration distribution of the first conductive type region corresponding to the light receiving pixel and the light shielding pixel of the specific pixel group is lower than the average concentration of the flat area of ​​the concentration distribution of the first conductive type region corresponding to the effective pixel located in the effective pixel area.

3. The light receiving element according to claim 1, wherein The specific pixel group includes one light receiving pixel and a plurality of light shielding pixels surrounding the one light receiving pixel, or includes two or more light receiving pixels arranged in a two-dimensional array and a plurality of light shielding pixels surrounding the two or more light receiving pixels.

4. The light receiving element according to claim 3, wherein The peripheral pixel region includes a plurality of the specific pixel groups, and the patterns of areas occupied by the light receiving pixels included in the specific pixel groups are two or more.

5. The light receiving element according to claim 1, wherein The peripheral pixel area includes an OPB pixel for obtaining a reference signal of an optical black level, the OPB pixel is the pixel different from the light receiving pixel and the light shielding pixel, and the concentration of the first conductive type impurity of the first conductive type area corresponding to the OPB pixel is the same as the concentration of the first conductive type impurity of the first conductive type area corresponding to the effective pixel.

6. The light receiving element according to claim 1, in, The compound semiconductor includes any one of InGaAs, InGaN, InAlN, InAsSb, InAs, InSb, and HgCdTe.

7. A light detection device, comprising: a light receiving element including a plurality of pixels having a common photoelectric conversion layer including a compound semiconductor; and a contact layer arranged on a surface of the photoelectric conversion layer on an opposite side to the light incident surface, the contact layer including a plurality of first conductive type regions formed corresponding to each of the plurality of pixels and a second conductive type region as a region other than the first conductive type region, a peripheral pixel region located outside an effective pixel region of a pixel region where the pixels are arranged including a specific pixel group including a light receiving pixel and a light shielding pixel arranged to surround the light receiving pixel, a concentration of a first conductive type impurity in the first conductive type region corresponding to the light receiving pixel and the light shielding pixel of the specific pixel group being lower than that in the first conductive type region corresponding to the effective pixel located in the effective pixel region; a color mixing parameter generating unit for generating, based on output signals of the light receiving pixel and the light shielding pixel of the specific pixel group, a color mixing parameter for reducing the influence of the charges moved from other said effective pixels from the respective output signals of said effective pixels located in said effective pixel region of said light receiving element; as well as An output signal correction unit corrects each output signal of the effective pixel according to the color mixing parameter generated by the color mixing parameter generation unit.

8. The light detection device according to claim 7, in, The color mixing parameter generating unit sets a range of the light-shielded pixels for generating the color mixing parameters according to a use environment.

9. The light detection device according to claim 8, in, The color mixing parameter generating unit expands the range of the light-shielded pixels used to generate the color mixing parameters when the temperature of the light receiving element is greater than or equal to the predetermined threshold, compared to a case where the temperature of the light receiving element is less than the predetermined threshold.

10. The light detection device according to claim 8, in, Compared with the case where the voltage applied to the photoelectric conversion layer is greater than a predetermined threshold, when the voltage applied to the photoelectric conversion layer is less than or equal to the predetermined threshold, the color mixing parameter generating unit expands the range of the shading pixels used to generate the color mixing parameters.

11. The light detection device according to claim 7, in, The peripheral pixel region includes a plurality of the specific pixel groups, and the patterns of the areas occupied by the light receiving pixels included in the specific pixel groups are two or more, The color mixing parameter generating unit generates the color mixing parameter for each of the specific pixel groups, and The output signal correction unit selects the color mixing parameter for correcting the output signal from among the plurality of color mixing parameters generated by the color mixing parameter generation unit for each output signal as a correction target, according to the magnitude of the output signal.

12. The light detection device according to claim 7, in, The color mixing parameter generating unit calculates a ratio of a magnitude of an output signal of the light shielding pixel to a magnitude of an output signal of the light receiving pixel as the color mixing parameter.

13. The light detection device according to claim 7, comprising: a storage unit for storing the color mixing parameters generated by the color mixing parameter generating unit, The output signal correction unit uses the color mixing parameters stored in the storage unit to correct the output signals of the effective pixels.

Images