Photoelectric conversion device, photoelectric conversion system, moving object, and apparatus

Abstract

The invention provides a photoelectric conversion device, a photoelectric conversion system, a moving object, and an apparatus. A photoelectric conversion device according to the present invention includes: a first pixel including a first avalanche photodiode; a second pixel including a second avalanche photodiode; and an isolation portion that isolates the first pixel and the second pixel, in which, in a plan view, a distance from a center of the first pixel to the isolation portion is longer than a distance from a center of the second pixel to the isolation portion.

Description

Technical Field

[0001] The present disclosure relates to a photoelectric conversion device, a photoelectric conversion system, a mobile object, and equipment. Background Art

[0002] A photoelectric conversion device capable of detecting single-photon-level weak light by using avalanche multiplication is known. U.S. Patent Application Publication No. 2017 / 0186798 discloses a photoelectric conversion device that electrically connects a sensor chip in which a plurality of pixels are arranged and a circuit chip in which a circuit for performing signal processing is formed by using a layered structure. It is also disclosed that an avalanche photodiode (APD) in which charge causes avalanche multiplication is used for a pixel in the sensor chip of the photoelectric conversion device.

[0003] In addition, a technique for using high-sensitivity pixels and low-sensitivity pixels to expand the dynamic range or suppress flicker is also known. Japanese Patent Application Laid-Open No. 2022-168741 discloses a light receiving device using APDs for high-sensitivity pixels and low-sensitivity pixels, respectively.

[0004] However, in a configuration in which both high-sensitivity pixels and low-sensitivity pixels include APDs, there is still room for considering a more appropriate pixel structure. Summary of the invention

[0005] In a first aspect, the present invention provides a photoelectric conversion device, comprising: a first pixel, including a first avalanche photodiode; a second pixel, including a second avalanche photodiode; and an isolation portion, which isolates the first pixel and the second pixel, wherein the distance from the center of the first pixel to the isolation portion in a plan view is longer than the distance from the center of the second pixel to the isolation portion.

[0006] In a second aspect, the present invention provides a photoelectric conversion device, comprising: a first pixel, including a first avalanche photodiode; and a second pixel, including a second avalanche photodiode; and is constructed so that light leakage from the first pixel to the second pixel is more strongly suppressed than light leakage from the second pixel to the first pixel.

[0007] In a third aspect, the present invention provides a photoelectric conversion device, comprising: a first pixel including a first avalanche photodiode; and a second pixel including a second avalanche photodiode, wherein a groove that is not arranged in the second pixel is arranged in the first pixel.

[0008] The present invention, in a fourth aspect, provides a photoelectric conversion system including the above-mentioned photoelectric conversion device and a signal processing unit that generates an image by using a signal output by the photoelectric conversion device.

[0009] The present invention provides, in a fifth aspect, a moving body including the above-mentioned photoelectric conversion device, the moving body including a control unit that controls movement of the moving body by using a signal output by the photoelectric conversion device.

[0010] In a sixth aspect, the present invention provides an apparatus comprising the above-mentioned photoelectric conversion device, and at least one of the following devices: an optical device corresponding to the photoelectric conversion device, a control device for controlling the photoelectric conversion device, a processing device for processing a signal output from the photoelectric conversion device, a display device for displaying information obtained by the photoelectric conversion device, a storage device for storing information obtained by the photoelectric conversion device, and a mechanical device that operates based on the information obtained by the photoelectric conversion device.

[0011] The present invention provides a suitable pixel structure in which the high-sensitivity pixel and the low-sensitivity pixel each include an avalanche photodiode.

[0012] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of a photoelectric conversion device according to an embodiment;

[0014] Figure 2 is a schematic diagram of a pixel substrate of a photoelectric conversion device according to an embodiment;

[0015] Figure 3 is a schematic diagram of a circuit substrate of a photoelectric conversion device according to an embodiment;

[0016] Figure 4A and Figure 4B is a configuration example of a pixel circuit of a photoelectric conversion device according to an embodiment;

[0017] Figure 5 is a schematic diagram showing driving of a pixel circuit of a photoelectric conversion device according to an embodiment;

[0018] Fig. 6A is a plan view of a photoelectric conversion device according to Embodiment 1;

[0019] Figure 6B is a cross-sectional view of a photoelectric conversion device according to Embodiment 1;

[0020] Fig. 7A is a plan view of a photoelectric conversion device according to a comparative example;

[0021] Figure 7B is a cross-sectional view of a photoelectric conversion device according to a comparative example;

[0022] Figure 8is a cross-sectional view of a modification of the photoelectric conversion device according to Embodiment 1;

[0023] Fig.9A is a plan view of a photoelectric conversion device according to Embodiment 2;

[0024] Fig. 9B is a cross-sectional view of a photoelectric conversion device according to Embodiment 2;

[0025] FIG. 10A to FIG. 10C is a plan view of a photoelectric conversion device according to Embodiment 3;

[0026] Fig.11A and Fig. 11B is a cross-sectional view of a photoelectric conversion device according to Embodiment 3;

[0027] FIG. 12A to FIG. 12C is a plan view of a photoelectric conversion device according to Embodiment 4;

[0028] Fig.13A and Fig. 13B is a cross-sectional view of a photoelectric conversion device according to Embodiment 4;

[0029] FIG. 14A to FIG. 14C is a plan view of a photoelectric conversion device according to Embodiment 5;

[0030] FIG. 15A to FIG. 15C is a cross-sectional view of a photoelectric conversion device according to Embodiment 5;

[0031] FIG. 16A to FIG. 16C is a plan view of a photoelectric conversion device according to Embodiment 6;

[0032] FIG. 17A to FIG. 17C is a cross-sectional view of a photoelectric conversion device according to Embodiment 6;

[0033] Fig.18 is a plan view of a photoelectric conversion device according to Embodiment 7;

[0034] FIG. 19A to FIG. 19C is a cross-sectional view of a photoelectric conversion device according to Embodiment 7;

[0035] Fig. 20 is a plan view of a modification of the photoelectric conversion device according to Embodiment 7;

[0036] Fig.21A and Fig.21B is a plan view of a photoelectric conversion device according to Embodiment 8;

[0037] FIG. 22A to FIG. 22C is a cross-sectional view of a photoelectric conversion device according to Embodiment 8;

[0038] Fig.23is a plan view of a photoelectric conversion device according to Embodiment 9;

[0039] FIG. 24A to FIG. 24C is a cross-sectional view of a photoelectric conversion device according to Embodiment 9;

[0040] Fig.25 is a diagram for explaining a photoelectric conversion system according to Embodiment 10;

[0041] Fig.26A is a diagram for explaining a photoelectric conversion system according to Embodiment 11;

[0042] Fig.26B is a diagram for explaining a moving body according to embodiment 11;

[0043] Fig. 27 is a diagram for explaining a distance image sensor according to Embodiment 12;

[0044] Fig.28 is a diagram for explaining an endoscopic surgery system according to embodiment 13;

[0045] Fig.29A and Fig.29B is a diagram for explaining smart glasses according to embodiment 14;

[0046] Fig. 30A and Fig. 30B is a diagram for explaining an electronic device according to embodiment 15;

[0047] Fig.31 is a diagram for explaining an X-ray CT apparatus according to Embodiment 16; and

[0048] Fig.32 This is a diagram for illustrating a device according to embodiment 17. DETAILED DESCRIPTION

[0049] The following embodiments are used to implement the technical concept of the present invention and do not limit the scope of the present invention. The size and positional relationship of the components indicated in each figure may be exaggerated for clarity. In the following description, the same constituent elements are marked with the same reference numerals, and their redundant descriptions may be omitted.

[0050] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, terms indicating specific directions or positions (e.g., "upper", "lower", "right", "left", etc.) may be used when necessary. These terms are used to assist in understanding the embodiments with reference to the accompanying drawings, and are not intended to limit the technical scope of the present invention by the meaning of these terms.

[0051] In this specification, a "plan view" refers to a view in a direction perpendicular to the light incident surface of the semiconductor layer. A "cross-sectional view" refers to a view of a cross section of the semiconductor layer perpendicular to the light incident surface. In the case where the light incident surface of the semiconductor layer is rough from a microscopic perspective, the plan view is defined based on the light incident surface of the semiconductor layer from a macroscopic perspective.

[0052] The semiconductor layer has a first surface and a second surface (a surface on the opposite side of the first surface) for light to enter. In this specification, the depth direction is the direction from the first surface of the semiconductor layer where the avalanche photodiode (APD) is arranged to the second surface. In the following, the "first surface" may be referred to as the "front side", and the "second surface" may be referred to as the "back side". The "depth" of the semiconductor layer at a point or region refers to the distance from the first surface (front side) at the point or region. In the case where Z1 is a point (or region) with a distance (depth) of d1 from the first surface, Z2 is a point (or region) with a distance (depth) of d2 from the first surface, and d1>d2 is established, it can be expressed as "Z1 is deeper than Z2" or "Z2 is shallower than Z1". In addition, in the case where Z3 is a point (or region) with a distance (depth) of d3 from the first surface, and d1>d3>d2 is established, it can be expressed as "Z3 has a depth between Z1 and Z2", or "Z3 is between Z1 and Z2 in the depth direction".

[0053] In the following description, it is assumed that the anode of the avalanche photodiode (APD) has a fixed potential and the signal is extracted from the cathode side. Therefore, the first conductive semiconductor region, that is, the region in which the charge having the same polarity as the signal charge is the majority carrier is an N-type semiconductor region, and the second conductive semiconductor region, that is, the region in which the charge having a polarity different from the signal charge is the majority carrier is a P-type semiconductor region. Even in the case where the cathode of the APD has a fixed potential and the signal is extracted from the anode side, the present invention is also established. In this case, the first conductive semiconductor region, that is, the region in which the charge having the same polarity as the signal charge is the majority carrier is a P-type semiconductor region, and the second conductive semiconductor region, that is, the region in which the charge having a polarity different from the signal charge is the majority carrier is an N-type semiconductor region. In the following description, one node of the APD has a fixed potential, but the potentials of the two nodes may vary.

[0054] In this specification, "impurity concentration" refers to the net impurity concentration obtained by subtracting the amount compensated by the reverse conductive impurities. In other words, "impurity concentration" refers to the net doping concentration. A region where the P-type added impurity concentration is higher than the N-type added impurity concentration is a P-type semiconductor region. Conversely, a region where the N-type added impurity concentration is higher than the P-type added impurity concentration is an N-type semiconductor region.

[0055] In the following embodiments, the interconnection of the elements of the loop may be mentioned. In this case, even if there are other elements between these elements, unless otherwise stated, these elements are also considered to be electrically interconnected. For example, element A is connected to a node of a capacitor element C including multiple nodes, and element B is connected to another node. Even in this case, unless otherwise stated, element A and element B are also considered to be electrically interconnected. In the case where the elements are interconnected without intermediate elements, it can be expressed as these elements being directly interconnected. In the above example, if no other elements are arranged between element A and capacitor element C, element A and capacitor element C can be said to be "directly interconnected".

[0056] In this specification, metal components such as wires and pads may be composed of a single element metal, or may be a mixture (alloy). For example, a wire described as a copper wire may be composed of copper alone, or may be composed mainly of copper with other elements added. In addition, for example, a pad connected to an external terminal may be composed of aluminum alone, or may be composed mainly of aluminum with other elements added. The copper wire and aluminum pad described here are examples, and the material may be changed to various other metals.

[0057] The wires and pads described here are examples of metal members used in the photoelectric conversion device, but other metal members may also be used.

[0058] In each embodiment to be described below, as an example of a photoelectric conversion device, an imaging device will be mainly described. However, the application of each embodiment is not limited to an imaging device, and there may be other examples of a photoelectric conversion device. For example, each embodiment is applicable to a distance measuring device (a distance measuring device using focus detection or time of flight (ToF)) and a photometric device (for example, a device for measuring the amount of incident light).

[0059] Will refer to Figures 1 to 5 The common structure of each embodiment of the photoelectric conversion device and the driving method thereof according to the present invention will be described.

[0060] Figure 1is a diagram depicting the configuration of a photoelectric conversion device 100 according to an embodiment of the present invention. In the following, as an example, a case where the photoelectric conversion device 100 is a stacked photoelectric conversion device is described. In other words, a photoelectric conversion device consisting of two stacked and electrically connected substrates, a sensor substrate 11 and a circuit substrate 21, is described as an example. However, the photoelectric conversion device is not limited to this. For example, a photoelectric conversion device in which a configuration included in the sensor substrate 11 and a configuration included in the circuit substrate 21 to be described below are arranged on a common semiconductor layer may be used. In the following description, a photoelectric conversion device in which a configuration included in the sensor substrate 11 and a configuration included in the circuit substrate 21 are arranged on a common semiconductor layer is also referred to as a "non-stacked photoelectric conversion device".

[0061] The sensor substrate 11 includes a first semiconductor layer and a first wiring structure, the first semiconductor layer having a later-mentioned photoelectric conversion element 102. The circuit substrate 21 includes a second semiconductor layer and a second wiring structure, the second semiconductor layer having a circuit such as a later-mentioned signal processing unit 103. The photoelectric conversion device 100 is composed of a second semiconductor layer, a second wiring structure, a first wiring structure, and a first semiconductor layer stacked in sequence.

[0062] Figure 1 A back-illuminated photoelectric conversion device is shown, in which light enters through the second surface (back surface), and the circuit substrate 21 is arranged on the first surface (front surface), which is the surface on the opposite side of the second surface. In the case of a non-stacked photoelectric conversion device, the surface on the side where the transistor of the signal processing circuit is arranged is called the "first surface". In the case of a front-illuminated photoelectric conversion device, the front surface is the second surface (light incident surface), and the back surface is the first surface.

[0063] In the following description, the sensor substrate 11 and the circuit substrate 21 are cut chips, but are not limited to chips. For example, each substrate may be a wafer. In addition, each substrate may be stacked in a wafer state and then cut, or may be first created as a chip and then each chip may be stacked by bonding.

[0064] The pixel region 12 is arranged on the sensor substrate 11 , and the circuit region 22 for processing a signal detected in the pixel region 12 is arranged on the circuit substrate 21 .

[0065] Figure 2 : is a layout diagram of the sensor substrate 11. Pixels 101 having photoelectric conversion elements 102 including avalanche photodiodes (APDs) are arranged in a two-dimensional manner so as to form a pixel region 12.

[0066] The pixel 101 is usually a pixel for forming an image, but when used for time of flight (ToF), it may not 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.

[0067] Figure 3 is a block diagram of the circuit substrate 21. The circuit substrate 21 includes: a signal processing unit 103, which processes Figure 2 The charge generated by the photoelectric conversion of the photoelectric conversion element 102 in the embodiment; the reading circuit 112; the control pulse generating unit 115; the horizontal scanning circuit unit 111; the signal line 113; the vertical scanning circuit unit 110; the driving line 116; and the output circuit 114.

[0068] Figure 2 Each of the photoelectric conversion elements 102 and Figure 3 Each of the signal processing units 103 in the TFT array is electrically connected via connection lines arranged for each pixel.

[0069] The vertical scanning circuit unit 110 receives the control pulse supplied from the control pulse generating unit 115, and supplies the control pulse to each pixel via the driving line 116. For the vertical scanning circuit unit 110, a logic circuit such as a shift register and an address decoder is used.

[0070] The control pulse generating unit 115 includes a signal generating unit 215 mentioned later, which generates a control signal P_CLK of the switch mentioned later. As described below, the signal generating unit 215 generates a pulse signal to control the switch. For example, Figure 4A As shown, the signal generating unit 215 may generate a common control signal P_CLK for a plurality of pixels in the pixel region 12, or as shown in FIG. Figure 4B As shown, the signal generating unit 215 can generate a control signal P_CLK for each pixel. In the case of generating a common control signal P_CLK, the common signal is generated so that at least one of the period, number of pulses and pulse width of the signal P_EXP (pulse signal) for controlling the exposure time corresponds to the exposure time. In the case of controlling the control signal P_CLK for each pixel, both the signal P_EXP and the input signal P_CLK_IN output from the control pulse generating unit 115 are used to generate a signal to control the exposure time. Preferably, the control pulse generating unit 115 includes, for example, a frequency division loop. Then simple control is possible, and an increase in the number of components can be prevented.

[0071] The signal output from the photoelectric conversion element 102 in each pixel is processed by the signal processing unit 103. A counter, a memory, and the like are arranged in the signal processing unit 103, and a digital value is stored in the memory.

[0072] The horizontal scanning circuit unit 111 inputs a control pulse to the signal processing unit 103, and the control pulse sequentially selects each column so as to read a signal from a memory storing a digital signal of each pixel.

[0073] For the selected column, a signal is output from the signal processing unit 103 of the pixel selected by the vertical scanning circuit unit 110 to the signal line 113 .

[0074] The signal output to the signal line 113 is output to a recording unit or a signal processing unit outside the photoelectric conversion device 100 via an output circuit 114 .

[0075] exist Figure 2 , the array of pixels 101 in the pixel area 12 may be arranged one-dimensionally. The functions of the signal processing unit 103 do not need to be arranged on a one-to-one basis for each of the pixels 101, but, for example, one signal processing unit 103 may be shared by a plurality of pixels 101, and signal processing may be performed sequentially for each pixel 101.

[0076] Figure 4A and Figure 4B is an example of a block diagram, including Figure 2 and Figure 3 The equivalent circuit of . Figure 4A is an example of a common signal generating unit 215 arranged for a plurality of pixels, and Figure 4B is an example in which the control signal P_CLK can be controlled for each pixel. Figure 4A Provide explanation.

[0077] exist Figure 4A In the embodiment, the photoelectric conversion element 102 including the APD 201 is arranged on the sensor substrate 11 , and other components are arranged on the circuit substrate 21 .

[0078] APD 201 generates charge pairs by photoelectric conversion according to incident light. Voltage VL (first voltage) is supplied to the anode of APD 201. Voltage VH (second voltage) higher than voltage VL supplied to the anode is supplied to the cathode of APD 201. Reverse bias is supplied to the anode and cathode so that APD 201 performs an avalanche multiplication operation. By supplying such a voltage, the charge generated by the incident light causes avalanche multiplication, thereby generating an avalanche current.

[0079] The reverse bias is supplied in a Geiger mode, in which the potential difference between the anode and the cathode during operation is greater than the breakdown voltage, or in a linear mode, in which the potential difference between the anode and the cathode during operation is approximately equal to or less than the breakdown voltage. An APD operating in a Geiger mode is called a SPAD. For example, the voltage VL (first voltage) is -30V, and the voltage VH (second voltage) is 1V. APD 201 can be operated in a linear mode or a Geiger mode. In the case of a SPAD, the potential difference is greater than that of an APD operating in a linear mode, and the effect of a high withstand voltage becomes significant.

[0080] The switch 202 is connected to a power line to which a driving voltage VH is supplied and the APD 201. The switch 202 is connected to one of the anode and the cathode of the APD 201. Then, the switch 202 switches the potential difference between the anode and the cathode of the APD 201 between a first potential difference that generates avalanche multiplication and a second potential difference that does not generate avalanche multiplication. In the following description, switching from the second potential difference to the first potential difference is also referred to as "turning ON" the switch 202, and switching from the first potential difference to the second potential difference is also referred to as "turning OFF" the switch 202. The switch 202 serves as a quenching element. When a signal is multiplied by avalanche multiplication, the switch 202 serves as a load loop (quenching loop), and performs a function of suppressing avalanche multiplication (quenching operation) by suppressing the voltage supplied to the APD 201. The switch 202 also has a function of returning the voltage supplied to the APD 201 to the driving voltage VH (recharging operation) by supplying a current of an amount causing a voltage drop in the quenching operation. In other words, the switch 202 serves as a control loop for controlling the generation of avalanche multiplication in the APD 201.

[0081] For example, the switch 202 may be formed of a MOS transistor. The control signal P_CLK of the switch 202 supplied from the signal generating unit 215 is applied to the gate electrode of the MOS transistor forming the switch 202. In this embodiment, the switch 202 is controlled to be ON or OFF by controlling the voltage applied to the gate electrode of the switch 202.

[0082] The signal processing unit 103 includes a waveform shaping unit 210, a counter circuit 211, and a selection circuit 212. In the present specification, it is sufficient that the signal processing unit 103 includes at least one of the waveform shaping unit 210, the counter circuit 211, and the selection circuit 212.

[0083] 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. Assume that the node on the input side of the waveform shaping unit 210 is node A, and the node on the output side of the waveform shaping unit 210 is node B. The waveform shaping unit 210 changes the output potential from node B according to whether the input potential of node A is at least a predetermined value or lower than a predetermined value. For example, if the input potential of node A is at least Figure 5 If the potential of the input to node A is lower than the threshold value, the output potential from node B becomes a low level. If the potential of the input to node A is lower than the threshold value, the output potential from node B becomes a high level. For example, an inverter circuit is used for the waveform shaping unit 210. Figure 4A In the example of FIG. 2 , one inverter is used for the waveform shaping unit 210 , but a circuit in which a plurality of inverters are connected in series may be used, or other circuits that produce a waveform shaping effect may be used.

[0084] The quenching operation and the recharging operation can be performed using the switch 202 according to the avalanche multiplication in the APD 201, but in some cases, the charge generated in the APD 201 may not be determined as an output signal, depending on the photon detection timing. For example, it is assumed that avalanche multiplication is generated in the APD 201, and the node A becomes a low level, and a recharging operation is performed. Generally, the determination threshold of the waveform shaping unit 210 is set to a potential higher than the potential difference that generates avalanche multiplication in the APD 201. If the recharging operation is performed and a photon enters the APD 201 when the potential of the node A is lower than the determination threshold, and the potential is a potential that can generate avalanche multiplication in the APD 201, avalanche multiplication is generated in the APD 201, and the voltage in the node A drops. In other words, the potential of the node A drops to a voltage lower than the determination threshold, so the potential change that crosses the determination threshold is not generated, and the output potential from the node B does not change. This means that even if avalanche multiplication is generated, the detection of the photon is not determined as a signal. Particularly under high illumination, photons continuously enter the APD 201 in a short period of time, so the incident light is not always determined as a signal. As a result, even if the illumination is high, the actual number of photons entering and the output signal is likely to differ.

[0085] On the other hand, if the switch 202 is switched ON or OFF by applying a control signal P_CLK to the switch 202, a signal can be determined even if photons continuously enter the APD 201 in a short period of time. Figure 5 In the example in which the control signal P_CLK is a pulse signal having a repetitive cycle, Figure 5A case where the switch 202 is switched ON or OFF at a predetermined clock frequency will be described in . However, even if the pulse signal is not a signal having a repetitive cycle, an effect of suppressing an increase in power consumption of the photoelectric conversion device 100 can be obtained.

[0086] The counter circuit 211 counts the pulse signal output from the waveform shaping unit 210 and holds the count value. When the control pulse pRES is supplied via the driving line 213, the count value of the signal held in the counter circuit 211 is reset.

[0087] The control pulse pSEL is Figure 4A The drive line 214 in Figure 3 The vertical scanning circuit unit 110 in the embodiment supplies the counter circuit 211 to the selection circuit 212, and switches the electrical connection or disconnection between the counter circuit 211 and the signal line 113. For example, the selection circuit 212 includes a buffer circuit for outputting the signal.

[0088] Electrical connection or disconnection can be switched by arranging a switch (e.g., transistor) between the switch 202 and the APD 201 or between the photoelectric conversion element 102 and the signal processing unit 103. In the same manner, the supply of the voltage VH or the voltage VL to the photoelectric conversion element 102 can be electrically switched using a switch (e.g., transistor).

[0089] In the configuration described in this embodiment, the counter circuit 211 is used. However, instead of the counter circuit 211, a time digital converter (hereinafter referred to as TDC) may be used, or the photoelectric conversion device 100 may use a memory to acquire the pulse detection timing. 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. In order to measure the timing of the pulse signal, the control pulse pREF (reference signal) is transmitted from the drive line 210 to the control line 211. Figure 3 The vertical scanning circuit unit 110 in the embodiment is supplied to the TDC. The TDC acquires a determined value as a digital signal, in which the input timing of the signal output from each pixel is based on the relative time of the control pulse pREF.

[0090] Figure 52 is a schematic diagram depicting the relationship between the control signal P_CLK of the switch, the potential of the node A, the potential of the node B, and the output signal. In the present embodiment, when the control signal P_CLK is at a high level, the supply of the driving voltage VH to the APD 201 is interrupted, and when the control signal P_CLK is at a low level, the driving voltage VH is supplied to the APD 201. The high level of the control signal P_CLK is, for example, 1V, and the low level of the control signal P_CLK is, for example, 0V. When the control signal P_CLK is at a high level, the switch is turned off, and when the control signal P_CLK is at a low level, the switch is turned on. The resistance value of the switch when the control signal P_CLK is at a high level is higher than the resistance value of the switch when the control signal P_CLK is at a low level. In the case where the control signal P_CLK is at a high level, even if avalanche multiplication is generated in the APD 201, it is difficult to perform a recharging operation, so the potential to be supplied to the APD 201 becomes the breakdown voltage of the APD 201 or less. As a result, the avalanche multiplication operation in the APD 201 stops.

[0091] like Figure 4A It is preferred that the switch 202 is composed of one transistor, and the one transistor performs the quenching operation and the recharging operation. Therefore, the number of loops can be reduced compared to the case where the quenching operation and the recharging operation are performed by different loop elements, respectively. In particular, in the case where each pixel has a counter loop and the signal of the SPAD is read for each pixel, it is preferred to reduce the loop area for the switch in order to arrange the counter loop, so the effect of configuring the switch 202 with one transistor becomes significant.

[0092] At time t1, the control signal P_CLK changes from a high level to a low level, so that the switch is turned on and the recharging operation starts in APD 201. As a result, the potential of the cathode of APD 201 becomes a high level. Then, the potential difference of the potentials applied to the anode and cathode of APD 201 becomes a state in which avalanche multiplication can be performed. The potential of the cathode is the same as that of node A. Therefore, when the potential of the cathode changes from a low level to a high level, the potential of node A becomes a determined threshold or greater at time t2. At this time, the pulse signal output from node B is inverted and changes from a high level to a low level. Then in APD 201, the pulse signal enters a state in which a potential difference is applied between the driving voltage VH and the driving voltage VL. The control signal P_CLK becomes a high level, and the switch is turned off.

[0093] Then, when the photon enters the APD 201 at time t3, avalanche multiplication is generated in the APD 201, and the voltage of the cathode drops. In other words, the voltage of the node A drops. As the voltage drop amount further increases and the voltage difference applied to the APD 201 decreases, the avalanche multiplication in the APD 201 stops at time t2, and the voltage level of the node A does not drop more than the predetermined value. When the voltage of the node A becomes lower than the determined threshold value during the drop, the voltage of the node B changes from a low level to a high level. In other words, a portion of the output waveform in the node A that exceeds the determined threshold value is shaped by the waveform shaping unit 210 and output from the node B as a signal. Then, the count value of the counter signal counted by the counter loop and output from the counter loop increases by 1LSB.

[0094] Photons enter the APD 201 between time t3 and time t4, but this is a period in which the switch is off, and the voltage applied to the APD 201 has no potential difference to cause avalanche multiplication, so the voltage level of the node A does not exceed the determination threshold.

[0095] At time t4, the control signal P_CLK changes from a high level to a low level, thereby turning on the switch. Due to this change, a current for compensating for the amount of voltage dropped from the driving voltage VH flows to node A, and the voltage of node A changes to the original voltage level. Here, the voltage of node A becomes a certain threshold value or more at time t5, so the pulse signal of node B is inverted and changes from a high level to a low level.

[0096] At time t6, node A is stabilized to the original voltage level, and the control signal P_CLK changes from a low level to a high level. The switch is thereby turned off. Thereafter, as described for time t1 to time t6, the potentials of various nodes, signal lines, etc. change according to the control signal P_CLK and the entry of photons.

[0097] Hereinafter, a photoelectric conversion device according to each embodiment will be described.

[0098] Implementation Method 1

[0099] Fig. 6A and Figure 6B The structure of the sensor substrate 11 of the photoelectric conversion device according to Embodiment 1 is shown. Fig. 6A 1 is a plan view depicting the configuration of the pixel region 12 , and is a schematic diagram of the semiconductor layer 300 of the sensor substrate 11 viewed from the first surface side. Figure 6B is Fig. 6A A cross-sectional view taken along line AA in FIG.

[0100] like Fig. 6A As shown, a plurality of APDs 201 are arranged on the semiconductor layer 300. Fig. 6AIn the figure, only three APDs 201 in one row×three columns are depicted to simplify the description, but in actual products, hundreds of thousands to millions of APDs 201 are formed in a two-dimensional array. One APD 201 corresponds to one pixel.

[0101] An isolation portion 330 is disposed in the semiconductor layer 300. The isolation portion is an isolation structure for reducing optical crosstalk (light leakage) between adjacent APDs 201. Fig. 6A In the figure, the isolating portion 330 is drawn as a line, but in fact the isolating portion 330 has a thickness. The APD 201 is arranged in each segment separated by the isolating portion 330. Thus, a plurality of pixels are isolated by the isolating portion 330. The segment corresponding to one pixel has a roughly (approximately) square shape in a plan view. In other words, the isolating portion 330 surrounds one pixel of a roughly square shape in a plan view. The contact plug 326 of the cathode wiring formed in the wiring structure 320 is arranged roughly at the center of the pixel (segment), and the contact plug 324 of the anode wiring is arranged on the edge of the pixel.

[0102] like Figure 6B As shown, the sensor substrate 11 has a structure in which a semiconductor layer 300 and a wiring structure 320 are stacked. The surface of the semiconductor layer 300 located on the side where the wiring structure 320 is located is called a "first surface", and the surface of the semiconductor layer 300 located on the opposite side of the first surface is called a "second surface". The semiconductor layer 300 is composed of silicon, for example. A fixed charge film 310, an insulating film 311, a flattening film 312, etc. are sequentially stacked on the second surface of the semiconductor layer 300, and a microlens 313 corresponding to each pixel is arranged above these films. In other words, the photoelectric conversion device according to Embodiment 1 has a back-illuminated structure in which light enters the semiconductor layer 300 from the second surface side. The second surface is also referred to as a "light incident surface". The following structure can be used for the light incident surface. For example, an uneven structure having at least one concave portion or convex portion is arranged on the second surface (light incident surface). The uneven structure is composed of silicon constituting the semiconductor layer 300 and other components. For example, an insulator such as a silicon oxide film, a silicon oxynitride film, or a silicon nitride film is arranged in a concave portion formed in the semiconductor layer 300. Thus, an interface which is not parallel to the second surface and has a refractive index difference is formed. With this configuration, incident light is diffracted, thereby improving sensitivity to light in the infrared region.

[0103] The fixed charge film 310 is composed of a dielectric material having a negative fixed charge and is arranged on the entire second surface of the semiconductor layer 300. The material of the fixed charge film 310 is selected from: for example, hafnium oxide, aluminum oxide, zirconium oxide, titanium oxide, tantalum oxide and ruthenium oxide, and aluminum oxide or hafnium oxide is particularly preferred. The fixed charge film 310 can be composed of a plurality of layers. The insulating film 311 is arranged on the fixed charge film 310 in a manner covering the entire second surface. Silicon oxide film, silicon oxynitride film or silicon nitride film can be appropriately used for the insulating film 311. The insulating film 311 can be composed of a plurality of layers. In addition to the planarizing film 312, a filter layer of a color filter or an infrared cutoff filter (not shown) can be arranged on the second surface side of the semiconductor layer 300.

[0104] The wiring structure 320 is a structure in which wiring 321, contact plugs 324 for anode wiring, contact plugs 326 for cathode wiring, and the like are arranged in an insulating layer 329. The surface of the lower side (the opposite side of the semiconductor layer 300) of the wiring structure 320 is a bonding surface with the circuit substrate 21, and a plurality of bonding portions 328 (metal bonding portions) are arranged on the bonding surface.

[0105] The semiconductor layer 300 includes a first semiconductor region 301, a second semiconductor region 302, a third semiconductor region 303, a fourth semiconductor region 304, a fifth semiconductor region 305, a sixth semiconductor region 306, a seventh semiconductor region 307, and an eighth semiconductor region 308. Each of these semiconductor regions is a region where impurities are added by ion implantation, or a region where impurities are added when a semiconductor substrate is formed by epitaxial growth. Here, the first semiconductor region 301, the fifth semiconductor region 305, the sixth semiconductor region 306, and the seventh semiconductor region 307 are first conductivity type (N type in embodiment 1) semiconductor regions. The second semiconductor region 302, the third semiconductor region 303, the fourth semiconductor region 304, and the eighth semiconductor region 308 are second conductivity type (P type in embodiment 1) semiconductor regions.

[0106] The first semiconductor region 301 is a first conductivity type (N type in Embodiment 1) semiconductor region, and is arranged on the first surface of the semiconductor layer 300. Fig. 6A As shown, the first semiconductor region 301 is formed in a circular shape at the center of the pixel (segment) in a plan view. A contact plug 326 for a cathode is connected to the center position of the first semiconductor region 301 .

[0107] The fourth semiconductor region 304 is a second conductivity type (P type in embodiment 1) semiconductor region and is arranged on the light entry side (side close to the second surface) of the first semiconductor region 301. The fourth semiconductor region 304 is formed in the form of a layer at a predetermined depth so that the first conductivity type epitaxial layer in one pixel (segment) is divided into an upper part and a lower part. The periphery of the fourth semiconductor region 304 contacts the isolation portion 330 surrounding the pixel. The first conductivity type epitaxial layer on the first surface side of the fourth semiconductor region 304 is the fifth semiconductor region 305, and the first conductivity type epitaxial layer on the second surface side of the fourth semiconductor region 304 is the seventh semiconductor region 307.

[0108] The first conductive type first semiconductor region 301 and the second conductive type fourth semiconductor region 304 form an avalanche multiplication portion AM through a PN junction. Signal charges generated in the seventh semiconductor region 307 by photoelectric conversion are collected in the avalanche multiplication portion AM. In order to improve the sensitivity of the pixel (APD 201), it is preferable to increase the size of the seventh semiconductor region 307 corresponding to the sensitivity region.

[0109] The sixth semiconductor region 306 has a first conductive type semiconductor region formed around the first semiconductor region 301. In a plan view, the sixth semiconductor region 306 is also formed in a circular shape. Here, the impurity concentrations of the first semiconductor region 301, the sixth semiconductor region 306, and the fifth semiconductor region 305 are set to satisfy the relationship of the first semiconductor region 301> the sixth semiconductor region 306> the fifth semiconductor region 305. In other words, the impurity concentration of the first semiconductor region 301 is set to be the highest, and the impurity concentration of the sixth semiconductor region 306 is set to be between the concentration of the first semiconductor region 301 and the concentration of the fifth semiconductor region 305. Thereby, the electrical connection between the cathode and the first semiconductor region 301 (i.e., the APD 201) can be ensured. The sixth semiconductor region 306 plays the role of a guard ring for relaxing the electric field.

[0110] The eighth semiconductor region 308 is a second conductive buried layer arranged as a portion of the second surface constituting the semiconductor layer 300. The periphery of the eighth semiconductor region 308 contacts the isolation portion 330 surrounding the pixel. The eighth semiconductor region 308 plays a role in suppressing noise from the second surface side. In addition, the voltage VL from the anode wiring can be supplied to the eighth semiconductor region 308 via the second semiconductor region 302. In this case, a potential gradient for collecting charges can be formed.

[0111] The isolation part 330 is formed of the second conductivity type second semiconductor region 302 and prevents electrons from transferring between pixels using a potential barrier. The isolation part 330 also constitutes a part of the second surface of the semiconductor layer 300.

[0112] The third semiconductor region 303 is arranged on the first surface of the semiconductor layer 300, and is a connection portion of the second semiconductor region 302 that electrically connects the contact plug 324 of the anode wiring and the isolation portion 330. The second semiconductor region 302 and the third semiconductor region 303 are both of the second conductivity type (P type in Embodiment 1).

[0113] like Fig. 6A As shown, the third semiconductor region 303 is arranged on a portion corresponding to the contact plug 324. In a region other than the third semiconductor region 303, the second conductive type semiconductor region is not exposed on the first surface.

[0114] like Figure 6B As shown, the shape of the microlens 313 is different between the pixel 601 at both ends and the pixel 602 at the center. Due to this difference in shape, the sensitivity of the pixel 601 and the sensitivity of the pixel 602 are different. The pixel 601 is a high-sensitivity pixel having a higher sensitivity than the pixel 602, and the pixel 602 is a low-sensitivity pixel having a lower sensitivity than the pixel 601.

[0115] Fig. 7A and Figure 7B The structure of a sensor substrate 11 of a photoelectric conversion device according to a comparative example is shown. Fig. 7A 1 is a plan view depicting the configuration of the pixel region 12 , and is a schematic diagram of the semiconductor layer 300 of the sensor substrate 11 viewed from the first surface side. Figure 7B is Fig. 7A The cross-sectional view taken at line AA in FIG. Fig. 6A , Figure 6B , Fig. 7A and Figure 7B As shown, the basic structure of the sensor substrate 11 of the comparative example is the same as the basic structure of the sensor substrate 11 according to the first embodiment.

[0116] like Fig. 7A and Figure 7BAs shown, in the comparative example, the size of the high-sensitivity pixel 601 and the size of the low-sensitivity pixel 602 are the same. Therefore, the degree of suppressing the optical crosstalk (light leakage) from the high-sensitivity pixel 601 to the low-sensitivity pixel 602 and the degree of suppressing the optical crosstalk from the low-sensitivity pixel 602 to the high-sensitivity pixel 601 are the same. In the high-sensitivity pixel 601, avalanche multiplication (avalanche luminescence) is generated more strongly than in the low-sensitivity pixel 602. Therefore, the optical crosstalk from the high-sensitivity pixel 601 to the low-sensitivity pixel 602 becomes greater than the optical crosstalk from the low-sensitivity pixel 602 to the high-sensitivity pixel 601.

[0117] Therefore, in Embodiment 1, the optical crosstalk (light leakage) from the high-sensitivity pixel 601 to the low-sensitivity pixel 602 is more strongly suppressed than the optical crosstalk from the low-sensitivity pixel 602 to the high-sensitivity pixel 601. Specifically, Fig. 6A and Figure 6B As shown, the size of the low-sensitivity pixel 602 is smaller than the high-sensitivity pixel 601 (the size of the high-sensitivity pixel 601 is larger than the low-sensitivity pixel 602). More specifically, the following condition 1-1 is satisfied.

[0118] Condition 1-1: In a plan view, a distance L11 from the center of the high-sensitivity pixel 601 to the isolation portion 330 is longer than a distance L12 from the center of the low-sensitivity pixel 602 to the isolation portion 330 .

[0119] Furthermore, in Embodiment 1, the following conditions 1-2 are also satisfied.

[0120] Condition 1-2: In a plan view, the distance L13 is longer than the distance L14. Here, the distance L13 is the distance from the edge of the high-sensitivity pixel 601 on the side where the isolation portion 330 of the first semiconductor region 301 is located (isolation portion side) to the isolation portion 330. The distance L14 is the distance from the edge of the low-sensitivity pixel 602 on the side where the isolation portion 330 of the first semiconductor region 301 is located to the isolation portion 330.

[0121] By satisfying condition 1-1 (and condition 1-2), the distance from the avalanche multiplying portion AM of the high-sensitivity pixel 601 to the isolation portion 330 becomes longer than the distance from the avalanche multiplying portion AM of the low-sensitivity pixel 602 to the isolation portion 330. Thus, the optical crosstalk (light leakage) from the high-sensitivity pixel 601 to the low-sensitivity pixel 602 is more strongly suppressed than the optical crosstalk from the low-sensitivity pixel 602 to the high-sensitivity pixel 601. As a result, the dispersion of the optical crosstalk (light leakage) between pixels can be reduced. Specifically, the difference between the optical crosstalk from the high-sensitivity pixel 601 to the low-sensitivity pixel 602 and the optical crosstalk from the low-sensitivity pixel 602 to the high-sensitivity pixel 601 can be reduced.

[0122] In the above, an example of changing the sensitivity of a pixel by changing the shape of the microlens 313 is described, but the method for changing the sensitivity is not limited thereto. For example, the sensitivity of a pixel may be reduced by using a light shielding filter 800, such as Figure 8 shown.

[0123] Implementation Method 2

[0124] Fig.9A and Fig. 9B The structure of the sensor substrate 11 of the photoelectric conversion device according to Embodiment 2 is shown. Fig.9A 1 is a plan view depicting the configuration of the pixel region 12 , and is a schematic diagram of the semiconductor layer 300 of the sensor substrate 11 viewed from the first surface side. Fig. 9B is Fig.9A A cross-sectional view taken along line AA in FIG.

[0125] In Embodiment 1, the size of the low-sensitivity pixel 602 is smaller than the size of the high-sensitivity pixel 601 (the size of the high-sensitivity pixel 601 is larger than the size of the low-sensitivity pixel 602). In Embodiment 2, the groove 900 (which is not arranged in the low-sensitivity pixel 602) is arranged in the high-sensitivity pixel 601, as shown in FIG. Fig.9A and Fig. 9B In a plan view, the groove 900 surrounds the first semiconductor region 301 and the sixth semiconductor region 306. The groove 900 is formed at a depth shallower than that of the fourth semiconductor region 304 (in the depth direction from the first surface).

[0126] In Embodiment 2, the size of the high-sensitivity pixel 601 is the same as the size of the low-sensitivity pixel 602, and Conditions 1-1 and 1-2 of Embodiment 1 are not satisfied. However, since the groove 900 is formed in the high-sensitivity pixel 601, the optical crosstalk (light leakage) from the high-sensitivity pixel 601 is more strongly suppressed. As a result, the difference between the optical crosstalk from the high-sensitivity pixel 601 to the low-sensitivity pixel 602 and the optical crosstalk from the low-sensitivity pixel 602 to the high-sensitivity pixel 601 can be reduced.

[0127] The trench 900 may have a deep trench isolation (DTI) structure, and metal may be buried in the DTI structure to improve light shielding performance. The trench 900 may be composed of an insulating film, a metal member, a fixed charge film, polysilicon, or a combination of a plurality of these members.

[0128] Implementation 3

[0129] FIG. 10A to FIG. 10C , Fig.11A and Fig. 11BThe structure of the sensor substrate 11 of the photoelectric conversion device according to Embodiment 3 is shown. FIG. 10A to FIG. 10C It is a plan view depicting the structure of the pixel region 12 .

[0130] Fig. 10A and Fig. 10B is a schematic diagram of the semiconductor layer 300 of the sensor substrate 11 viewed from the first surface side. Fig. 10C 3 is a schematic diagram showing the configuration of the microlens 313 . Fig.11A is Fig. 10A The cross-sectional view is taken at line AA in Fig. 11B is Fig. 10A A cross-sectional view taken along line BB in FIG.

[0131] In Embodiment 1, the size of the low-sensitivity pixel 602 is smaller than that of the high-sensitivity pixel 601 (the size of the high-sensitivity pixel 601 is larger than that of the low-sensitivity pixel 602). However, in the small low-sensitivity pixel 602, the anode electrode (contact plug 324) supplies the anode potential to the semiconductor region constituting the isolation portion 330. In addition, the cathode electrode (contact plug 326) supplies the cathode potential to the first semiconductor region 301. Therefore, the distance between the semiconductor region constituting the isolation portion 330 supplied with the anode potential and the first semiconductor region 301 supplied with the cathode potential becomes shorter, and noise caused by the electric field between these electrodes may increase.

[0132] In Embodiment 3, the first isolation portion 330-1 and the second isolation portion 330-2 are arranged as isolation portions for isolating a plurality of pixels, such as Fig.11A and Fig. 11B shown. Fig. 10A 3 shows the configuration of the first isolation portion 330-1, the cathode contact plug 326, etc. Fig. 10B The configuration of the second isolation portion 330 - 2 , the contact plug 324 for the anode, the contact plug 326 for the cathode, and the like are shown.

[0133] The first isolation section 330-1 isolates each region of a plurality of pixels on the side close to the second surface (light incident surface). Specifically, the first isolation section 330-1 isolates each region of a plurality of pixels on the second surface side of the fourth semiconductor region 304. The first isolation section 330-1 corresponds to the isolation section 330 of embodiment 1. The second isolation section 330-2 isolates each region of a plurality of pixels on the side away from the second surface. Specifically, the second isolation section 330-2 isolates each region of a plurality of pixels on the first surface side of the fourth semiconductor region 304. Both the first isolation section 330-1 and the second isolation section 330-2 are formed by a second conductive type semiconductor region.

[0134] like Fig. 10A As shown, the first isolation section 330-1 is formed to satisfy the conditions 1-1 and 1-2 in Embodiment 1. As a result, similar to Embodiment 1, the difference between the optical crosstalk from the high-sensitivity pixel 601 to the low-sensitivity pixel 602 and the optical crosstalk from the low-sensitivity pixel 602 to the high-sensitivity pixel 601 can be reduced.

[0135] In addition, if Fig. 10A and Fig. 10B As shown, the second isolation portion 330 - 2 is formed to satisfy the following condition 2-1.

[0136] Condition 2-1: In a plan view, a distance L21 from the center of the low-sensitivity pixel 602 to the second isolation portion 330 - 2 is greater than a distance L12 from the center of the low-sensitivity pixel 602 to the first isolation portion 330 - 1 .

[0137] By satisfying the condition 2-1, a decrease in the distance between the semiconductor region constituting the second isolation portion 330-2 supplied with the anode potential and the first semiconductor region 301 supplied with the cathode potential can be suppressed, and generation (increase) of noise can be suppressed.

[0138] In addition, in implementation mode 3, the following condition 2-2 is also satisfied, such as Fig. 10A and Fig. 10B shown.

[0139] Condition 2-2: In a plan view, a distance L22 from the center of the high-sensitivity pixel 601 to the second isolation portion 330 - 2 is approximately the same as a distance L21 from the center of the low-sensitivity pixel 602 to the second isolation portion 330 - 2 .

[0140] By satisfying condition 2-2, the deviation of the influence of the electric field between the anode and the cathode on the pixel can be reduced. Specifically, the difference between the influence of the electric field between the anode and the cathode on the high-sensitivity pixel 601 and the influence of the electric field between the anode and the cathode on the low-sensitivity pixel 602 can be reduced.

[0141] Condition 2-2 can be interpreted as the following condition 2-3.

[0142] Condition 2-3: In a plan view, the distance from the cathode electrode (contact plug 326 ) to the anode electrode (contact plug 324 ) of the high-sensitivity pixel 601 is approximately the same as the distance from the cathode electrode to the anode electrode of the low-sensitivity pixel 602 .

[0143] Implementation 4

[0144] FIG. 12A to FIG. 12C , Fig.13A and Fig. 13B The structure of the sensor substrate 11 of the photoelectric conversion device according to Embodiment 4 is shown. FIG. 12A to FIG. 12C It is a plan view depicting the structure of the pixel region 12 .

[0145] Fig. 12A and Fig. 12B is a schematic diagram of the semiconductor layer 300 of the sensor substrate 11 viewed from the first surface side, and Fig. 12C 3 is a schematic diagram showing the configuration of the microlens 313 . Fig. 12A 3 shows the configuration of the first isolation portion 330-1, the cathode contact plug 326, etc. Fig. 12B The configuration of the second isolation portion 330 - 2 , the contact plug 324 for the anode, the contact plug 326 for the cathode, and the like are shown. Fig.13A is Fig. 12A The cross-sectional view is taken at line AA in Fig. 13B is Fig. 12A A cross-sectional view taken along line BB in FIG. A configuration different from that of Embodiment 3 will be described below.

[0146] In Embodiment 3, one low-sensitivity pixel 602 is arranged for three high-sensitivity pixels 601. Specifically, four pixels (three high-sensitivity pixels 601 and one low-sensitivity pixel 602) are arranged in two rows x two columns, as shown in FIG. FIG. 10A to FIG. 10C shown.

[0147] In Embodiment 4, one low-sensitivity pixel 602 is arranged for four high-sensitivity pixels 601. Specifically, one low-sensitivity pixel 602 is arranged at the center of four high-sensitivity pixels 601 arranged in two rows and two columns, as shown in FIG. FIG. 12A to FIG. 12C As shown in . Thus, a Bayer array of high-sensitivity pixels 601 can be realized.

[0148] Furthermore, in Embodiment 4, both Conditions 1-1 and 1-2 in Embodiment 1 and Conditions 2-1 and 2-2 in Embodiment 3 are satisfied. Therefore, effects similar to those in Embodiment 1 and effects similar to those in Embodiment 3 can be achieved.

[0149] Implementation method 5

[0150] FIG. 14A to FIG. 14C and FIG. 15A to FIG. 15C The structure of the sensor substrate 11 of the photoelectric conversion device according to Embodiment 5 is shown. FIG. 14A to FIG. 14C It is a plan view depicting the structure of the pixel region 12 . Fig.14A is a schematic diagram of the semiconductor layer 300 of the sensor substrate 11 viewed from the first surface side. Fig. 14B is a schematic diagram showing the configuration of the bonding portion 328 (metal bonding portion), Fig. 14C 3 is a schematic diagram showing the configuration of the microlens 313 . Fig.15A is Fig.14AThe cross-sectional view taken at line AA in Fig. 15B is Fig.14A The cross-sectional view is taken at line BB in Fig. 15C is Fig.14A A cross-sectional view taken along line CC in FIG. A configuration different from that of Embodiment 1 will be described below.

[0151] In Embodiment 1, the size of the low-sensitivity pixel 602 is smaller than the size of the high-sensitivity pixel 601 (the size of the high-sensitivity pixel 601 is larger than the size of the low-sensitivity pixel 602). However, in this configuration, the arrangement of the cathode electrode (contact plug 326) and the arrangement of the metal junction (junction portion 328) have an influence on improving the integration degree of the pixel and further miniaturization of the pixel.

[0152] Therefore, in Embodiment 5, the configuration of the cathode electrode (contact plug 326) and the configuration of the metal joint (joint portion 328) are optimized, so that the integration of pixels can be improved and the pixels can be further miniaturized. In Embodiment 5, a plurality of high-sensitivity pixels 601 are arranged at approximately equal intervals in the row direction (first direction) and the column direction (second direction perpendicular to the first direction), respectively, as shown in FIG. FIG. 14A to FIG. 14C As shown. In the same manner, a plurality of low-sensitivity pixels 602 are arranged at approximately equal intervals in the row direction and the column direction, respectively. Then, a plurality of cathode electrodes (contact plugs 326) corresponding to a plurality of pixels (including a plurality of high-sensitivity pixels 601 and a plurality of low-sensitivity pixels 602) are arranged at approximately equal intervals in a first diagonal direction and a second diagonal direction, respectively. The first diagonal direction is a direction that bisects the row direction and the column direction (a third direction that bisects the first direction and the second direction), and the second diagonal direction is a direction perpendicular to the first diagonal direction (a fourth direction that is perpendicular to the third direction). In addition, the positions of the plurality of bonding portions 328 (metal bonding portions) corresponding to the plurality of pixels, respectively, are positions that are approximately the same as the positions of the plurality of cathode electrodes (contact plugs 326), as shown in FIG. Fig. 14B shown.

[0153] Therefore, it is easy to use a configuration in which the low-sensitivity pixels 602 are offset by 1 / 2 pitch from the high-sensitivity pixels 601 (a configuration in which one low-sensitivity pixel 602 is arranged approximately at the center of four high-sensitivity pixels 601 arranged in two rows × two columns). In addition, it is easier to improve the integration of pixels and further miniaturize the pixels.

[0154] Furthermore, in Embodiment 5, the distance between the cathode electrode (contact plug 326) and the anode electrode (contact plug 324) is approximately constant, as shown in FIG. Fig.14AAs shown. In addition, in each of the row direction and the column direction, the cathode electrode (contact plug 326) and the anode electrode (contact plug 324) are arranged at approximately equal intervals. In each of the first diagonal direction and the second diagonal direction, the cathode electrode (contact plug 326) and the anode electrode (contact plug 324) are arranged at approximately equal intervals. Through this configuration, the integration can also be improved, and the pixel can be further miniaturized.

[0155] exist Fig.14A In the embodiment of the present invention, the anode electrodes (contact plugs 324) are arranged on all four sides of the high-sensitivity pixel 601, but the anode electrodes may be sparsely arranged. For example, one electrode may be arranged for a plurality of pixels.

[0156] In addition, in Embodiment 5, if Fig. 15C As shown, there is a region in which there is no isolation portion 330 on the first surface side of the sensitive region (seventh semiconductor region 307). Since the isolation portion 330 (second semiconductor region 302) is not exposed on the first surface, this prevents the charge (noise) generated near the first surface from entering the sensitive region through the second conductive semiconductor region.

[0157] Implementation 6

[0158] FIG. 16A to FIG. 16C and FIG. 17A to FIG. 17C The structure of the sensor substrate 11 of the photoelectric conversion device according to Embodiment 6 is shown. FIG. 16A to FIG. 16C It is a plan view depicting the structure of the pixel region 12 . Fig.16A is a schematic diagram of the semiconductor layer 300 of the sensor substrate 11 viewed from the first surface side. Fig. 16B is a schematic diagram showing the configuration of the bonding portion 328 (metal bonding portion), Fig. 16C 3 is a schematic diagram showing the configuration of the microlens 313 . Fig.17A is Fig.16A The cross-sectional view taken at line AA in Fig. 17B is Fig.16A The cross-sectional view taken at line BB in Fig. 17C is Fig.16A A cross-sectional view taken along line CC in FIG. A configuration different from that of Embodiment 5 will be described below.

[0159] In Embodiment 6, like Embodiment 5, one low-sensitivity pixel 602 is arranged approximately at the center of four high-sensitivity pixels 601 arranged in two rows by two columns, as shown in FIG. FIG. 16A to FIG. 16C shown.

[0160] In Embodiment 6, the isolation section 330 surrounds the high-sensitivity pixel 601 having an approximately octagonal shape, and surrounds the low-sensitivity pixel 602 having an approximately square shape formed by approximately four octagonal shapes corresponding to the four high-sensitivity pixels 601, as shown in FIG. FIG. 16A to FIG. 16C shown.

[0161] In addition, in Embodiment 6, a groove 1700 is formed in the isolation portion 330 so as not to penetrate the isolation portion 330 in the depth direction. FIG. 17A to FIG. 17C By forming the groove 1700, the optical crosstalk can be further reduced.

[0162] Since the isolation portion 330 surrounds the high-sensitivity pixel 601 of a roughly octagonal shape, the right angle portion can be minimized in the isolation portion 330. Minimizing the right angle portion can suppress electric field concentration. In addition, the groove can be formed more easily, and thus the damage to the semiconductor region when the groove is formed can be reduced, and the generation (increase) of noise due to such damage can be prevented.

[0163] In Embodiment 5, a portion of the microlens 313 of the high-sensitivity pixel 601 overlaps with a region of the low-sensitivity pixel 602, as shown in FIG. Fig. 14C As shown, unnecessary light enters the low-sensitivity pixel 602. In Embodiment 6, on the other hand, the isolation portion 330 surrounds the high-sensitivity pixel 601 in an octagonal shape, thereby preventing the microlens 313 of another pixel from overlapping on the pixel area. Fig. 16C As shown. Therefore, it is possible to prevent unnecessary light from entering the pixel.

[0164] Implementation 7

[0165] Fig.18 and FIG. 19A to FIG. 19C The structure of the sensor substrate 11 of the photoelectric conversion device according to Embodiment 7 is shown. Fig.18 1 is a plan view depicting the configuration of the pixel region 12 , and is a schematic diagram of the semiconductor layer 300 of the sensor substrate 11 viewed from the first surface side. Fig.19A is Fig.18 The cross-sectional view taken at line AA in Fig.19B is Fig.18 The cross-sectional view taken at line BB in Fig.19C is Fig.18 A cross-sectional view taken along the CC line in FIG. A configuration different from that of Embodiment 6 will be described below.

[0166] In Embodiment 6, a groove 1700 is formed in the isolation portion 330 so as not to penetrate the isolation portion 330 in the depth direction. FIG. 17A to FIG. 17CIn Embodiment 7, a groove 1900 is formed in the isolation portion 330 and penetrates the isolation portion 330 in the depth direction, as shown in FIG. FIG. 19A to FIG. 19C By forming the through grooves, light crosstalk can be reduced compared to the case of not forming the through grooves.

[0167] In the case of forming a through groove, an anode electrode (contact plug 324) must be independently arranged for each of the two pixels sandwiching the groove. This is the number and arrangement of the contact plugs 324 (and the third semiconductor region 303) in Embodiment 6 ( Fig.16A and FIG. 17A to FIG. 17C ) and implementation mode 7 ( Fig.18 and FIG. 19A to FIG. 19C ) are different from each other.

[0168] The configuration of the anode electrode (contact plug 324) is not particularly limited, and a plurality of anode electrodes (contact plug 324) may be concentrated in one location, for example, as shown in FIG. Fig. 20 As shown. Thus, the integration of pixels can be further improved, or the pixels can be further miniaturized. Fig. 20 In the configuration in which the partition 330 surrounds the high-sensitivity pixel 601 having a substantially octagonal shape and surrounds the low-sensitivity pixel 602 having a substantially square shape, a plurality of anode electrodes (contact plugs 324) can be easily concentrated in one location.

[0169] Implementation 8

[0170] Fig.21A , Fig.21B and FIG. 22A to FIG. 22C The structure of the sensor substrate 11 of the photoelectric conversion device according to Embodiment 8 is shown. Fig.21A and Fig.21B 1 is a plan view depicting the configuration of the pixel region 12 , and is a schematic diagram of the semiconductor layer 300 of the sensor substrate 11 viewed from the first surface side. Fig.22A is Fig.21A The cross-sectional view taken at line AA in Fig. 22B is Fig.21A The cross-sectional view taken at line BB in Fig. 22C is Fig.21A A cross-sectional view taken along the CC line in FIG. A configuration different from that of Embodiment 6 will be described below.

[0171] In Embodiment 8, a first isolation portion 330-1 and a second isolation portion 330-2 are arranged as isolation portions for isolating a plurality of pixels. Fig.21A , Fig.21B as well as FIG. 22A to FIG. 22C As shown, it is the same as Embodiment 3 and Embodiment 4. Fig.21A1 shows the configuration of the first isolation portion 330-1 and the cathode contact plug 326, etc., Fig.21B The configuration of the second isolation portion 330 - 2 , the contact plug 324 for the anode, the contact plug 326 for the cathode, and the like are shown.

[0172] In addition, in Embodiment 8, Conditions 1-1 and 1-2 in Embodiment 1 and Conditions 2-1 and 2-2 in Embodiment 3 are all satisfied. The other configurations are the same as those in Embodiment 6. Fig.21B As shown, the plurality of second isolation portions 330 - 2 are arranged at approximately equal intervals in the first diagonal direction and the second diagonal direction, respectively. Thus, it is easier to satisfy the conditions 2-1 and 2-2.

[0173] As described above, in Embodiment 8, effects similar to those in Embodiment 1, effects similar to those in Embodiment 3, effects similar to those in Embodiment 4, and effects similar to those in Embodiment 6 can be achieved.

[0174] Implementation method 9

[0175] Fig.23 and FIG. 24A to FIG. 24C The structure of the sensor substrate 11 of the photoelectric conversion device according to Embodiment 9 is shown. Fig.23 1 is a plan view depicting the configuration of the pixel region 12 , and is a schematic diagram of the semiconductor layer 300 of the sensor substrate 11 viewed from the first surface side. Fig.23 The configuration of the second isolation portion 330 - 2 , the contact plug 324 for the anode, the contact plug 326 for the cathode, and the like are shown. Fig.24A is Fig.23 The cross-sectional view taken at line AA in Fig. 24B is Fig.23 The cross-sectional view taken at line BB in Fig.24C is Fig.23 A cross-sectional view taken along the CC line in FIG. A configuration different from that of Embodiment 8 will be described below.

[0176] In Embodiment 9, a groove 1901 is formed in the first isolation portion 330-1 so as not to penetrate the first isolation portion 330-1 in the depth direction. FIG. 24A to FIG. 24CAs shown. In addition, a groove 1902 that does not penetrate the second isolation portion 330-2 is formed in the second isolation portion 330-2. In embodiment 8, the second isolation portion 330-2 is formed on the first surface side of the fourth semiconductor region 304, but the groove 1902 of embodiment 9 is also formed on the second surface side of the fourth semiconductor region 304. By forming grooves 1901 and 1902, optical crosstalk can be further reduced. Both grooves 1901 and 1902 can have a deep trench isolation (DTI) structure. Grooves 1901 and 1902 can be composed of an insulating film, a fixed charge film, a metal component, polysilicon, or a combination of multiple of these components. For example, an insulating film can be buried in groove 1901, and a metal can be buried in groove 1902. The same material can be buried in groove 1901 and groove 1902.

[0177] Another feature of the ninth embodiment is that Fig.23 As shown, the configuration of the cathode electrode (contact plug 326 ) and the anode electrode (contact plug 324 ) is the same between the high-sensitivity pixel 601 and the low-sensitivity pixel 602 .

[0178] Embodiment 10

[0179] Will refer to Fig.25 A photoelectric conversion system according to Embodiment 10 will be described. Fig.25 is a block diagram depicting a general configuration of a photoelectric conversion system according to Embodiment 10.

[0180] The photoelectric conversion device described in Embodiments 1 to 9 is applicable to various photoelectric conversion systems. The photoelectric conversion system includes at least the photoelectric conversion device described in any of the above embodiments, and a signal processing unit that processes a signal output from the photoelectric conversion device. Examples of devices to which the photoelectric conversion system is applicable are: digital still cameras, digital video cameras, security cameras, copiers, fax machines, portable phones, vehicle-mounted cameras, observation satellites, sensors, and measuring instruments. The device to which the photoelectric conversion system is applied also includes a camera module composed of an optical system (e.g., a lens) and an imaging device. Fig.25 is a block diagram of a digital still camera as an example of these applications.

[0181] Fig.25The photoelectric conversion system illustrated in 2504 includes an imaging device 2504 as an example of a photoelectric conversion apparatus and a lens 2502 that forms an optical image of a subject on the imaging device 2504. The photoelectric conversion system also includes an aperture 2503 that changes the amount of light passing through the lens 2502, and a protector 2501 for protecting the lens 2502. The lens 2502 and the aperture 2503 constitute an optical system to collect light to the imaging device 2504. The imaging device 2504 is the photoelectric conversion apparatus (imaging device) according to any of the above-described embodiments, and converts the optical image formed by the lens 2502 into an electrical signal.

[0182] The photoelectric conversion system further includes a signal processing unit 2507, which is a signal generating unit that generates an image by processing an output signal output from the imaging device 2504. The signal processing unit 2507 performs an operation to output image data after performing various corrections and compressions as necessary. The signal processing unit 2507 may be formed on a semiconductor substrate on which the imaging device 2504 is arranged, or may be formed on a semiconductor substrate separated from the imaging device 2504. The imaging device 2504 and the signal processing unit 2507 may be formed on the same semiconductor substrate.

[0183] The photoelectric conversion system also includes a memory unit 2510 that temporarily stores image data, an external interface unit (external I / F unit) 2513 that communicates with an external computer, and the like. In addition, the photoelectric conversion system includes a recording medium 2512 (e.g., a semiconductor memory) that records or reads imaging data, and a recording medium control interface unit (recording medium control I / F unit) 2511 that records or reads the recording medium 2512. The recording medium 2512 may be built in the photoelectric conversion system, or may be removed therefrom.

[0184] Furthermore, the photoelectric conversion system includes: an overall control arithmetic unit 2509 that performs various arithmetic operations and controls the digital still camera as a whole; and a timing generation unit 2508 that outputs various timing signals to the imaging device 2504 and the signal processing unit 2507. Here, the timing signal and the like may be input from the outside, and it is sufficient if the photoelectric conversion system includes at least the imaging device 2504 and the signal processing unit 2507 that processes the output signal output from the imaging device 2504.

[0185] The imaging device 2504 outputs an imaging signal to the signal processing unit 2507. The signal processing unit 2507 performs predetermined signal processing on the imaging signal output from the imaging device 2504, and outputs image data. The signal processing unit 2507 generates an image using the imaging signal.

[0186] Therefore, according to Embodiment 10, a photoelectric conversion system to which the photoelectric conversion device (imaging apparatus) according to any of the above embodiments is applied can be realized.

[0187] Implementation 11

[0188] Will refer to Fig.26A and Fig.26B A photoelectric conversion system and a moving object according to Embodiment 11 will be described. Fig.26A is a diagram depicting the configuration of a photoelectric conversion system according to Embodiment 11, Fig.26B This is a diagram depicting the structure of a moving object according to Embodiment 11.

[0189] Fig.26A is an example of a photoelectric conversion system related to a vehicle-mounted camera. The photoelectric conversion system 2600 includes an imaging device 2610. The imaging device 2610 is a photoelectric conversion device (imaging device) according to any one of the above-mentioned embodiments. The photoelectric conversion system 2600 includes an image processing unit 2612, which performs image processing on a plurality of image data acquired by the imaging device 2610. The photoelectric conversion system 2600 also includes a distance acquisition unit 2616 and a collision determination unit 2618, the distance acquisition unit 2616 calculates the distance about the subject, and the collision determination unit 2618 determines whether a collision is possible based on the calculated distance. Here, the distance acquisition unit 2616 can acquire distance information about a time of flight (ToF) subject, or can acquire distance information using parallax information, etc. In other words, the distance information is information about parallax, defocus amount, distance about the subject, etc. The collision determination unit 2618 can use any of the distance information to determine the possibility of a collision. The distance information acquisition means can be implemented by dedicated hardware, or can also be implemented by a software module. In addition, the distance information acquisition means may be implemented by a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), or a combination thereof.

[0190] The photoelectric conversion system 2600 is connected to the vehicle information acquisition device 2620, and can acquire vehicle information such as vehicle speed, yaw rate, and steering angle. In addition, an ECU 2630 as a control device that outputs a control signal for generating a braking force on the vehicle based on the determination result of the collision determination unit 2618 is connected to the photoelectric conversion system 2600. The photoelectric conversion system 2600 is also connected to an alarm device 2640, which issues an alarm based on the determination result of the collision determination unit 2618 to warn the driver of the vehicle. For example, in the case where the possibility of collision is high according to the determination result of the collision determination unit 2618, the ECU 2630 controls the vehicle by applying brakes, slowing down the accelerator, reducing the engine output, etc. to prevent the collision or minimize the damage. The alarm device 2640 warns the user by, for example, outputting an alarm (e.g., sound), displaying an alarm message on a screen of a vehicle navigation system, etc., or applying vibration to a seat belt or a steering wheel.

[0191] In Embodiment 11, the photoelectric conversion system 2600 captures an image of the surroundings of the vehicle (such as the area in front of or behind the vehicle). Fig.26B The photoelectric conversion system (imaging range 2650) is shown in the case of capturing an image of the area in front of a vehicle. The vehicle information acquisition device 2620 sends an instruction to the photoelectric conversion system 2600 or the imaging device 2610. With this configuration, the accuracy of distance measurement can be improved.

[0192] An example of controlling a vehicle to avoid a collision with another vehicle is described here, but the present invention is also applicable to, for example, controlling a vehicle so as to follow another vehicle for automatic driving, or controlling a vehicle so as to automatically drive without deviating from a lane. In addition, the application of the photoelectric conversion system is not limited to vehicles such as vehicles, but is also applicable to ships, aircraft, or mobile bodies (mobile devices) such as industrial robots. The mobile body here includes one or both of a driving force generating unit that generates a driving force mainly for moving the mobile body and a rotating member for moving the mobile body. The driving force generating unit may be an engine, a motor, etc. The rotating member may be a tire, a wheel, a propeller of a ship, a propeller of an aircraft, etc. The application of the present invention is not limited to mobile bodies, but is applicable to various devices that use object recognition, such as an intelligent transportation system (ITS).

[0193] Implementation 12

[0194] Will refer to Fig. 27 A photoelectric conversion system according to Embodiment 12 will be described. Fig. 27 : is a block diagram depicting a configuration example of a distance image sensor as a photoelectric conversion system according to Embodiment 12.

[0195] like Fig. 27 As shown, the distance image sensor 2701 includes an optical system 2707, a photoelectric conversion device 2708, an image processing circuit 2704, a monitor 2705, and a memory 2706. The distance image sensor 2701 receives light emitted from a light source device 2709 to a subject and reflected by the surface of the subject, thereby acquiring a distance image according to the distance to the subject.

[0196] The optical system 2707 is composed of one or more lenses, and guides image light (incident light) from a subject to the photoelectric conversion device 2708 , and forms an image of the subject on a light receiving surface (sensor unit) of the photoelectric conversion device 2708 .

[0197] The photoelectric conversion device according to any of the above-described embodiments is used for the photoelectric conversion device 2708 , and a distance signal indicating a distance determined based on a light reception signal output from the photoelectric conversion device 2708 is supplied to the image processing circuit 2704 .

[0198] The image processing circuit 2704 performs image processing to construct a distance image based on the distance signal supplied from the photoelectric conversion device 2708. The distance image (image data) acquired by this image processing is supplied to the monitor 2705 and displayed at the monitor 2705, or supplied to the memory 2706 and stored (recorded) at the memory 2706.

[0199] In the distance image sensor 2701 thus configured, by applying the above-described photoelectric conversion device, a more accurate distance image can be acquired due to, for example, improvement in pixel characteristics.

[0200] Implementation 13

[0201] Will refer to Fig.28 A photoelectric conversion system according to Embodiment 13 will be described. Fig.28 This is a diagram depicting a schematic configuration example of an endoscopic surgery system as a photoelectric conversion system according to Embodiment 13.

[0202] Fig.28 The figure shows a state where an operator (physician) 2831 is using an endoscopic surgery system 2850 to perform surgery on a patient 2832 on a bed 2833. As shown here, the endoscopic surgery system 2850 is composed of an endoscope 2800, a surgical tool 2810, and a cart 2834, on which various devices used for endoscopic surgery are equipped.

[0203] The endoscope 2800 is composed of a lens barrel 2801, a region of a predetermined length from the distal end of which is inserted into the body cavity of a patient 2832, and a camera head 2802 connected to the base end of the lens barrel 2801. In the example shown, the endoscope 2800 is composed of a hard mirror including a hard lens barrel 2801, but the endoscope 2800 may be composed of a soft mirror including a soft lens barrel.

[0204] An opening is arranged at the end of the lens barrel 2801, and an objective lens is mounted in the opening. A light source device 2803 is connected to the endoscope 2800, so that light generated by the light source device 2803 is guided to the end of the lens barrel via a light guide extending inside the lens barrel 2801, and is emitted via the objective lens to an observation target inside the body cavity of the patient 2832. The endoscope 2800 may be a straight-view mirror, an oblique-view mirror, or a side-view mirror.

[0205] The camera 2802 is internally arranged with an optical system and a photoelectric conversion device, and the reflected light (observation light) from the observation target is collected by the optical system to 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, that is, an image signal corresponding to the observation image. The photoelectric conversion device (imaging device) described in any of the above embodiments can be used for the photoelectric conversion device. The image signal is sent to the camera control unit (CCU) 2835 as RAW data.

[0206] The CCU 2835 is composed of a central processing unit (CPU), a graphics processing unit (GPU), etc., and comprehensively controls the operations of the endoscope 2800 and the display device 2836. In addition, the CCU 2835 receives an image signal from the camera 2802, and performs various types of image processing such as development processing (demosaic processing) on ​​the image signal to display an image based on the image signal.

[0207] Under control from the CCU 2835 , the display device 2836 displays an image based on the image signal on which image processing has been performed by the CCU 2835 .

[0208] The light source device 2803 is constituted by, for example, a light source such as a light emitting diode (LED), and supplies illumination light to the endoscope 2800 to image a surgical area or the like.

[0209] The input device 2837 is an input interface of the endoscopic surgery system 2850. The user can input various types of information and instructions to the endoscopic surgery system 2850 via the input device 2837.

[0210] The treatment tool control device 2838 controls the driving of the energy treatment tool 2812 for burning or cutting tissue, sealing blood vessels, and the like.

[0211] The light source device 2803 may be, for example, a white light source composed of an LED, a laser light source, or a combination thereof, which supplies illumination light to the endoscope 2800 to image the surgical area. In the case where 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 the white balance of the captured image can be adjusted in the light source device 2803. In addition, in this case, by emitting a laser beam from each of the R, G, and B laser light sources to the observation target in a time-sharing manner, and by controlling the drive of the imaging element of the camera 2802 in synchronization with the emission timing, images corresponding to each R, G, and B can be captured in a time-sharing manner. According to this method, a color image can be acquired without arranging a color filter in the imaging element.

[0212] The drive of the light source device 2803 can be controlled so that the intensity of the light to be output changes at each predetermined time. If the drive of the imaging element of the camera 2802 is controlled to be synchronized with the timing of changing the intensity of the light, images are acquired in a time-sharing manner, and these images are combined, and then an image in a high dynamic range without black clipping and white clipping can be generated.

[0213] The light source device 2803 can be configured to supply light with a predetermined wavelength band corresponding to special light observation. In special light observation, the wavelength dependence of the absorption of light in body tissue is used. Specifically, compared with the illumination light (i.e., white light) in general observation, a predetermined tissue (such as a blood vessel of the surface layer of the mucosa) is imaged with high contrast by illumination light of a narrower wavelength band. In special light observation, fluorescence observation can be performed to obtain an image by emitting fluorescence generated by excitation light. In fluorescence observation, for example, excitation light is emitted to body tissue, and the fluorescence generated by the body tissue is observed, or a reagent, such as indocyanine green (ICG), is locally injected into the body tissue, and excitation light corresponding to the fluorescence wavelength of the reagent is emitted to the body tissue to obtain a fluorescent image. The light source device 2803 can be configured to supply narrowband light and / or excitation light corresponding to special light observation in this way.

[0214] Implementation 14

[0215] Will refer to Fig.29A and Fig.29B A photoelectric conversion system according to a fourteenth embodiment will be described. Fig.29AGlasses 2900 (smart glasses) are shown, which are a photoelectric conversion system according to Embodiment 14. Glasses 2900 include a photoelectric conversion device 2902. The photoelectric conversion device 2902 is a photoelectric conversion device (imaging device) according to any of the above-mentioned embodiments. A display device including a light-emitting device such as an OLED or an LED may be arranged on the rear side of a lens 2901. One photoelectric conversion device 2902 may be included, or a plurality of photoelectric conversion devices 2902 may be included. A combination of a plurality of types of photoelectric conversion devices may be used. The position where the photoelectric conversion device 2902 is arranged is not limited to Fig.29A .

[0216] The glasses 2900 further include a control device 2903. The control device 2903 serves as a power source to supply power to the photoelectric conversion device 2902 and the above-mentioned display device. In addition, the control device 2903 controls the operation of the photoelectric conversion device 2902 and the display device. In the lens 2901, an optical system for collecting light to the photoelectric conversion device 2902 is formed.

[0217] Fig.29B Glasses 2910 (smart glasses) according to an application example are shown. Glasses 2910 include a control device 2912, and a photoelectric conversion device and a display device corresponding to the photoelectric conversion device 2902 are provided in the control device 2912. The photoelectric conversion device in the control device 2912 and an optical system for projecting light emitted from the display device are formed on a lens 2911, and an image is projected onto the lens 2911. The control device 2912 serves as a power supply for supplying power to the photoelectric conversion device and the display device, and also controls the operation of the photoelectric conversion device and the display device. The control device may include a line of sight detection unit to detect the line of sight of the wearer. Infrared light can be used to detect the line of sight. The infrared emitting unit emits infrared light to the eyeball of the user who is looking at the displayed image. The image of the captured eyeball can be acquired by detecting the reflected light from the eyeball of the emitted infrared light by an imaging unit including a light receiving element. The degradation of image quality is reduced by including a reducing device for reducing the light from the infrared emitting unit to the display unit in a plan view.

[0218] The user's line of sight to the displayed image is detected from a captured image of the eyeball obtained by capturing the image using infrared light. A known method can be used for line of sight detection using a captured image of the eyeball. For example, a line of sight detection method based on a Purkinje image generated by reflection of illumination light on the cornea can be used.

[0219] Specifically, a line of sight detection process based on the pupil cornea reflection method is performed to detect the user's line of sight by calculating a line of sight vector indicating the orientation (rotation angle) of the eyeball based on an image of the pupil included in a captured image of the eyeball and a Purkinje image using the pupil cornea reflection method.

[0220] The display device of Embodiment 14 may include a photoelectric conversion device having a light receiving element, and control a display image of the display device based on information on a user's line of sight received from the photoelectric conversion device.

[0221] Specifically, the display device determines a first field of view area that the user is looking at, 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 from the 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 set to be lower than the first field of view area.

[0222] A first display area and a second display area different from the first display area may be provided for the display area, and a higher priority area of ​​the first display area and the second display area may be determined based on the line of sight information. The first display area and the second display area may be determined by a control device of the display device, or may be determined by and received from an external control device. The resolution of the higher priority area may be controlled to be higher than the resolution of areas other than the higher priority area. In other words, the resolution of the lower priority area may be set to be low.

[0223] AI can be used to determine the first field of view area or the area with high priority. AI can be a model built using the image of the eyeball and the direction the eyeball actually sees in the image as training data, thereby estimating the angle of sight and the distance to the target object pointed by the sight from the image of the eyeball. The AI ​​program can be included in the display device, the photoelectric conversion device, or the external device. In the case where the external device includes the AI ​​program, the AI ​​program is sent to the display device via communication.

[0224] If the display is controlled based on visual detection, the present invention can be appropriately applied to smart glasses, which also include a photoelectric conversion device for capturing external images. The smart glasses can display the captured external information in real time.

[0225] Implementation 15

[0226] The above-mentioned photoelectric conversion device and photoelectric conversion system can be applied to electronic devices such as smartphones and tablet computers.

[0227] Fig. 30A and Fig. 30B is a diagram illustrating an example of an electronic device 3000 equipped with a photoelectric conversion device. Fig. 30A The front side of the electronic device 3000 is shown, and Fig. 30BThe back side of the electronic device 3000 is shown.

[0228] like Fig. 30A As shown, a display 3010 for displaying an image is arranged at the center of the front of the electronic device 3000. Also arranged along the upper side of the front of the electronic device 3000 are front cameras 3021 and 3022 using a photoelectric conversion device, an IR light source 3030 emitting infrared light, and a visible light source 3040 emitting visible light.

[0229] In addition, if Fig. 30B As shown, rear cameras 3051 and 3052 using a photoelectric conversion device, an IR light source 3060 that emits infrared light, and a visible light source 3070 that emits visible light are arranged along the upper side of the back side of the electronic device 3000.

[0230] In the electronic device 3000 thus constructed, it is possible to capture a higher quality image, for example, by applying the above-mentioned photoelectric conversion device. In addition, the photoelectric conversion device can be applied to electronic devices such as infrared sensors, distance measurement sensors using active infrared light sources, security cameras, and personal or biometric authentication cameras. As a result, the accuracy, performance, etc. of these electronic devices can be improved.

[0231] Implementation 16

[0232] Fig.31 31 is a block diagram illustrating an X-ray CT apparatus according to Embodiment 16. The above-described photoelectric conversion device and photoelectric conversion system are applicable to a detector of the X-ray CT apparatus. The X-ray CT apparatus 3100 according to Embodiment 16 includes an X-ray generation unit 3110, a wedge 3111, a collimator 3112, an X-ray detection unit 3120, a top plate 3130, a rotating frame 3140, and a high voltage generation device 3150. The X-ray CT apparatus 3100 also includes a data acquisition system (DAS) 3151, a signal processing unit 3152, a display unit 3153, and a control unit 3154.

[0233] The X-ray generating unit 3110 is constituted by, for example, a vacuum tube for generating X-rays. High voltage and filament current from the high voltage generating device 3150 are supplied to the vacuum tube of the X-ray generating unit 3110. X-rays are generated by thermal electrons emitted from the cathode (filament) to the anode (target).

[0234] The wedge 3111 is a filter for adjusting the amount of X-rays emitted from the X-ray generation unit 3110. The wedge 3111 attenuates the amount of X-rays so that the X-rays emitted from the X-ray generation unit 3110 to the subject generate a predetermined distribution. The collimator 3112 is composed of a lead plate or the like to narrow the radiation range of the X-rays transmitted through the wedge 3111. The X-rays generated in the X-ray generation unit 3110 are shaped into a cone beam shape via the collimator 3112 and emitted to the subject on the top plate 3130.

[0235] The X-ray detection unit 3120 is composed of the above-mentioned photoelectric conversion device or photoelectric conversion system. The X-ray detection unit 3120 detects X-rays emitted from the X-ray generation unit 3110 and transmitted through the subject, and outputs a signal corresponding to the X-ray amount to the DAS 3151.

[0236] The rotating frame 3140 is annular and rotatable. The X-ray generating unit 3110 (wedge 3111, collimator 3112) and the X-ray detecting unit 3120 are arranged facing each other in the rotating frame 3140. The X-ray generating unit 3110 and the X-ray detecting unit 3120 can rotate together with the rotating frame 3140.

[0237] The high voltage generating device 3150 includes a boosting circuit, and outputs a high voltage to the X-ray generating unit 3110. The DAS 3151 includes an amplifying circuit and an A / D converting circuit, and outputs a signal from the X-ray detecting unit 3120 to the signal processing unit 3152 as digital data.

[0238] The signal processing unit 3152 includes a central processing unit (CPU), a read-only memory (ROM), and a random access memory (RAM), and can perform image processing on digital data. The display unit 3153 includes a flat display device, etc., and can display an X-ray image. The control unit 3154 includes a CPU, ROM, RAM, etc., and controls the operation of the X-ray CT apparatus 3100 as a whole.

[0239] Implementation 17

[0240] Will refer to Fig.32 A photoelectric conversion system according to Embodiment 17 will be described. Fig.32 17 is a block diagram showing a schematic configuration of an imaging system SYS as a photoelectric conversion system according to Embodiment 17. The imaging system SYS includes at least the photoelectric conversion device according to any of the above embodiments and a signal processing unit that processes a signal output from the photoelectric conversion device.

[0241] The imaging system SYS is a camera or information terminal including an image capturing function. The imaging system SYS is constructed using an imaging device IS. The imaging device IS may further include a package PKG that accommodates an imaging device IC. The package PKG may include a substrate for fixing the imaging device IC and a cover facing the imaging device IC. The package PKG may include a connecting member (a member for connecting terminals arranged on the substrate and terminals arranged on the imaging device IC). The imaging device IS may include a plurality of imaging device ICs arranged in a common package PKG. In addition, the imaging device IS may include an imaging device IC and other semiconductor device ICs stacked in a common package PKG.

[0242] The imaging system SYS may include an optical system OU (optical device) to form an image on the imaging device IS. The imaging system SYS includes at least one of a control device CU, a processing device PU, a display device DU, and a storage device MU. The control device CU controls the imaging device IS, and the processing device PU processes a signal acquired from the imaging device IS. In addition, the display device DU displays the image acquired from the imaging device IS, and the storage device MU stores the image acquired from the imaging device IS.

[0243] other

[0244] Various devices have been described in the above embodiments, but the present invention may also include a mechanical device. The mechanical device in the camera may drive components of the optical system for zooming, focusing, or performing a shutter operation. The mechanical device in the camera may also move the photoelectric conversion device for vibration prevention operation.

[0245] The device may be a transport device such as a vehicle, a ship, an aircraft, etc. The mechanical device in the transport device may be used as a mobile device. The device used as a transport device is suitable for transporting a photoelectric conversion device, or assisting and / or automatically driving (operating) based on an image capture function. The processing device for assisting and / or automatically driving (operating) may perform processing based on information acquired by the photoelectric conversion device to operate the mechanical device as a mobile device.

[0246] The above-mentioned embodiments can be changed as needed without departing from the technical idea of ​​the present invention. The disclosure of this specification includes not only the contents stated in the specification, but also all matters that can be grasped from this specification and the drawings of this specification. The disclosure of this specification also includes the complement of the concepts stated in this specification. In other words, if it is stated in this specification that A is greater than B, for example, it can be said that this specification discloses "A is not greater than B", even if "A is not greater than B" is not stated. Because if "A is greater than B" is stated, the situation of "A is not greater than B" is assumed.

[0247] In this specification, expressions such as "A or B", "at least one of A and B", "at least one of A or / and B", and "one or more of A or / and B" may be used. In this case, unless otherwise specified, all possible combinations of the listed items may be included. In other words, it should be understood that the above expressions disclose all cases: including at least one A, including at least one B, and including both at least one A and at least one B. This applies to combinations of three or more elements.

[0248] According to the present invention, a suitable pixel structure may be provided in a configuration in which a high-sensitivity pixel and a low-sensitivity pixel each include an avalanche photodiode.

[0249] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A photoelectric conversion device, comprising: a first pixel comprising a first avalanche photodiode; a second pixel comprising a second avalanche photodiode; and an isolation portion that isolates the first pixel and the second pixel, wherein A distance from a center of the first pixel to the partition in a plan view is longer than a distance from a center of the second pixel to the partition.

2. The photoelectric conversion device according to claim 1, wherein The isolation portion is a first isolation portion that isolates a region of the first pixel on a side close to a light incident surface and a region of the second pixel on a side close to the light incident surface, The photoelectric conversion device further includes a second isolation portion that isolates a region of the first pixel on a side away from the light incident surface and a region of the second pixel on a side away from the light incident surface, and In the plan view, a distance from a center of the second pixel to the second partition is longer than a distance from a center of the second pixel to the first partition.

3. The photoelectric conversion device according to claim 1, wherein The isolation portion is a first isolation portion that isolates a region of the first pixel on a side close to a light incident surface and a region of the second pixel on a side close to the light incident surface, The photoelectric conversion device further includes a second isolation portion that isolates a region of the first pixel on a side away from the light incident surface and a region of the second pixel on a side away from the light incident surface, and In the plan view, a distance from a center of the first pixel to the second partition is substantially the same as a distance from a center of the second pixel to the second partition.

4. The photoelectric conversion device according to claim 1, wherein The first avalanche photodiode includes a first semiconductor region of a first conductivity type, The second avalanche photodiode includes a first conductivity type second semiconductor region, and In the plan view, a distance from an edge of the first semiconductor region on the isolation portion side to the isolation portion is longer than a distance from an edge of the second semiconductor region on the isolation portion side to the isolation portion.

5. The photoelectric conversion device according to claim 2, wherein a plurality of first pixels are arranged at substantially equal intervals in each of a first direction and a second direction perpendicular to the first direction, a plurality of second pixels are arranged at substantially equal intervals in each of the first direction and the second direction, and A plurality of second partitions are arranged at substantially equal intervals in each of a third direction bisecting the first direction and the second direction and a fourth direction perpendicular to the third direction.

6. The photoelectric conversion device according to claim 3, wherein In the plan view, a distance from the cathode electrode of the first pixel to the anode electrode of the first pixel is substantially the same as a distance from the cathode electrode of the second pixel to the anode electrode of the second pixel.

7. The photoelectric conversion device according to claim 5, wherein In each of the third direction and the fourth direction, a plurality of cathode electrodes respectively corresponding to a plurality of pixels including the plurality of first pixels and the plurality of second pixels are arranged at substantially equal intervals.

8. The photoelectric conversion device according to claim 7, wherein The isolation portion isolates a plurality of the pixels, and In the plan view, The second pixel is arranged approximately at the center of four first pixels arranged in two rows×two columns, and The partition surrounds the first pixel having a substantially octagonal shape, and surrounds the second pixel having a substantially square shape formed by four of the substantially octagonal shapes respectively corresponding to the four first pixels.

9. The photoelectric conversion device according to claim 8, further comprising a plurality of metal junctions respectively corresponding to the plurality of pixels on the side opposite to the light incident surface, In the plan view, positions of the plurality of metal bonding portions are substantially the same as positions of the plurality of cathode electrodes.

10. A photoelectric conversion device comprising: a first pixel comprising a first avalanche photodiode; and a second pixel comprising a second avalanche photodiode; and The photoelectric conversion device is configured so that light leakage from the first pixel to the second pixel is more strongly suppressed than light leakage from the second pixel to the first pixel.

11. The photoelectric conversion device according to claim 10, further comprising an isolation portion that isolates the first pixel and the second pixel, wherein In a plan view, a distance from a center of the first pixel to the partition is longer than a distance from a center of the second pixel to the partition.

12. The photoelectric conversion device according to claim 11, wherein The first avalanche photodiode includes a first semiconductor region of a first conductivity type, The second avalanche photodiode includes a first conductivity type second semiconductor region, and In the plan view, a distance from an edge of the first semiconductor region on the isolation portion side to the isolation portion is longer than a distance from an edge of the second semiconductor region on the isolation portion side to the isolation portion.

13. The photoelectric conversion device according to claim 11, wherein The isolation portion is a first isolation portion that isolates a region of the first pixel on a side close to a light incident surface and a region of the second pixel on a side close to the light incident surface, The photoelectric conversion device further includes a second isolation portion that isolates a region of the first pixel on a side away from the light incident surface and a region of the second pixel on a side away from the light incident surface, and In the plan view, a distance from a center of the second pixel to the second partition is longer than a distance from a center of the second pixel to the first partition.

14. The photoelectric conversion device according to claim 13, wherein In the plan view, a distance from a center of the first pixel to the second partition is substantially the same as a distance from a center of the second pixel to the second partition.

15. The photoelectric conversion device according to claim 13, wherein a plurality of first pixels are arranged at substantially equal intervals in each of a first direction and a second direction perpendicular to the first direction, a plurality of second pixels are arranged at substantially equal intervals in each of the first direction and the second direction, and A plurality of second partitions are arranged at substantially equal intervals in each of a third direction bisecting the first direction and the second direction and a fourth direction perpendicular to the third direction.

16. The photoelectric conversion device according to claim 13, wherein In the plan view, a distance from the cathode electrode of the first pixel to the anode electrode of the first pixel is substantially the same as a distance from the cathode electrode of the second pixel to the anode electrode of the second pixel.

17. The photoelectric conversion device according to claim 11, wherein a plurality of first pixels are arranged at substantially equal intervals in each of a first direction and a second direction perpendicular to the first direction, a plurality of second pixels are arranged at substantially equal intervals in each of the first direction and the second direction, and A plurality of cathode electrodes respectively corresponding to a plurality of pixels including the plurality of first pixels and the plurality of second pixels are respectively arranged at approximately equal intervals in each of a third direction bisecting the first direction and the second direction and a fourth direction perpendicular to the third direction.

18. The photoelectric conversion device according to claim 17, wherein The isolation portion isolates a plurality of the pixels, and In the plan view, The second pixel is arranged approximately at the center of four first pixels arranged in two rows×two columns, and The partition surrounds the first pixel having a substantially octagonal shape, and surrounds the second pixel having a substantially square shape formed by four of the substantially octagonal shapes respectively corresponding to the four first pixels.

19. The photoelectric conversion device according to claim 18, further comprising a plurality of metal junctions respectively corresponding to the plurality of pixels on the side opposite to the light incident surface, In the plan view, positions of the plurality of metal bonding portions are substantially the same as positions of the plurality of cathode electrodes.

20. The photoelectric conversion device according to claim 10, wherein A groove which is not arranged in the second pixel is arranged in the first pixel.

21. A photoelectric conversion device comprising: a first pixel comprising a first avalanche photodiode; and A second pixel comprising a second avalanche photodiode, wherein A groove which is not arranged in the second pixel is arranged in the first pixel.

22. A photoelectric conversion system, comprising: The photoelectric conversion device according to any one of claims 1 to 21; and A signal processing unit generates an image by using the signal output by the photoelectric conversion device.

23. A moving body comprising the photoelectric conversion device according to any one of claims 1 to 21, the moving body comprising a control unit that controls movement of the moving body by using a signal output by the photoelectric conversion device.

24. An apparatus comprising: The photoelectric conversion device according to any one of claims 1 to 21; and At least one of the following: an optical device corresponding to the photoelectric conversion device, a control device for controlling the photoelectric conversion device, a processing device for processing a signal output from the photoelectric conversion device, a display device for displaying information acquired by the photoelectric conversion device, a storage device for storing information acquired by the photoelectric conversion device, and A mechanical device that operates based on information acquired by the photoelectric conversion device.

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