Photoelectric conversion device

Abstract

To improve a performance of a photoelectric conversion device.SOLUTION: A photoelectric conversion device having a plurality of pixels, comprises: a first surface; and a second surface opposite to the first surface, and comprises: a semiconductor layer having a plurality of APDs; and a wiring layer having a first wiring and a second wiring, and is provided to the first surface side. Each of the plurality of pixels contains: a first APD; a second APD that is adjacent to the first APD in a first direction; and an ML that is distributed in common to the first and second APDs, and provided on the side of the second surface. In the first direction, a width of the first wiring distributed to between the plurality of pixels is wider than a width of the first wiring distributed to between the second wiring of the first APD and the second wiring of the second APD.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a photoelectric conversion device. [Background technology]

[0002] Photoelectric conversion devices including an avalanche photodiode (hereinafter, APD) are known. Patent Document 1 shows a configuration in which a microlens is arranged on a plurality of pixels including an APD to enable phase difference detection. Patent Document 2 shows a configuration in which a reflective structure using metal wiring is provided on a plurality of pixels including an APD in order to improve sensitivity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-141122 A [Patent Document 2] JP 2018-088488 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration disclosed in Prior Document 1, there are concerns about a decrease in sensitivity and crosstalk to adjacent pixels due to light penetrating into the wiring layer. In addition, when the configuration disclosed in Prior Document 2 is applied to a photoelectric conversion device in which one microlens is arranged on multiple APDs, the arrangement of the metal wiring relative to the light collecting position becomes less optimal than when one microlens is arranged on one APD. This may result in a decrease in sensitivity and an increase in crosstalk. [Means for solving the problem]

[0005] One aspect of the present invention is a photoelectric conversion device having a plurality of pixels, the device having a first surface and a second surface opposite to the first surface, the device having a semiconductor layer having a plurality of avalanche photodiodes, a first wiring, and a second wiring, and a wiring layer provided on the side of the first surface, wherein each of the plurality of pixels includes a first avalanche photodiode, a second avalanche photodiode adjacent to the first avalanche photodiode in a first direction, and a microlens arranged in common to the first avalanche photodiode and the second avalanche photodiode and provided on the side of the second surface, the width of the first wiring arranged between the second wiring of the first avalanche photodiode and the second wiring of the second avalanche photodiode being wider than the width of the first wiring arranged between the plurality of pixels in the first direction.

[0006] Another aspect of the present invention is a photoelectric conversion device having a plurality of pixels, the device having a first surface and a second surface opposite to the first surface, the device having a semiconductor layer having a plurality of avalanche photodiodes, a first wiring, and a second wiring, and a wiring layer provided on the side of the first surface, each of the plurality of pixels including a first avalanche photodiode, a second avalanche photodiode adjacent to the first avalanche photodiode in a first direction, and a microlens arranged in common to the first avalanche photodiode and the second avalanche photodiode and provided on the side of the second surface, the first wiring not being provided between the second wiring of the first avalanche photodiode and the second wiring of the second avalanche photodiode in the first direction. Effect of the Invention

[0007] According to the present invention, the performance of a photoelectric conversion device can be improved. [Brief description of the drawings]

[0008] [Figure 1]FIG. 1 is a schematic diagram of an imaging device. [Diagram 2] FIG. 2 is a schematic diagram of a pixel array. [Diagram 3] FIG. 1 is a block diagram of an imaging device. [Figure 4] FIG. 2 is an equivalent circuit diagram of a pixel. [Diagram 5] FIG. 2 is a diagram illustrating the operation of a SPAD pixel. [Figure 6] 11 is a comparative example of a cross-sectional view of a pixel. [Figure 7] 11 is a comparative example of a plan view of a pixel. [Figure 8] 1 is a plan view of a pixel of an imaging device according to a first embodiment. [Figure 9] 2 is a cross-sectional view of a pixel of the imaging device according to the first embodiment. FIG. [Figure 10] 2 is a cross-sectional view of a pixel of the imaging device according to the first embodiment. FIG. [Figure 11] FIG. 11 is a plan view of a pixel of an imaging device according to a second embodiment. [Figure 12] FIG. 11 is a cross-sectional view of a pixel of an imaging device according to a second embodiment. [Figure 13] FIG. 11 is a plan view of a pixel of an imaging device according to a third embodiment. [Figure 14] FIG. 13 is a plan view of a pixel of an imaging device according to a fourth embodiment. [Figure 15] FIG. 13 is a cross-sectional view of a pixel of an imaging device according to a fourth embodiment. [Figure 16] FIG. 13 is a plan view of a pixel of an imaging device according to a fifth embodiment. [Figure 17] FIG. 13 is a cross-sectional view of a pixel of an imaging device according to a fifth embodiment. [Figure 18] FIG. 13 is a plan view of a pixel of an imaging device according to a sixth embodiment. [Figure 19] FIG. 13 is a cross-sectional view of a pixel of an imaging device according to a sixth embodiment. [Figure 20] FIG. 13 is a functional block diagram of a photoelectric conversion system according to a fifth embodiment. [Figure 21] FIG. 13 is a functional block diagram of a photoelectric conversion system according to a sixth embodiment. [Figure 22]FIG. 13 is a functional block diagram of a photoelectric conversion system according to a seventh embodiment. [Figure 23] FIG. 13 is a functional block diagram of a photoelectric conversion system according to an eighth embodiment. [Figure 24] FIG. 13 is a functional block diagram of a photoelectric conversion system according to a ninth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The following embodiments are intended to embody the technical ideas of the present invention, and are not intended to limit the present invention. The sizes and positional relationships of the components shown in the drawings may be exaggerated to clarify the description. In the following description, the same components may be designated by the same reference numerals, and the description may be omitted.

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following description, terms indicating specific directions or positions (for example, "upper", "lower", "right", "left" and other terms including these terms) will be used as necessary. The use of these terms is for the purpose of facilitating understanding of the embodiment with reference to the drawings, and the technical scope of the present invention is not limited by the meaning of these terms.

[0011] In the following description, the anode of the avalanche photodiode (APD) is set to a fixed potential, and a signal is taken from the cathode side. Therefore, the first conductive type semiconductor region having charges of the same polarity as the signal charge as the majority carrier is an N-type semiconductor region, and the second conductive type semiconductor region having charges of a different polarity from the signal charge as the majority carrier is a P-type semiconductor region. The present invention is also valid when the cathode of the APD is set to a fixed potential, and a signal is taken from the anode side. In this case, the first conductive type semiconductor region having charges of the same polarity as the signal charge as the majority carrier is a P-type semiconductor region, and the second conductive type semiconductor region having charges of a different polarity from the signal charge as the majority carrier is an N-type semiconductor region. In the following, a case where one node of the APD is set to a fixed potential will be described, but the potentials of both nodes may fluctuate.

[0012] In this specification, when the term "impurity concentration" is used simply, it means the net impurity concentration minus the amount compensated by the impurity of the opposite conductivity type. In other words, "impurity concentration" refers to the NET doping concentration. A region where the P-type doped impurity concentration is higher than the N-type doped impurity concentration is a P-type semiconductor region. Conversely, a region where the N-type doped impurity concentration is higher than the P-type doped impurity concentration is an N-type semiconductor region.

[0013] In this specification, the term "planar view" refers to a view from a direction perpendicular to the surface of the semiconductor layer opposite to the light incident surface described below. Also, the term "cross section" refers to a surface in a direction perpendicular to the surface of the semiconductor layer opposite to the light incident surface. Note that, when the light incident surface of the semiconductor layer is a rough surface when viewed microscopically, the planar view is defined based on the light incident surface of the semiconductor layer when viewed macroscopically.

[0014] The semiconductor layer 300 described later has a first surface and a second surface that faces the first surface and on which light is incident. In this specification, the depth direction is the direction from the first surface of the semiconductor layer 300 on which the APD is arranged to the second surface. Hereinafter, the "first surface" may be referred to as the "front surface" and the "second surface" may be referred to as the "back surface." The direction from a predetermined position on the semiconductor layer 300 toward the back surface of the semiconductor layer 300 may be expressed as "deep." Also, the direction from a predetermined position on the semiconductor layer 300 toward the front surface of the semiconductor layer 300 may be expressed as "shallow."

[0015] First, a configuration common to each embodiment will be described with reference to FIGS. 1 to 5. FIG.

[0016] FIG. 1 is a diagram showing the configuration of a stacked photoelectric conversion device 100. The photoelectric conversion device 100 is configured by stacking and electrically connecting two substrates, a sensor substrate 11 and a circuit substrate 21. The sensor substrate 11 has a first semiconductor layer (semiconductor layer 300) having a photoelectric conversion element 102 described later, and a first wiring structure. The circuit substrate 21 has a second semiconductor layer having circuits such as a signal processing portion 103 described later, and a second wiring structure. The photoelectric conversion device 100 is configured by stacking the second semiconductor layer, the second wiring structure, the first wiring structure, and the first semiconductor layer in this order. The photoelectric conversion device described in each embodiment is a back-illuminated photoelectric conversion device in which light is incident from the second surface and a circuit substrate is disposed on the first surface.

[0017] In the following, the sensor substrate 11 and the circuit substrate 21 will be described as diced chips, but are not limited to chips. For example, each substrate may be a wafer. Also, each substrate may be stacked in a wafer state and then diced, or each chip may be stacked and bonded after being chipped from the wafer state.

[0018] A pixel region 12 is disposed on the sensor substrate 11, and a circuit region 22 that processes signals detected in the pixel region 12 is disposed on the circuit substrate 21.

[0019] 2 is a diagram showing an example of the arrangement of the sensor substrate 11. Pixels 101, each having a photoelectric conversion element 102 including an APD, are arranged in a two-dimensional array in a plan view to form a pixel region 12.

[0020] The pixel 101 is typically a pixel for forming an image, but when used for TOF (Time of Flight), it does not necessarily have to form an image. In other words, the pixel 101 may be a pixel for measuring the time when light arrives and the amount of light.

[0021] 3 is a configuration diagram of the circuit board 21. It has a signal processing unit 103 that processes electric charges photoelectrically converted by the photoelectric conversion element 102 in FIG. 2, a readout circuit 112, a control pulse generating unit 115, a horizontal scanning circuit unit 111, a signal line 113, and a vertical scanning circuit unit 110.

[0022] The photoelectric conversion element 102 in FIG. 2 and the signal processing unit 103 in FIG. 3 are electrically connected via connection wiring provided for each pixel.

[0023] The vertical scanning circuit section 110 receives a control pulse supplied from a control pulse generating section 115 and supplies the control pulse to each pixel. The vertical scanning circuit section 110 uses logic circuits such as a shift register and an address decoder.

[0024] The signal output from the photoelectric conversion element 102 of the pixel is processed by a signal processing unit 103. The signal processing unit 103 is provided with a counter, a memory, etc., and digital values ​​are held in the memory.

[0025] The horizontal scanning circuit unit 111 inputs a control pulse for sequentially selecting each column to the signal processing unit 103 in order to read out the signal from the memory of each pixel in which the digital signal is held.

[0026] A signal is output to the signal line 113 from the signal processing unit 103 of the pixel selected by the vertical scanning circuit unit 110 for the selected column.

[0027] The signal output to the signal line 113 is output via an output circuit 114 to a recording unit or a signal processing unit outside the photoelectric conversion device 100 .

[0028] 2, the photoelectric conversion elements in the pixel region may be arranged one-dimensionally. The function of the signal processing unit does not necessarily need to be provided for each of the photoelectric conversion elements, and for example, one signal processing unit may be shared by a plurality of photoelectric conversion elements to perform signal processing sequentially.

[0029] 2 and 3, a plurality of signal processing units 103 are arranged in a region overlapping the pixel region 12 in a planar view. A vertical scanning circuit unit 110, a horizontal scanning circuit unit 111, a readout circuit 112, an output circuit 114, and a control pulse generating unit 115 are arranged so as to overlap between an end of the sensor substrate 11 and an end of the pixel region 12 in a planar view. In other words, the sensor substrate 11 has the pixel region 12 and a non-pixel region arranged around the pixel region 12. A vertical scanning circuit unit 110, a horizontal scanning circuit unit 111, a readout circuit 112, an output circuit 114, and a control pulse generating unit 115 are arranged in a region overlapping the non-pixel region in a planar view.

[0030] FIG. 4 is an example of a block diagram including the equivalent circuits of FIG. 2 and FIG.

[0031] In FIG. 2, a photoelectric conversion element 102 having an APD 201 is provided on a sensor substrate 11, and other members are provided on a circuit substrate 21.

[0032] The APD 201 generates charge pairs according to the incident light by photoelectric conversion. A voltage VL (first voltage) is supplied to the anode of the APD 201. A voltage VH (second voltage) higher than the voltage VL supplied to the anode is supplied to the cathode of the APD 201. A reverse bias voltage that causes the APD 201 to perform avalanche multiplication is supplied to the anode and cathode. With such a voltage supplied, the charges generated by the incident light undergo avalanche multiplication, generating an avalanche current.

[0033] When a reverse bias voltage is supplied, there are two modes: a Geiger mode in which the potential difference between the anode and cathode is greater than the breakdown voltage, and a linear mode in which the potential difference between the anode and cathode is close to or less than the breakdown voltage.

[0034] An APD operated in the Geiger mode is called a SPAD (single photon avalanche diode). For example, the voltage VL (first voltage) is −30 V, and the voltage VH (second voltage) is 1 V. The APD 201 may be operated in either the linear mode or the Geiger mode.

[0035] The quench element 202 is connected to a power supply that supplies a voltage VH and the APD 201. The quench element 202 functions as a load circuit (quench circuit) during signal multiplication by avalanche multiplication, and has a function of suppressing avalanche multiplication by suppressing the voltage supplied to the APD 201 (quench operation). The quench element 202 also has a function of returning the voltage supplied to the APD 201 to the voltage VH by flowing a current equivalent to the voltage drop caused by the quench operation (recharge operation).

[0036] The signal processing section 103 has a waveform shaping section 210, a counter circuit 211, and a selection circuit 212. In this specification, it is sufficient that the signal processing section 103 has any one of the waveform shaping section 210, the counter circuit 211, and the selection circuit 212.

[0037] The waveform shaping unit 210 shapes the potential change of the cathode of the APD 201 obtained when a photon is detected, and outputs a pulse signal. For example, an inverter circuit is used as the waveform shaping unit 210. Although an example in which one inverter is used as the waveform shaping unit 210 is shown in Fig. 4, a circuit in which a plurality of inverters are connected in series may be used, or another circuit having a waveform shaping effect may be used.

[0038] The counter circuit 211 counts the pulse signal output from the waveform shaping unit 210 and holds the count value. When a control pulse pRES is supplied via a drive line 213, the signal held in the counter circuit 211 is reset.

[0039] A control pulse pSEL is supplied to the selection circuit 212 from the vertical scanning circuit unit 110 in Fig. 3 via a drive line 214 (not shown in Fig. 3) in Fig. 4, and switches between electrical connection and non-connection between the counter circuit 211 and the signal line 113. The selection circuit 212 includes, for example, a buffer circuit for outputting a signal.

[0040] The electrical connection may be switched by disposing a switch such as a transistor between the quench element 202 and the APD 201 or between the photoelectric conversion element 102 and the signal processing unit 103. Similarly, the supply of the voltage VH or the voltage VL to the photoelectric conversion element 102 may be electrically switched using a switch such as a transistor.

[0041] In this embodiment, a configuration using the counter circuit 211 has been shown. However, instead of the counter circuit 211, the photoelectric conversion device 100 may be configured to acquire the pulse detection timing using a time-to-digital converter (hereinafter, TDC) and a memory. In this case, the generation timing of the pulse signal output from the waveform shaping unit 210 is converted into a digital signal by the TDC. To measure the timing of the pulse signal, a control pulse pREF (reference signal) is supplied to the TDC from the vertical scanning circuit unit 110 in FIG. 3 via a drive line. The TDC acquires, as a digital signal, a signal obtained by converting the input timing of the signal output from each pixel via the waveform shaping unit 210 into a relative time based on the control pulse pREF.

[0042] FIG. 5 is a diagram showing a schematic diagram of the relationship between the operation of an APD and an output signal.

[0043] Fig. 5(a) is a diagram in which the APD 201, the quench element 202, and the waveform shaping unit 210 of Fig. 4 are extracted. Here, the input side of the waveform shaping unit 210 is node A, and the output side is node B. Fig. 5(b) shows the waveform change of node A in Fig. 5(a), and Fig. 5(c) shows the waveform change of node B in Fig. 5(a).

[0044] Between time t0 and time t1, a potential difference of VH-VL is applied to the APD 201 in FIG. 5(a). When a photon is incident on the APD 201 at time t1, avalanche multiplication occurs in the APD 201, an avalanche multiplication current flows through the quench element 202, and the voltage at nodeA drops. When the voltage drop amount becomes larger and the potential difference applied to the APD 201 becomes smaller, the avalanche multiplication of the APD 201 stops as at time t2, and the voltage level at nodeA does not drop by more than a certain value. After that, between time t2 and time t3, a current that compensates for the voltage drop from the voltage VL flows through nodeA, and at time t3, nodeA is stabilized to the original potential level. At this time, the part of the output waveform at nodeA that exceeds a certain threshold is shaped by the waveform shaping unit 210 and output as a signal at nodeB.

[0045] The arrangement of the signal lines 113, the readout circuits 112, and the output circuits 114 is not limited to that shown in Fig. 3. For example, the signal lines 113 may be arranged to extend in the row direction, and the readout circuits 112 may be arranged at the ends of the signal lines 113.

[0046] The photoelectric conversion devices of the respective embodiments will be described below.

[0047] (First embodiment) The photoelectric conversion device according to the first embodiment will be described with reference to FIGS.

[0048] 6 and 7 show comparative examples of photoelectric conversion devices having pixels provided with a reflective metal structure made of cathode wiring 301 and anode wiring 302. The pixel on the left in Fig. 6 has one microlens 323 arranged for one APD, while the pixel on the right in Fig. 6 has two APDs that share one microlens 323. In other words, in the pixel on the right in Fig. 6, the microlens 323 is arranged in common to the first avalanche photodiode and the second avalanche photodiode.

[0049] As shown in FIG. 6, the photoelectric conversion device according to this comparative example is a back-illuminated photoelectric conversion device, and a wiring layer in which wiring such as a cathode wiring 301 and an anode wiring 302 is arranged is provided on the front side of the semiconductor layer 300. The cathode wiring 301 is a wiring that supplies a voltage to one terminal (cathode terminal) of the APD, and the anode wiring 302 is a wiring that supplies a voltage to the other terminal (anode terminal) of the APD. FIG. 7 shows the positional relationship of the wiring in a plan view seen from the back side. FIG. 7 does not necessarily show only structures that exist on the same plane. In the photoelectric conversion device according to the comparative example, both one APD arranged under one microlens 323 and two APDs sharing one microlens 323 have cathode wiring 301 and anode wiring 302 that are symmetrical with respect to the cathode contact 303. The distance d1 between the anode wirings 302 of each APD is constant regardless of whether the microlens 323 is shared or not.

[0050] The effect of improving the sensitivity of the photoelectric conversion device by the reflective metal structure will be described using the pixel on the left in FIG. 6. Light that enters the semiconductor layer 300 is photoelectrically converted in the semiconductor layer 300. A part of the incident light reaches the wiring layer without being photoelectrically converted, and is reflected by the cathode wiring 301 and the anode wiring 302 arranged in the wiring layer, and returns to the semiconductor layer 300. Even light that would not normally penetrate the wiring layer and be photoelectrically converted due to this reflection is photoelectrically converted in the wiring layer 300. In other words, the sensitivity of the photoelectric conversion device can be improved by providing a reflective metal structure. In particular, light with a long wavelength that is difficult to be photoelectrically converted is more likely to penetrate deep into the semiconductor layer 300, so the effect of improving the sensitivity by this reflective metal structure is greater.

[0051] As shown in the pixel on the right in Fig. 6, in a configuration in which one microlens 323 is shared by multiple APDs, the position at which incident light is focused by microlens 323 is shifted from the center position of each APD. For example, in the configuration shown in Fig. 6, light is focused in the area between the APDs that share the microlens. Therefore, in the conventional pixel structure, incident light passes through the wiring layer without being reflected by the metal wiring in the wiring layer, and the sensitivity improvement effect of the reflective metal cannot be fully obtained.

[0052] The structure of the photoelectric conversion device according to this embodiment in a plan view will be described with reference to Fig. 8. Fig. 8 is a schematic plan view showing one pixel having two APDs among the multiple pixels included in the pixel region 12, and illustrates each structure necessary for explaining the positional relationship in a plan view as seen from the back surface side. Therefore, it does not necessarily illustrate only structures that exist on the same plane.

[0053] For example, the anode wiring 302 overlaps the separation layer 324 when viewed in a plan view from the back surface side of the semiconductor layer 300, and therefore the separation layer 324 is shown in front in the plan view. The cathode wiring 302 is continuously disposed in a portion overlapping with the separation portion 324 when viewed in a plan view from the back surface side, forming a mesh-like configuration. In order to particularly explain the arrangement of the cathode wiring 301 and the anode wiring 302, some of the other structures are omitted in Fig. 8.

[0054] 8, each pixel 101 includes at least one APD, and in this embodiment, a configuration including two APDs is shown. A pixel isolation layer 324 is disposed between the pixels or between the APDs. Note that, in the following description, a configuration in which the pixel 101 is configured with two APDs will be described, but the number of APDs included in the pixel 101 is not limited to this.

[0055] A microlens 323 is arranged on the light incident surface side of the pixel. Figure 8 shows an example in which the microlenses 323 are arranged on two APDs in a 1 row x 2 column arrangement. By configuring the microlenses to be shared by multiple APDs in this way, it is possible to capture the light beam that has passed through a certain area of ​​the objective lens with each APD, and to detect the amount of defocus and its direction from the output difference between the APD group below the microlens 323. This realizes image plane phase difference autofocus that enables both imaging and phase difference detection.

[0056] Next, the details of each semiconductor region arranged in the semiconductor layer 300 will be described from the cross sections taken along the lines AA' and BB' in Fig. 8 with reference to Fig. 9 and Fig. 10. Fig. 9 is a schematic cross-sectional view taken along the line AA', and shows the pinning film 321, the planarization layer 322, and the microlens layer 323 formed on the rear surface side of the substrate in addition to the semiconductor layer 300. Furthermore, it shows a part of the cathode contact 303 and the cathode wiring 301, and the anode contact 304 and the anode wiring 302 formed on the front surface side of the substrate and connected to the semiconductor layer 300.

[0057] 9, the APD is arranged with a first conductive type first semiconductor region 311 and a second semiconductor region 312, and the first semiconductor region 311 and the second semiconductor region 312 form a PN junction. When a predetermined reverse bias voltage is applied to the first semiconductor region 311 and the second semiconductor region 312, electrons accelerated by an electric field cause avalanche multiplication. In addition, a fifth semiconductor region 315 (e.g., a P epitaxial layer or an N epitaxial layer) with a low impurity concentration is provided in a region on the back surface side of the second semiconductor region 312 in the semiconductor layer 300. Therefore, the depletion layer is configured to spread toward the back surface side of the semiconductor layer 300 by applying a reverse bias voltage.

[0058] The seventh semiconductor region 317 is arranged so that at least a part of it contacts the end of the first semiconductor region 311 in order to suppress edge breakdown, which occurs at a low voltage in an end of the first semiconductor region 311 due to a strong electric field being applied to that region. Many dangling bonds, which are unbonded bonds of silicon, exist near the interface between the pixel separation layer 324 and the semiconductor layer 300, and dark current occurs through these defect levels. In order to suppress the generation of this dark current, the third semiconductor region 313 of the second conductivity type is arranged so as to contact the pixel separation portion 324. For the same reason, the fourth semiconductor region of the second conductivity type is arranged on the back side of the semiconductor layer 300. In addition, the pinning film 321 is formed on the back side interface of the semiconductor layer 300 to induce holes on the semiconductor layer 300 side, thereby suppressing dark current.

[0059] On the wiring layer on the surface side of the semiconductor layer 300, a cathode wiring 301 and an anode wiring 302 are arranged. Regarding the above two types of wirings, the light incident on the semiconductor layer 300 is reflected again into the semiconductor layer 300, so that the incident light is efficiently photoelectrically converted.

[0060] The pixel cross-sectional structure in the cross-section of the line segment BB' shown in FIG. 8 in FIG. 10 will be described. FIG. 9 shows a cross-section in the sharing direction of the microlenses 323. The light condensing position of the microlenses 323 is not the center position of each APD, but the position between the APDs sharing the microlenses 323. In such a configuration, in order to reflect the incident light with the anode wiring 302, it is preferable to widen the width of the anode wiring 302 arranged between the APDs sharing the microlenses 323. In other words, arranging the gap between the cathode wiring 301 and the anode wiring 302, which are separated to ensure withstand voltage, at a position away from the light condensing position of the microlenses 323 is a desirable arrangement from the viewpoint of improving sensitivity.

[0061] As shown in FIG. 9, the width d1 corresponding to the side of the anode wiring 302 that does not share the microlenses 323 and the width d2 corresponding to the side that shares the microlenses 323 satisfy d1 < d2. In the first direction in which the APDs are arranged, it can also be said that the width of the first wiring (anode wiring) arranged between the second wirings (cathode wirings) of the APDs is wider than the width of the first wiring arranged between the plurality of pixels. By adopting a configuration that satisfies the above conditions, it is possible to provide a photoelectric conversion device with improved sensitivity in a pixel configuration in which a plurality of APDs share the microlenses 323.

[0062] Note that the pixels in which one microlens 323 is arranged on one APD shown on the left in FIGS. 8 to 10 may or may not be included in the photoelectric conversion device. The effects of the present application can be obtained if the pixels have a configuration in which two APDs shown on the right in FIGS. 8 to 10 share one microlens 323.

[0063] (Second Embodiment) The second embodiment will be described with reference to FIGS. 11 and 12. In this embodiment, the number of APDs sharing the microlens 323 is different from that in the first embodiment. FIG. 12 shows a cross section of the photoelectric conversion device having the planar structure shown in FIG. 11 along the line segment CC'.

[0064] Note that, similar to FIG. 8, FIG. 11 is not necessarily a plan view showing only the structure existing in the same plane. For example, since the anode wiring 302 overlaps the separation layer 324 when viewed in plan from the back side of the semiconductor layer 300, the separation layer 324 is shown in the front in FIG. 8. The cathode wiring 302 is also continuously arranged at a position overlapping the separation portion 324 when viewed in plan from the back side, forming a mesh-like configuration.

[0065] As shown in FIGS. 11 and 12, the microlens 323 is shared by four APDs arranged in a 2-row × 2-column manner. In other words, in the right pixel of FIG. 11, the microlens 323 is commonly arranged for the first avalanche photodiode, the second avalanche photodiode, the third avalanche photodiode, and the fourth avalanche photodiode. In each APD, the width d1 of the anode wiring 302 on the side not adjacent to the other APD sharing the microlens 323 and the width d2 of the anode wiring 302 on the side adjacent to the other APD not sharing the microlens 323 satisfy d1 < d2.

[0066] Even when the microlens 323 is shared by the APDs arranged in a 2-row × 2-column manner, the condensing position of the microlens 323 is not at the central position of each APD but at a position between the four APDs. Therefore, by setting the width of the cathode wiring 301 as d1 < d2 and arranging the cathode wiring 301 at the orthographic projection portion near the center of the microlens, the incident light can be reflected more efficiently, and the sensitivity improvement effect can be obtained.

[0067] Furthermore, by configuring the four APDs to share the microlens 323, the direction of phase difference detection can be made different for each pixel. That is, in the first embodiment, only phase difference detection in a first direction is possible, but in this embodiment, phase difference detection in a second direction perpendicular to the first direction is also possible. In the photoelectric conversion device according to this embodiment, phase difference detection is possible in more directions than in the photoelectric conversion device according to the first embodiment, and high-precision autofocusing is possible for more subjects.

[0068] Third embodiment The third embodiment will be described with reference to Fig. 13. This embodiment differs from the first and second embodiments in that not only the cathode wiring 301 but also the position of the first semiconductor region 311 is indicated.

[0069] When the avalanche region that multiplies the signal charge has regions where the cathode wiring 301 overlaps in a plan view and regions where it does not, the effect of the electric field from the cathode wiring 301 on the avalanche region differs in each region. This makes it difficult to form a uniform electric field in the avalanche region, which may result in increased noise or reduced sensitivity.

[0070] 13, for each APD sharing a microlens 323, the first semiconductor region 311 is disposed at a position that is included in the cathode wiring 301 in a planar view. In other words, the entire surface of the first semiconductor region 311 is covered by the cathode wiring 301 in a planar view. This allows the cathode wiring 301 to be disposed at any position in the avalanche region, making it possible to uniform the effect of the electric field from the cathode wiring 301 on the avalanche region and suppressing deterioration of noise and deterioration of sensitivity.

[0071] Furthermore, by arranging the peripheral part of the cathode wiring 301 at an equal distance from the peripheral part of the first semiconductor region 311, the influence from the cathode wiring 301 within the avalanche region can be made more uniform. Therefore, as shown in FIG. 13, a structure in which the peripheral part of the first semiconductor region 311 and the peripheral part of the cathode wiring 301 are located at an equal distance is more desirable. In other words, in a plan view, a structure in which the shape of the first semiconductor region 311 and the shape of the cathode wiring 301 are similar is desirable. Also in this embodiment, as shown in FIG. 13, by satisfying d1 < d2 with respect to the width of the cathode wiring 301, a sensitivity improvement effect can be obtained.

[0072] (Fourth Embodiment) This embodiment will be described with reference to FIGS. 14 and 15. In this embodiment, the arrangement of the anode wiring 302 is different from that in the first to third embodiments.

[0073] In the photoelectric conversion devices shown in the first to third embodiments, the aim was to improve the sensitivity by a suitable reflective metal structure in pixels where a plurality of APDs share the microlens 323. On the other hand, the photoelectric conversion device shown in this embodiment aims to suppress crosstalk between pixels sharing the microlens 323. This is because when a structure that reflects light to improve sensitivity by providing a reflective metal structure on the surface side of the semiconductor layer 300 is applied to pixels where a plurality of APDs share the microlens 323, there is a concern that crosstalk may occur between the APDs due to the reflected light.

[0074] The configuration of this embodiment will be described with reference to FIG. 14. As shown in FIG. 14, a plurality of APDs share a microlens 323, and the anode wiring 302 is not disposed between the APDs of pixels that share the microlens 323. Note that, like FIG. 8 and FIG. 11, FIG. 14 is not necessarily a plan view illustrating only structures that exist on the same plane. For example, the anode wiring 302 overlaps with the separation layer 324 when viewed in a plan view from the back surface side of the semiconductor layer 300, and therefore the separation layer 324 is shown in front in FIG. 14. The cathode wiring 302 is continuously disposed in a portion that overlaps with the separation portion 324 when viewed in a plan view from the back surface side, forming a mesh-like configuration.

[0075] Fig. 15 shows a cross-sectional structure along line segment DD' of a photoelectric conversion device having the planar structure shown in Fig. 14. Anode wiring 302 is provided between pixels that do not share microlens 323 and pixels that share microlens 323, but anode wiring 302 is not provided between the APDs of pixels that share microlens 323.

[0076] In such a configuration, incident light penetrates into the wiring layer without being reflected by the anode wiring 302. This prevents light reflected by the anode wiring 302 from entering the APD that shares the microlens 323, thereby reducing crosstalk.

[0077] Fifth embodiment The present embodiment will be described with a focus on the differences from the fourth embodiment, with reference to Figures 16 and 17. The present embodiment also aims to reduce crosstalk between APDs that share a microlens 323, and differs from the fourth embodiment in the arrangement of the cathode wiring 301.

[0078] The arrangement of the anode wiring 302 and the cathode wiring 301 in the photoelectric conversion device according to this embodiment is shown in FIG. 16. The anode wiring 302 is not provided between the APDs of the pixels sharing the microlens 323, similar to the photoelectric conversion device according to the fourth embodiment. Further, regarding the distance d1 between the cathode wirings 301 between the APDs sharing the microlens 323 and the distance d2 between the cathode wirings 301 between the APDs not sharing the microlens 323, d1 < d2. Note that, similar to FIGS. 8, 11, and 14, FIG. 16 is not a plan view showing only the structure existing in the same plane.

[0079] FIG. 17 shows the cross-sectional structure of the photoelectric conversion device having the planar structure described in FIG. 16 along the line segment EE'. The cathode wiring 301 arranged in the wiring layer is formed eccentrically in a direction away from the pixels sharing the microlens 323. It can also be said that the center of gravity of the cathode wiring 301 is farther from the opposing sides of the APDs than the center of each APD. Alternatively, it can also be said that the distance from the first side of the cathode wiring to the side where the APDs face each other is farther than the distance from the second side of the cathode wiring facing the first side to the side of the anode wiring facing the second side of the cathode wiring. With such a configuration, compared with the configuration described in the fourth embodiment, the component of the incident light condensed between the APDs sharing the microlens 323 that enters the wiring layer increases. Therefore, crosstalk between the pixels sharing the microlens 323 due to reflection of the anode wiring 302 can be further suppressed.

[0080] (Sixth Embodiment) This embodiment will be described with reference to FIGS. 18 and 19. This embodiment also aims to reduce crosstalk between the APDs sharing the microlens 323, and the arrangement of the cathode wiring 301 is different from that of the fourth and fifth embodiments.

[0081] 18 shows the arrangement of the anode wiring 302 and the cathode wiring 301 in the photoelectric conversion device according to the present embodiment. As in the photoelectric conversion device according to the fourth embodiment, the anode wiring 302 is not provided between the APDs of pixels that share the microlens 323. Furthermore, with respect to the distance d1 between the cathode wirings 301 between the APDs that share the microlens 323 and the distance d2 between the cathode wirings 301 between the APDs that do not share the microlens 323, d1>d2. Note that, like FIGS. 8, 11, 14, and 18, FIG. 18 is not necessarily a plan view illustrating only structures that exist on the same plane.

[0082] Fig. 19 shows a cross-sectional structure of a photoelectric conversion device having the planar structure shown in Fig. 18 taken along line segment FF'. The cathode wiring 301 arranged in the wiring layer is formed eccentrically toward the pixel side that shares the microlens 323. With this configuration, incident light focused between the APDs that share the microlens 323 is more easily reflected than in the fourth and fifth embodiments. With this configuration, crosstalk between the APDs that share the microlens 323 due to reflection at the anode wiring 302 is suppressed, while the cathode wiring 301 provides an effect of improving sensitivity.

[0083] Seventh embodiment The photoelectric conversion system according to this embodiment will be described with reference to Fig. 20. Fig. 20 is a block diagram showing a schematic configuration of the photoelectric conversion system according to this embodiment.

[0084] The photoelectric conversion devices described in the first to fourth embodiments are applicable to various photoelectric conversion systems. Examples of the applicable photoelectric conversion systems include digital still cameras, digital camcorders, security cameras, copiers, fax machines, mobile phones, car-mounted cameras, and observation satellites. Camera modules equipped with an optical system such as a lens and an imaging device are also included in the photoelectric conversion systems. FIG. 20 illustrates a block diagram of a digital still camera as an example of these.

[0085] The photoelectric conversion system illustrated in FIG. 20 includes an image pickup device 1004, which is an example of a photoelectric conversion device, and a lens 1002 that forms an optical image of a subject on the image pickup device 1004. The system further includes an aperture 1003 for varying the amount of light passing through the lens 1002, and a barrier 1001 for protecting the lens 1002. The lens 1002 and the aperture 1003 are an optical system that focuses light on the image pickup device 1004. The image pickup device 1004 is a photoelectric conversion device according to any one of the above embodiments, and converts an optical image formed by the lens 1002 into an electrical signal. The photoelectric conversion system also includes a signal processing unit 1007 that is an image generating unit that generates an image by processing an output signal output from the image pickup device 1004. The signal processing unit 1007 performs various corrections and compressions as necessary to output image data. The signal processing unit 1007 may be formed on a semiconductor substrate on which the image pickup device 1004 is provided, or may be formed on a semiconductor substrate separate from the image pickup device 1004.

[0086] The photoelectric conversion system further includes a memory unit 1010 for temporarily storing image data, and an external interface unit (external I / F unit) 1013 for communicating with an external computer or the like. The photoelectric conversion system further includes a recording medium 1012 such as a semiconductor memory for recording or reading out imaging data, and a recording medium control interface unit (recording medium control I / F unit) 1011 for recording or reading out data on the recording medium 1012. The recording medium 1012 may be built into the photoelectric conversion system, or may be removable.

[0087] The photoelectric conversion system further includes an overall control / calculation unit 1009 that performs various calculations and controls the entire digital still camera, and a timing generation unit 1008 that outputs various timing signals to the image capture device 1004 and the signal processing unit 1007. Here, the timing signals and the like may be input from outside, and the photoelectric conversion system only needs to include at least the image capture device 1004 and the signal processing unit 1007 that processes the output signal output from the image capture device 1004.

[0088] The imaging device 1004 outputs an imaging signal to a signal processing unit 1007. The signal processing unit 1007 performs predetermined signal processing on the imaging signal output from the imaging device 1004, and outputs image data. The signal processing unit 1007 generates an image using the imaging signal.

[0089] In this way, according to this embodiment, it is possible to realize a photoelectric conversion system to which the photoelectric conversion device (imaging device) according to any one of the above embodiments is applied.

[0090] Eighth embodiment The photoelectric conversion system and the moving object of this embodiment will be described with reference to Fig. 21. Fig. 21 is a diagram showing the configuration of the photoelectric conversion system and the moving object of this embodiment.

[0091] FIG. 21(a) shows an example of a photoelectric conversion system related to an in-vehicle camera. The photoelectric conversion system 1300 has an imaging device 1310. The imaging device 1310 is the photoelectric conversion device described in any of the above embodiments. The photoelectric conversion system 1300 has an image processing unit 1312 that performs image processing on a plurality of image data acquired by the imaging device 1310, and a parallax acquisition unit 1314 that calculates parallax (phase difference of parallax images) from the plurality of image data acquired by the photoelectric conversion system 1300. The photoelectric conversion system 1300 also has a distance acquisition unit 1316 that calculates a distance to an object based on the calculated parallax, and a collision determination unit 1318 that determines whether or not there is a possibility of collision based on the calculated distance. Here, the parallax acquisition unit 1314 and the distance acquisition unit 1316 are examples of distance information acquisition means that acquire distance information to an object. That is, the distance information is information on the parallax, the defocus amount, the distance to the object, and the like. The collision determination unit 1318 may determine the possibility of a collision using any of these pieces of distance information. The distance information acquisition means may be realized by dedicated hardware, or may be realized by a software module. In addition, it may be realized by a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or the like, or may be realized by a combination of these.

[0092] The photoelectric conversion system 1300 is connected to a vehicle information acquisition device 1320, and can acquire vehicle information such as vehicle speed, yaw rate, and steering angle. The photoelectric conversion system 1300 is also connected to a control ECU 1330, which is a control unit that outputs a control signal to generate a braking force for the vehicle based on the judgment result of the collision judgment unit 1318. The photoelectric conversion system 1300 is also connected to an alarm device 1340 that issues an alarm to the driver based on the judgment result of the collision judgment unit 1318. For example, when the judgment result of the collision judgment unit 1318 indicates that a collision is highly likely, the control ECU 1330 performs vehicle control to avoid a collision and reduce damage by applying the brakes, releasing the accelerator, suppressing engine output, etc. The alarm device 1340 warns the user by sounding an alarm, displaying alarm information on a screen of a car navigation system, etc., or vibrating a seat belt or steering wheel.

[0093] In this embodiment, the surroundings of the vehicle, for example, the front or rear, are imaged by the photoelectric conversion system 1300. Fig. 21(b) shows a photoelectric conversion system for imaging the area in front of the vehicle (imaging range 1350). A vehicle information acquisition device 1320 sends instructions to the photoelectric conversion system 1300 or the imaging device 1310. This configuration can further improve the accuracy of distance measurement.

[0094] Although the above describes an example of control to prevent collision with other vehicles, the present invention can also be applied to control of automatic driving by following other vehicles, control of automatic driving to prevent deviation from lanes, etc. Furthermore, the photoelectric conversion system is not limited to vehicles such as the vehicle itself, but can be applied to moving bodies (moving devices) such as ships, aircraft, and industrial robots. In addition, the present invention can be applied not only to moving bodies, but also to a wide range of devices that use object recognition, such as intelligent transport systems (ITS).

[0095] Ninth embodiment The photoelectric conversion system of this embodiment will be described with reference to Fig. 22. Fig. 22 is a block diagram showing an example of the configuration of a range image sensor which is the photoelectric conversion system of this embodiment.

[0096] 22, the distance image sensor 401 is configured to include an optical system 407, a photoelectric conversion device 408, an image processing circuit 404, a monitor 405, and a memory 406. The distance image sensor 401 can obtain a distance image according to the distance to the subject by receiving light (modulated light or pulsed light) that is projected from a light source device 409 toward the subject and reflected from the surface of the subject.

[0097] The optical system 407 is configured to have one or more lenses, and guides image light (incident light) from a subject to a photoelectric conversion device 408 , forming an image on the light receiving surface (sensor portion) of the photoelectric conversion device 408 .

[0098] As the photoelectric conversion device 408 , the photoelectric conversion device of each of the above-mentioned embodiments is applied, and a distance signal indicating a distance determined from a light reception signal output from the photoelectric conversion device 408 is supplied to the image processing circuit 404 .

[0099] The image processing circuit 404 performs image processing to construct a distance image based on the distance signal supplied from the photoelectric conversion device 408. The distance image (image data) obtained by this image processing is then supplied to a monitor 405 for display, or supplied to a memory 406 for storage (recording).

[0100] In the range image sensor 401 configured in this way, by applying the above-described photoelectric conversion device, it is possible to obtain, for example, a more accurate range image as the pixel characteristics improve.

[0101] (Tenth embodiment) The photoelectric conversion system of this embodiment will be described with reference to Fig. 23. Fig. 23 is a diagram showing an example of a schematic configuration of an endoscopic surgery system which is the photoelectric conversion system of this embodiment.

[0102] 23 shows a state in which an operator (doctor) 1131 is performing surgery on a patient 1132 on a patient bed 1133 using an endoscopic surgery system 1150. As shown in the figure, the endoscopic surgery system 1150 is composed of an endoscope 1100, a surgical tool 1110, and a cart 1134 on which various devices for endoscopic surgery are mounted.

[0103] The endoscope 1100 is composed of a lens barrel 1101, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 1132, and a camera head 1102 connected to the base end of the lens barrel 1101. In the illustrated example, the endoscope 1100 is configured as a so-called rigid lens barrel having a rigid lens barrel 1101, but the endoscope 1100 may be configured as a so-called flexible lens barrel having a flexible lens barrel.

[0104] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 1101. A light source device 1203 is connected to the endoscope 1100, and light generated by the light source device 1203 is guided to the tip of the lens barrel 1101 by a light guide extending inside the lens barrel 1101, and is irradiated via the objective lens toward an observation target in a body cavity of a patient 1132. The endoscope 1100 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0105] An optical system and a photoelectric conversion device are provided inside the camera head 1102, and reflected light (observation light) from an observation target is collected by the optical system onto the photoelectric conversion device. The observation light is photoelectrically converted by the photoelectric conversion device to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to an observation image. The photoelectric conversion device described in each of the above-mentioned embodiments can be used as the photoelectric conversion device. The image signal is transmitted to a camera control unit (CCU) 1135 as RAW data.

[0106] The CCU 1135 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and performs overall control of the operations of the endoscope 1100 and the display device 1136. Furthermore, the CCU 1135 receives an image signal from the camera head 1102, and performs various types of image processing on the image signal, such as development processing (demosaic processing), for displaying an image based on the image signal.

[0107] Under the control of the CCU 1135 , the display device 1136 displays an image based on an image signal that has been subjected to image processing by the CCU 1135 .

[0108] The light source device 1203 is composed of a light source such as an LED (Light Emitting Diode), and supplies the endoscope 1100 with irradiation light when photographing an operation site or the like.

[0109] The input device 1137 is an input interface for the endoscopic surgery system 1150. A user can input various information and instructions to the endoscopic surgery system 1150 via the input device 1137.

[0110] The treatment tool control device 1138 controls the driving of the energy treatment tool 1112 for cauterizing tissue, incising, sealing blood vessels, or the like.

[0111] The light source device 1203 that supplies irradiation light to the endoscope 1100 when photographing the surgical site can be composed of a white light source composed of, for example, an LED, a laser light source, or a combination of these. When the white light source is composed of a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, so that the white balance of the captured image can be adjusted in the light source device 1203. In this case, it is also possible to capture images corresponding to each of the RGB colors in a time-division manner by irradiating the observation target with laser light from each of the RGB laser light sources in a time-division manner and controlling the driving of the image sensor of the camera head 1102 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter to the image sensor.

[0112] Furthermore, the light source device 1203 may be controlled to change the intensity of the light it outputs at predetermined time intervals. By controlling the driving of the image sensor of the camera head 1102 in synchronization with the timing of the change in the light intensity to acquire images in a time-division manner and synthesizing the images, it is possible to generate an image with a high dynamic range that is free of so-called blocked-up shadows and blown-out highlights.

[0113] The light source device 1203 may be configured to supply light in a predetermined wavelength band corresponding to the special light observation. In the special light observation, for example, the wavelength dependency of light absorption in body tissue is utilized. Specifically, a predetermined tissue such as blood vessels on the mucous membrane surface is photographed with high contrast by irradiating light in a narrower band than the irradiation light (i.e., white light) in normal observation. Alternatively, the special light observation may be a fluorescent observation in which an image is obtained by fluorescence generated by irradiating excitation light. In the fluorescent observation, it is possible to irradiate excitation light to the body tissue and observe the fluorescence from the body tissue, or to locally inject a reagent such as indocyanine green (ICG) into the body tissue and irradiate the body tissue with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 1203 may be configured to supply narrow band light and / or excitation light corresponding to such special light observation.

[0114] (Eleventh embodiment) The photoelectric conversion system of this embodiment will be described with reference to Figs. 24(a) and (b). Fig. 24(a) describes glasses 1600 (smart glasses) which are the photoelectric conversion system of this embodiment. The glasses 1600 have a photoelectric conversion device 1602. The photoelectric conversion device 1602 is the photoelectric conversion device described in each of the above embodiments. A display device including a light-emitting device such as an OLED or LED may be provided on the rear side of the lens 1601. The photoelectric conversion device 1602 may be one or more. A combination of multiple types of photoelectric conversion devices may also be used. The arrangement position of the photoelectric conversion device 1602 is not limited to that shown in Fig. 24(a).

[0115] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the photoelectric conversion device 1602 and the display device. The control device 1603 also controls the operations of the photoelectric conversion device 1602 and the display device. The lens 1601 is formed with an optical system for focusing light on the photoelectric conversion device 1602.

[0116] FIG. 24(b) illustrates glasses 1610 (smart glasses) according to one application example. The glasses 1610 have a control device 1612, and the control device 1612 is equipped with a photoelectric conversion device corresponding to the photoelectric conversion device 1602 and a display device. The lens 1611 is formed with an optical system for projecting light emitted from the photoelectric conversion device in the control device 1612 and the display device, and an image is projected onto the lens 1611. The control device 1612 functions as a power source for supplying power to the photoelectric conversion device and the display device, and controls the operation of the photoelectric conversion device and the display device. The control device may have a line of sight detection unit that detects the line of sight of the wearer. Infrared light may be used for detecting the line of sight. The infrared light emission unit emits infrared light to the eyeball of a user gazing at a display image. An imaging unit having a light receiving element detects the reflected light of the emitted infrared light from the eyeball, thereby obtaining an image of the eyeball. By having a reduction means for reducing light from the infrared light emission unit to the display unit in a planar view, deterioration of image quality is reduced.

[0117] The gaze of the user with respect to the displayed image is detected from an image of the eyeball obtained by capturing infrared light. Any known method can be applied to gaze detection using the image of the eyeball. As an example, a gaze detection method based on a Purkinje image formed by reflection of irradiated light on the cornea can be used.

[0118] More specifically, the gaze detection process is performed based on the pupil-corneal reflex method. Using the pupil-corneal reflex method, a gaze vector that indicates the direction (rotation angle) of the eyeball is calculated based on the pupil image and the Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0119] The display device of this embodiment may have a photoelectric conversion device having a light receiving element, and may control the display image of the display device based on information about the user's line of sight from the photoelectric conversion device.

[0120] Specifically, the display device determines a first field of view area to which the user gazes and a second field of view area other than the first field of view area based on the line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be received from an external control device. In the display area of ​​the display device, the display resolution of the first field of view area may be controlled to be higher than the display resolution of the second field of view area. In other words, the resolution of the second field of view area may be lower than that of the first field of view area.

[0121] The display area may have a first display area and a second display area different from the first display area, and a high priority area may be determined from the first display area and the second display area based on line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be determined by an external control device and received. The resolution of the high priority area may be controlled to be higher than the resolution of areas other than the high priority area. In other words, the resolution of an area with a relatively low priority may be lowered.

[0122] AI may be used to determine the first field of view area and areas with high priority. The AI ​​may be a model configured to estimate the angle of the line of sight and the distance to an object at the end of the line of sight from the image of the eyeball, using as teacher data an image of the eyeball and the direction in which the eyeball in the image was actually looking. The AI ​​program may be included in the display device, the photoelectric conversion device, or an external device. If included in the external device, it is transmitted to the display device via communication.

[0123] When display control is performed based on visual recognition detection, the present invention is preferably applicable to smart glasses further including a photoelectric conversion device for capturing an image of the outside world. The smart glasses can display captured outside information in real time.

[0124] [Modified embodiment] The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, an example in which a part of the configuration of any of the embodiments is added to another embodiment, or an example in which a part of the configuration of another embodiment is replaced with another embodiment is also included in the embodiments of the present invention.

[0125] Further, the photoelectric conversion systems shown in the seventh and eighth embodiments are examples of photoelectric conversion systems to which the photoelectric conversion device can be applied, and the photoelectric conversion systems to which the photoelectric conversion device of the present invention can be applied are not limited to the configurations shown in Fig. 20 to Fig. 24. The same applies to the ToF system shown in the ninth embodiment, the endoscope shown in the tenth embodiment, and the smart glasses shown in the eleventh embodiment.

[0126] It should be noted that the above-mentioned embodiments are merely examples of the implementation of the present invention, and the technical scope of the present invention should not be interpreted as being limited by these embodiments. In other words, the present invention can be implemented in various forms without departing from its technical concept or main features.

[0127] The present disclosure has the following configuration.

[0128] (Configuration 1) A photoelectric conversion device having a plurality of pixels, the photoelectric conversion device comprising: a first surface and a second surface opposite to the first surface; a semiconductor layer having a plurality of avalanche photodiodes; a first wiring; and a second wiring; and a wiring layer provided on the side of the first surface, wherein each of the plurality of pixels includes a first avalanche photodiode, a second avalanche photodiode adjacent to the first avalanche photodiode in a first direction, and a microlens commonly disposed for the first avalanche photodiode and the second avalanche photodiode and provided on the side of the second surface, and wherein the width of the first wiring disposed between the second wiring of the first avalanche photodiode and the second wiring of the second avalanche photodiode is wider in the first direction than the width of the first wiring disposed between the plurality of pixels.

[0129] (Configuration 2) 2. The photoelectric conversion device according to configuration 1, wherein the first wiring supplies a voltage to one terminal of the avalanche photodiode, and the second wiring supplies a voltage to the other terminal of the avalanche photodiode.

[0130] (Configuration 3) the first avalanche photodiode includes, in order from the first surface side, a first semiconductor region of a first conductivity type, and a second semiconductor region of a second conductivity type forming a PN junction between the first semiconductor region and the first semiconductor region; 3. The photoelectric conversion device according to claim 1, wherein, in a plan view, the second wiring of the first avalanche photodiode overlaps with the first semiconductor region of the first avalanche photodiode.

[0131] (Configuration 4) The photoelectric conversion device described in configuration 3, characterized in that, in a planar view, the shape of the first semiconductor region of the first avalanche photodiode and the shape of the second wiring of the first avalanche photodiode are similar to each other.

[0132] (Configuration 5) The photoelectric conversion device described in any one of configurations 1 to 4, characterized in that each of the plurality of pixels includes a third avalanche photodiode and a fourth avalanche photodiode, and the third avalanche photodiode and the fourth avalanche photodiode share the microlens with the first avalanche photodiode and the second avalanche photodiode.

[0133] (Configuration 6) 6. A photoelectric conversion system comprising: a photoelectric conversion device according to any one of configurations 1 to 5; and a signal processing unit that generates an image using a signal output from the photoelectric conversion device.

[0134] (Configuration 7) A moving object including the photoelectric conversion device according to any one of configurations 1 to 5, further comprising a control unit that controls the movement of the moving object using a signal output by the photoelectric conversion device.

[0135] (Configuration 8) A photoelectric conversion device having a plurality of pixels, the photoelectric conversion device comprising: a first surface; a second surface opposite to the first surface; a semiconductor layer having a plurality of avalanche photodiodes; a first wiring; and a second wiring; and a wiring layer provided on the side of the first surface, wherein each of the plurality of pixels includes a first avalanche photodiode, a second avalanche photodiode adjacent to the first avalanche photodiode in a first direction, and a microlens commonly disposed for the first avalanche photodiode and the second avalanche photodiode and provided on the side of the second surface, the photoelectric conversion device being characterized in that the first wiring is not provided between the second wiring of the first avalanche photodiode and the second wiring of the second avalanche photodiode in the first direction.

[0136] (Configuration 9) 2. The photoelectric conversion device according to configuration 1, wherein the first wiring supplies a voltage to one terminal of the avalanche photodiode, and the second wiring supplies a voltage to the other terminal of the avalanche photodiode.

[0137] (Configuration 10) The photoelectric conversion device described in configuration 8 or 9, wherein the first avalanche photodiode includes, from the first surface side, a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type forming a PN junction between the first semiconductor region and the first semiconductor region, and in a planar view, the second wiring of the first avalanche photodiode overlaps with the first semiconductor region of the first avalanche photodiode.

[0138] (Configuration 11) The photoelectric conversion device described in configuration 10, characterized in that, in a planar view, the shape of the first semiconductor region of the first avalanche photodiode and the shape of the second wiring of the first avalanche photodiode are similar to each other.

[0139] (Configuration 12) A photoelectric conversion device described in any one of configurations 8 to 11, characterized in that the center of gravity of the second wiring of the first avalanche photodiode is farther from the opposing side of the first avalanche photodiode and the second avalanche photodiode than the center of the first avalanche photodiode.

[0140] (Configuration 13) The photoelectric conversion device described in configuration 12, characterized in that the distance between a first side of the second wiring and the side is greater than the distance between a second side opposite the first side of the second wiring and the first wiring opposite the second side.

[0141] (Configuration 14) The photoelectric conversion device described in any one of structures 8 to 13, characterized in that the center of gravity of the second wiring of the first avalanche photodiode is closer to the opposing side of the first avalanche photodiode and the second avalanche photodiode than the center of the first avalanche photodiode.

[0142] (Configuration 15) The photoelectric conversion device described in configuration 14, characterized in that the distance between a first side of the second wiring and the side is closer than the sum of the distance between a second side opposite the first side of the second wiring and the first wiring opposite the second side, and the width of the first wiring.

[0143] (Configuration 16) The photoelectric conversion device described in any one of structures 8 to 15, wherein each of the plurality of pixels includes a third avalanche photodiode and a fourth avalanche photodiode, and the third avalanche photodiode and the fourth avalanche photodiode share the microlens with the first avalanche photodiode and the second avalanche photodiode.

[0144] (Configuration 17) A photoelectric conversion system comprising: a photoelectric conversion device according to any one of configurations 8 to 16; and a signal processing unit that generates an image using a signal output from the photoelectric conversion device.

[0145] (Configuration 18) A moving object including the photoelectric conversion device according to any one of claims 8 to 16, A moving body comprising: a control unit that controls the movement of the moving body using a signal output from the photoelectric conversion device. [Explanation of symbols]

[0146] 201 Avalanche photodiode 323 Micro Lens 301 Cathode wiring 302 Anode wiring

Claims

1. A photoelectric conversion device having multiple pixels, A semiconductor layer having a first surface and a second surface facing the first surface, and having a plurality of avalanche photodiodes, It comprises a first wiring and a second wiring, and has a wiring layer provided on the side of the first surface, Each of the aforementioned plurality of pixels is The first avalanche photodiode and The first avalanche photodiode and a second avalanche photodiode adjacent to it in the first direction, The first avalanche photodiode and the second avalanche photodiode are provided with a microlens in common, and the microlens is provided on the side of the second surface. A photoelectric conversion device characterized in that, in the first direction, the width of the first wiring arranged between the second wiring of the first avalanche photodiode and the second wiring of the second avalanche photodiode is wider than the width of the first wiring arranged between the plurality of pixels.

2. The first wiring supplies voltage to one terminal of the avalanche photodiode. The photoelectric conversion device according to claim 1, characterized in that the second wiring supplies voltage to the other terminal of the avalanche photodiode.

3. The first avalanche photodiode includes, in order from the first surface side, a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type that forms a PN junction with the first semiconductor region, The photoelectric conversion device according to claim 1, characterized in that, in a plan view, the second wiring of the first avalanche photodiode overlaps with the first semiconductor region of the first avalanche photodiode.

4. The photoelectric conversion device according to claim 3, characterized in that, in a plan view, the shape of the first semiconductor region of the first avalanche photodiode and the shape of the second wiring of the first avalanche photodiode are similar.

5. Each of the plurality of pixels includes a third avalanche photodiode and a fourth avalanche photodiode. The photoelectric conversion device according to claim 1, characterized in that the third avalanche photodiode and the fourth avalanche photodiode share the first avalanche photodiode and the second avalanche photodiode with the microlens.

6. The photoelectric conversion device according to claim 1, A photoelectric conversion system characterized by having a signal processing unit that generates an image using the signal output by the aforementioned photoelectric conversion device.

7. A mobile body including the photoelectric conversion device described in claim 1, A mobile body characterized by having a control unit that controls the movement of the mobile body using a signal output by the photoelectric converter.

8. A photoelectric conversion device having multiple pixels, A semiconductor layer having a first surface and a second surface facing the first surface, and having a plurality of avalanche photodiodes, It comprises a first wiring and a second wiring, and has a wiring layer provided on the side of the first surface, Each of the aforementioned plurality of pixels is The first avalanche photodiode and The first avalanche photodiode and a second avalanche photodiode adjacent to it in the first direction, The first avalanche photodiode and the second avalanche photodiode are provided with a microlens in common, and the microlens is provided on the side of the second surface. A photoelectric conversion device characterized in that, in the first direction, the first wiring is not provided between the second wiring of the first avalanche photodiode and the second wiring of the second avalanche photodiode.

9. The first wiring supplies voltage to one terminal of the avalanche photodiode. The photoelectric conversion device according to claim 8, characterized in that the second wiring supplies voltage to the other terminal of the avalanche photodiode.

10. The first avalanche photodiode includes, in order from the first surface side, a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type that forms a PN junction with the first semiconductor region, The photoelectric conversion device according to claim 8, characterized in that, in a plan view, the second wiring of the first avalanche photodiode overlaps with the first semiconductor region of the first avalanche photodiode.

11. The photoelectric conversion device according to claim 10, characterized in that, in a plan view, the shape of the first semiconductor region of the first avalanche photodiode and the shape of the second wiring of the first avalanche photodiode are similar.

12. The photoelectric conversion device according to claim 8, characterized in that the center of gravity of the second wiring of the first avalanche photodiode is further from the side facing the first avalanche photodiode than the center of the first avalanche photodiode.

13. The photoelectric conversion device according to claim 12, wherein the distance between the first side of the second wiring and the side is greater than the distance between the second side of the second wiring facing the first side and the first wiring facing the second side.

14. The photoelectric conversion device according to claim 8, characterized in that the center of gravity of the second wiring of the first avalanche photodiode is closer to the side facing the first avalanche photodiode and the second avalanche photodiode than to the center of the first avalanche photodiode.

15. The photoelectric conversion device according to claim 14, characterized in that the distance between the first side of the second wiring and the side is closer than the sum of the distance between the second side of the second wiring facing the first side, the distance between the first wiring facing the second side, and the width of the first wiring.

16. Each of the plurality of pixels includes a third avalanche photodiode and a fourth avalanche photodiode. The photoelectric conversion device according to claim 8, characterized in that the third avalanche photodiode and the fourth avalanche photodiode share the first avalanche photodiode and the second avalanche photodiode with the microlens.

17. The photoelectric conversion device according to claim 8, A photoelectric conversion system characterized by having a signal processing unit that generates an image using the signal output by the aforementioned photoelectric conversion device.

18. A mobile body including the photoelectric converter described in claim 8, A mobile body characterized by having a control unit that controls the movement of the mobile body using a signal output by the photoelectric converter.

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