Light receiving device, X-ray imaging device, and electronic equipment

Abstract

A light-receiving device according to an embodiment of the present disclosure includes: a semiconductor substrate having a light-receiving region in which a plurality of light-receiving elements is arranged two-dimensionally in a matrix form and a peripheral region provided around the light-receiving region; a first first-conductivity-type region that is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and is connected to a first electrode in the light-receiving region; a second first-conductivity-type region that is provided around the respective first first-conductivity-type region, which is provided for each light-receiving element, and is connected to a second electrode at the interface of the first surface; an electrically floating third first-conductivity-type region that is provided around the respective second first-conductivity-type region, which is provided for each light-receiving element, at the interface of the first surface; an electrically floating fourth first-conductivity-type region that is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region in the peripheral region; and a first second-conductivity-type region that is formed to be embedded in the semiconductor substrate and faces the second first-conductivity-type region, third first-conductivity-type region, and fourth first-conductivity-type region.

Description

Technical Field

[0001] The present disclosure relates to a light receiving device, an X-ray imaging device, and an electronic device suitable for X-ray imaging for medical use or non-destructive inspection, for example.

Background Art

[0002] Solid-state imaging devices are used in various applications such as imaging devices such as digital still cameras and video cameras, electronic devices such as portable terminal devices having an imaging function, or electromagnetic wave sensors that detect various wavelengths other than visible light. Among solid-state imaging devices, there is an APS (Active Pixel Sensor) equipped with an amplification element for each pixel, and a CMOS (complementary MOS) image sensor (CIS) that reads out signal charges accumulated in a photodiode, which is a photoelectric conversion element, via a MOS (Metal Oxide Semiconductor) transistor is widely used.

[0003] In sensors for scientific applications that require highly sensitive measurement, a light receiving element (PIN photodiode) having a structure in which a photoelectric conversion region and a floating diffusion region (FD) are integrated is used (see, for example, Patent Document 1). Such a light receiving element is easy to manufacture from a simple structure. In addition, an arbitrary potential difference can be applied to the pn junction forming the photoelectric conversion region. Therefore, it is easy to increase the thickness of the photoelectric conversion region.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] By the way, in a light receiving device used as an X-ray imaging device, reduction of variations in pixel characteristics over the entire pixel array is required.

[0006] It is desirable to provide a light receiving device, an X-ray imaging device, and an electronic device capable of reducing variations in pixel characteristics in a light receiving area.

[0007] In one embodiment of the present disclosure First The light receiving device includes a semiconductor substrate having a light receiving area in which a plurality of light receiving elements are two-dimensionally arranged in a matrix, and a peripheral area provided around the light receiving area. In the light receiving area, a first first-conductivity-type region provided at the interface of the first surface of the semiconductor substrate for each light receiving element and connected to a first electrode, and a second first-conductivity-type region provided around the first first-conductivity-type region provided for each light receiving element at the interface of the first surface and connected to a second electrode, and a third first-conductivity-type region that is electrically floating, provided around the second first-conductivity-type region provided for each light receiving element at the interface of the first surface. In the peripheral area, a fourth first-conductivity-type region provided at the interface of the first surface of the semiconductor substrate around the light receiving area and electrically floating, and a first second-conductivity-type region embedded in the semiconductor substrate and facing the second first-conductivity-type region, the third first-conductivity-type region, and the fourth first-conductivity-type region. In this case, the first second conductivity type region facing the fourth first conductivity type region in the peripheral region has a higher impurity concentration than the first second conductivity type region provided in the light-receiving region. . A second light-receiving device according to one embodiment of the present disclosure comprises a semiconductor substrate having a light-receiving region in which a plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, and in the light-receiving region, a first first conductivity type region provided at the interface of a first surface of the semiconductor substrate for each light-receiving element and connected to a first electrode, a second first conductivity type region provided at the interface of the first surface for each light-receiving element and connected to a second electrode, a third first conductivity type region provided at the interface of the first surface for each light-receiving element and electrically floating, and in the peripheral region, provided at the interface of the first surface of the semiconductor substrate around the light-receiving region. The semiconductor comprises an electrically floating fourth first conductivity type region and a first second conductivity type region embedded in the semiconductor substrate and facing the second first conductivity type region, the third first conductivity type region, and the fourth first conductivity type region. The third first conductivity type region and the fourth first conductivity type region each consist of multiple regions. At the interface of the first surface, second second conductivity type regions are further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. The second second conductivity type regions provided between multiple fourth first conductivity type regions have a higher impurity concentration than the second second conductivity type regions provided between multiple third first conductivity type regions.A third light-receiving device according to one embodiment of the present disclosure comprises a semiconductor substrate having a light-receiving region in which a plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region; a first conductivity type region provided at the interface of a first surface of the semiconductor substrate for each light-receiving element in the light-receiving region and connected to a first electrode; a second conductivity type region provided at the interface of the first surface for each light-receiving element and connected to a second electrode; a third conductivity type region provided at the interface of the first surface for each light-receiving element and electrically floating; and a peripheral region provided at the interface of the first surface of the semiconductor substrate around the light-receiving region. Furthermore, it comprises an electrically floating fourth first conductivity type region and a first second conductivity type region embedded and formed within the semiconductor substrate, facing the second first conductivity type region, the third first conductivity type region, and the fourth first conductivity type region. The third first conductivity type region and the fourth first conductivity type region each consist of multiple units. At the interface of the first surface, second second conductivity type regions are further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. The width of the second second conductivity type region provided between multiple fourth first conductivity type regions is wider than the width of the second second conductivity type region provided between multiple third first conductivity type regions.A fourth light-receiving device according to one embodiment of the present disclosure comprises a semiconductor substrate having a light-receiving region in which a plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, and in the light-receiving region, a first first conductivity type region provided at the interface of a first surface of the semiconductor substrate for each light-receiving element and connected to a first electrode, a second first conductivity type region provided around the first first conductivity type region provided for each light-receiving element at the interface of the first surface and connected to a second electrode, and a second first conductivity type region provided at the interface of the first surface for each light-receiving element The device comprises a third first conductivity type region provided around the area and electrically floating, a fourth first conductivity type region provided at the interface of the first surface of the semiconductor substrate around the light-receiving area in the peripheral region and electrically floating, a first second conductivity type region embedded in the semiconductor substrate and facing the second first conductivity type region, the third first conductivity type region, and the fourth first conductivity type region, and a sixth first conductivity type region embedded in the semiconductor substrate and facing the first second conductivity type region on the second surface side facing the first surface of the semiconductor substrate.

[0008] In one embodiment of the present disclosure The 1st to 4th The X-ray imaging device includes the light receiving device according to one embodiment of the present disclosure, which has a plurality of light receiving elements that generate signal charges based on X-rays. The 1st to 4th light receiving device each and is provided with.

[0009] In one embodiment of the present disclosure The 1st to 4th The electronic device includes the X-ray imaging device according to one embodiment of the present disclosure. The 1st to 4th X-ray imaging device each and is provided with.

[0010] In one embodiment of the present disclosure The 1st to 4th The light receiving device, the X-ray imaging device according to one embodiment, The 1st to 4th and the electronic device according to one embodiment The 1st to 4thIn the electronic device, a plurality of photodetectors are arranged in a matrix in a two-dimensional manner, each having a first conductivity type region connected to a first electrode at the interface of a first surface of a semiconductor substrate, a second conductivity type region located around the first conductivity type region and connected to a second electrode, and a third conductivity type region located around the second conductivity type region and in an electrically floating state. A fourth conductivity type region in an electrically floating state is provided around the photodetector region, and a first second conductivity type region is embedded and formed within the semiconductor substrate, facing the second and third conductivity type regions and extending to the fourth conductivity type region. This reduces fluctuations in the potential of the photodetectors located on the outermost periphery of the photodetector region. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic cross-sectional view showing an example of the configuration of a light-receiving device according to an embodiment of the present disclosure. [Figure 2] Figure 1 is a schematic plan view showing the overall configuration of the light receiving device. [Figure 3] Figure 1 is a schematic planar diagram showing the diffusion pattern of impurities on the surface of the semiconductor substrate of the photodetector. [Figure 4] This is a conceptual diagram of the potential at the periphery of the light-receiving area of ​​a typical X-ray imaging device. [Figure 5] This is a schematic cross-sectional view showing an example of the configuration of a light-receiving device according to Modification 1 of this disclosure. [Figure 6] This figure shows the surface potential of the semiconductor substrate near the boundary between the light-receiving region and the surrounding region under each condition. [Figure 7] This is a schematic plan view showing an example of the configuration of a light receiving device according to Modification 2 of this disclosure. [Figure 8] This is a schematic cross-sectional view showing an example of the configuration of a light-receiving device according to Modification 3 of this disclosure. [Figure 9A] This is a schematic plan view showing an example of the configuration of a light receiving device according to Modification 4 of this disclosure. [Figure 9B] This is a schematic plan view illustrating another example of the configuration of the light receiving device according to Modification 4 of this disclosure. [Figure 10] This is a schematic cross-sectional view showing an example of the configuration of a light-receiving device according to Modification 5 of the present disclosure. [Figure 11] Figure 10 is a schematic plan view showing the overall configuration of the light receiving device. [Figure 12A] This is a schematic plan view illustrating another example of the configuration of a light-receiving device according to Modification 5 of the present disclosure. [Figure 12B] This is a schematic cross-sectional view showing another example of the configuration of the light receiving device according to Modification 5 of this disclosure. [Figure 12C] This is a schematic cross-sectional view showing another example of the configuration of the light receiving device according to Modification 5 of this disclosure. [Figure 13] This is a schematic plan view showing an example of the layout of the pixel edge guard ring of a light-receiving device according to Modification 6 of this disclosure. [Figure 14] This figure shows the surface potential of the semiconductor substrate near the boundary between the light-receiving region and the surrounding region of the photodetector shown in Figure 13. [Figure 15] This is a schematic plan view illustrating the layout of a pixel edge guard ring as a comparative example. [Figure 16] This figure shows the surface potential of the semiconductor substrate near the boundary between the light-receiving region and the surrounding region when a pixel edge guard ring is present, as shown in Figure 15. [Figure 17A] This is a schematic plan view showing another example of the layout of the pixel edge guard ring of the light receiving device according to Modification 6 of this disclosure. [Figure 17B] This is a schematic plan view showing another example of the layout of the pixel edge guard ring of the light receiving device according to Modification 6 of this disclosure. [Figure 18] This is a schematic plan view showing an example of a light receiving device according to Modification 7 of the present disclosure. [Figure 19] This is a schematic plan view showing another example of a light receiving device according to Modification 7 of the present disclosure. [Figure 20] This is a schematic plan view showing another example of a light receiving device according to Modification 7 of the present disclosure. [Figure 21] This is a block diagram showing the configuration of an X-ray imaging device. [Figure 22] Figure 21 is a block diagram showing a detailed configuration example of the column selection section. [Modes for carrying out the invention]

[0012] The embodiments described below will be explained in detail with reference to the drawings. The following description is one specific example of the disclosure, and the disclosure is not limited to the following embodiments. Furthermore, the disclosure is not limited to the arrangement, dimensions, dimensional ratios, etc., of each component shown in each drawing. The order of explanation is as follows. One embodiment (an example of an imaging device having a pixel edge guard ring provided around the light-receiving area and an embedded layer extending below the pixel edge guard ring) 2. Variations 2-1. Modification Example 1 (Example in which a high-density embedding layer is provided below the pixel edge guard ring) 2-2. Variation 2 (Another example of pixel edge guard ring layout) 2-3. Modification 3 (Example in which a high-density n-type conductive region is provided between the pixel edge guard rings) 2-4. Modification 4 (Another example of pixel edge guard ring layout) 2-5. Modification 5 (Example in which the barrier layer extends to the surrounding area) 2-6. Modification 6 (Another example of pixel edge guard ring layout) 2-7. Variation 7 (Other Variations) 3. Examples of application

[0013] <1. Embodiment> Figure 1 schematically shows an example of a cross-sectional configuration of a light-receiving device (light-receiving device 1) according to one embodiment of the present disclosure. Figure 2 schematically shows the overall planar configuration of the light-receiving device 1 shown in Figure 1, and Figure 1 shows a cross-section along line II shown in Figure 2. The light-receiving device 1 is applicable, for example, to radiation imaging devices (e.g., X-ray imaging device 100; see Figure 21) and electromagnetic wave detection devices that read information about an object based on radiation (e.g., alpha rays, beta rays, gamma rays, and X-rays, etc.) to image the object.

[0014] [Configuration of the light receiving device] The light-receiving device 1 has a light-receiving region 110A in which light-receiving elements, each consisting of a PIN (Positive Intrinsic Negative) type photodiode that applies a reverse bias between the front surface S1 (first surface) and the back surface S2 (second surface) of a semiconductor substrate 11, are arranged two-dimensionally in the row and column directions as one pixel (unit pixel P), and a peripheral region 110B provided around it.

[0015] In this embodiment, we will describe the case in which the holes among the excitons (electron-hole pairs) generated by photoelectric conversion are read out as the signal charge. Also, in the figure, the "-" (minus) attached to "p" and "n" indicates a low concentration of p-type or n-type impurities, and the "+" (plus) indicates a high concentration of p-type or n-type impurities. The relative magnitudes of the p-type and n-type impurities are as follows: - <p<p + ,n - <n<n + That is the case.

[0016] The semiconductor substrate 11 is composed of, for example, an n-type, p-type, or i-type (intrinsic semiconductor) semiconductor and has a pn junction or pin junction that serves as a photoelectric conversion region inside. In this embodiment, an n-type semiconductor substrate is used as the semiconductor substrate 11, and a p-type conductivity region 13 (first conductivity region) and an n-type conductivity region 14 (second conductivity region) are partially formed at the interface of the surface S1, and an n-type conductivity layer (second conductivity layer) 12 is formed at the interface of the back surface S2 facing the surface S1. The film thickness (hereinafter simply referred to as thickness) of the semiconductor substrate 11 in the stacking direction (Y-axis direction) is, for example, 10 μm or more and 700 μm or less.

[0017] The semiconductor substrate 11 may be, for example, a silicon substrate, but is not limited to this. The semiconductor substrate 11 may be made of, for example, germanium (Ge), gallium arsenide (GaAs), indium gallium arsenide (InGaAs), zinc selenide (ZnSe), gallium nitride (GaN), or indium gallium nitride (InGaN).

[0018] The p-type conductive region 13 is a region in which p-type impurities are diffused (p-type impurity region), and multiple p-type conductive regions are formed at the interface of the surface S1 of the semiconductor substrate 11. Specifically, the p-type conductive region 13 has six regions: a region constituting the anode 13A, a region constituting the drain 13B, a region constituting the guard ring 13C, a region constituting the high-voltage guard ring 13D, a region constituting the charge collection ring (CCR) 13E, and a region constituting the pixel edge guard ring 13F, and each region is provided spaced apart from the others. The anode 13A, drain 13B, and guard ring 13C are provided in the light-receiving region 110A, for example, for each unit pixel P. The high-voltage guard ring 13D, CCR 13E, and pixel edge guard ring 13F are provided in the peripheral region 110B.

[0019] The n-type conductivity region 14 is a region where n-type impurities are diffused (n-type impurity region), and multiple n-type conductivity regions are formed at the interface of the surface S1 of the semiconductor substrate 11. Specifically, the n-type conductivity region 14 has a region constituting the cathode 14A and one or more n-type conductivity regions 14B, 14C, and each region is spaced apart from the others. The cathode 14A is located in the peripheral region 110B. The n-type conductivity region 14B is located around the anode 13A. The n-type conductivity region 14C is located between multiple p-type conductivity regions provided at the interface of the surface S1 of the semiconductor substrate 11.

[0020] An insulating layer 21 containing one or more wiring layers is provided on the surface S1 side of the semiconductor substrate 11. Although not shown, electrodes 31, 32 for applying predetermined voltages to the anode 13A, drain 13B, CCR 13E, and cathode 14A, a ground (GND) 33, a power supply (VDD) 34, and logic circuits are formed on the insulating layer 21 and the substrate is placed on top of it.

[0021] [Configuration of the light-receiving area] As described above, multiple unit pixels P are arranged in a matrix in a two-dimensional manner in the light-receiving region 110A. Each unit pixel P is provided with a light-receiving element consisting of a PIN-type photodiode to which a reverse bias is applied, as described above.

[0022] A unit pixel P (photodetector) has an anode 13A, a drain 13B, and a plurality of guard rings 13C (13C1, 13C2, 13C3) at the interface of the surface S1 of the semiconductor substrate 11. An n-type conductivity region 14B is provided at the interface of the surface S1 of the semiconductor substrate 11 between the anode 13A and the drain 13B, and between the anode 13A and the drain 13B, there are p-type impurity regions with a lower concentration than the anode 13A and the drain 13B, respectively, adjacent to the anode 13A and the drain 13B. For convenience, the low-concentration p-type impurity region between the anode 13A and the n-type conductivity region 14B is referred to as Lightly Doped Anode (LDA) 13G1, and the low-concentration p-type impurity region between the drain 13B and the n-type conductivity region 14B is referred to as Lightly Doped Drain (LDD) 13G2. n-type conductive regions 14C are provided at the interfaces of the surface S1 of the semiconductor substrate 11 between multiple 13C1, 13C2, and 13C3. Inside the semiconductor substrate 11, an embedded layer 17 made of an n-type impurity diffusion layer and a barrier layer 18 made of a p-type impurity diffusion layer are formed. The unit pixel P is further provided with a gate electrode 22 within an insulating layer 21 between the anode 13A and the drain 13B.

[0023] Anode 13A removes p-type impurities, for example, 1e 18 cm -3 ~1e 21 cm -3It is a p-type impurity region containing impurities at a concentration of, which corresponds to a specific example of the "first first conductivity type region" of the present disclosure. The anode 13A is one to which a voltage for reading out holes (h+) as signal charges, for example, among the carriers generated by photoelectric conversion, is applied, and is connected to the electrode 31 (first electrode). The anode 13A is individually formed, for example, substantially at the center of the unit pixel P. The planar shape of the anode 13A is not particularly limited, and may be circular (for example, see FIG. 3) or polygonal. The anode 13A, for example, partially protrudes toward the back surface S2 side from the bottom surface of the buried layer 17 described later. The size of the anode 13A depends on the size of the unit pixel P, but for example, when the pitch of the unit pixel P is 10 μm or more and 100 μm or less, it is, for example, 0.1 μm or more and 10 μm or less.

[0024] The drain 13B contains p-type impurities at a concentration of, for example, 1e 18 cm -3 ~1e 21 cm -3 It is a p-type impurity region containing impurities at a concentration of, which corresponds to a specific example of the "second first conductivity type region" of the present disclosure. The drain 13B is one to which a voltage for discharging the dark current generated at the interface of the surface S1 of the semiconductor substrate 11, for example, during X-ray irradiation, is applied, and is connected to the electrode 32 (second electrode), for example. The drain 13B is formed in a ring shape around the anode 13A, and the dark current generated at the interface of the surface S1 of the semiconductor substrate 11 by X-ray irradiation is constantly discharged from the drain 13B. Thereby, it is possible to prevent the dark current from flowing into the anode 13A. The planar shape of the drain 13B is not particularly limited, and may be an annular shape or polygonal (for example, see FIG. 3).

[0025] The guard ring 13C contains p-type impurities at a concentration of, for example, 1e 18 cm -3 ~1e 21 cm -3This is a p-type impurity region containing a certain concentration, and corresponds to a specific example of the "third first conductivity type region" of this disclosure. The guard ring 13C is for mitigating electric field concentration on the drain 13B and simultaneously generating a horizontal electric field that assists in the transfer of signal charges (holes) in the horizontal direction (e.g., the XY plane direction). The guard ring 13C is formed in a ring shape around the drain 13B so as to surround the anode 13A and the drain 13B. Unlike the anode 13A and the drain 13B, the guard ring 13C is electrically floating. The guard ring 13C is formed in multiples, for example, at the interface of the surface S1 of the semiconductor substrate 11, in a substantially concentric or substantially concentric polygonal shape centered on the anode 13A. Specifically, as shown in Figures 1 and 3, the guard ring 13C consists of, for example, three p-type conductivity type regions and is formed in a triple layer (guard rings 13C1, 13C2, 13C3) around the drain 13B. In this way, by providing multiple guard rings 13C, the electric field concentration can be dispersed to multiple locations, and a horizontal electric field can be generated over a wide area.

[0026] When the drain 13B and guard ring 13C are formed in a polygonal shape (for example, rectangular), it is preferable to form the corners in a curved shape, as shown in Figure 3. This reduces the concentration of the electric field at the corners. In addition, although Figure 3 shows an example in which the drain 13B and guard ring 13C are continuously provided around the anode 13A, the arrangement is not limited to this. For example, they may be partially cut or formed intermittently.

[0027] The line width of the rings constituting the drain 13B and guard ring 13C is, for example, between 0.100 μm and 10 μm. The distance between the drain 13B and guard ring 13C is, for example, between 0.100 μm and 10 μm. Note that the line widths of the drain 13B and guard ring 13C do not necessarily have to be constant.

[0028] The n-type conductive layer 12 contains n-type impurities, for example, 1e 18 cm -3 ~1e21 cm -3 The n-type conductive layer is a layer containing a certain concentration and is formed at the interface of the back surface S2 of the semiconductor substrate 11. For example, in the peripheral region 110B, a power supply voltage is applied to the n-type conductive layer 12 from a cathode 14A provided at the interface of the surface S1 of the semiconductor substrate 11 via a neutral region formed outside the depletion region formed on the semiconductor substrate 11. As a result, when, for example, holes among the carriers generated by photoelectric conversion are read out as signal charges through the anode 13A, electrons (e-) are discharged from the cathode 14A through the n-type conductive layer 12. The thickness of the n-type conductive layer 12 depends on the configuration of the unit pixel P, but for example, when the pitch of the unit pixel P is 10 μm or more and 100 μm or less, it is formed with a thickness of, for example, 1 μm from the interface of the back surface S2 of the semiconductor substrate 11.

[0029] The method of connecting the power supply to the n-type conductive layer 12 is not limited to the above. For example, electrodes may be formed on the n-type conductive layer 12, and VDD 34 may be connected to them to apply the power supply voltage from the back surface S2 side of the semiconductor substrate 11.

[0030] The n-type conductivity region 14B is provided near the interface of the surface S1 of the semiconductor substrate 11 between the anode 13A and the drain 13B. The n-type conductivity region 14B contains n-type impurities, for example, 1e 16 cm -3 ~1e 19 cm -3 It contains at the following concentration. The thickness of the n-type conductive region 14B depends on the configuration of the unit pixel P, but for example, when the pitch of the unit pixel P is 10 μm or more and 100 μm or less, it is formed with a thickness of, for example, 0.1 μm to 3 μm from the interface of the surface S1 of the semiconductor substrate 11.

[0031] The n-type conductivity region 14C is provided at the interface of the surface S1 of the semiconductor substrate 11 between the drain 13B and the guard ring 13C1 and between adjacent guard rings 13C1, 13C2, and 13C3. The n-type conductivity region 14C contains n-type impurities, for example, 1e 16 cm -3 ~1e 19 cm -3It contains at the following concentration. The thickness of the n-type conductive region 14C depends on the configuration of the unit pixel P, but for example, when the pitch of the unit pixel P is 10 μm or more and 100 μm or less, it is formed with a thickness of, for example, 0.1 μm to 3 μm from the interface of the surface S1 of the semiconductor substrate 11.

[0032] LDD13G1 and LDD13G2 are provided at the interface of the surface S1 of the semiconductor substrate 11 between the anode 13A and the n-type conductivity region 14B, and between the n-type conductivity region 14B and the drain 13B, respectively. The impurity concentrations of LDD13G1 and LDD13G2 are lower than the impurity concentrations of the p-type conductivity region 13 that constitutes the anode 13A, drain 13B, and guard ring 13C, and are such that they are depleted by fixed charges (holes) generated at the interface of the insulating layer 21 with the surface S1 of the semiconductor substrate 11 by X-ray irradiation, for example. Specifically, although it depends on the amount of X-ray irradiation, for example, the peak concentration is 1e 19 cm -3 The following low concentrations are observed. The thickness of LDD13G1 and LDD13G2 depends on the configuration of the unit pixel P, but for example, when the pitch of the unit pixel P is 10 μm or more and 100 μm or less, they are formed with a thickness of, for example, 0.1 μm to 3 μm from the interface of the surface S1 of the semiconductor substrate 11.

[0033] The embedded layer 17 corresponds to one specific example of the "first second conductivity type region" of this disclosure. The embedded layer 17 is intended to prevent holes (signal charges) among the carriers generated in the semiconductor substrate 11 by photoelectric conversion from being transferred to the drain 13B or guard ring 13C. The embedded layer 17 is located inside the semiconductor substrate 11, specifically in the vicinity of the p-type conductivity region 13, for example, 1e 14 cm -3 ~1e 17 cm -3It is composed of an n-type impurity diffusion layer containing a concentration of . More specifically, the embedded layer 17 is provided in the region corresponding to the drain 13B and the guard ring 13C, and has an opening in the region facing the anode 13A. As a result, the signal charge generated in the semiconductor substrate 11 is efficiently read out from the anode 13A. The embedded layer 17 is formed so as not to be in direct contact with the drain 13B and the guard ring 13C. The embedded layer 17 is positioned, for example, at a location of 1 μm to 10 μm from the surface S1 of the semiconductor substrate 11.

[0034] The barrier layer 18 corresponds to a specific example of the "sixth first conductivity type region" of this disclosure. The barrier layer 23 is for preventing signal charge from disappearing from the guard ring 13C to the drain 13B. The barrier layer 18 is formed inside the semiconductor substrate 11 at a position opposite to the embedded layer 17, on the back surface S2 side of the embedded layer 17. The barrier layer 18 extends over, for example, multiple unit pixels P, and is in contact with the anode 13A at, for example, the center of the unit pixel P. The barrier layer 18 contains p-type impurities that are equal to or less than the impurity concentration of the n-type conductivity region constituting the embedded layer 17, for example, 1e 14 cm -3 ~1e 17 cm -3 It is composed of a p-type impurity diffusion layer containing at a certain concentration. The barrier layer 18 is formed at a deeper position than the embedded layer 17, and is located, for example, at a position of 1.1 μm to 11 μm from the surface S1 of the semiconductor substrate 11.

[0035] The insulating layer 21 is formed using an inorganic insulating material. Examples of inorganic insulating materials include silicon oxide (SiO2), silicon nitride (SiN), aluminum oxide (Al2O3), and hafnium oxide (HfO2). The insulating layer 21 is formed containing at least one of these materials. Within the insulating layer 21, one or more wiring layers are formed using, for example, a metallic material or polysilicon (poly-Si).

[0036] The gate electrode 22 is provided, for example, within the insulating layer 21 between the anode 13A and the drain 13B. The gate electrode 22 is for applying an electric field to the interface of the surface S1 of the semiconductor substrate 11 between the anode 13A and the drain 13B. Specifically, it applies an electric field in a direction that moves holes generated near the interface of the surface S1 of the semiconductor substrate 11 away from the interface of the semiconductor substrate 11. More specifically, a negative (-) voltage is applied to the gate electrode 22 with respect to the potential of the semiconductor substrate 11, thereby applying an electric field of, for example, 0.5 MV / cm or more to the interface of the surface S1 of the semiconductor substrate 11. The gate electrode 22 is also for reducing the volume of the insulating layer 21 provided on the semiconductor substrate 11 between the anode 13A and the drain 13B. This reduces the increase in positive fixed charge generated within the insulating layer 21 near the interface of the insulating layer 21 with the surface S1 of the semiconductor substrate 11 due to X-ray irradiation, and the increase in the interface state of the surface S1 of the semiconductor substrate 11. The gate electrode 22 is provided, for example, between the anode 13A and the drain 13B so as to surround the anode 13A in a plan view. The gate electrode 22 can be formed using, for example, polysilicon (poly-Si). The polysilicon constituting this gate electrode 22 may be an intrinsic semiconductor free of impurities, or it may be an impurity semiconductor containing n-type or p-type impurities.

[0037] [Manufacturing method for photodetectors] The photodetector constituting the unit pixel P can be manufactured, for example, as follows. First, an n-type conductive layer 12 is formed on the back surface S2 of the semiconductor substrate 11 using ion implantation technology. Next, a mask is formed in a predetermined area on the surface S1 of the semiconductor substrate 11, and then a p-type impurity diffusion layer (barrier layer 18) is formed by doping with a p-type impurity (e.g., boron (B)) using ion implantation technology. Next, an n-type impurity diffusion layer (embedding layer 17) is formed by doping with an n-type impurity (e.g., phosphorus (P)). Subsequently, a mask is formed in a predetermined area on the surface S1 of the semiconductor substrate 11, and then an anode 13A, drain 13B, and guard ring 13C are formed by doping with a p-type impurity (e.g., boron (B)) using ion implantation technology. Next, a mask is formed in a predetermined area of ​​the surface S1 of the semiconductor substrate 11, and then n-type impurities (e.g., phosphorus (P)) or p-type impurities (e.g., boron (B)) are doped using ion implantation technology to sequentially form n-type conductive regions 14B, 14C, LDD 13G1, and LDD 13G2. Then, an insulating film (gate insulating film) is formed on the surface S1 of the semiconductor substrate 11 as an insulating layer 21 using, for example, CVD (Chemical Vapor Deposition). Next, a polysilicon film is deposited on the gate insulating film using, for example, CVD, and then the polysilicon film is patterned using, for example, photolithography to form a gate electrode 22 between the anode 13A and the drain 13B. After that, an insulating layer 21 as an interlayer insulating layer and one or more wiring layers are sequentially formed. This completes the photodetector shown in Figure 1.

[0038] [Configuration of peripheral areas] As shown in Figure 2, in the peripheral region 110B, a high-voltage guard ring 13D is provided in a ring shape around the light-receiving region 110A, and outside of that, a cathode 14A is provided in a ring shape around the light-receiving region 110A, similar to the high-voltage guard ring 13D. Inside the high-voltage guard ring 13D, a CCR 13E is provided in a ring shape around the light-receiving region 110A, similar to the high-voltage guard ring 13D. Furthermore, inside the high-voltage guard ring 13D, specifically between the light-receiving region 110A and the CCR 13E, a pixel edge guard ring 13F is provided in a ring shape around the light-receiving region 110A, similar to the high-voltage guard ring 13D.

[0039] The high-pressure resistant guard ring 13D contains p-type impurities, for example, 1e 18 cm -3 ~1e 21 cm -3 This is a p-type impurity region containing a certain concentration, intended to mitigate the high electric field formed on the surface S1 of the semiconductor substrate 11 between the unit pixel P and the cathode 14A. The high-voltage guard ring 13D is electrically floating and is formed in multiples around the light-receiving region 110A, for example, along the outline of the light-receiving region 110A. The high-voltage guard ring 13D is formed, for example, from the interface of the surface S1 of the semiconductor substrate 11, with a thickness of, for example, 0.1 μm to 3 μm.

[0040] CCR13E removes p-type impurities, for example, 1e 18 cm -3 ~1e 21 cm -3This is a p-type impurity region containing a certain concentration, and corresponds to a specific example of the "fifth first conductivity type region" of this disclosure. CCR13E is for preventing dark current generated in the region from the surface S1 to the back surface 11S2 of the semiconductor substrate 11, from the high-voltage guard ring 13D to the cathode 14A, from flowing into the light-receiving region 110A. CCR13E is connected to GND 33, for example, and a fixed potential (0V) is applied to it. The line width of the ring constituting CCR13E is, for example, 3 μm or more, and the thickness of CCR13E is formed, for example, from the interface of the surface S1 of the semiconductor substrate 11 to, for example, 0.1 μm to 3 μm.

[0041] The pixel edge guard ring 13F blocks p-type impurities, for example, 1e 18 cm -3 ~1e 21 cm -3 This is a p-type impurity region containing a certain concentration, and corresponds to a specific example of the "fourth first conductivity type region" of this disclosure. The pixel edge guard ring 13F is for forming the potential between the light-receiving region 110A and CCR13E to be a mirror image of the potential between the boundary of the unit pixel P and the anode 13A. The pixel edge guard ring 13F, like the high-voltage guard ring 13D, is electrically floating and is formed in multiples around the light-receiving region 110A, for example, along the outline of the light-receiving region 110A. The line width of the ring constituting the pixel edge guard ring 13F is, for example, 0.2 μm to 10 μm, and the thickness of the pixel edge guard ring 13F is, for example, 0.1 μm to 3 μm from the interface of the surface S1 of the semiconductor substrate 11.

[0042] Cathode 14A contains n-type impurities, for example, 1e 18 cm -3 ~1e 21 cm -3This is an n-type impurity region containing a certain concentration, and is provided, for example, on the outermost periphery of the peripheral region 110B, surrounding the light-receiving region 110A. The cathode 14A is connected to VDD34 to apply a voltage to the n-type conductive layer 12 to discharge, for example, electrons (e-) from the carriers generated by photoelectric conversion. The line width of the ring constituting the cathode 14A is, for example, 10 μm or more, and the thickness of the cathode 14A is formed, for example, from the interface of the surface S1 of the semiconductor substrate 11 to, for example, 0.1 μm to 3 μm.

[0043] Furthermore, a p-type conductive region 15 with a low impurity concentration may be provided around the p-type conductive region 13 that constitutes the high-pressure-resistant guard ring 13D and CCR13E. The impurity concentration of the p-type conductive region 15 is, for example, 1e 15 cm -3 ~1e 18 cm -3 It is formed at a low concentration. Furthermore, although not shown in the figures, for example, near the interface of the surface S1 of the semiconductor substrate 11 between the high-voltage guard rings 13D, n-type impurities are formed, for example, 1e 16 cm -3 ~1e 19 cm -3 It is also possible to form an n-type conductive region containing at a concentration of .

[0044] In the light-receiving device 1 of this embodiment, the vicinity of the boundary between the light-receiving region 110A and the peripheral region 110B basically exhibits mirror image symmetry. Specifically, the layout of the n-type and p-type impurity regions formed at the interface of the surface S1 of the semiconductor substrate 11 on the peripheral region 110B side from the anode 13A of the unit pixel P located on the outermost periphery of the light-receiving region 110A, and the layout of the n-type and p-type impurity regions formed at the interface of the surface S1 of the semiconductor substrate 11 on the side of the CCR 13E (on the light-receiving region 110A side), etc., exhibit mirror image symmetry.

[0045] For example, at the interface of the surface S1 of the semiconductor substrate 11 at the boundary between the light-receiving region 110A and the peripheral region 110B, an n-type conductive region 16 is provided in a ring shape surrounding the light-receiving region 110A. Using this n-type conductive region 16 as an axis of symmetry, pixel edge guard rings 13F1, 13F2, and 13F3 are provided in the peripheral region 110B, similar to the guard rings 13C1, 13C2, and 13C3 provided in the light-receiving region 110A. Furthermore, the n-type conductive region 14C provided between the drain 13B and guard ring 13C1 and between adjacent pixel edge guard rings 13F1, 13F2, and 13F3 in the light-receiving region 110A is also provided between adjacent pixel edge guard rings 13F1, 13F2, and 13F3 in the peripheral region 110B and between pixel edge guard ring 13F and CCR13E. Furthermore, in a cross-sectional view, the embedded layer 17 provided on the outermost unit pixel P of the light-receiving region 110A extends below the pixel edge guard ring 13F. As a result, the potentials of the guard rings 13C1, 13C2, and 13C3 of the unit pixels P located on the outermost edge of the light-receiving region 110 become equal to the potentials of the guard rings 13C1, 13C2, and 13C3 of the unit pixels P located inside the light-receiving region 110.

[0046] Unlike the embedded layer 17, it is preferable that the barrier layer 18 be formed up to the edge of the light-receiving region 110A and not below the pixel edge guard ring 13F. If the barrier layer 18 extends below the pixel edge guard ring 13F, the potential of the semiconductor substrate 11 in the peripheral region 110B will not rise until the barrier layer 18 is depleted, which may cause characteristic differences within the chip. In contrast, as in this embodiment, by providing a region below the embedded layer 17 in the peripheral region 110B where the barrier layer 18 is not formed, the embedded layer 17 propagates potential in accordance with the potential of the semiconductor substrate 11, making it possible to continuously raise the potential of the surface S1 of the semiconductor substrate 11 without the breakdown of the pn junction between the embedded layer 17 and the barrier layer 18.

[0047] [Effects / Effects] In the light-receiving device 1 of this embodiment, a pixel edge guard ring 13F that is electrically floating is provided around a light-receiving region 110A in which a plurality of unit pixels P, each having a light-receiving element, are arranged in a two-dimensional matrix, and the embedded layer 17 is extended below the pixel edge guard ring 13F. As a result, the potential around the light-receiving region 110A can be formed to be a mirror image of the potential between the boundary of the unit pixels P and the anode 13A. This reduces fluctuations in the potential of the unit pixels P located on the outermost periphery of the light-receiving region 110A. This will be explained below.

[0048] Silicon direct conversion X-ray sensors collect electrons and holes generated by photoelectric conversion in a depletion layer. In typical visible light sensors, a power supply voltage such as 3V or 5V is applied to form a depletion layer to a depth of several micrometers on the silicon substrate. In contrast, X-ray sensors apply a power supply voltage, such as 300V or 500V, depending on the wavelength of the X-rays, to deplete the silicon substrate to a depth of 650μm. When such high voltages are applied to the silicon substrate, the electric field strength can become locally high, and breakdown occurs when the electric field exceeds a certain level.

[0049] To prevent this breakdown, an X-ray sensor equipped with a high-voltage guard ring has been proposed. The high-voltage guard ring mitigates the electric field strength by distributing the applied voltage through several layers of electrically floating impurity diffusion layers placed around the pixel. Furthermore, to prevent the dark current generated by the high-voltage guard ring from flowing into the pixel, an X-ray sensor has been proposed that includes a CCR (Critical Current Collector) between the high-voltage guard ring and the pixel array to collect the dark current generated by the high-voltage guard ring.

[0050] For example, as shown in Figure 4, in a silicon direct conversion type X-ray sensor, if a power reduction of, for example, 300V is applied to the cathode 1200 to deplete the silicon substrate, a potential of several tens of volts is formed at the edge of the pixel (anode 1300) which is set to 0V (GND). Generally, since the CCR is set to 0V (GND), if a structure to control the potential of the silicon substrate is not incorporated between the edge of the pixel array and the CCR, the potential of the pixels located on the outermost periphery will be affected by the potential of the CCR and will be different from the desired potential. This can lead to characteristic fluctuations in the pixels located on the outermost periphery, specifically problems such as poor signal charge transmission, deterioration of charge dissipation rate, and increased leakage current.

[0051] In contrast, in this embodiment, a p-type conductive region 13 is provided at the boundary between the light-receiving region 110A and the peripheral region 110B, for example, in a mirror image relationship in a plan view. Specifically, an electrically floating pixel edge guard ring 13F is provided around the light-receiving region 110A, so as to be mirror-image symmetric to the guard ring 13C of the unit pixel P located on the outermost periphery of the light-receiving region 110A. As a result, the potential of the surface S1 of the semiconductor substrate 11 is also mirror-image, and the potential of the unit pixel P located on the outermost periphery becomes equivalent to the potential of the unit pixel P located on the inside. Therefore, variations in pixel characteristics between the unit pixel P located on the outermost periphery and the unit pixel P located on the inside, such as signal charge transfer, collection efficiency, and leakage current, are reduced. Furthermore, in this embodiment, the embedded layer 17, which is located opposite the drain 13B and guard ring 13C of the light-receiving region 110A, is also made to be in a mirror image relationship. As a result, the potential of the surface S1 of the outermost unit pixel P becomes equivalent to the potential of the surface S1 of the inner unit pixel P.

[0052] As described above, the light receiving device 1 of this embodiment prevents deterioration of the pixel characteristics of the unit pixels P arranged on the outermost edge of the light receiving area 110A, and reduces variations in pixel characteristics in the light receiving area 110A.

[0053] Next, modified examples 1 to 7 of the present disclosure and examples of their application will be described. In the following, components similar to those in the above embodiments will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0054] <2. Variant> (2-1. Variation 1) Figure 5 schematically shows an example of the cross-sectional configuration of a light-receiving device (light-receiving device 1A) according to Modification 1 of the present disclosure. Similar to the above embodiment, the light-receiving device 1A consists of, for example, a PIN-type photodiode that applies a reverse bias between the front and back surfaces of a semiconductor substrate 11, and constitutes one pixel (unit pixel P) in a radiation image sensor (e.g., X-ray imager 100) or electromagnetic wave detection device that reads information about a subject (images of a subject) based on radiation (e.g., alpha rays, beta rays, gamma rays, and X-rays, etc.). The light-receiving device 1A of this modification differs from the above embodiment in that the impurity concentration of the embedded layer 17X formed below the pixel edge guard ring 13F is higher than that of the embedded layer 17 provided in the light-receiving area 110A.

[0055] If the impurity concentration of the embedded layer 17 is the same below the drain 13B and guard ring 13C and below the pixel edge guard ring 13F, then the difference in area between the anode 13A and the CCR 13E, both of which are subjected to a fixed potential of, for example, 0V, can cause a difference in the extent of the depletion layer. For example, the CCR 13E generally has a larger area than the anode 13A. As a result, the depletion layer tends to spread more easily on the CCR 13E side compared to the anode 13A side, and the depletion of the embedded layer 17 causes a difference in potential between the guard ring 13C and the pixel edge guard ring 13F, which have their potentials rising, leading to a deterioration in withstand voltage.

[0056] For example, as shown in Figure 6, there is no problem when the potential of the guard ring 13C of the unit pixel P located on the outermost edge of the light-receiving region 110A is equal to the potential of the pixel edge guard ring 13F (A). However, when the potential of the guard ring 13C of the unit pixel P located on the outermost edge of the light-receiving region 110A is higher than the potential of the pixel edge guard ring 13F (B), a high electric field region may be generated on the guard ring 13C side, potentially causing breakdown. On the other hand, when the potential of the guard ring 13C of the unit pixel P located on the outermost edge of the light-receiving region 110A is lower than the potential of the pixel edge guard ring 13F (C), a high electric field region may be generated on the pixel edge guard ring 13F side, potentially causing breakdown.

[0057] In contrast, in this modified example, the impurity concentration of the n-type impurity diffusion layer constituting the embedded layer 17X formed below the pixel edge guard ring 13F is set to a higher concentration (for example, 2e) than that of the embedded layer 17 provided in the light-receiving region 110A. 14 cm -3 ~2e 17 cm -3 This ensures that the depletion layer of the embedded layer 17 provided in the light-receiving area 110A and the depletion layer of the embedded layer 17X provided below the pixel edge guard ring 13F are aligned. Therefore, it is possible to prevent deterioration of the voltage resistance due to a potential difference between the outermost guard ring 13C of the light-receiving area 110A and the pixel edge guard ring 13F.

[0058] (2-2. Variation 2) Figure 7 schematically shows an example of the planar configuration of a light receiving device (light receiving device 1B) according to Modification 2 of this disclosure. In the above embodiment, an example is shown in which the same number of pixel edge guard rings 13F as the number of guard rings 13C are provided, but it is also possible to provide more pixel edge guard rings 13F (pixel edge guard rings 13F1, ... 13Fn) than the number of guard rings 13C. This makes it easier for the potential of the surface S1 of the semiconductor substrate 11 of the pixel edge guard ring 13F to rise, and makes it possible to reduce the occurrence of a potential difference between the guard ring 13C and the pixel edge guard ring 13F due to the area difference between the anode 13A and CCR 13E as described above.

[0059] (2-3. Variation 3) Figure 8 schematically shows an example of a cross-sectional configuration of a light receiving device (light receiving device 1C) according to Modification 3 of the present disclosure. In the above embodiment, an example is shown in which n-type conductive regions 14C are provided between the drain 13B and the guard ring 13C1, between adjacent guard rings 13C1, 13C2, 13C3, between adjacent pixel edge guard rings 13F1, 13F2, 13F3, and between the pixel edge guard ring 13F3 and CCR13E. However, n-type conductive regions 14D with a higher density than the n-type conductive regions 14C may be provided between adjacent pixel edge guard rings 13F1, 13F2, 13F3 and between the pixel edge guard ring 13F3 and CCR13E. This makes it easier for the potential of the surface S1 of the semiconductor substrate 11 of the pixel edge guard ring 13F to increase, and reduces the occurrence of a potential difference between the guard ring 13C and the pixel edge guard ring 13F due to the area difference between the anode 13A and CCR 13E as described above.

[0060] (2-4. Modification 4) Figure 9A schematically shows an example of the planar configuration of a light-receiving device (light-receiving device 1D) according to Modification 4 of this disclosure. Figure 9B schematically shows another example of the planar configuration of a light-receiving device (light-receiving device 1D) according to Modification 4 of this disclosure. In the above embodiment, an example is shown in which a pixel end guard ring 13F having the same line width as the ring constituting the guard ring 13C is provided, but the invention is not limited to this.

[0061] For example, as shown in Figure 9A, the line width of the rings constituting each pixel edge guard ring 13F1, 13F2, 13F3, 13F4, 13F5 may be made narrower than that of guard ring 13C, and the width of the n-type conductive region 14C provided between them may be widened to increase the formation area of ​​the n-type conductive region 14C. Furthermore, as shown in Figure 9B, the number of pixel edge guard rings 13F may be reduced to further widen the width of the n-type conductive region 14C and further increase the formation area of ​​the n-type conductive region 14C. This makes it easier to further increase the potential of the surface S1 of the semiconductor substrate 11 of the pixel edge guard ring 13F. Therefore, it is possible to further reduce the occurrence of a potential difference between the guard ring 13C and the pixel edge guard ring 13F due to the area difference between the anode 13A and CCR 13E as described above.

[0062] (2-5. Modification 5) Figure 10 schematically shows an example of the cross-sectional configuration of a light-receiving device (light-receiving device 1E) according to Modification 5 of this disclosure. Figure 11 schematically shows an example of the overall planar configuration of the light-receiving device 1E shown in Figure 10. In the above embodiment, an example is shown in which the barrier layer 18 is formed only in the light-receiving area 110A, but the invention is not limited to this.

[0063] For example, the barrier layer 18 may extend below the CCR13E, as shown in Figures 10 and 11, and an opening H may be provided in a part below the pixel edge guard rings 13F1, 13F2, and 13F3. In this case, the CCR13E may protrude toward the back surface S2 and be connected to the barrier layer 18. Alternatively, as shown in Figure 12A, the barrier layer 18 may be provided separately below the CCR13E.

[0064] Furthermore, when the barrier layer 18 is formed to extend to the peripheral region 110B, for example, below CCR13E, the embedded layer 17 may be extended to the outside of CCR13E, as shown in Figure 12B. In this case, extended portions 13X extending from CCR13E towards the back surface S2 are provided in a dot pattern, and the embedded layer 17 extends to the outside of CCR13E through the gaps in the dot-shaped extended portions 13X. Alternatively, as shown in Figure 12C, the embedded layer 17 may be made to protrude further into the back surface S2 than the barrier layer 18 below the pixel edge guard rings 13F1, 13F2, and 13F3.

[0065] As a result, similar to the embodiment described above, the potential of the surface S1 of the semiconductor substrate 11 can be continuously increased in accordance with the increase in the voltage of VDD34, without the breakdown of the pn junction between the embedded layer 17 and the barrier layer 18 due to reverse bias.

[0066] (2-6. Variation 6) Figure 13 schematically shows another example of the layout of the pixel edge guard ring 13F as a modification of the light receiving device 1 of the above embodiment. In the above embodiment, as shown in Figure 15, an example was shown in which a plurality of ring-shaped pixel edge guard rings 13F1, 13F2, and 13F3 are provided around the light receiving area 110A, continuous along the outer shape of the light receiving area 110A, but the embodiment is not limited to this. For example, as shown in Figure 13, pixel edge guard rings 13F1, 1F2, 13F3, and 13F4 having the same layout as the drain 13B and guard rings 13C1, 13C2, and 13C3 which divide the unit pixel P into two equal parts may be arranged symmetrically along the side of the unit pixel P.

[0067] As shown in Figure 15, when a ring-shaped pixel edge guard ring 13F is provided around the light-receiving region 110A, following the outline of the light-receiving region 110A, a difference in the extent of the depletion layer occurs due to the asymmetry in the layout between the guard ring 13C and the pixel edge guard ring 13F. As a result, for example, the potential at the III-III line shown in Figure 15 may be lower with respect to the pixel edge guard ring 13F than the potential of the guard ring 13C between adjacent unit pixels P, as shown in Figure 16.

[0068] In contrast, in this modified example, pixel edge guard rings 13F1, 1F2, 13F3, and 13F4 are provided, having the same layout as the drain 13B and guard rings 13C1, 13C2, and 13C3, which divide the unit pixel P into two equal parts and are symmetrical along the edge of the unit pixel P located on the outermost periphery of the light-receiving region 110A. As a result, for example, the potential along the II-II line shown in Figure 13 becomes equivalent to the potential of the unit pixel P located on the outermost periphery and the potential of the adjacent pixel edge guard ring 13F, as shown in Figure 14. Therefore, in the light-receiving region 110A, it becomes possible to further equalize the pixel characteristics of the unit pixel P located on the outermost periphery and the unit pixel P located on the inside.

[0069] Furthermore, the layout of the pixel edge guard rings 13F may be as follows. For example, as shown in Figure 17A, the pixel edge guard rings 13F1, 13F2, 13F3, and 13F4, which are provided along the edges of each unit pixel P, may be arranged so that the spacing between their ends is increased. This can mitigate the electric field at the ends of each pixel edge guard ring 13F1, 13F2, 13F3, and 13F4. Alternatively, as shown in Figure 17B, for example, the pixel edge guard rings 13F1, 13F2, 13F3, and 13F4, which are provided along the edges of each unit pixel P, may be connected to form a meandering series of pixel edge guard rings 13F.

[0070] (2-7. Variation 7) Furthermore, the light receiving device of this disclosure (for example, light receiving device 1) may have the following configuration.

[0071] For example, in the above embodiments, an example was shown in which multiple unit pixels P are arranged in a matrix and the shape of the light-receiving area 110A is approximately rectangular, but the shape of the light-receiving area 110A is not limited to this. Multiple unit pixels P can be arranged arbitrarily, and for example, as shown in Figure 18, the shape of the light-receiving area 110A may be a polygon other than approximately rectangular.

[0072] Furthermore, in example modification 6, the GND terminals are provided for each row and column in accordance with the multiple unit pixels P arranged in a matrix in the light-receiving area 110A. However, each GND terminal may be connected to one another, as shown in Figure 19.

[0073] Furthermore, although the above embodiments show an example where the unit pixel P is approximately rectangular in shape, the shape of the unit pixel P is not limited to this. For example, as shown in Figure 20, it may be approximately a regular hexagon, or it may be a polygon or a circle.

[0074] <3. Application Examples> Figure 21 shows the functional configuration of an X-ray imaging device 100 as an example of an electronic device using the light receiving device (for example, light receiving device 1) described in the above embodiments and modifications 1 to 6. The X-ray imaging device 100 reads information about a subject (images the subject) based on incident radiation Rrad (for example, alpha rays, beta rays, gamma rays, X-rays, etc.). This X-ray imaging device 100 is equipped with a pixel section (light receiving area 110A), and the driving circuit (peripheral circuit section) for this light receiving area 110A is equipped with a row scanning section 121, an A / D conversion section 122, a column scanning section 123, and a system control section 124.

[0075] (Light receiving area 110A) The light-receiving area 110A is equipped with multiple unit pixels (imaging pixels) P that generate signal charges based on radiation. The multiple unit pixels P are arranged in a matrix in two dimensions. As shown in Figure 1, the horizontal direction (row direction) within the light-receiving area 110A is defined as the "H" direction, and the vertical direction (column direction) is defined as the "V" direction.

[0076] (Row scanning unit 121) The row scanning unit 121 is composed of a shift register circuit and predetermined logic circuits, as described later, and is a pixel driving unit (row scanning circuit) that drives multiple unit pixels P in row units (horizontal line units) within the light-receiving area 110A (line sequential scanning). Specifically, the row scanning unit 121 performs imaging operations such as readout and reset operations of each unit pixel P by line sequential scanning, for example. Line sequential scanning is performed by supplying the aforementioned row scanning signal to each unit pixel P via the readout control line Lread.

[0077] (A / D conversion unit 122) The A / D conversion unit 122 has multiple column selection units 125, one for each of the multiple (four in this case) signal lines Lsig, and performs A / D conversion (analog-to-digital conversion) based on the signal voltage (voltage corresponding to the signal charge) input via the signal line Lsig. As a result, output data Dout (imaging signal) consisting of digital signals is generated and output to the outside.

[0078] Each column selection unit 125 includes, for example, a charge amplifier 172, a capacitive element (such as a capacitor or feedback capacitance element) C1, a switch SW1, a sample-and-hold (S / H) circuit 173, a multiplexer circuit (selection circuit) 174 including four switches SW2, and an A / D converter 175, as shown in Figure 22. Of these, the charge amplifier 172, capacitive element C1, switch SW1, S / H circuit 173, and switch SW2 are provided for each signal line Lsig. The multiplexer circuit 174 and A / D converter 175 are provided for each column selection unit 125. The charge amplifier 172, capacitive element C1, and switch SW1 constitute the charge amplifier circuit.

[0079] The charge amplifier 172 is an amplifier that converts the signal charge read from the signal line Lsig into a voltage (QV conversion). In this charge amplifier 172, one end of the signal line Lsig is connected to the negative (-) input terminal, and a predetermined reset voltage Vrst is input to the positive (+) input terminal. The output terminal and the negative input terminal of the charge amplifier 172 are connected via a parallel connection circuit of a capacitive element C1 and a switch SW1, which is a feedback connection. That is, one terminal of the capacitive element C1 is connected to the negative input terminal of the charge amplifier 172, and the other terminal is connected to the output terminal of the charge amplifier 172. Similarly, one terminal of the switch SW1 is connected to the negative input terminal of the charge amplifier 172, and the other terminal is connected to the output terminal of the charge amplifier 172. The on / off state of this switch SW1 is controlled by a control signal (ampretrieval control signal) supplied from the system control unit 124 via the ampretrieval control line Lcarst.

[0080] The S / H circuit 173 is located between the charge amplifier 172 and the multiplexer circuit 174 (switch SW2), and is a circuit for temporarily holding the output voltage Vca from the charge amplifier 172.

[0081] The multiplexer circuit 174 is a circuit that selectively connects or disconnects each S / H circuit 173 and the A / D converter 175 by sequentially turning on one of the four switches SW2 in accordance with the scanning drive by the column scanning unit 123.

[0082] The A / D converter 175 is a circuit that generates and outputs the output data Dout described above by performing A / D conversion on the output voltage from the S / H circuit 173, which is input via switch SW2.

[0083] (Column scanning unit 123) The column scanning unit 123 is configured to include, for example, a shift register and an address decoder (not shown), and sequentially drives each switch SW2 in the column selection unit 125 while scanning them. Through this selective scanning by the column scanning unit 123, the signals of each unit pixel P (the output data Dout) read out via each of the signal lines Lsig are sequentially output to the outside.

[0084] (System Control Unit 124) The system control unit 124 controls the operation of the row scanning unit 121, the A / D conversion unit 122, and the column scanning unit 123. Specifically, the system control unit 124 has a timing generator that generates the various timing signals (control signals) mentioned above, and controls the drive of the row scanning unit 121, the A / D conversion unit 122, and the column scanning unit 123 based on the various timing signals generated by this timing generator. Based on the control of the system control unit 124, the row scanning unit 121, the A / D conversion unit 122, and the column scanning unit 123 each perform imaging drive (line sequential imaging drive) for multiple unit pixels P within the light-receiving area 110A, thereby acquiring output data Dout from the light-receiving area 110A.

[0085] The embodiments and modifications 1 to 7, as well as application examples, have been described above. However, the contents of this disclosure are not limited to the embodiments described above, and various modifications are possible. For example, in the embodiments described above, examples using holes as signal charges were shown, but electrons may be used as signal charges. In that case, the conductivity types of each component will be the opposite.

[0086] Furthermore, the configuration of the unit pixel P (photodetector) described in the above embodiments is merely an example, and other impurity regions may also be included. Moreover, the materials and thicknesses of each layer are also merely examples and are not limited to those described above. Furthermore, although an X-ray imaging device 100 was given as the application example above, the photodetector 1 described in the above embodiments can also be applied to radiation imaging devices and electromagnetic wave detection devices that are not limited to X-rays.

[0087] Furthermore, the effects described herein are merely illustrative and not limiting, and other effects may also occur.

[0088] Furthermore, this disclosure can also take the following configuration. According to the technology with the following configuration, a plurality of photodetectors are arranged in a matrix in a two-dimensional manner around a photodetector region, each having a first first conductivity type region connected to a first electrode, a second first conductivity type region provided around the first first conductivity type region and connected to a second electrode, and a third first conductivity type region provided around it and in an electrically floating state. In addition, a fourth first conductivity type region in an electrically floating state is provided around the photodetector region, which is facing the second first conductivity type region and the third first conductivity type region and extends to the fourth first conductivity type region. This is embedded and formed within the semiconductor substrate. As a result, fluctuations in the potential of the photodetectors arranged on the outermost periphery of the photodetector region are reduced, and variations in pixel characteristics in the photodetector region are reduced. (1) A semiconductor substrate having a light-receiving region in which multiple light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each of the light-receiving elements, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, Embedded and formed within the semiconductor substrate, the first second conductivity region facing the second first conductivity region, the third first conductivity region, and the fourth first conductivity region Equipped with, In the aforementioned peripheral region, the first second conductivity type region facing the fourth first conductivity type region has a higher impurity concentration than the first second conductivity type region provided in the light-receiving region. A light-receiving device. (2) The light-receiving device according to (1), wherein, at the boundary position between the light-receiving region and the peripheral region, the third first conductivity type region and the first second conductivity type region provided on the outermost outermost light-receiving element of the light-receiving region, and the fourth first conductivity type region and the first second conductivity type region provided in the peripheral region, have mirror image symmetry in a cross-sectional view. (3) The light receiving device according to (1) or (2), further comprising a fifth first conductivity type region provided around the light receiving region with the fourth first conductivity type region in between, and to which a fixed potential is applied. (4 ) before The third first conductivity type region and the fourth first conductivity type region each consist of multiple parts. The number of the fourth first conductivity type region is greater than the number of the third first conductivity type region. Any one of the above (1) to (3) The light receiving device described above. (5) The third first conductivity type region and the fourth first conductivity type region each consist of multiple elements. At the interface of the first surface, a second second conductivity type region is further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. Any one of the above (1) to (3) The light receiving device described above. (6) The second second conductivity type region, provided between a plurality of the fourth first conductivity type regions, has a higher impurity concentration than the second second conductivity type region, provided between a plurality of the third first conductivity type regions. (5) above The light receiving device described above. (7) The width of the second second conductivity type region provided between the plurality of fourth first conductivity type regions is wider than the width of the second second conductivity type region provided between the plurality of third first conductivity type regions. (5) above The light receiving device described above. (8) Embedded within the semiconductor substrate, the semiconductor substrate further has a sixth first conductivity region facing the first second conductivity region on the second surface side facing the first surface of the semiconductor substrate, Any one of the above (1) through (7) The light receiving device described above. (9) The aforementioned The sixth first conductivity type region is provided only in the light-receiving region. (8) The light receiving device described above. (10) The sixth first conductivity type region extends below the first first conductivity type region and is connected to the first first conductivity type region and the sixth first conductivity type region. (8) or (9) above The light receiving device described above. (11) The fourth first conductivity type region is provided continuously around the light-receiving region and meanders according to the pitch of the plurality of light-receiving elements arranged in a matrix in two dimensions within the light-receiving region. Any one of the above (1) to (10) The light receiving device described above. (12) The fourth first conductivity type region is provided independently around the light-receiving region, for each row and column of the plurality of light-receiving elements arranged in a matrix in two dimensions within the light-receiving region. Any one of the above (1) through (11) The light receiving device described above. (13) The fourth first conductivity type region consists of multiple regions, The spacing between the multiple fourth first conductivity type regions is wider towards the terminal end. (12) The light receiving device described above. (14) The light-receiving element has a planar shape that is approximately rectangular or approximately hexagonal. Any one of the above (1) through (13) The light receiving device described above. (15) The aforementioned semiconductor substrate is composed of an intrinsic semiconductor. Any one of the above (1) to (14) The light receiving device described above. (16) The semiconductor substrate has a depletion region in the light-receiving region and a neutral region in the peripheral region. Any one of the above (1) through (15) The light receiving device described above. (17) The photodetector is a PN junction type photodetector that applies a reverse bias between the first surface of the semiconductor substrate and the second surface facing the first surface. (16) The light receiving device described above. (18) A semiconductor substrate having a light-receiving region in which multiple light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each of the light-receiving elements, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and comprises a first second conductivity region facing the second first conductivity region, the third first conductivity region, and the fourth first conductivity region, The third first conductivity type region and the fourth first conductivity type region each consist of multiple elements. At the interface of the first surface, a second second conductivity type region is further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. The second second conductivity type region, located between a plurality of the fourth first conductivity type regions, has a higher impurity concentration than the second second conductivity type region, located between a plurality of the third first conductivity type regions. Light receiving device. (19) A semiconductor substrate having a light-receiving region in which multiple light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each of the light-receiving elements, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and comprises a first second conductivity region facing the second first conductivity region, the third first conductivity region, and the fourth first conductivity region, The third first conductivity type region and the fourth first conductivity type region each consist of multiple elements. At the interface of the first surface, a second second conductivity type region is further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. The width of the second second conductivity type region provided between the plurality of fourth first conductivity type regions is wider than the width of the second second conductivity type region provided between the plurality of third first conductivity type regions. Light receiving device. (20) A semiconductor substrate having a light-receiving region in which multiple light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each of the light-receiving elements, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, Embedded within the semiconductor substrate, a first second conductivity region facing the second first conductivity region, the third first conductivity region, and the fourth first conductivity region, Embedded within the semiconductor substrate, a sixth first conductivity region is formed on the second surface side of the semiconductor substrate facing the first surface, and a sixth first conductivity region is formed on the second surface side facing the first second conductivity region. A light-receiving device. (21) Multiple photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each of the light-receiving elements, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, Embedded and formed within the semiconductor substrate, the first second conductivity region facing the second first conductivity region, the third first conductivity region, and the fourth first conductivity region It has, In the aforementioned peripheral region, the first second conductivity type region facing the fourth first conductivity type region has a higher impurity concentration than the first second conductivity type region provided in the light-receiving region. X-ray imaging device. (twenty two) Multiple photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each of the light-receiving elements, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and comprises a first second conductivity region facing the second first conductivity region, the third first conductivity region, and the fourth first conductivity region, The third first conductivity type region and the fourth first conductivity type region each consist of multiple elements. At the interface of the first surface, a second second conductivity type region is further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. The second second conductivity type region, located between a plurality of the fourth first conductivity type regions, has a higher impurity concentration than the second second conductivity type region, located between a plurality of the third first conductivity type regions. X-ray imaging device. (twenty three) Multiple photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each of the light-receiving elements, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and comprises a first second conductivity region facing the second first conductivity region, the third first conductivity region, and the fourth first conductivity region, The third first conductivity type region and the fourth first conductivity type region each consist of multiple elements. At the interface of the first surface, a second second conductivity type region is further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. The width of the second second conductivity type region provided between the plurality of fourth first conductivity type regions is wider than the width of the second second conductivity type region provided between the plurality of third first conductivity type regions. X-ray imaging device. (twenty four) Multiple photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each of the light-receiving elements, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, Embedded within the semiconductor substrate, a first second conductivity region facing the second first conductivity region, the third first conductivity region, and the fourth first conductivity region, Embedded within the semiconductor substrate, a sixth first conductivity region is formed on the second surface side of the semiconductor substrate facing the first surface, and a sixth first conductivity region is formed on the second surface side facing the first second conductivity region. An X-ray imaging device equipped with [a specific feature / feature]. (twenty five) Equipped with an X-ray imaging device, The aforementioned X-ray imaging apparatus, Multiple photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each of the light-receiving elements, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, Embedded and formed within the semiconductor substrate, the first second conductivity region facing the second first conductivity region, the third first conductivity region, and the fourth first conductivity region It has, In the aforementioned peripheral region, the first second conductivity type region facing the fourth first conductivity type region has a higher impurity concentration than the first second conductivity type region provided in the light-receiving region. electronic equipment. (26) Equipped with an X-ray imaging device, The aforementioned X-ray imaging apparatus, Multiple photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each of the light-receiving elements, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and has a second first conductivity type region, a third first conductivity type region, and a first second conductivity type region facing the fourth first conductivity type region, The third first conductivity type region and the fourth first conductivity type region each consist of multiple elements. At the interface of the first surface, a second second conductivity type region is further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. The second second conductivity type region, located between a plurality of the fourth first conductivity type regions, has a higher impurity concentration than the second second conductivity type region, located between a plurality of the third first conductivity type regions. electronic equipment. (27) Equipped with an X-ray imaging device, The aforementioned X-ray imaging apparatus, Multiple photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each of the light-receiving elements, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and has a second first conductivity type region, a third first conductivity type region, and a first second conductivity type region facing the fourth first conductivity type region, The third first conductivity type region and the fourth first conductivity type region each consist of multiple elements. At the interface of the first surface, a second second conductivity type region is further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. The width of the second second conductivity type region provided between the plurality of fourth first conductivity type regions is wider than the width of the second second conductivity type region provided between the plurality of third first conductivity type regions. electronic equipment. (28) Equipped with an X-ray imaging device, The aforementioned X-ray imaging apparatus, Multiple photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each of the light-receiving elements, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, Embedded within the semiconductor substrate, a first second conductivity region facing the second first conductivity region, the third first conductivity region, and the fourth first conductivity region, Embedded within the semiconductor substrate, a sixth first conductivity region is formed on the second surface side of the semiconductor substrate facing the first surface, and a sixth first conductivity region is formed on the second surface side facing the first second conductivity region. A powerful electronic device.

[0089] This application claims priority based on Japanese Patent Application No. 2021-112165, filed with the Japan Patent Office on 6 July 2021, and all contents of that application are incorporated herein by reference.

[0090] Those skilled in the art will understand that various modifications, combinations, subcombinations, and changes can be conceived depending on design requirements and other factors, and that these fall within the scope of the attached claims and their equivalents.

Claims

1. A semiconductor substrate having a light-receiving region in which multiple light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each light-receiving element, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and comprises a second first conductivity region, a third first conductivity region, and a first second conductivity region facing the fourth first conductivity region, In the aforementioned peripheral region, the first second conductivity region facing the fourth first conductivity region has a higher impurity concentration than the first second conductivity region provided in the light-receiving region. Light receiving device.

2. The light-receiving device according to claim 1, wherein, at the boundary position between the light-receiving region and the peripheral region, the third first conductivity type region and the first second conductivity type region provided on the outermost outermost light-receiving element of the light-receiving region, and the fourth first conductivity type region and the first second conductivity type region provided in the peripheral region, have mirror image symmetry in a cross-sectional view.

3. The light receiving device according to claim 1, further comprising a fifth first conductivity region provided around the light receiving region with the fourth first conductivity region in between, and to which a fixed potential is applied.

4. The third first conductivity type region and the fourth first conductivity type region each consist of a plurality of elements. The light receiving device according to claim 1, wherein the number of the fourth first conductivity type regions is greater than the number of the third first conductivity type regions.

5. The third first conductivity type region and the fourth first conductivity type region each consist of a plurality of elements. The light receiving device according to claim 1, wherein, at the interface of the first surface, a second second conductivity region is further provided between adjacent third first conductivity region, between adjacent third first conductivity region and fourth first conductivity region, and between adjacent fourth first conductivity region.

6. The light receiving device according to claim 5, wherein the second second conductivity type region provided between a plurality of fourth first conductivity type regions has a higher impurity concentration than the second second conductivity type region provided between a plurality of third first conductivity type regions.

7. The light receiving device according to claim 5, wherein the width of the second second conductivity type region provided between a plurality of fourth first conductivity type regions is wider than the width of the second second conductivity type region provided between a plurality of third first conductivity type regions.

8. The light receiving device according to claim 1, further comprising a sixth first conductivity region that is embedded and formed within the semiconductor substrate and faces the first second conductivity region on the second surface side of the semiconductor substrate facing the first surface.

9. The light receiving device according to claim 8, wherein the sixth first conductivity region is provided only in the light receiving region.

10. The light receiving device according to claim 9, wherein the sixth first conductivity type region extends below the first first conductivity type region and is connected to the first first conductivity type region and the sixth first conductivity type region.

11. The light-receiving device according to claim 1, wherein the fourth first conductivity type region is provided continuously around the light-receiving region and meanders according to the pitch of a plurality of light-receiving elements arranged in a matrix in two dimensions within the light-receiving region.

12. The light-receiving device according to claim 1, wherein the fourth first conductivity type region is independently provided around the light-receiving region, for each row and column of a plurality of light-receiving elements arranged in a matrix in two dimensions within the light-receiving region.

13. The fourth first conductivity type region consists of a plurality of, The light receiving device according to claim 12, wherein the spacing between the plurality of the fourth first conductivity type regions is wider towards the terminal ends.

14. The light-receiving device according to claim 1, wherein the light-receiving element has a planar shape that is substantially rectangular or substantially hexagonal.

15. The light receiving device according to claim 1, wherein the semiconductor substrate is made of an intrinsic semiconductor.

16. The light receiving device according to claim 1, wherein the semiconductor substrate has a depletion region in the light receiving region and a neutral region in the peripheral region.

17. The photodetector according to claim 16, wherein the photodetector is a PN junction type photodetector that applies a reverse bias between the first surface of the semiconductor substrate and the second surface facing the first surface.

18. A semiconductor substrate having a light-receiving region in which a plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each light-receiving element, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and comprises a second first conductivity region, a third first conductivity region, and a first second conductivity region facing the fourth first conductivity region, The third first conductivity type region and the fourth first conductivity type region each consist of a plurality of elements. At the interface of the first surface, a second second conductivity type region is further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. The second second conductivity type region, located between a plurality of the fourth first conductivity type regions, has a higher impurity concentration than the second second conductivity type region, located between a plurality of the third first conductivity type regions. Light receiving device.

19. A semiconductor substrate having a light-receiving region in which a plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each light-receiving element, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and comprises a second first conductivity region, a third first conductivity region, and a first second conductivity region facing the fourth first conductivity region, The third first conductivity type region and the fourth first conductivity type region each consist of a plurality of elements. At the interface of the first surface, a second second conductivity type region is further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. The width of the second second conductivity type region provided between the plurality of fourth first conductivity type regions is wider than the width of the second second conductivity type region provided between the plurality of third first conductivity type regions. Light receiving device.

20. A semiconductor substrate having a light-receiving region in which a plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each light-receiving element, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, Embedded and formed within the semiconductor substrate, a first second conductivity region facing the second first conductivity region, the third first conductivity region, and the fourth first conductivity region, Embedded within the semiconductor substrate, a sixth first conductivity region is formed on the second surface side of the semiconductor substrate facing the first surface, and a sixth first conductivity region is formed on the second surface side facing the first second conductivity region. A light-receiving device.

21. Multiple photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each light-receiving element, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and has a second first conductivity type region, a third first conductivity type region, and a first second conductivity type region facing the fourth first conductivity type region, In the aforementioned peripheral region, the first second conductivity region facing the fourth first conductivity region has a higher impurity concentration than the first second conductivity region provided in the light-receiving region. X-ray imaging device.

22. A plurality of photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each light-receiving element, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and comprises a second first conductivity region, a third first conductivity region, and a first second conductivity region facing the fourth first conductivity region, The third first conductivity type region and the fourth first conductivity type region each consist of a plurality of elements. At the interface of the first surface, a second second conductivity type region is further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. The second second conductivity type region, located between a plurality of the fourth first conductivity type regions, has a higher impurity concentration than the second second conductivity type region, located between a plurality of the third first conductivity type regions. X-ray imaging device.

23. A plurality of photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each light-receiving element, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and comprises a second first conductivity region, a third first conductivity region, and a first second conductivity region facing the fourth first conductivity region, The third first conductivity type region and the fourth first conductivity type region each consist of a plurality of elements. At the interface of the first surface, a second second conductivity type region is further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. The width of the second second conductivity type region provided between the plurality of fourth first conductivity type regions is wider than the width of the second second conductivity type region provided between the plurality of third first conductivity type regions. X-ray imaging device.

24. A plurality of photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each light-receiving element, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, Embedded and formed within the semiconductor substrate, a first second conductivity region facing the second first conductivity region, the third first conductivity region, and the fourth first conductivity region, Embedded within the semiconductor substrate, a sixth first conductivity region is formed on the second surface side of the semiconductor substrate facing the first surface, and a sixth first conductivity region is formed on the second surface side facing the first second conductivity region. An X-ray imaging device equipped with [a specific feature].

25. Equipped with an X-ray imaging device, The aforementioned X-ray imaging apparatus, Multiple photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each light-receiving element, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and has a second first conductivity type region, a third first conductivity type region, and a first second conductivity type region facing the fourth first conductivity type region, In the aforementioned peripheral region, the first second conductivity region facing the fourth first conductivity region has a higher impurity concentration than the first second conductivity region provided in the light-receiving region. electronic equipment.

26. A device comprising an X-ray imaging apparatus, The aforementioned X-ray imaging apparatus, Multiple photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each light-receiving element, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and has a second first conductivity type region, a third first conductivity type region, and a first second conductivity type region facing the fourth first conductivity type region, The third first conductivity type region and the fourth first conductivity type region each consist of a plurality of elements. At the interface of the first surface, a second second conductivity type region is further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. The second second conductivity type region, located between a plurality of the fourth first conductivity type regions, has a higher impurity concentration than the second second conductivity type region, located between a plurality of the third first conductivity type regions. electronic equipment.

27. ​​comprising an X-ray imaging device, The aforementioned X-ray imaging apparatus, Multiple photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each light-receiving element, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, It is embedded and formed within the semiconductor substrate and has a second first conductivity type region, a third first conductivity type region, and a first second conductivity type region facing the fourth first conductivity type region, The third first conductivity type region and the fourth first conductivity type region each consist of a plurality of elements. At the interface of the first surface, a second second conductivity type region is further provided between adjacent third first conductivity type regions, between adjacent third first conductivity type regions and fourth first conductivity type regions, and between adjacent fourth first conductivity type regions. The width of the second second conductivity type region provided between the plurality of fourth first conductivity type regions is wider than the width of the second second conductivity type region provided between the plurality of third first conductivity type regions. electronic equipment.

28. comprising an X-ray imaging device, The aforementioned X-ray imaging apparatus, Multiple photodetectors that generate signal charges based on X-rays, A semiconductor substrate having a light-receiving region in which the plurality of light-receiving elements are arranged in a matrix in two dimensions, and a peripheral region provided around the light-receiving region, In the light-receiving region, a first conductivity type region is provided at the interface of the first surface of the semiconductor substrate for each light-receiving element and connected to the first electrode, At the interface of the first surface, a second first conductivity region is provided around each of the first conductivity region provided for each of the light-receiving elements and is connected to the second electrode, At the interface of the first surface, a third first conductivity region is provided around each of the second first conductivity region provided for each light-receiving element, and is electrically floating. In the aforementioned peripheral region, a fourth first conductivity type region is provided at the interface of the first surface of the semiconductor substrate around the light-receiving region and is electrically floating, Embedded and formed within the semiconductor substrate, a first second conductivity region facing the second first conductivity region, the third first conductivity region, and the fourth first conductivity region, Embedded within the semiconductor substrate, a sixth first conductivity region is formed on the second surface side of the semiconductor substrate facing the first surface, and a sixth first conductivity region is formed on the second surface side facing the first second conductivity region. A powerful electronic device.

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