Photoelectric conversion device, photoelectric conversion system, and mobile body

Abstract

To restrain light emission caused by formation of an unintended current path.SOLUTION: In a sensor substrate 301, a semiconductor layer SL includes a pixel array region PAR, a scribe region SCR containing an outer edge EDG of the semiconductor layer, a peripheral region PR arranged therebetween, and a separation section 341 that electrically separates the peripheral region from the scribe region. Each of a plurality of pixels 101 includes an avalanche photodiode having a first semiconductor region 311 of a first conductivity type and a second semiconductor region 315 of a second conductivity type. The peripheral region includes a first region 341 of a first conductivity type and a second region 342 of a second conductivity type, and the scribe region includes a third region 343 of a first conductivity type. A wiring structure WS includes a first conductive path ECPA that electrically connects the first region and the third region, and a voltage supply line 381 to which a predetermined voltage between the voltage of the first semiconductor region and the voltage of the second semiconductor region is supplied. The first region and the voltage supply line are electrically connected to each other by a second conductive path ECPB.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a photoelectric conversion device, a photoelectric conversion system, and a mobile object. [Background technology]

[0002] In an avalanche photodiode, a reverse bias voltage is applied between the anode and cathode, which can cause avalanche multiplication. Under this reverse bias, electrons generated by photon collisions with semiconductor atoms are accelerated by a strong electric field, colliding with other semiconductor atoms and releasing multiple electrons. These electrons then collide with other semiconductor atoms, releasing even more electrons. This chain reaction results in electron multiplication. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-099383 Summary of the Invention [Problem to be solved by the invention]

[0004] Photoelectric conversion devices with avalanche photodiodes require a large electric field to generate avalanche multiplication. Therefore, if the tip end becomes charged, an unintended current path is likely to be formed between the tip end and the anode. Current flowing through this current path recombines holes and electrons, causing light emission, which can be detected by a pixel. While not particularly relevant to the present invention, Patent Document 1 describes an advantageous structure for reducing the effects of light incident on the peripheral region of a photoelectric conversion device.

[0005] An object of the present invention is to provide an advantageous technique for suppressing light emission due to the formation of an unintended current path. [Means for solving the problem]

[0006] One aspect of the present invention relates to a photoelectric conversion device having a semiconductor layer and a wiring structure, in which the semiconductor layer includes a pixel array region having a plurality of pixels, a scribe region including an outer edge of the semiconductor layer, a peripheral region disposed between the pixel array region and the scribe region, and a separation portion that electrically separates the peripheral region from the scribe region, and each of the plurality of pixels includes a first semiconductor region of a first conductivity type having charges of a first polarity as majority carriers, and a second semiconductor region of a second conductivity type having charges of a second polarity different from the first polarity as majority carriers. the peripheral region includes a first region of the first conductivity type and a second region of the second conductivity type, and the second region is supplied with the same voltage as that supplied to the second semiconductor region; the scribe region includes a third region of the first conductivity type; the wiring structure includes a first conductive path electrically connecting the first region and the third region, and a voltage supply line to which a predetermined voltage between the voltage of the first semiconductor region and the voltage of the second semiconductor region is supplied, and the first region and the voltage supply line are electrically connected by a second conductive path. [Effects of the Invention]

[0007] According to the present invention, an advantageous technique is provided for suppressing light emission due to the formation of an unintended current path. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a basic configuration of a photoelectric conversion device according to an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of the configuration of a sensor substrate. [Figure 3] FIG. 2 is a diagram showing an example of the configuration of a circuit board. [Figure 4] FIG. 2 is an equivalent circuit diagram of one pixel and its signal processing unit. [Figure 5] 3A to 3C are diagrams illustrating the operation of a pixel. [Figure 6] FIG. 1 is a plan view of a photoelectric conversion device according to a first embodiment. [Figure 7]FIG. 1 is a cross-sectional view of a photoelectric conversion device according to a first embodiment. [Figure 8] A diagram illustrating the problem. [Figure 9] FIG. 10 is a plan view of a photoelectric conversion device according to a second embodiment. [Figure 10] FIG. 10 is a cross-sectional view of a photoelectric conversion device according to a second embodiment. [Figure 11] FIG. 10 is a cross-sectional view of a photoelectric conversion device according to a third embodiment. [Figure 12] FIG. 10 is a cross-sectional view of a photoelectric conversion device according to a fourth embodiment. [Figure 13] FIG. 10 is a cross-sectional view of a photoelectric conversion device according to a fifth embodiment. [Figure 14] FIG. 13 is a cross-sectional view of a photoelectric conversion device according to a sixth embodiment. [Figure 15] FIG. 13 is a functional block diagram of a photoelectric conversion system according to a seventh embodiment. [Figure 16] FIG. 13 is a functional block diagram of a photoelectric conversion system according to an eighth embodiment. [Figure 17] FIG. 13 is a functional block diagram of a photoelectric conversion system according to a ninth embodiment. [Figure 18] FIG. 22 is a functional block diagram of a photoelectric conversion system according to a tenth embodiment. [Figure 19] FIG. 20 is a diagram of a photoelectric conversion system according to an eleventh embodiment. [Figure 20] FIG. 23 is a diagram of a photoelectric conversion system according to a twelfth embodiment. [Figure 21] FIG. 23 is a functional block diagram of a photoelectric conversion system according to a thirteenth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0010] Hereinafter, embodiments 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 intended to facilitate understanding of the embodiments with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention.

[0011] In this specification, the term "planar view" refers to viewing the photoelectric conversion device from a direction perpendicular to the light incident surface of the semiconductor layer, and is synonymous with an orthogonal projection onto the light incident surface. Furthermore, the term "cross-sectional view" refers to a surface in a direction perpendicular to the light incident surface of the semiconductor layer. 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.

[0012] In the following description of exemplary embodiments, the anode of an avalanche photodiode (hereinafter also referred to as an APD) is set to a fixed potential, and a signal is extracted from the cathode side. Therefore, the first conductivity type semiconductor region having majority carriers of charges of a first polarity, the same as the signal charge, is an N-type semiconductor region, and the second conductivity type semiconductor region having majority carriers of charges of a second polarity, different from the signal charge, is a P-type semiconductor region. Note that the present invention also applies when the cathode of the APD is set to a fixed potential and a signal is extracted from the anode side. In this case, the first conductivity type semiconductor region having majority carriers of charges of a first polarity, the same as the signal charge, is a P-type semiconductor region, and the second conductivity type semiconductor region having majority carriers of charges of a second polarity, different from the signal charge, is an N-type semiconductor region. While the following description focuses on a case where one node of the APD is set to a fixed potential, the potentials of both nodes may fluctuate.

[0013] In this specification, when the term "impurity concentration" is used simply, it means the net impurity concentration minus the amount compensated for by impurities 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.

[0014] First, a basic configuration and driving method common to photoelectric conversion devices and driving methods thereof according to a plurality of embodiments to be described later will be described with reference to FIGS. 1, 2, 3, 4, and 5. FIG.

[0015] FIG. 1 illustrates a basic configuration of a photoelectric conversion device 100 according to an embodiment. Here, an example in which the photoelectric conversion device 100 is configured as a stacked-type photoelectric conversion device is described. However, the present invention is also applicable to photoelectric conversion devices other than stacked-type photoelectric conversion devices. The photoelectric conversion device 100 may be configured by stacking multiple substrates, including a sensor substrate 301 and a circuit substrate 401, and electrically connecting the multiple substrates. The sensor substrate 301 may have a first semiconductor layer having a photoelectric conversion element 102 (described later) and a first wiring structure. The circuit substrate 401 may have a second semiconductor layer having circuits such as a signal processing unit 103 (described later) and a second wiring structure. The photoelectric conversion device 100 may be configured by stacking the second semiconductor layer, the second wiring structure, the first wiring structure, and the first semiconductor layer in this order, for example. The photoelectric conversion device described as the following embodiment may be, for example, a back-illuminated photoelectric conversion device. However, the photoelectric conversion device according to the present invention may also be configured as a front-illuminated photoelectric conversion device.

[0016] The sensor substrate 301 and the circuit substrate 401 may each be a chip diced from a wafer, but these substrates are not limited to chips. For example, each substrate may be a wafer. Furthermore, multiple substrates may be stacked in the wafer state and then diced, or multiple chips may be stacked or joined after being diced.

[0017] The sensor substrate 301 may include a semiconductor layer including a pixel array region 12 having a plurality of pixels and a peripheral region 13 arranged around the pixel array region 12. The region between the outer edge of the pixel array region 12 and the outer edge of the sensor substrate 301 (the scribe region including the outer edge) may be the peripheral region 13. Circuit elements such as active elements may or may not be arranged in the peripheral region 13. The circuit substrate 401 may include a semiconductor layer including a circuit region 22 that processes signals detected by pixels in the pixel array region 12.

[0018] 2 is a diagram showing an example of the configuration of the sensor substrate 301. In the pixel array region 12, a plurality of pixels 101 can be arranged in a two-dimensional array to form a plurality of rows and a plurality of columns. Each pixel 101 can include a photoelectric conversion element 102 including an avalanche photodiode (APD).

[0019] The pixels 101 arranged in the pixel array region 12 may be pixels for forming an image. However, when the sensor substrate 301 or the photoelectric conversion device 100 is applied to TOF (Time of Flight), each pixel 101 does not necessarily have to be a pixel for forming an image. In other words, the pixel 101 may be a pixel for measuring the time and amount of light that arrives.

[0020] 3 is a diagram showing the configuration of a circuit board 401. The circuit board 401 may include, for example, a signal processing unit 103 that processes a signal (electrical signal) generated in response to an electric charge (signal charge) generated by photoelectric conversion in the photoelectric conversion element 102. The circuit board 401 may also include a readout circuit 112, a control pulse generation unit 115, a horizontal scanning circuit unit 111, a signal line 113, and a vertical scanning circuit unit 110. One signal processing unit 103 may be provided for one pixel 101. The photoelectric conversion element 102 in FIG. 2 and the signal processing unit 103 in FIG. 3 may be electrically connected via connection wiring provided for each pixel 101.

[0021] The vertical scanning circuit unit 110 may be configured, for example, to receive a first control pulse supplied from the control pulse generation unit 115, generate a second control pulse, and supply the second control pulse to each pixel 101. The vertical scanning circuit unit 110 may include, for example, logic circuits such as a shift register and an address decoder. A signal output from the photoelectric conversion element 102 of each pixel 101 may be processed by a signal processing unit 103 provided corresponding to that pixel 101. The signal processing unit 103 may include a counter, a memory, etc., and the memory may hold digital values.

[0022] The horizontal scanning circuit unit 111 can be configured to supply the signal processing unit 103 with a third control pulse that sequentially selects each column in order to read out the signal from the memory of each pixel 101 that holds the digital signal. The circuit board 401 can have a plurality of signal lines 113. Signals are output to the plurality of signal lines 113 from the signal processing unit 103 assigned to the pixels 101 in the row selected by the vertical scanning circuit unit 110. The signals output to the plurality of signal lines 113 can be output to a recording unit or a signal processing unit outside the photoelectric conversion device 100 via an output circuit 114.

[0023] 2, the photoelectric conversion elements 102 or pixels 101 may be arranged one-dimensionally in the pixel array region 12. Each signal processing unit 103 may be assigned to at least two photoelectric conversion elements 102 or pixels 101.

[0024] 2 and 3, a plurality of signal processing units 103 may be arranged in a region overlapping the pixel array region 12 in a planar view. Then, a vertical scanning circuit unit 110, a horizontal scanning circuit unit 111, a readout circuit 112, an output circuit 114, and a control pulse generation unit 115 may be arranged so as to overlap a region between the outer edge of the sensor substrate 301 and the outer edge of the pixel array region 12 in a planar view. In other words, the vertical scanning circuit unit 110, the horizontal scanning circuit unit 111, the readout circuit 112, the output circuit 114, and the control pulse generation unit 115 may be arranged in a region overlapping the peripheral region 13 of the sensor substrate 301 in a planar view.

[0025] FIG. 4 illustrates an equivalent circuit of one pixel 101 in FIG. 2 and one signal processing unit 103 in FIG. 3. The APD 201 generates charge pairs in response to incident light through 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 may be supplied to the cathode of the APD 201. A reverse bias voltage that can cause the APD 201 to perform avalanche multiplication may be supplied between the anode and cathode. With such a reverse bias voltage supplied between the anode and cathode, charges generated by incident light may cause avalanche multiplication, generating an avalanche current.

[0026] A mode in which an APD is operated with a voltage between the anode and cathode greater than the breakdown voltage is called Geiger mode. A mode in which an APD is operated with a voltage between the anode and cathode close to or less than the breakdown voltage is called linear mode. An APD operated in Geiger mode is called a SPAD. 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 linear mode or Geiger mode.

[0027] The quench element 202 can be arranged to connect a power supply that supplies voltage VH to the APD 201. The quench element 202 functions as a load circuit (quench circuit) during signal multiplication by avalanche multiplication, and has the function of suppressing avalanche multiplication by suppressing the voltage supplied to the APD 201 (quench operation). The quench element 202 also has the function of returning the voltage supplied to the APD 201 to voltage VH by flowing a current equivalent to the voltage drop caused by the quench operation (recharge operation).

[0028] The signal processing unit 103 may include a waveform shaping unit 210, a counter circuit 211, and a selection circuit 212. The signal processing unit 103 may be a circuit including at least one of the waveform shaping unit 210, the counter circuit 211, and the selection circuit 212. The waveform shaping unit 210 may shape the potential change of the cathode of the APD 201 obtained upon photon detection and output a pulse signal. For example, an inverter circuit may be used as the waveform shaping unit 210. In FIG. 4, the waveform shaping unit 210 is configured with one inverter, but the waveform shaping unit 210 may include a series connection of multiple inverters or may include another circuit that has a waveform shaping effect.

[0029] The counter circuit 211 can count the pulse signals output from the waveform shaping unit 210 and hold the count value. The counter circuit 211 can also be configured to reset the signal held in the counter circuit 211 by receiving a control pulse pRES via a drive line 213. The selection circuit 212 can receive a control pulse pSEL from the vertical scanning circuit unit 110 in FIG. 3 via a drive line 214 in FIG. 4 (not shown in FIG. 3), and can switch between electrical connection and disconnection between the counter circuit 211 and the signal line 113. The selection circuit 212 can include, for example, a buffer circuit for outputting a signal.

[0030] A switch such as a transistor may be disposed between the quench element 202 and the APD 201 and / or between the photoelectric conversion element 102 and the signal processing unit 103 to control the electrical connection. Similarly, the supply of the voltage VH and / or the voltage VL to the photoelectric conversion element 102 may be controlled by a switch such as a transistor.

[0031] The photoelectric conversion device 100 may be configured to acquire pulse detection timing using a time-to-digital converter (hereinafter referred to as TDC) and a memory instead of the counter circuit 211. The generation timing of the pulse signal output from the waveform shaping unit 210 may be converted into a digital signal by the TDC. To measure the timing of the pulse signal, a control pulse pREF (reference signal) may be supplied to the TDC from the vertical scanning circuit unit 110 in FIG. 1 via a drive line. The TDC may acquire, 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.

[0032] 5 is a diagram schematically illustrating the relationship between the operation of the APD 201 and the output signal. FIG. 5(a) is a diagram illustrating the APD 201, the quench element 202, and the waveform shaping unit 210 excerpted from FIG. 4. Here, the input side of the waveform shaping unit 210 is referred to as node A, and the output side is referred to as node B. FIG. 5(b) shows the waveform change at node A in FIG. 5(a), and FIG. 5(c) shows the waveform change at node B in FIG. 5(a).

[0033] 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 node A drops. As the voltage drop increases and the potential difference applied to the APD 201 decreases, the avalanche multiplication operation of the APD 201 stops, as shown at time t2, and the voltage level at node A no longer drops below a certain value. After that, between time t2 and time t3, a current flows through node A from voltage VL to compensate for the voltage drop, and at time t3, node A returns to its original potential level. At this time, the portion of the output waveform at node A that exceeds a certain threshold is shaped by the waveform shaping unit 210 and output as a signal at node B.

[0034] 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.

[0035] FIG. 6 shows a plan view of the photoelectric conversion device 100 of the first embodiment. FIG. 7 shows a cross-sectional view of the photoelectric conversion device 100 of the first embodiment. Here, FIG. 7 is a cross-sectional view taken along line X-X' in FIG. 6. The photoelectric conversion device 100 or the sensor substrate 301 includes a semiconductor layer SL and a wiring structure WS. The semiconductor layer SL may include a pixel array region PAR having a plurality of pixels 101, a scribe region SCR including an outer edge EDG of the semiconductor layer SL, and a peripheral region PR disposed between the pixel array region PAR and the scribe region SCR. The semiconductor layer SL may also include an isolation portion 361 that electrically isolates the peripheral region PR from the scribe region SCR. The isolation portion 361 may have a structure similar to the insulating isolation portion 324 between the pixels 101 in the pixel array region PAR. The scribe region SCR is a portion that remains at the edge of each sensor substrate 301 after a wafer, on which a plurality of sensor substrates 301 are arranged as a chip region, is cut along the scribe lines to form a plurality of chips into the sensor substrates 301, i.e., a portion of the scribe line. Each of the plurality of pixels 101 includes an avalanche photodiode 201. From another perspective, the photoelectric conversion device 100, the sensor substrate 301, or the pixel array region includes a plurality of avalanche photodiodes 201. The separation portion 361 can be arranged to surround the peripheral region PR, preferably to surround the entire periphery of the peripheral region PR.

[0036] The semiconductor layer SL may include an isolation portion 363 disposed between the pixel array region PAR and the peripheral region PR. The isolation portion 363 may have a structure similar to the insulating isolation portion 324 between the pixels 101 in the pixel array region PAR. The pixel array region PAR may include a semiconductor region 316. The peripheral region PR may include a semiconductor region 391 electrically isolated from the pixel array region PAR. The scribing region SCR may include the semiconductor region 391. The semiconductor region 316 and the semiconductor region 391 may be semiconductor regions having the same conductivity type. The semiconductor region 316 and the semiconductor region 391 may have a first conductivity type, a second conductivity type, or may be intrinsic semiconductor regions. The semiconductor region 316 and the semiconductor region 391 may be formed by epitaxial growth, for example.

[0037] The semiconductor layer SL has a first surface S1 and a second surface S2 opposite to the first surface S1. The wiring structure WS may be arranged such that the first surface S1 is located between the second surface S2 and the wiring structure WS. The pinning layer 331 may be arranged to cover the second surface S2. The pinning layer 331 may extend to cover the pixel array region PAR, the peripheral region PR, and the scribe region SCR. In another aspect, the pinning layer 331 may extend to cover the pixel array region PAR and the peripheral region PR. The photoelectric conversion device 100 may further include a microlens array 323. The semiconductor layer SL may be arranged between the microlens array 323 and the wiring structure WS.

[0038] Each pixel 101 includes an avalanche photodiode (APD 201), and the APD 201 may include a first semiconductor region 311 of a first conductivity type as a cathode and a second semiconductor region 315 of a second conductivity type as an anode. The second semiconductor regions 315 of the multiple pixels 101 may be electrically connected to each other, and a common voltage may be supplied to the second semiconductor regions 315 of the multiple pixels 101. The first conductivity type is a conductivity type in which charges of a first polarity are the majority carriers. The second conductivity type is a conductivity type in which charges of a second polarity different from the first polarity are the majority carriers. The first semiconductor region 311 of the first conductivity type may be arranged on a first surface S1 side of the first semiconductor layer SL (pixel array region PAR). The second semiconductor region 315 of the second conductivity type may be arranged on a second surface S2 side of the first semiconductor layer SL (pixel array region PAR). A voltage capable of causing avalanche multiplication operation can be supplied between the first semiconductor region 311 and the second semiconductor region 315. Each pixel 101 can include a semiconductor region 313 of a first conductivity type disposed between the first semiconductor region 311 as a cathode and the second semiconductor region 315 as an anode and in close proximity to the first semiconductor region 311. The concentration of impurities of the first conductivity type in the semiconductor region 313 is lower than the concentration of impurities of the first conductivity type in the first semiconductor region 311 of the first conductivity type as a cathode.

[0039] Each pixel 101 may include a semiconductor region 312 of a second conductivity type between a first semiconductor region 311 of a first conductivity type serving as a cathode and a second semiconductor region 315 of a second conductivity type serving as an anode. For example, if the semiconductor region 312 is the same node as the second semiconductor region 315 serving as an anode, the semiconductor region 312 may also function as an anode. The region between the first semiconductor region 311 and the semiconductor region 312 may serve as an avalanche multiplication region. A semiconductor region 316 of a first conductivity type or a second conductivity type may be disposed between the first surface S1 and the semiconductor region 312 of the second conductivity type so as to surround the first semiconductor region 311 of the first conductivity type serving as a cathode. When the semiconductor region 316 has the first conductivity type, the impurity concentration of the first conductivity type in the semiconductor region 316 is lower than the impurity concentration of the first conductivity type in the semiconductor region 313. When the semiconductor region 316 has the second conductivity type, the concentration of the impurities of the second conductivity type in the semiconductor region 316 is lower than the concentration of the impurities of the second conductivity type in the semiconductor region 312 of the second conductivity type.

[0040] A semiconductor region 316 of the first conductivity type or the second conductivity type may be disposed between the semiconductor region 312 of the second conductivity type and the second semiconductor region 315 of the second conductivity type serving as an anode. When the semiconductor region 316 has the first conductivity type, the impurity concentration of the first conductivity type in the semiconductor region 316 may be lower than the impurity concentration of the first conductivity type in the semiconductor region 313. When the semiconductor region 316 has the second conductivity type, the impurity concentration of the second conductivity type in the semiconductor region 316 may be lower than the impurity concentration of the second conductivity type in the semiconductor region 312 of the second conductivity type.

[0041] The semiconductor region 316 may include a portion arranged between the second semiconductor region 315 of the second conductivity type as an anode and the semiconductor region 317 of the first conductivity type, and a portion surrounding the side of the semiconductor region 317 of the first conductivity type.

[0042] A second conductivity type isolation region 314 may be arranged between adjacent pixels 101 among the plurality of pixels 101. A second conductivity type contact region 319 may be arranged between the second conductivity type isolation region 314 and the first surface S1 so as to be electrically connected to the second conductivity type isolation region 314. The second conductivity type impurity concentration in the second conductivity type contact region 319 is higher than the second conductivity type impurity concentration in the second conductivity type isolation region 314. The second conductivity type isolation region 314 may be arranged so as to be electrically connected to a second conductivity type second semiconductor region 315 serving as an anode. An anode voltage (anode potential) may be supplied to the second conductivity type contact region 319 via a conductive path arranged in the wiring structure WL, thereby supplying the anode voltage (anode potential) to the second conductivity type second semiconductor region 315 serving as an anode.

[0043] An insulating isolation portion 324 may be disposed in the second-conductivity-type isolation region 314. The insulating isolation portion 324 may include a groove provided in the isolation region 314 and an insulator disposed so as to cover at least the surface (inner surface) of the groove. The insulator may be a film, and the inside of the film may be filled with an insulating material or a conductive material. The insulating isolation portion 324 may be referred to as DTI (Deep Trench Isolation). The insulating isolation portion 324 or the groove may be disposed so as to penetrate the semiconductor layer SL, or may be disposed so as not to penetrate the semiconductor layer SL. The insulating isolation portion 324 or the groove may electrically separate the second-conductivity-type isolation region 314 into an isolation region on one pixel 101 side and an isolation region on the adjacent pixel 101 side. The insulating isolation portion 324 may be configured to include a groove, an insulator disposed so as to cover the inner surface of the groove, and a metal or a light-shielding material disposed inside the insulator.

[0044] A pinning layer 331 may be disposed on the second surface S2 side of the second semiconductor region 315 of the second conductivity type serving as an anode. The pinning layer 331 may also be referred to as a fixed charge film. The pinning layer 331 is disposed so as to be in contact with the second surface S2 and may be formed, for example, by atomic layer deposition (ALD). The pinning layer 331 may be made of a material selected from hafnium oxide, aluminum oxide, zirconium oxide, titanium oxide, tantalum oxide, and ruthenium oxide. The pinning layer 331 may be composed of multiple layers. The aforementioned film covering the surface (inner surface) of the groove provided in the separation region 314 may be the pinning layer 331.

[0045] The pinning layer 331 may be covered with an insulating film 321. The insulating film 321 may be, for example, a silicon oxide film, a silicon nitride film, or a silicon nitride oxide film. The insulating film 321 may be composed of multiple films. The insulating film 321 may be covered with a planarization layer 322. A microlens array 323 may be disposed on the planarization layer 322. The example shown in FIG. 7 is a back-illuminated type in which light from the outside is incident on the second surface S of the semiconductor layer SL through the microlens array 323, but the photoelectric conversion device 100 may also be configured as a front-illuminated type. Although not shown, in addition to the planarization layer 322, a filter layer such as a color filter or an infrared light cut filter may be provided on the second surface S2 side of the semiconductor layer SL.

[0046] The peripheral region PR may include a first region 341 of a first conductivity type in which charges of a first polarity are the majority carriers, and a second region 342 of a second conductivity type in which charges of a second polarity different from the first polarity are the majority carriers. The first region 341 and the second region 342 may be disposed in a semiconductor region 391 of the peripheral region PR. The second region 342 may be supplied with the same voltage as that supplied to the second semiconductor region 315 of the pixel 101 (APD 201). Supplying the same voltage may also mean that the same voltage is applied to each region. The first region 341 and the second conductive path ECPB may form a charge discharge path that extracts charges of the first polarity from the peripheral region PR (semiconductor region 391).

[0047] The scribe region SCR may include a third region 343 of the first conductivity type. When the semiconductor region 391 has the first conductivity type, the impurity concentration of the first conductivity type in the semiconductor region 391 is lower than the impurity concentration of the first conductivity type in the first region 341 and the third region 343. When the semiconductor region 391 has the second conductivity type, the impurity concentration of the second conductivity type in the semiconductor region 391 is lower than the impurity concentration of the second conductivity type in the second region 342.

[0048] The wiring structure WS may include a first conductive path ECPA electrically connecting the first region 341 of the first conductivity type and the third region 343 of the first conductivity type. The wiring structure WS may also include a voltage supply line 381 to which a predetermined voltage V1 (e.g., −3 V) between the voltage of the first semiconductor region 313 of the APD 201 (cathode voltage) and the voltage of the second semiconductor region 315 of the APD 201 (anode voltage) is supplied. The first region 341 in the peripheral region PR (semiconductor region 391) and the voltage supply line 381 may be electrically connected by a second conductive path ECPB disposed in the peripheral region PR (semiconductor region 391). This allows the predetermined voltage V1 to be supplied from the voltage supply line 381 to the first region 341 via the second conductive path ECPB and further to the third region 343 via the first conductive path ECPA. This prevents a voltage that causes avalanche multiplication from being applied between the first region 341 and the second region 342. Preventing avalanche multiplication prevents light emission due to charge recombination caused by the formation of a current path. Note that, although the predetermined voltage V1 is supplied via the junction between the sensor substrate and the circuit substrate in Fig. 7, it may be supplied from the sensor substrate side without passing through the circuit substrate or junction.

[0049] 8 schematically illustrates the problem of unintended current paths being formed due to charging of the scribe region SCR. When the scribe region SCR is charged, a current path 371 can be formed from the semiconductor region 391 of the scribe region SCR through the third region 343, the first conductive path ECPA, the first region 341, and the semiconductor region 391 to the second region 342 of the second conductivity type. The current flowing through the current path 371 causes charge recombination at the pn junction, which can generate light. Furthermore, if an electric field that causes avalanche multiplication is present in the current path 371, the amount of charge flowing through the current path can be significantly increased, thereby enhancing the light emission.

[0050] Therefore, as described above, in the first embodiment, a predetermined voltage V1 (for example, −3 V) between the cathode voltage and anode voltage of the APD 201 is supplied to the first region 341 and the third region 343. This prevents avant-lanche multiplication from occurring, and prevents light from being generated by charge recombination.

[0051] FIG. 9 shows a plan view of the photoelectric conversion device 100 of the second embodiment. FIG. 6 is also used as another plan view of the photoelectric conversion device 100 of the second embodiment. FIG. 10 shows a cross-sectional view of the photoelectric conversion device 100 of the second embodiment. FIG. 10 is a cross-sectional view taken along line X-X' in FIGS. 6 and 9. Matters not mentioned in the second embodiment may follow the first embodiment. FIG. 9 shows an example of the arrangement of the charge discharging unit CD in the photoelectric conversion device 100 of the second embodiment, and FIG. 6 shows an example of the arrangement of the second conduction path ECPB in the photoelectric conversion device 100 of the second embodiment.

[0052] In the photoelectric conversion device 100 of the second embodiment, the peripheral region PR includes a fourth region 344 of the first conductivity type and a fifth region 345 of the first conductivity type. The fifth region of the first conductivity type may be arranged to electrically connect the first region 341 of the first conductivity type and the fourth region 344 of the first conductivity type. The fourth region 344 and the fifth region 345 may form at least a part of the second conduction path ECPB. The voltage supply line 381 may be electrically connected to the fourth region 344.

[0053] The first region 341, the fourth region 344, the fifth region 345 and the voltage supply line 381 can form a charge discharge path CD that extracts charges of the first polarity from the peripheral region PR (semiconductor region 391).

[0054] The fifth region 345 may be disposed in the same depth range as the first region 341 and the fourth region 344. In another aspect, the fifth region 345 may be disposed in the same depth range as the first region 341, the third region 343, and the fourth region 344. In yet another aspect, the fifth region 345 may be disposed in the same depth range as the first region 341, the third region 343, the fourth region 344, and the first semiconductor region 311.

[0055] The first conductive path ECPA may include, for example, a conductive pattern WP1, a first plug P1 electrically connecting the conductive pattern WP1 to the first region 341, and a second plug P2 electrically connecting the conductive pattern WP1 to the third region 343. The voltage supply line 381 may include a third plug P3 electrically connected to the fourth region 344. A configuration in which the fourth region 344 and the first region 341 are electrically connected by the fifth region 345 disposed in the semiconductor region 391 may result in a reasonable electrical resistance between the fourth region 344 and the first region 341. This is advantageous for preventing an unintended large current from flowing between the scribe region SCR and the fourth region 344 due to charging of the scribe region SCR.

[0056] In one example, the distance between the first plug P1 and the third plug P3 is greater than the distance between the first plug P1 and the second plug P2. Alternatively, the distance between the first plug P1 and the third plug P3 may be smaller than the distance between the first plug P1 and the second plug P2. In one example, the electrical resistance between the first plug P1 and the third plug P3 is greater than the electrical resistance between the first plug P1 and the second plug P2. Alternatively, the electrical resistance between the first plug P1 and the third plug P3 may be smaller than the electrical resistance between the first plug P1 and the second plug P2. In one example, the first plug P1 is disposed between the second plug P2 and the third plug P3.

[0057] FIG. 11 shows a cross-sectional view of a photoelectric conversion device 100 according to a third embodiment. The third embodiment is a modification of the second embodiment, and details not mentioned in the third embodiment may conform to the second embodiment. The photoelectric conversion device 100 according to the third embodiment includes a first-conductivity-type electric field relaxation region 355 disposed in the semiconductor region 391 so as to surround the fourth region 344 and the fifth region 345. In another aspect, the photoelectric conversion device 100 according to the third embodiment includes a first-conductivity-type electric field relaxation region 355 disposed in the semiconductor region 391 so as to surround the first region 341, the third region 343, the fourth region 344, and the fifth region 345. The electric field relaxation region 355 is effective in suppressing the formation of unintended current paths due to avalanche multiplication caused by charging of the scribe region SCR and in suppressing light emission due to charge recombination.

[0058] FIG. 12 shows a cross-sectional view of a photoelectric conversion device 100 according to a fourth embodiment. The fourth embodiment is a modification of the third embodiment, and details not specifically mentioned in the fourth embodiment may follow the third embodiment. In the fourth embodiment, the peripheral region PR includes a fourth region 344 of the first conductivity type and a sixth region 356 of the first conductivity type arranged to electrically connect the first region 341 and the fourth region 344. The fourth region 344 and the sixth region 356 may form at least a portion of the second conductive path ECPB. The sixth region 356 has a lower concentration of first conductivity type impurities than the first region 341 and the fourth region 344. This configuration increases the electrical resistance between the first region 341 and the fourth region 344, for example, compared to the third embodiment. This is advantageous for preventing unintended large currents from flowing between the scribe region SCR and the fourth region 344 due to charging of the scribe region SCR.

[0059] The sixth region 356 may have a side surface serving as a first conductivity type electric field relaxation region arranged in the semiconductor layer SL so as to surround the first region 341 and the fourth region 344. That is, the sixth region 356 may include a portion that relaxes the electric field acting on the first region 341 and the fourth region 344. From another perspective, the sixth region 356 may have a side surface serving as a first conductivity type electric field relaxation region arranged in the semiconductor region 391 so as to surround the first region 341, the third region 343, and the fourth region 344. That is, the sixth region 356 may include a portion that relaxes the electric field acting on the first region 341, the third region 343, and the fourth region 344. The sixth region 356 is effective in suppressing avalanche multiplication due to charging of the scribe region SCR and in preventing charge recombination due to the formation of an unintended current path from causing light emission.

[0060] 13 shows a cross-sectional view of a photovoltaic device 100 according to a fifth embodiment. The fifth embodiment is a modification of the fourth embodiment, and matters not mentioned in the fifth embodiment may follow the fourth embodiment. In the fifth embodiment, the second conductive path ECPB further includes a second conductive pattern WP2 arranged in the wiring structure WS so as to supply a predetermined voltage V1 to the first region 341 and the fourth region 344. The sixth embodiment may function to electrically connect the first region 341 and the fourth region 344 with low resistance.

[0061] In the fifth embodiment, the sixth region 356 can have a side surface as a first conductivity type electric field relaxation region arranged in the semiconductor region 391 so as to surround the first region 341 and the fourth region 344. From another perspective, the sixth region 356 can have a side surface as a first conductivity type electric field relaxation region arranged in the semiconductor region 391 so as to surround the first region 341, the third region 343, and the fourth region 344.

[0062] 14 shows a cross-sectional view of a photoelectric conversion device 100 according to a sixth embodiment. The sixth embodiment is a modification of the fifth embodiment, and matters not mentioned in the sixth embodiment may follow those of the fifth embodiment. In the sixth embodiment, the sixth region 356 in the fifth embodiment is removed. The sixth embodiment is advantageous in preventing the formation of a current path from the scribe region SCR to the peripheral region PR due to charging of the scribe region SCR.

[0063] Application examples of the photoelectric conversion device 100 according to the first to sixth embodiments will be described below as seventh to thirteenth embodiments.

[0064] The photoelectric conversion system according to the seventh embodiment will be described with reference to Fig. 15. Fig. 15 is a block diagram showing a schematic configuration of the photoelectric conversion system according to the seventh embodiment.

[0065] The above-described photoelectric conversion device 100 can be applied to various photoelectric conversion systems. Examples of applicable photoelectric conversion systems include digital still cameras, digital camcorders, surveillance cameras, copiers, fax machines, mobile phones, vehicle-mounted cameras, and observation satellites. Camera modules equipped with an optical system such as a lens and an imaging device are also included in photoelectric conversion systems. Fig. 15 illustrates a block diagram of a digital still camera as an example of such systems.

[0066] 15 includes an imaging device 1004, which is an example of a photoelectric conversion device. The photoelectric conversion system 1000 also includes a lens 1002 that forms an optical image of a subject on the imaging device 1004, an aperture 1003 that adjusts the amount of light passing through the lens 1002, and a barrier 1001 that protects the lens 1002. The lens 1002 and the aperture 1003 form an optical system (optical device) that focuses light on the imaging device 1004. The imaging device 1004 is the photoelectric conversion device 100 (imaging device) of any of the above embodiments, and converts the optical image formed by the lens 1002 into an electrical signal.

[0067] The photoelectric conversion system 1000 also has a signal processing unit 1007, which is an image generation unit that generates an image by processing an output signal output by the imaging device 1004. The signal processing unit 1007 functions as a processing device that performs various corrections and compressions as necessary and outputs image data. The signal processing unit 1007 may be formed on the same semiconductor substrate on which the imaging device 1004 is provided, or may be formed on a semiconductor substrate separate from the imaging device 1004. Furthermore, the imaging device 1004 and the signal processing unit 1007 may be formed on the same semiconductor substrate.

[0068] The photoelectric conversion system 1000 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 1000 also 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 from the recording medium 1012. The recording medium control I / F unit 1011 and the recording medium 1012 may form part of a storage device. The recording medium 1012 may be built into the photoelectric conversion system 1000, or may be removable.

[0069] The photoelectric conversion system 1000 further includes an overall control and 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. The overall control and calculation unit 1009 and the timing generation unit 1008 may form part of a control device for controlling the operation of the photoelectric conversion system 1000. Here, timing signals and the like may be input from outside, and the photoelectric conversion system 1000 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.

[0070] 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. Although not shown in FIG. 15 , a display device such as a display for displaying the generated image may be provided in the photoelectric conversion system 1000. As described above, according to this embodiment, it is possible to realize a photoelectric conversion system 1000 to which the photoelectric conversion device 100 (imaging device) of any of the above embodiments is applied.

[0071] A photoelectric conversion system 1300 and a mobile object 1301 according to the eighth embodiment will be described with reference to Fig. 16(a) and Fig. 16(b). Fig. 16(a) and Fig. 16(b) are diagrams showing the configurations of the photoelectric conversion system 1300 and the mobile object 1301 according to the fourth embodiment.

[0072] FIG. 16(a) shows an example of a photoelectric conversion system related to an in-vehicle camera. The photoelectric conversion system 1300 includes an image capturing device 1310. The image capturing device 1310 is the photoelectric conversion device 100 (image capturing device) described in any of the above embodiments. The photoelectric conversion system 1300 includes an image processing unit 1312 that performs image processing on multiple pieces of image data acquired by the image capturing device 1310. The photoelectric conversion system 1300 also includes a distance acquisition unit 1316 that calculates the distance to an object, and a collision determination unit 1318 that determines whether or not there is a possibility of a collision based on the calculated distance. Here, the distance acquisition unit 1316 may acquire distance information to the object using a Time of Flight (ToF) method, or may acquire distance information using parallax information, etc. In other words, the distance information is information related to parallax, defocus amount, distance to the object, etc. The collision determination unit 1318 may determine the possibility of a collision using any of this distance information. The distance acquisition unit 1316 may be realized by dedicated hardware or a software module. The distance acquisition unit 1316 may also be realized by a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or a combination thereof.

[0073] 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 an ECU 1330, which is a control device that outputs a control signal to generate a braking force for the vehicle based on the determination result of a collision determination 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 determination result of the collision determination unit 1318. For example, if the determination result of the collision determination unit 1318 indicates a high collision possibility, the ECU 1330 controls the drive device (mechanical device) 1360 by applying the brakes, releasing the accelerator, suppressing engine output, or other vehicle control to avoid the collision and mitigate damage. The alarm device 1340 warns the user by sounding an alarm, displaying alarm information on a screen of a car navigation system, or vibrating a seat belt or steering wheel.

[0074] In this embodiment, the photoelectric conversion system 1300 captures an image of the periphery of a vehicle (mobile body 1301), for example, the front or rear. Fig. 16(b) shows a photoelectric conversion system for capturing an image of the area in front of the vehicle (image capturing range 1350). A vehicle information acquisition device 1320 sends instructions to the photoelectric conversion system 1300 or the image capturing device 1310. This configuration can further improve the accuracy of distance measurement.

[0075] While the above describes an example of control to prevent collisions with other vehicles, the photoelectric conversion system 1300 can also be applied to other autonomous driving control systems, such as control systems that automatically follow other vehicles and automatically drive vehicles to avoid drifting out of their lanes. Furthermore, the photoelectric conversion system 1300 can be applied not only to vehicles such as automobiles, but also to moving bodies (mobile devices) such as ships, aircraft, and industrial robots. The moving body includes one or both of a driving force generating unit that generates a driving force primarily used to move the moving body and a rotating body primarily used to move the moving body. The driving force generating unit can be an engine, a motor, or the like. The rotating body can be a tire, a wheel, a ship's screw, an aircraft's propeller, or the like. In addition to moving bodies, the photoelectric conversion system 1300 can be applied to a wide range of devices that use object recognition, such as intelligent transport systems (ITS).

[0076] The photoelectric conversion system of the ninth embodiment will be described with reference to Fig. 17. Fig. 17 is a block diagram showing an example of the configuration of a range image sensor 1401 which is the photoelectric conversion system of this embodiment.

[0077] 17, the range image sensor 1401 is configured to include an optical system 1407, a photoelectric conversion device 1408, an image processing circuit 1404, a monitor 1405, and a memory 1406. The range image sensor 1401 can obtain a range image according to the distance to the subject by receiving light (modulated light or pulsed light) that is projected toward the subject from a light source device 1409 and reflected from the surface of the subject.

[0078] The optical system 1407 is configured to have one or more lenses, and guides image light (incident light) from a subject to the photoelectric conversion device 1408, forming an image on the light receiving surface (sensor section) of the photoelectric conversion device 1408.

[0079] The photoelectric conversion device 1408 is the photoelectric conversion device 100 according to each of the above-described embodiments, and a distance signal indicating a distance determined from a light receiving signal output from the photoelectric conversion device 1408 is supplied to the image processing circuit 1404.

[0080] The image processing circuit 1404 performs image processing to construct a distance image based on the distance signal supplied from the photoelectric conversion device 1408. The distance image (image data) obtained by this image processing is then supplied to a monitor 1405 for display, or supplied to a memory 1406 for storage (recording).

[0081] In the range image sensor 1401 configured in this way, by applying the above-described photoelectric conversion device 100, it is possible to obtain, for example, a more accurate range image as the pixel characteristics improve.

[0082] The photoelectric conversion system of the tenth embodiment will be described with reference to Fig. 18. Fig. 16 is a diagram showing an example of a schematic configuration of an endoscopic surgery system 1250 which is the photoelectric conversion system of this embodiment.

[0083] 18 shows a state in which an operator (doctor) 1231 is performing surgery on a patient 1232 on a patient bed 1233 using an endoscopic surgery system 1250. As shown in the figure, the endoscopic surgery system 1250 includes an endoscope 1200, a surgical tool 1210, and a cart 1234 on which various devices for endoscopic surgery are mounted.

[0084] The endoscope 1200 includes a lens barrel 1201, a region of which a predetermined length from the tip is inserted into a body cavity of a patient 1232, and a camera head 1202 connected to the base end of the lens barrel 1201. In the illustrated example, the endoscope 1200 is configured as a so-called rigid lens barrel having a rigid lens barrel 1201, but the endoscope 1200 may also be configured as a so-called flexible lens barrel having a flexible lens barrel.

[0085] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 1201. A light source device 1203 is connected to the endoscope 1200, and light generated by the light source device 1203 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 1201, and is irradiated via the objective lens towards an observation target inside a body cavity of a patient 1232. The endoscope 1200 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0086] An optical system and a photoelectric conversion device are provided inside the camera head 1202, and light reflected from an object to be observed (observation light) is focused onto the photoelectric conversion device by the optical system. 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 may be the photoelectric conversion device 100 (image capture device) described in each of the above-described embodiments. The image signal is transmitted as RAW data to a camera control unit (CCU) 1235.

[0087] The CCU 1235 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and comprehensively controls the operations of the endoscope 1200 and the display device 1236. Furthermore, the CCU 1235 receives an image signal from the camera head 1202 and performs various image processing on the image signal, such as development processing (demosaic processing), to display an image based on the image signal.

[0088] Under the control of the CCU 1235 , the display device 1236 displays an image based on the image signal that has been subjected to image processing by the CCU 1235 .

[0089] The light source device 1203 is configured from a light source such as an LED (Light Emitting Diode), and supplies the endoscope 1200 with irradiation light when photographing an operation site or the like.

[0090] The input device 1237 is an input interface for the endoscopic surgery system 1250. A user can input various information and instructions to the endoscopic surgery system 1250 via the input device 1237.

[0091] The treatment tool control device 1238 controls the driving of the energy treatment tool 1212 for cauterizing tissue, incising, sealing blood vessels, or the like.

[0092] The light source device 1203, which supplies illumination light to the endoscope 1200 when photographing the surgical site, can be configured from a white light source configured from, for example, an LED, a laser light source, or a combination of these. When the white light source is configured from a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, making it possible to adjust the white balance of the captured image in the light source device 1203. In this case, it is also possible to capture images corresponding to each RGB color in a time-division manner by irradiating the object of observation with laser light from each RGB laser light source in a time-division manner and controlling the drive of the image sensor of the camera head 1202 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.

[0093] Furthermore, the light source device 1203 may be controlled to change the intensity of light it outputs at predetermined time intervals. By controlling the driving of the image sensor of the camera head 1202 in synchronization with the timing of the change in light intensity to acquire images in a time-division manner and combining 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.

[0094] The light source device 1203 may also be configured to supply light in a predetermined wavelength band corresponding to special light observation. Special light observation utilizes, for example, the wavelength dependency of light absorption in body tissue. Specifically, specific tissue, such as blood vessels on the surface of the mucosa, can be photographed with high contrast by irradiating light with a narrower band than the light (i.e., white light) used in normal observation. Alternatively, special light observation may involve fluorescence observation, in which an image is obtained using fluorescence generated by irradiating excitation light. Fluorescence observation may involve irradiating excitation light onto body tissue and observing the fluorescence from the body tissue, or locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating 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.

[0095] A photoelectric conversion system according to an eleventh embodiment will be described with reference to FIGS. 19(a) and 19(b). FIG. 19(a) illustrates glasses 1600 (smart glasses) that are the photoelectric conversion system of this embodiment. The glasses 1600 include a photoelectric conversion device 1602. The photoelectric conversion device 1602 is the photoelectric conversion device 100 (imaging 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 of the photoelectric conversion device 1602 is not limited to that shown in FIG. 19(a).

[0096] 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 onto the photoelectric conversion device 1602.

[0097] FIG. 19(b) illustrates glasses 1610 (smart glasses) according to one application example. The glasses 1610 include a control device 1612, which includes a photoelectric conversion device corresponding to the photoelectric conversion device 1602 and a display device. A lens 1611 includes an optical system for projecting light emitted from the photoelectric conversion device 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 include a gaze detection unit for detecting the gaze of the wearer. Infrared light may be used for gaze detection. The infrared light emitter emits infrared light toward the eyeball of a user gazing at a displayed image. An imaging unit with a light receiving element detects the reflected light of the emitted infrared light from the eyeball, thereby obtaining an image of the eyeball. A reduction unit for reducing light from the infrared light emitter to the display unit in a planar view reduces degradation of image quality.

[0098] The gaze of the user relative to the displayed image is detected from an image of the eyeball captured using infrared light. Any known method can be used for gaze detection using an 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.

[0099] More specifically, gaze detection processing is performed based on the pupil-corneal reflex method, which calculates a gaze vector representing the direction (rotation angle) of the eyeball based on the pupil image and Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0100] The display device of this embodiment may have a photoelectric conversion device having a light receiving element, and may control the image displayed on the display device based on information on the user's line of sight from the photoelectric conversion device.

[0101] Specifically, the display device determines a first field of view area where 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 determined by an external control device and received. 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.

[0102] The display area may include 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.

[0103] Note that 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 gaze and the distance to an object in the line of sight from an image of the eyeball, using as training 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 an external device, it is transmitted to the display device via communication.

[0104] When display control is performed based on visual recognition detection, the present invention is preferably applied to smart glasses that further include a photoelectric conversion device for capturing images of the outside world. The smart glasses can display captured external information in real time.

[0105] The twelfth embodiment will be described with reference to Figures 20(a) and 20(b). The above-described photoelectric conversion device and photoelectric conversion system may be applied to electronic devices such as so-called smartphones and tablets.

[0106] 20(a) and 20(b) are diagrams showing an example of an electronic device 1500 equipped with a photoelectric conversion device. Fig. 20(a) shows the front side of the electronic device 1500, and Fig. 20(b) shows the back side of the electronic device 1500.

[0107] 20(a), a display 1510 for displaying an image is disposed in the center of the surface of the electronic device 1500. Then, along the upper side of the surface of the electronic device 1500, front cameras 1521 and 1522 using the above-described photoelectric conversion device 100, an IR light source 1530 for emitting infrared light, and a visible light source 1540 for emitting visible light are disposed.

[0108] Also, as shown in Figure 20(b), along the upper edge of the back of the electronic device 1500, rear cameras 1551 and 1552 using the above-mentioned photoelectric conversion device 100, an IR light source 1560 that emits infrared light, and a visible light source 1570 that emits visible light are arranged.

[0109] In the electronic device 1500 configured as described above, by applying the above-described photoelectric conversion device 100, it is possible to capture, for example, higher quality images. Note that the photoelectric conversion device can also be applied to other electronic devices such as infrared sensors, distance measuring sensors using active infrared light sources, security cameras, and personal or biometric authentication cameras. This can improve the accuracy and performance of these electronic devices.

[0110] 21 is a block diagram of an X-ray CT apparatus according to this embodiment. The photoelectric conversion device 100 described above is applicable to the detector of the X-ray CT apparatus. The X-ray CT apparatus 30 according to this embodiment includes an X-ray generation unit 310, a wedge 316, a collimator 318, an X-ray detection unit 320, a tabletop 330, a rotating frame 340, and a high-voltage generation device 350. The X-ray CT apparatus 30 also includes a data acquisition system (DAS) 351, a signal processing unit 352, a display unit 353, and a control unit 354.

[0111] The X-ray generating unit 310 is composed of, for example, a vacuum tube that generates X-rays. A high voltage and a filament current are supplied to the vacuum tube of the X-ray generating unit 310 from a high voltage generator 350. X-rays are generated by irradiating the anode (target) with thermoelectrons from the cathode (filament).

[0112] The wedge 316 is a filter that adjusts the amount of X-rays irradiated from the X-ray generation unit 310. The wedge 316 attenuates the amount of X-rays so that the X-rays irradiated from the X-ray generation unit 310 to the subject have a predetermined distribution. The collimator 318 is made of a lead plate or the like that narrows the irradiation range of the X-rays that have passed through the wedge 316. The X-rays generated by the X-ray generation unit 310 are shaped into a cone beam via the collimator 318 and are irradiated onto the subject on the tabletop 330.

[0113] The X-ray detection unit 320 is configured using the above-mentioned photoelectric conversion device 100. The X-ray detection unit 320 detects X-rays emitted from the X-ray generation unit 310 and passed through the subject, and outputs a signal corresponding to the X-ray dose to the DAS 351.

[0114] The rotating frame 340 has an annular shape and is configured to be rotatable. An X-ray generation unit 310 (wedge 316, collimator 318) and an X-ray detection unit 320 are arranged facing each other inside the rotating frame 340. The X-ray generation unit 310 and the X-ray detection unit 320 can rotate together with the rotating frame 340.

[0115] The high voltage generator 350 includes a booster circuit and outputs a high voltage to the X-ray generation unit 310. The DAS 351 includes an amplifier circuit and an A / D conversion circuit and outputs a signal from the X-ray detection unit 320 to the signal processing unit 352 as digital data.

[0116] The signal processing unit 352 includes a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory), and is capable of performing image processing on digital data. The display unit 353 includes a flat display device and is capable of displaying X-ray images. The control unit 354 includes a CPU, ROM, RAM, and the like, and controls the overall operation of the X-ray CT device 30.

[0117] The above-described embodiments can be modified as appropriate without departing from the spirit of the present invention. The disclosure of this specification includes not only what is described herein but also all matters that can be understood from the specification and the accompanying drawings. The disclosure of this specification also includes the complement of the concepts described herein. In other words, if the specification contains a statement that "A is greater than B," even if the statement that "A is not greater than B" is omitted, the specification can still be said to disclose that "A is not greater than B." This is because the statement that "A is greater than B" presupposes that the case in which "A is not greater than B" is taken into consideration.

[0118] The disclosure of the present specification includes the following configurations. (Item 1) A photoelectric conversion device having a semiconductor layer and a wiring structure, the semiconductor layer includes a pixel array region having a plurality of pixels, a scribe region including an outer edge of the semiconductor layer, a peripheral region disposed between the pixel array region and the scribe region, and an isolation portion electrically isolating the peripheral region and the scribe region, each of the plurality of pixels includes an avalanche photodiode having a first semiconductor region of a first conductivity type in which charges of a first polarity are majority carriers, and a second semiconductor region of a second conductivity type in which charges of a second polarity different from the first polarity are majority carriers; the peripheral region includes a first region of the first conductivity type and a second region of the second conductivity type, and the second region is supplied with the same voltage as that supplied to the second semiconductor region; the scribe region includes a third region of the first conductivity type; the wiring structure includes a first conductive path that electrically connects the first region and the third region, and a voltage supply line to which a predetermined voltage between a voltage of the first semiconductor region and a voltage of the second semiconductor region is supplied; the first region and the voltage supply line are electrically connected by a second conductive path; A photoelectric conversion device characterized by: (Item 2) The separation portion is arranged to surround the entire peripheral region. 2. The photoelectric conversion device according to item 1, (Item 3) the peripheral region further includes a fourth region of the first conductivity type and a fifth region of the first conductivity type electrically connecting the first region and the fourth region; the fourth region and the fifth region constitute at least a part of the second conductive path. 3. The photoelectric conversion device according to item 1 or 2, (Item 4) The fifth region is disposed in the same depth range as the fourth region. 4. The photoelectric conversion device according to item 3, (Item 5) the first conductive path includes a conductive pattern, a first plug that electrically connects the conductive pattern to the first region, and a second plug that electrically connects the conductive pattern to the third region; the voltage supply line includes a third plug electrically connected to the fourth region; 5. The photoelectric conversion device according to item 3 or 4, (Item 6) The distance between the first plug and the third plug is greater than the distance between the first plug and the second plug. 6. The photoelectric conversion device according to item 5, (Item 7) an electrical resistance value between the first plug and the third plug is greater than an electrical resistance value between the first plug and the second plug; 7. The photoelectric conversion device according to item 5 or 6, (Item 8) The first plug is disposed between the second plug and the third plug. 8. The photoelectric conversion device according to any one of items 5 to 7, wherein: (Item 9) an electric field relaxation region of the first conductivity type disposed in the semiconductor layer so as to surround the fourth region and the fifth region; 9. The photoelectric conversion device according to any one of items 3 to 8, wherein: (Item 10) an electric field relaxation region of the first conductivity type disposed in the semiconductor layer so as to surround the first region, the third region, the fourth region, and the fifth region; 9. The photoelectric conversion device according to any one of items 3 to 8, wherein: (Item 11) the peripheral region includes a fourth region of the first conductivity type and a sixth region of the first conductivity type arranged to electrically connect the first region and the fourth region; the fourth region and the sixth region constitute at least a part of the second conductive path; the sixth region has a lower concentration of the first conductivity type impurity than the first region and the fourth region; 3. The photoelectric conversion device according to item 1 or 2, (Item 12) the sixth region includes a portion that is arranged to surround the first region and the fourth region and that relieves an electric field acting on the first region and the fourth region; Item 12. The photoelectric conversion device according to item 11. (Item 13) the sixth region includes a portion that is arranged to surround the first region, the third region, and the fourth region and that relieves an electric field acting on the first region, the third region, and the fourth region; Item 12. The photoelectric conversion device according to item 11. (Item 14) the second conductive path further includes a second conductive pattern disposed in the wiring structure so as to supply the predetermined voltage to the first region and the fourth region; 14. The photoelectric conversion device according to any one of items 11 to 13, (Item 15) the peripheral region further includes a fourth region of the first conductivity type; the second conductive path includes a second conductive pattern disposed in the wiring structure so as to supply the predetermined voltage to the first region and the fourth region. 3. The photoelectric conversion device according to item 1 or 2, (Item 16) the semiconductor layer has a first surface and a second surface opposite to the first surface, and the wiring structure is disposed such that the first surface is located between the second surface and the wiring structure; a pinning layer disposed so as to cover the second surface; 16. The photoelectric conversion device according to any one of items 1 to 15, (Item 17) the pinning layer extends to cover the pixel array region, the peripheral region, and the scribe region; 17. The photoelectric conversion device according to item 16, (Item 18) Further comprising a microlens array, the semiconductor layer is disposed between the microlens array and the wiring structure; 18. The photoelectric conversion device according to any one of items 1 to 17, (Item 19) The photoelectric conversion device according to any one of items 1 to 18, a signal processing unit that processes a signal output from the photoelectric conversion device; A photoelectric conversion system comprising: (Item 20) 19. A moving body comprising the photoelectric conversion device according to claim 1, further comprising a control unit that controls movement of the moving body using a signal output from the photoelectric conversion device.

[0119] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0120] SL: semiconductor layer, WS: wiring structure, PAR: pixel array region, SCR: scribe region, PR: peripheral region, PR1: first peripheral region, PR2: second peripheral region, 361: isolation portion, 341: first region, 342: second region, 343: third region, 344: fourth region, 345: fifth region, 355: fifth region, ECPA: first conductive path, ECPB: second conductive path

Claims

1. A photoelectric conversion device having a semiconductor layer and a wiring structure, the semiconductor layer includes a pixel array region having a plurality of pixels, a scribe region including an outer edge of the semiconductor layer, a peripheral region disposed between the pixel array region and the scribe region, and an isolation portion electrically isolating the peripheral region and the scribe region, each of the plurality of pixels includes an avalanche photodiode having a first semiconductor region of a first conductivity type in which charges of a first polarity are majority carriers, and a second semiconductor region of a second conductivity type in which charges of a second polarity different from the first polarity are majority carriers; the peripheral region includes a first region of the first conductivity type and a second region of the second conductivity type, and the second region is supplied with the same voltage as that supplied to the second semiconductor region; the scribe region includes a third region of the first conductivity type; the wiring structure includes a first conductive path that electrically connects the first region and the third region, and a voltage supply line to which a predetermined voltage between a voltage of the first semiconductor region and a voltage of the second semiconductor region is supplied; the first region and the voltage supply line are electrically connected by a second conductive path; A photoelectric conversion device characterized by:

2. The separation portion is arranged to surround the entire peripheral region.

2. The photoelectric conversion device according to claim 1.

3. the peripheral region further includes a fourth region of the first conductivity type and a fifth region of the first conductivity type electrically connecting the first region and the fourth region; the fourth region and the fifth region constitute at least a part of the second conductive path; 2. The photoelectric conversion device according to claim 1.

4. The fifth region is disposed in the same depth range as the fourth region.

4. The photoelectric conversion device according to claim 3.

5. the first conductive path includes a conductive pattern, a first plug that electrically connects the conductive pattern to the first region, and a second plug that electrically connects the conductive pattern to the third region; the voltage supply line includes a third plug electrically connected to the fourth region; 4. The photoelectric conversion device according to claim 3.

6. The distance between the first plug and the third plug is greater than the distance between the first plug and the second plug.

6. The photoelectric conversion device according to claim 5.

7. an electrical resistance value between the first plug and the third plug is greater than an electrical resistance value between the first plug and the second plug; 6. The photoelectric conversion device according to claim 5.

8. The first plug is disposed between the second plug and the third plug.

6. The photoelectric conversion device according to claim 5.

9. an electric field relaxation region of the first conductivity type disposed in the semiconductor layer so as to surround the fourth region and the fifth region; 4. The photoelectric conversion device according to claim 3.

10. an electric field relaxation region of the first conductivity type disposed in the semiconductor layer so as to surround the first region, the third region, the fourth region, and the fifth region; 4. The photoelectric conversion device according to claim 3.

11. the peripheral region includes a fourth region of the first conductivity type and a sixth region of the first conductivity type arranged to electrically connect the first region and the fourth region; the fourth region and the sixth region constitute at least a part of the second conductive path; the sixth region has a lower concentration of the first conductivity type impurity than the first region and the fourth region; 2. The photoelectric conversion device according to claim 1.

12. the sixth region includes a portion that is arranged to surround the first region and the fourth region and that relieves an electric field acting on the first region and the fourth region; 12. The photoelectric conversion device according to claim 11.

13. the sixth region includes a portion that is arranged to surround the first region, the third region, and the fourth region and that relieves an electric field acting on the first region, the third region, and the fourth region; 12. The photoelectric conversion device according to claim 11.

14. the second conductive path further includes a second conductive pattern disposed in the wiring structure so as to supply the predetermined voltage to the first region and the fourth region; 12. The photoelectric conversion device according to claim 11.

15. the peripheral region further includes a fourth region of the first conductivity type; the second conductive path includes a second conductive pattern disposed in the wiring structure so as to supply the predetermined voltage to the first region and the fourth region; 2. The photoelectric conversion device according to claim 1.

16. the semiconductor layer has a first surface and a second surface opposite to the first surface, and the wiring structure is disposed such that the first surface is located between the second surface and the wiring structure; a pinning layer disposed to cover the second surface; 2. The photoelectric conversion device according to claim 1.

17. the pinning layer extends to cover the pixel array region, the peripheral region, and the scribe region; 17. The photoelectric conversion device according to claim 16.

18. Further comprising a microlens array, the semiconductor layer is disposed between the microlens array and the wiring structure; 2. The photoelectric conversion device according to claim 1.

19. The photoelectric conversion device according to any one of claims 1 to 18, a signal processing unit that processes a signal output from the photoelectric conversion device; A photoelectric conversion system comprising:

20. A moving body comprising the photoelectric conversion device according to claim 1 , further comprising a control unit that controls movement of the moving body using a signal output from the photoelectric conversion device.

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