Photoelectric conversion device, light detection system, and movable object

Abstract

The photoelectric conversion device is configured by stacking a first substrate, a second substrate, and a third substrate, and includes a plurality of pixels, each pixel including a photoelectric conversion unit including an APD, and a signal processing unit processing a signal output from the photoelectric conversion unit. The signal processing unit includes a quenching circuit connected to the APD and a processing circuit that processes a signal corresponding to an incidence of light on the APD. The APD is disposed on the first substrate, at least a portion of the quench circuit is disposed on the second substrate, and at least a portion of the process circuit is disposed on the third substrate. Each of the plurality of pixels includes a plurality of electrical connection portions between the second substrate and the third substrate, a portion of the plurality of electrical connection portions constituting a portion of an input signal line to the processing circuit, and another portion constituting a portion of an output signal line from the processing circuit.

Description

Technical Field

[0001] The present invention relates to a photoelectric conversion device, a light detection system, and a movable body. Background Art

[0002] A photoelectric conversion device including a pixel array in which a plurality of pixels, each including an avalanche photodiode (APD), are arranged in a two-dimensional array is known. Patent Document 1 discloses a photoelectric conversion device configured by stacking a first substrate provided with an APD array, and second and third substrates provided with circuits for controlling the operation of the APD array and processing signals output from the APD array.

[0003] [Prior art literature]

[0004] [Patent Document]

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-113123 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] However, in the configuration described in Patent Document 1, the functional blocks constituting the circuit for controlling the operation of the APD array and processing the signals output from the APD array are not necessarily appropriately distributed to the second substrate and the third substrate, which may hinder improvement in characteristics and high integration.

[0008] An object of the present invention is to provide a technology for promoting high integration and improvement of characteristics of functional blocks of pixel circuits and peripheral circuits in a photoelectric conversion device configured by stacking three or more substrates.

[0009] Solutions for solving problems

[0010] According to one disclosure of the present specification, there is provided a photoelectric conversion device configured by stacking at least a first substrate, a second substrate, and a third substrate, the photoelectric conversion device including a plurality of pixels, each pixel including: a photoelectric conversion unit having an avalanche photodiode; and a signal processing unit configured to process a signal output from the photoelectric conversion unit, wherein the signal processing unit of each pixel in the plurality of pixels includes: a quenching circuit connected to the avalanche photodiode; and a processing circuit configured to process a signal corresponding to the incidence of light on the avalanche photodiode, wherein the avalanche photodiode is arranged on the first substrate, wherein at least a portion of the quenching circuit is arranged on the second substrate, wherein at least a portion of the processing circuit is arranged on the third substrate, wherein each pixel in the plurality of pixels includes a plurality of electrical connections between the second substrate and the third substrate, and wherein a portion of the plurality of electrical connections constitutes a portion of an input signal line to the processing circuit, and another portion of the plurality of electrical connections constitutes a portion of an output signal line from the processing circuit.

[0011] According to another disclosure of the present specification, a photoelectric conversion device is provided, which is configured by stacking at least a first substrate, a second substrate and a third substrate, the photoelectric conversion device including a plurality of pixels and a plurality of output lines, the plurality of pixels being arranged to form a plurality of rows and a plurality of columns, and each pixel including: a photoelectric conversion unit including an avalanche photodiode; and a signal processing unit configured to process a signal output from the photoelectric conversion unit; the plurality of output lines are provided corresponding to the plurality of rows or the plurality of columns, and each output line is connected to pixels of a corresponding row or a corresponding column, wherein the signal processing unit of each pixel in the plurality of pixels includes: an input node connected to the avalanche photodiode; a processing circuit configured to process a signal corresponding to the incidence of light on the avalanche photodiode; and an output node connected to the output line, wherein the avalanche photodiode is arranged on the first substrate, wherein the input node and output node of the signal processing unit and the output line are arranged on the second substrate, and wherein at least a portion of the processing circuit is arranged on the third substrate.

[0012] Effects of the Invention

[0013] According to the present invention, in a photoelectric conversion device configured by stacking three or more substrates, high integration of functional blocks of pixel circuits and peripheral circuits and improved characteristics can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] [ Figure 1 ]

[0015] Figure 1 is a block diagram showing a schematic configuration of a photoelectric conversion apparatus according to a first embodiment of the present invention (Part 1).

[0016] [ Figure 2 ]

[0017] Figure 2 is a block diagram showing a schematic configuration of a photoelectric conversion apparatus according to a first embodiment of the present invention (Part 2).

[0018] [ Figure 3 ]

[0019] Figure 3 is a block diagram showing a configuration example of a pixel of the photoelectric conversion device according to the first embodiment of the present invention.

[0020] [ Figure 4 ]

[0021] Figure 4 is a perspective diagram showing a configuration example of a photoelectric conversion device according to a first embodiment of the present invention.

[0022] [ Figure 5A ]

[0023] Figure 5A is a diagram (Part 1) illustrating basic operations of a photoelectric conversion unit in the photoelectric conversion apparatus according to the first embodiment of the present invention.

[0024] [ Figure 5B ]

[0025] Figure 5B 2 is a diagram showing a basic operation of a photoelectric conversion unit in the photoelectric conversion apparatus according to the first embodiment of the present invention (Part 2).

[0026] [ Figure 5C ]

[0027] Figure 5C is a diagram (Part 3) illustrating the basic operation of the photoelectric conversion unit in the photoelectric conversion apparatus according to the first embodiment of the present invention.

[0028] [ Figure 6 ]

[0029] Figure 6 is a diagram schematically showing a stacked structure of pixels in the photoelectric conversion device according to the first embodiment of the present invention.

[0030] [ Figure 7 ]

[0031] Figure 7 is a diagram schematically showing a stacked structure of pixels in a photoelectric conversion device according to a modification of the first embodiment of the present invention.

[0032] [ Figure 8 ]

[0033] Figure 8 is a diagram schematically showing a stacked structure of pixels in a photoelectric conversion device according to a modification of the second embodiment of the present invention.

[0034] [ Figure 9 ]

[0035] Figure 9 is a diagram schematically showing a stacked structure of pixels in a photoelectric conversion device according to a third embodiment of the present invention.

[0036] [ Figure 10 ]

[0037] Figure 10 is a diagram schematically showing a stacked structure of pixels in a photoelectric conversion device according to a modification of the third embodiment of the present invention.

[0038] [ Figure 11 ]

[0039] Figure 11 is a diagram showing a connection relationship between a vertical scanning circuit unit and a pixel area in a photoelectric conversion device according to a fourth embodiment of the present invention.

[0040] [ Figure 12 ]

[0041] Figure 12 is a diagram schematically showing a stacked structure of a vertical scanning circuit unit in a photoelectric conversion device according to a fourth embodiment of the present invention.

[0042] [ Figure 13 ]

[0043] Figure 13 is a diagram showing a connection relationship between a readout circuit unit and a pixel region in a photoelectric conversion device according to a fifth embodiment of the present invention.

[0044] [ Figure 14 ]

[0045] Figure 14 is a diagram schematically showing a stacked structure of a readout circuit unit in a photoelectric conversion device according to a fifth embodiment of the present invention.

[0046] [ Figure 15 ]

[0047] Figure 15 FIG. 1 is a diagram schematically showing a stacked structure of a transmitter in a photoelectric conversion device according to a modification of the sixth embodiment of the present invention.

[0048] [ Figure 16 ]

[0049] Figure 16 is a diagram schematically showing a stacked structure of a photoelectric conversion device according to a seventh embodiment of the present invention.

[0050] [ Figure 17 ]

[0051] Figure 17 is a diagram schematically showing a stacked structure of a photoelectric conversion device according to a seventh embodiment of the present invention.

[0052] [ Figure 18 ]

[0053] Figure 18 is a diagram schematically showing a stacked structure of a photoelectric conversion device according to a seventh embodiment of the present invention.

[0054] [ Figure 19 ]

[0055] Figure 19 is a block diagram showing a schematic configuration of a light detection system according to an eighth embodiment of the present invention.

[0056] [ Figure 20 ]

[0057] Figure 20 is a block diagram showing a schematic configuration of a range image sensor according to a ninth embodiment of the present invention.

[0058] [ Figure 21 ]

[0059] Figure 21 : is a schematic diagram showing a configuration example of an endoscopic surgery system according to a tenth embodiment of the present invention.

[0060] [ Figure 22A ]

[0061] Figure 22A is a schematic diagram (part 1) showing a configuration example of a movable body according to an eleventh embodiment of the present invention.

[0062] [ Figure 22B ]

[0063] Figure 22B is a schematic diagram showing a configuration example of a movable body according to an eleventh embodiment of the present invention (part 2).

[0064] [ Figure 22C ]

[0065] Figure 22C is a schematic diagram showing a configuration example of a movable body according to an eleventh embodiment of the present invention (part 3).

[0066] [ Figure 23 ]

[0067] Figure 23 is a block diagram showing a schematic configuration of a light detection system according to an eleventh embodiment of the present invention.

[0068] [ Figure 24 ]

[0069] Figure 24 is a flowchart showing the operation of the light detection system according to the eleventh embodiment of the present invention.

[0070] [ Figure 25A ]

[0071] Figure 25A is a schematic diagram showing a schematic configuration of a light detection system according to a twelfth embodiment of the present invention (part 1).

[0072] [ Figure 25B ]

[0073] Figure 25B is a schematic diagram showing a schematic configuration of a light detection system according to a twelfth embodiment of the present invention (Part 2). DETAILED DESCRIPTION

[0074] The following embodiments are intended to embody the technical ideas of the present invention and are not intended to limit the present invention. For clarity of description, the sizes and positional relationships of the components shown in the drawings may be exaggerated. In the following description, the same reference numerals are used for the same components, and descriptions thereof are sometimes omitted.

[0075] [First embodiment]

[0076] Will refer to Figures 1 to 4 A schematic configuration of a photoelectric conversion apparatus according to a first embodiment of the present invention is described. Figure 1 and Figure 2 is a block diagram showing a schematic configuration of a photoelectric conversion apparatus according to the present embodiment. Figure 3 is a block diagram showing a configuration example of a pixel of the photoelectric conversion device according to the present embodiment. Figure 4 is a perspective diagram showing a configuration example of the photoelectric conversion device according to the present embodiment.

[0077] like Figure 1 As shown, the photoelectric conversion device 100 according to this embodiment includes a pixel area 10, a vertical scanning circuit unit 40, a readout circuit unit 50, a horizontal scanning circuit unit 60, a digital front end (DFE) 70, a transmitter circuit unit (TX) 80 and a control pulse generating unit 90.

[0078] The pixel area 10 is provided with a plurality of pixels 12 arranged in an array to form a plurality of rows and a plurality of columns. As described later, each pixel 12 may include a photoelectric conversion unit including a photoelectric conversion element and a signal processing unit that processes a signal output from the photoelectric conversion unit. The number of pixels 12 constituting the pixel area 10 is not particularly limited. For example, as in a general digital camera, the pixel area 10 may be composed of a plurality of pixels 12 arranged in an array of thousands of rows and thousands of columns. Alternatively, the pixel area 10 may include a plurality of pixels 12 arranged in one row or one column. Alternatively, one pixel 12 may constitute the pixel area 10.

[0079] In each row of the pixel array of the pixel region 10, the control lines 14 are arranged to extend in a first direction ( Figure 1 The control lines 14 are each connected to the pixels 12 arranged in the first direction and form a signal line shared by these pixels 12. The first direction in which the control lines 14 extend may be referred to as a row direction or a horizontal direction. Each control line 14 may include a plurality of signal lines for supplying a plurality of types of control signals to the pixels 12. The control lines 14 of each row are connected to the vertical scanning circuit unit 40.

[0080] Furthermore, in each column of the pixel array of the pixel region 10, the output lines 16 are arranged so as to extend in a second direction ( Figure 1 The output lines 16 extend in a vertical direction (in the vertical direction). Each of the output lines 16 is connected to the pixels 12 arranged in the second direction and forms a signal line shared by these pixels 12. The second direction in which the output lines 16 extend can be referred to as a column direction or a vertical direction. Each of the output lines 16 may include a plurality of signal lines for transmitting a plurality of bits of digital signals output from the pixels 12 bit by bit.

[0081] The control lines 14 of each row are connected to a vertical scanning circuit unit 40. The vertical scanning circuit unit 40 is a control circuit having the following functions: in response to the control signal output from the control pulse generating unit 90, it generates a control signal for driving the pixel 12, and supplies the generated control signal to the pixel 12 via the control line 14. As the vertical scanning circuit unit 40, a logic circuit such as a shift register or an address decoder can be used. The vertical scanning circuit unit 40 sequentially scans the pixels 12 in the pixel area 10 row by row to output the pixel signals of the pixels 12 to the readout circuit unit 50 via the output line 16.

[0082] The output line 16 of each column is connected to the readout circuit unit 50. The readout circuit unit 50 includes a plurality of holding units (not shown) provided corresponding to the columns of the pixel array of the pixel region 10, and has a function of holding the pixel signals of the pixels 12 of each column output from the pixel region 10 in units of rows via the output line 16 in the holding unit of the corresponding column.

[0083] The horizontal scanning circuit unit 60 is a control circuit that generates a control signal for reading out pixel signals from the holding units of each column of the readout circuit unit 50 in response to the control signal output from the control pulse generating unit 90, and supplies the generated control signal to the readout circuit unit 50. A logic circuit such as a shift register or an address decoder can be used as the horizontal scanning circuit unit 60. The horizontal scanning circuit unit 60 sequentially scans the holding units of each column of the readout circuit unit 50 and sequentially outputs the pixel signals held in the holding units to the digital front end 70.

[0084] The DFE 70 is a signal processing circuit unit that performs predetermined digital signal processing on the pixel signals output from the readout circuit unit 50. The DFE 70 sequentially outputs the pixel signals subjected to the digital signal processing to the TX 80.

[0085] The TX 80 is a circuit unit that includes an external interface circuit and outputs the pixel signal output from the readout circuit unit 50 to the outside of the photoelectric conversion device 100. There is no particular limitation on the external interface circuit included in the TX 80. As the external interface circuit, for example, a SerDes (SERializer / DESerializer) transmission circuit such as an LVDS (Low Voltage Differential Signaling) circuit or an SLVS (Scalable Low Voltage Signaling) circuit can be applied.

[0086] The control pulse generating unit 90 is a control circuit for generating control signals for controlling the operation and timing of the vertical scanning circuit unit 40, the readout circuit unit 50, and the horizontal scanning circuit unit 60, and for supplying the generated control signals to each functional block. At least a portion of the control signals for controlling the operation and timing of the vertical scanning circuit unit 40, the readout circuit unit 50, and the horizontal scanning circuit unit 60 may be supplied from outside the photoelectric conversion device 100.

[0087] The connection mode of each functional block of the photoelectric conversion device 100 is not limited to Figure 1 , and for example also as Figure 2 Configured as shown.

[0088] exist Figure 2In the configuration example of FIG, output lines 16 extending in a first direction are arranged in each row of the pixel array of the pixel region 10. Each of the output lines 16 is connected to the pixels 12 arranged in the first direction, and forms a signal line common to these pixels 12. Control lines 18 extending in a second direction are arranged in each column of the pixel array of the pixel region 10. Each of the control lines 18 is connected to the pixels 12 arranged in the second direction, and forms a signal line common to these pixels 12.

[0089] The control line 18 of each column is connected to the horizontal scanning circuit unit 60. The horizontal scanning circuit unit 60 generates a control signal for reading out a pixel signal from the pixel 12 in response to the control signal output from the control pulse generating unit 90, and supplies the generated control signal to the pixel 12 via the control line 18. Specifically, the horizontal scanning circuit unit 60 sequentially scans the plurality of pixels 12 in the pixel area 10 in units of columns, and outputs the pixel signals of the pixels 12 in each row belonging to the selected column to the output line 16.

[0090] The output lines 16 of each row are connected to the readout circuit unit 50. The readout circuit unit 50 includes a plurality of holding units (not shown) provided corresponding to the respective rows of the pixel array of the pixel region 10, and has a function of holding the pixel signals of the pixels 12 of each row output from the pixel region 10 in units of columns via the output lines 16 in the holding units of the corresponding rows.

[0091] The readout circuit unit 50 sequentially outputs the pixel signals held in the holding units of the respective rows to the DFE 70 in response to the control signal output from the control pulse generating unit 90 .

[0092] Figure 2 Other configurations in the configuration example can be used with Figure 1 The configuration is the same as in the configuration example.

[0093] like Figure 3 As shown, each pixel 12 includes a photoelectric conversion unit 20 and a signal processing unit 30. The photoelectric conversion unit 20 includes a photoelectric conversion element 22 and outputs a signal corresponding to the incident light. The signal processing unit 30 is a signal processing circuit that processes the signal output from the photoelectric conversion unit 20. The signal processing unit 30 includes a functional block 30A including a quenching circuit 32, a waveform shaping circuit 34, and a selection circuit 38, and a functional block 30B including a processing circuit 36. Figure 3 In the case of the pixel configuration shown, the control lines 14 of each row may include a signal line 14A to which a control signal pRES is supplied from the vertical scanning circuit unit 40 and a signal line 14B to which a control signal pSEL is supplied from the vertical scanning circuit unit 40 .

[0094] The photoelectric conversion element 22 can be an avalanche photodiode (hereinafter referred to as "APD"). The anode of the APD constituting the photoelectric conversion element 22 is connected to a node to which the voltage VL is supplied. The cathode of the APD constituting the photoelectric conversion element 22 is connected to one terminal of the quenching circuit 32. The connection node between the photoelectric conversion element 22 and the quenching circuit 32 is an output node of the photoelectric conversion unit 20. The other terminal of the quenching circuit 32 is connected to a node to which a voltage VH higher than the voltage VL is supplied. The voltage VL and the voltage VH are set so as to apply a reverse bias voltage sufficient to cause the APD to perform an avalanche multiplication operation. In one example, a negative high voltage is applied as the voltage VL, and a positive voltage equivalent to the power supply voltage is applied as the voltage VH. For example, the voltage VL is -30V, and the voltage VH is 1V.

[0095] The photoelectric conversion element 22 can be configured by an APD as described above. When a reverse bias voltage sufficient to perform avalanche multiplication operation is supplied to the APD, the charge carriers generated by the light incident on the APD cause avalanche multiplication and generate an avalanche current. The operating modes in the state of supplying a reverse bias voltage to the APD include a Geiger mode and a linear mode. The Geiger mode is an operating mode in which the voltage applied between the anode and the cathode is set to a reverse bias voltage greater than the breakdown voltage of the APD. The linear mode is an operating mode in which the voltage applied between the anode and the cathode is set to a reverse bias voltage close to or lower than the breakdown voltage of the APD. An APD operating in Geiger mode is called a SPAD (single photon avalanche diode). The APD constituting the photoelectric conversion element 22 can operate in a linear mode or a Geiger mode.

[0096] The quenching circuit 32 has a function of converting the change in the avalanche current generated in the photoelectric conversion element 22 into a voltage signal. In addition, the quenching circuit 32 serves as a load circuit (quenching circuit) when the signal is multiplied by avalanche multiplication, and has a function of suppressing avalanche multiplication by reducing the voltage applied to the photoelectric conversion element 22. The operation of the quenching circuit 32 to suppress avalanche multiplication is called a quenching operation. In addition, the quenching circuit 32 has a function of restoring the voltage supplied to the photoelectric conversion element 22 to the voltage VH by allowing a current corresponding to the voltage drop caused by the quenching operation to flow. The operation of restoring the voltage supplied from the quenching circuit 32 to the voltage VH to the voltage VH is called a recharging operation. The quenching circuit 32 can be configured by a resistor, a MOS transistor, and the like.

[0097] The waveform shaping circuit 34 includes an input node and an output node to which the output signal of the photoelectric conversion unit 20 is supplied. The waveform shaping circuit 34 has a function of converting the analog signal supplied from the photoelectric conversion unit 20 into a pulse signal. The waveform shaping circuit 34 can be configured by a logic circuit including a NOT circuit (inverter circuit), a NOR circuit, a NAND circuit, etc. The output node of the waveform shaping circuit 34 is connected to the processing circuit 36.

[0098] The processing circuit 36 ​​has an input node to which the output signal of the waveform shaping circuit 34 is supplied, an input node connected to the control line 14, and an output node. The processing circuit 36 ​​has a function of performing predetermined signal processing on the output signal of the waveform shaping circuit 34 and holding the processed signal or the processing result. However, the processing circuit 36 ​​is not particularly limited, and may be, for example, a counter circuit. In this case, the processing circuit 36 ​​counts the pulses superimposed on the signal output from the waveform shaping circuit 34 and holds the count value as the counting result. The signal supplied from the vertical scanning circuit unit 40 to the processing circuit 36 ​​via the control line 14 may include an enable signal for controlling the pulse counting period (exposure period), a reset signal for resetting the count value held by the processing circuit 36, and the like. As an example, Figure 3 A reset signal (control signal pRES) is shown supplied via signal line 14A The output node of processing circuit 36 ​​is connected to selection circuit 38 .

[0099] The selection circuit 38 has a function of switching the electrical connection state (connection or non-connection) between the processing circuit 36 ​​and the output line 16. The selection circuit 38 switches the electrical connection state (connection or non-connection) between the processing circuit 36 ​​and the output line 16 according to the selection signal supplied from the vertical scanning circuit unit 40 via the control line 14 (or Figure 2 The connection state between the processing circuit 36 ​​and the output line 16 is switched by a selection signal supplied from the horizontal scanning circuit unit 60 via the control line 18 in the configuration example of FIG. Figure 3 A selection signal (control signal pSEL) is shown supplied via signal line 14B. Processing circuit 36 ​​may include buffer circuitry for the output signal.

[0100] Pixels 12 are typically a unit structure that outputs pixel signals for forming an image. However, when aiming at distance measurement using the TOF (Time of Flight) method, pixels 12 do not necessarily need to be a unit structure that outputs pixel signals for forming an image. In other words, pixels 12 may be a unit structure that outputs a signal for measuring the time and amount of light arrival.

[0101] One signal processing unit 30 does not have to be provided for each pixel 12, and one signal processing unit 30 may be provided for a plurality of pixels 12. In this case, signal processing of a plurality of pixels 12 may be sequentially performed using one signal processing unit 30.

[0102] The photoelectric conversion device 100 according to this embodiment is configured as a stacked-type photoelectric conversion device in which a plurality of substrates are stacked. Figure 4 As shown, the photoelectric conversion device 100 is configured by stacking three substrates of a sensor substrate 110 , a circuit substrate 120 , and a circuit substrate 130 and electrically connecting these substrates to each other.

[0103] At least the photoelectric conversion unit 20, one of the components of the pixel 12, can be arranged on the sensor substrate 110. The functional block 30A of the signal processing unit 30, one of the components of the pixel 12, can be arranged on the circuit substrate 120. The functional block 30B of the signal processing unit 30, one of the components of the pixel 12, can be arranged on the circuit substrate 130. The pixel region 10 is provided in each of the sensor substrate 110, the circuit substrate 120, and the circuit substrate 130 so as to overlap with each other in a top view. The photoelectric conversion unit 20, the functional block 30A, and the functional block 30B of each of the plurality of pixels 12 configuring the pixel region 10 are provided on the sensor substrate 110, the circuit substrate 120, and the circuit substrate 130 so as to overlap with each other in a top view. The photoelectric conversion unit 20 and the functional block 30A, as well as the functional block 30A and the functional block 30B, are electrically connected to each other via connection wiring (not shown) provided for each pixel 12. Here, the term "top view" refers to viewing from a direction perpendicular to the surface of the sensor substrate 110.

[0104] The circuit substrates 120 and 130 may further include a vertical scanning circuit unit 40, a readout circuit unit 50, a horizontal scanning circuit unit 60, a DFE 70, a TX 80, and a control pulse generating unit 90. The vertical scanning circuit unit 40, the readout circuit unit 50, the horizontal scanning circuit unit 60, the DFE 70, the TX 80, and the control pulse generating unit 90 may be arranged around the pixel area 10 in the circuit substrates 120 and 130. Each of the vertical scanning circuit unit 40, the readout circuit unit 50, the horizontal scanning circuit unit 60, the DFE 70, the TX 80, and the control pulse generating unit 90 may be provided on one of the circuit substrates 120 and 130, or may be provided by being divided into the circuit substrates 120 and 130.

[0105] By configuring the stacked photoelectric conversion device 100, the degree of component integration can be increased, achieving higher functionality. In particular, by arranging the photoelectric conversion element 20 and the signal processing unit 30 on separate substrates, the photoelectric conversion elements 22 can be arranged at a high density without sacrificing their light-receiving area, thereby improving photon detection efficiency. Furthermore, by arranging the functional blocks 30A and 30B of the signal processing unit 30 on separate substrates, the photoelectric conversion elements 22 can be arranged at a high density while achieving high integration and functionality of the processing circuit 36 ​​that constitutes the functional block 30B.

[0106] exist Figure 4 In the present invention, the sensor substrate 110 and the circuit substrates 120 and 130 are assumed to be the chips to be cut. However, the sensor substrate 110 and the circuit substrates 120 and 130 are not limited to chips. For example, the sensor substrate 110 and the circuit substrates 120 and 130 can each be a wafer. In addition, the sensor substrate 110 and the circuit substrates 120 and 130 can be stacked in a wafer state and then cut, or they can be stacked and bonded after forming chips.

[0107] Next, refer to Figures 5A to 5C The basic operation of the photoelectric conversion unit 20 in the photoelectric conversion apparatus according to the present embodiment is described. Figures 5A to 5C 1 is a diagram illustrating basic operations of the photoelectric conversion element 22 , the quenching circuit 32 , and the waveform shaping circuit 34 in the photoelectric conversion device according to this embodiment. Figure 5A 1 is a circuit diagram of the photoelectric conversion element 22 , the quenching circuit 32 , and the waveform shaping circuit 34 . Figure 5B The waveform of the signal at the input node (node ​​A) of the waveform shaping circuit 34 is shown. Figure 5C 1 and 2 show the waveform of a signal at an output node (node ​​B) of the waveform shaping circuit 34. Here, in order to simplify the description, it is assumed that the waveform shaping circuit 34 is configured by an inverter circuit.

[0108] At time t0, a reverse bias voltage having a potential difference corresponding to (VH - VL) is applied to the photoelectric conversion element 22. Although a reverse bias voltage sufficient to cause avalanche multiplication is applied between the anode and cathode of the APD constituting the photoelectric conversion element 22, no carriers serving as seeds for avalanche multiplication exist in a state where no photons are incident on the photoelectric conversion element 22. Therefore, avalanche multiplication does not occur in the photoelectric conversion element 22, and no current flows through the photoelectric conversion element 22.

[0109] At a subsequent time t1, it is assumed that a photon is incident on the photoelectric conversion element 22. When the photon enters the photoelectric conversion element 22, electron-hole pairs are generated by photoelectric conversion, and avalanche multiplication occurs using these carriers as seeds, causing an avalanche multiplication current to flow through the photoelectric conversion element 22. When this avalanche multiplication current flows through the quenching circuit 32, a voltage drop occurs across the quenching circuit 32, and the voltage of the node A begins to drop. When the voltage drop at the node A increases and the avalanche multiplication stops at a time t3, the voltage level of the node A no longer drops.

[0110] When avalanche multiplication in the photoelectric conversion element 22 stops, a current compensating for the voltage drop flows from the node to which the voltage VL is supplied to the photoelectric conversion element 22 to the node A, and the voltage of the node A gradually increases. Thereafter, at time t5, the node A is stabilized to the original voltage level.

[0111] The waveform shaping circuit 34 binarizes the signal input from the node A according to a predetermined judgment threshold value, and outputs a signal from the node B. Specifically, the waveform shaping circuit 34 outputs a low-level signal from the node B when the voltage level of the node A exceeds the judgment threshold value, and outputs a high-level signal from the node B when the voltage level of the node A is equal to or lower than the judgment threshold value. For example, Figure 5B As shown, it is assumed that the voltage of node A is equal to or lower than the judgment threshold value during the period from time t2 to time t4. In this case, as shown in FIG. Figure 5C As shown, the signal level at the node B becomes low level in the period from time t0 to time t2 and in the period from time t4 to time t5, and becomes high level in the period from time t2 to time t4.

[0112] Thus, the analog signal input from the node A is waveform-shaped into a digital signal by the waveform shaping circuit 34. The pulse signal output from the waveform shaping circuit 34 in response to the incidence of photons on the photoelectric conversion element 22 is a photon detection pulse signal.

[0113] Figure 6 is a schematic diagram showing the pixel 12 Figure 4Figure 1 shows a stacked structure. Node A, which serves as an electrical connection between the photoelectric conversion element 20 and the signal processing unit 30, serves as a communication path between the sensor substrate 110 and the circuit substrate 120. Node B, which serves as an electrical connection between the waveform shaping circuit 34 and the processing circuit 36, and node C, which serves as an electrical connection between the processing circuit 36 ​​and the selection circuit 38, form a communication path between the circuit substrate 120 and the circuit substrate 130. Specifically, the analog signal output from the photoelectric conversion element 22 of the sensor substrate 110 is input to the waveform shaping circuit 34 of the circuit substrate 120 via node A. The pulse signal output from the waveform shaping circuit 34 reaches the processing circuit 36 ​​of the circuit substrate 130 via node B, undergoes predetermined processing by the processing circuit 36, and is then input to the selection circuit 38 of the circuit substrate 120 via node C. To facilitate wiring with the selection circuit 38, the output line 16 is preferably arranged on the same circuit substrate 120 as the selection circuit 38.

[0114] As described above, node B and node C each constitute a portion of the plurality of electrical connections between circuit substrate 120 and circuit substrate 130 included in each pixel 12. Node B constitutes a portion of the input signal line to processing circuit 36, and node C constitutes a portion of the output signal line from processing circuit 36.

[0115] By adopting such a configuration, only the processing circuit 36 ​​can be arranged in the pixel area 10 of the circuit substrate 130, and the area of ​​the processing circuit 36 ​​can be further increased. That is, according to this embodiment, the selection circuit 38 does not affect the area of ​​the processing circuit 36, and a high degree of integration and high functionality of the processing circuit 36 ​​can be achieved. In addition, by arranging the selection circuit 38 and the processing circuit 36 ​​on different substrates, the component size of the selection circuit 38 can be increased. As a result, the driving capability of the selection circuit 38 can be increased, and the waveform quality of the signal transmitted to the subsequent circuit can be improved. In particular, since large parasitic capacitance is coupled to the output line 16 to which the plurality of pixels 12 are connected, the effect of increasing the driving capability of the selection circuit 38 is significant.

[0116] The power supply voltage supplied to the elements provided on the circuit substrate 120 may be the same as or different from the power supply voltage supplied to the elements provided on the circuit substrate 130. In other words, the withstand voltage of the elements mounted on the circuit substrate 120 may be the same as or different from the withstand voltage of the elements mounted on the circuit substrate 130. For example, the withstand voltage of the elements mounted on the circuit substrate 120 may be higher than the withstand voltage of the elements mounted on the circuit substrate 130. In this case, taking into account the characteristics of the photoelectric conversion element 22, the tunable voltage range of the voltage VL can be expanded. An element with a high withstand voltage is, for example, a transistor with a relatively thick gate insulating film, and an element with a low withstand voltage is, for example, a transistor with a relatively thin gate insulating film.

[0117] In such Figure 7 As shown, when the power supply voltage of the circuit substrate 130 is a voltage VM between the voltage VH and the voltage VL, by setting the power supply voltage of the waveform shaping circuit 34 to the voltage VM, the signal amplitude at the node B can be suppressed and the signal amplitude can be prevented from exceeding the withstand voltage of the processing circuit 36. When the power supply voltage of the selection circuit 38 is set to a voltage VH higher than the power supply voltage of the circuit substrate 130, the signal amplitude in the output line 16 can be increased, and the waveform quality can be improved.

[0118] It is also possible to mix multiple types of components with different withstand voltages on circuit substrate 120. For example, quenching circuit 32 and waveform shaping circuit 34 can be configured from components with relatively high withstand voltages, while selection circuit 38 can be configured from components with relatively low withstand voltages. In this case, since smaller components generally have lower withstand voltages, selection circuit 38 can be implemented with a smaller area or lower output resistance. This improves the degree of freedom in the circuit configuration of selection circuit 38 and improves the waveform quality of the signal output to output line 16.

[0119] Components with large size, high withstand voltage, and high current drive capability can be arranged on the circuit substrate 120, and components with small size and high operating speed can be arranged on the circuit substrate 130. Note that the components with small size and high operating speed are, for example, transistors with relatively short channel lengths, and the components with large size, high withstand voltage, and high current drive capability are, for example, transistors with relatively long channel lengths or relatively wide channel widths. In this case, the minimum channel length of the transistors constituting the functional blocks arranged on the circuit substrate 130 is shorter than the minimum channel length of the transistors constituting the functional blocks arranged on the circuit substrate 120.

[0120] In this embodiment, the interconnect (wiring) forming node C can be a single-bit interconnect or a group of multiple-bit interconnects. Furthermore, not all components of processing circuit 36 ​​need to be arranged on circuit substrate 130, and some components can be arranged on circuit substrate 120. Furthermore, in situations where the maximum level of integration of processing circuit 36 ​​is not required, at least a portion of the components constituting quenching circuit 32, waveform shaping circuit 34, and selection circuit 38 can be arranged on circuit substrate 120. Consequently, the level of integration of components other than processing circuit 36 ​​of signal processing unit 30 can be improved.

[0121] As described above, according to the present embodiment, in a photoelectric conversion device configured by stacking three or more substrates, high integration of functional blocks configuring pixels and improved characteristics can be achieved.

[0122] [Second embodiment]

[0123] Will refer to Figure 8 A photoelectric conversion device according to a second embodiment of the present invention is described. Figure 8 Components identical to those of the photoelectric conversion device according to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted or simplified.

[0124] The photoelectric conversion device according to this embodiment is the same as the photoelectric conversion device according to the first embodiment except for the configuration of the pixel 12. In this embodiment, the difference from the pixel 12 of the first embodiment will be mainly described, and the same parts as those of the first embodiment will be omitted as appropriate.

[0125] like Figure 8 As shown, the pixel 12 of the photoelectric conversion device according to this embodiment is Figure 6 The pixel 12 of the photoelectric conversion device according to the first embodiment shown differs in that node C, which serves as the output terminal of the processing circuit 36, is connected not only to the selection circuit 38 but also to the quenching circuit 32. By configuring the pixel 12 in this manner, the processing results in the processing circuit 36 ​​can be fed back to the quenching circuit 32, thereby controlling the operation of the quenching circuit 32. For example, if the processing circuit 36 ​​includes a function for counting the number of photons incident on the pixel 12, that is, a counter for counting the number of pulses generated at node B, the quenching circuit 32 can be controlled based on the count value of the counter. For example, when the count value of the counter reaches the maximum count value of the processing circuit 36, the quenching circuit 32 can be controlled to cut off the current path between the node to which the voltage VH is supplied and the photoelectric conversion element 22.

[0126] Likewise, the node C, which is the output terminal of the processing circuit 36, can be connected to the waveform shaping circuit 34, and the processing result in the processing circuit 36 ​​can be fed back to the waveform shaping circuit 34. For example, when the processing circuit 36 ​​has a function of counting the number of photons incident on the pixel 12, that is, a counter that counts the number of pulses generated at the node B, the waveform shaping circuit 34 can be controlled according to the count value of the counter. For example, when the count value of the counter reaches the maximum count value of the processing circuit 36, the waveform shaping circuit 34 can be controlled so as not to output a pulse to the node B.

[0127] In this embodiment, the interconnects forming node C may be interconnects of one bit or a group of interconnects of multiple bits. When the interconnects forming node C are a group of interconnects of multiple bits, the interconnects fed back to quenching circuit 32 or waveform shaping circuit 34 may be interconnects of one bit or a group of interconnects of multiple bits.

[0128] As described above, according to the present embodiment, in a photoelectric conversion device configured by stacking three or more substrates, high integration of functional blocks configuring pixels and improved characteristics can be achieved.

[0129] [Third embodiment]

[0130] Will refer to Figure 9 and Figure 10 A photoelectric conversion device according to a third embodiment of the present invention is described. Figure 9 is a schematic diagram showing a configuration example of a pixel in the photoelectric conversion device according to the present embodiment. Figure 10 Components identical to those of the photoelectric conversion device according to the first or second embodiment are denoted by the same reference numerals, and their description will be omitted or simplified.

[0131] The photoelectric conversion device according to this embodiment is the same as the photoelectric conversion device according to the first embodiment except for the configuration of the pixel 12. In this embodiment, the difference from the pixel 12 of the first embodiment will be mainly described, and the description of the parts that are the same as those of the first embodiment will be appropriately omitted.

[0132] In the pixel 12 of the photoelectric conversion device according to the present embodiment, one pixel 12 includes a plurality of photoelectric conversion elements 22. That is, for example, Figure 9 As shown, the pixel 12 includes four photoelectric conversion elements 22A, 22B, 22C, and 22D, four quenching circuits 32A, 32B, 32C, and 32D corresponding thereto, and four waveform shaping circuits 34A, 34B, 34C, and 34D. The pixel 12 having such a configuration is suitable for configuring a SiPM (silicon photomultiplier) or a macro pixel that realizes one function using multiple photoelectric conversion elements.

[0133] The photoelectric conversion elements 22A, 22B, 22C, and 22D are connected to the quenching circuits 32A, 32B, 32C, and 32D and the waveform shaping circuits 34A, 34B, 34C, and 34D via nodes A1, A2, A3, and A4, respectively. The output terminals of the waveform shaping circuits 34A, 34B, 34C, and 34D are connected to the processing circuit 36 ​​via nodes B1, B2, B3, and B4. By arranging a plurality of photoelectric conversion elements 22, quenching circuits 32, and waveform shaping circuits 34 in this manner, even when a plurality of photoelectric conversion elements 22 are arranged in one pixel 12, the degree of integration of the processing circuit 36 ​​can be improved. Although Figure 9 A configuration example in which one pixel 12 includes four photoelectric conversion elements 22 is shown, but the number of photoelectric conversion elements 22 included in one pixel 12 may be two, three, five, or more.

[0134] For example Figure 10 As shown in FIG, the logic unit 42 can be arranged between the waveform shaping circuits 34A, 34B, 34C, and 34D and the processing circuit 36. For example, the output terminals of the waveform shaping circuits 34A, 34B, 34C, and 34D can be connected to the input terminal of the logic unit 42, and the output terminal of the logic unit 42 can be connected to the input terminal of the processing circuit 36 ​​via the node B'. In this case, by arranging the logic unit 42 on the circuit substrate 120 and connecting the circuit substrate 120 and the circuit substrate 130 at the node B', the number of interconnections connecting the circuit substrate 120 and the circuit substrate 130 can be reduced, and the ease of manufacturing and the yield can be improved. The logic unit 42 is a functional block that performs logical operations on signals corresponding to the incidence of light on the photoelectric conversion elements 22A to 22D, and can be configured by, for example, an OR circuit, a memory, or an external light removal circuit that outputs a signal only when the plurality of photoelectric conversion elements 22 detect a photon.

[0135] As described above, according to the present embodiment, in a photoelectric conversion device configured by stacking three or more substrates, high integration of functional blocks configuring pixels and improved characteristics can be achieved.

[0136] [Fourth embodiment]

[0137] Will refer to Figure 11 and Figure 12 A photoelectric conversion device according to a fourth embodiment of the present invention is described. Figure 11 and Figure 12 Components identical to those of the photoelectric conversion apparatuses according to the first to third embodiments are denoted by the same reference numerals, and their descriptions will be omitted or simplified.

[0138] In this embodiment, the connection relationship between the pixel region 10 and the vertical scanning circuit unit 40 will be described. The configuration described in any of the first to third embodiments can be applied to each of the plurality of pixels 12 arranged in the pixel region 10. In addition, the configuration described in any of the first to third embodiments can also be applied to other functional blocks of the photoelectric conversion device.

[0139] like Figure 11 As shown, the vertical scanning circuit unit 40 in the photoelectric conversion device according to this embodiment includes a logic unit 44 and a plurality of output units 46 corresponding to each row of the pixel region 10. The logic unit 44 is connected to the control pulse generating unit 90 (see Figure 1 or Figure 2The output units 46 of each row are connected to the logic unit 44. The logic unit 44 generates a signal for controlling the pixels 12 in response to the control signal generated by the control pulse generating unit 90. The signal generated by the logic unit 44 is supplied to the pixels 12 of the corresponding row via the output units 46 of each row and the control line 14.

[0140] The logic unit 44 is a functional block that performs logic operations and signal generation, and is preferably arranged on the circuit substrate 130 from the viewpoint of improving the degree of integration and achieving high functionality. On the other hand, in order to supply the signal generated by the logic unit 44 to the pixel 12 without reducing the waveform quality as much as possible, the output unit 46 needs to have a large driving capability, that is, a large element size. From such a viewpoint, it is desirable that in the output unit 46, functional blocks corresponding to the signal lines 14A and 14B are arranged on the circuit substrate 120 and the circuit substrate 130, respectively, according to the arrangement of the signal lines 14A and 14B. For example, Figure 12 As shown, when the output unit 46 includes the drive circuit 48A that drives the signal line 14A and the drive circuit 48B that drives the signal line 14B, it is preferable to arrange the drive circuit 48A on the circuit substrate 120 and arrange the drive circuit 48B on the circuit substrate 130 .

[0141] Although an example of the element arrangement in the vertical scanning circuit unit 40 is described in this embodiment, the same configuration can be applied to the horizontal scanning circuit unit 60. Therefore, in the horizontal scanning circuit unit 60, the same effects as those obtained by the vertical scanning circuit unit 40 of this embodiment can also be obtained.

[0142] As described above, in the present embodiment, the functional blocks constituting the vertical scanning circuit unit 40 and the horizontal scanning circuit unit 60 are distributed and arranged on the appropriate circuit substrates 120 and 130 in accordance with the arrangement of the functional blocks 30A and 30B of the signal processing unit 30 on the circuit substrates 120 and 130. Therefore, according to the present embodiment, while maintaining the waveform quality of the signals generated by the vertical scanning circuit unit 40 and the horizontal scanning circuit unit 60, the degree of integration can be improved and the functionality thereof can be increased.

[0143] Note that the configuration of the vertical scanning circuit unit 40 described in this embodiment is merely an example and is not limited thereto. The circuit substrates 120 and 130 to which the functional blocks constituting the vertical scanning circuit unit 40 and the horizontal scanning circuit unit 60 are distributed can be appropriately selected according to the characteristics required of each circuit. Generally, from the perspectives of area saving, power saving, and high integration, it is desirable that the functional blocks constituting the vertical scanning circuit unit 40 and the horizontal scanning circuit unit 60, except for the functional blocks constituting the output stage, are preferably constituted by fine elements, and preferably arranged on the circuit substrate 130. It is preferred that the functional blocks constituting the output stage be arranged on the same substrate as the functional blocks of the corresponding pixels 12.

[0144] [Fifth embodiment]

[0145] Will refer to Figure 13 and Figure 14 A photoelectric conversion device according to a fifth embodiment of the present invention is described. Figure 13 and Figure 14 Components identical to those of the photoelectric conversion apparatuses according to the first to third embodiments are denoted by the same reference numerals, and their descriptions will be omitted or simplified.

[0146] In this embodiment, the connection relationship between the pixel region 10 and the readout circuit unit 50 will be described. The configuration described in any of the first to third embodiments can be applied to each of the plurality of pixels 12 arranged in the pixel region 10. In addition, the configuration described in any of the first to fourth embodiments can be applied to other functional blocks of the photoelectric conversion device.

[0147] like Figure 13 As shown, the readout circuit unit 50 in the photoelectric conversion device according to this embodiment includes a plurality of receiving circuits 52 corresponding to the columns of the pixel region 10. The output lines 16 corresponding to the columns, the control pulse generating unit 90 (see FIG. 1 ) and the like are connected to the control pulse generating unit 90. Figure 1 or Figure 2 ) is supplied to a control line 54, and an output line 56 to which a signal of the receiving circuit 52 is output is connected to the receiving circuit 52 of each column.

[0148] For example Figure 14As shown in FIG, each receiving circuit 52 includes a receiving unit 52A that receives a pixel signal output via an output line 16 and a processing unit 52B that processes the pixel signal output from the receiving unit 52A. The output line 16 is connected to an input node of the receiving unit 52A, and an output node of the receiving unit 52A is connected to an input node of the processing unit 52B. The control node of the processing unit 52B is connected to a control line 54, and the output node of the processing unit 52B is connected to an output line 56.

[0149] The receiving unit 52A is required to have high gain and low offset to allow the waveform quality of the pixel signal output via the output line 16 to deteriorate, and the receiving units 52A of the plurality of receiving circuits 52 are required to have small characteristic deviations. Therefore, it is desirable to increase the element size of the receiving unit 52A. On the other hand, the processing unit 52B is a block that performs predetermined processing on the signal output from the receiving unit 52A, and it is desirable to reduce the element size to increase the degree of integration. From such a point of view, as for example Figure 14 As shown in FIG, it is preferable to arrange the receiving unit 52A on the circuit substrate 120 and the processing unit 52B on the circuit substrate 130. By configuring the readout circuit unit 50 in this manner, both good characteristics and improved integration can be achieved. From the perspective of easy wiring with the output line 16 arranged on the circuit substrate 120, it is preferable to arrange the receiving unit 52A on the circuit substrate 120.

[0150] Furthermore, since the DFE 70 is a functional block that performs various logical operations and processes on the pixel signals output from the readout circuit unit 50, it is desirable to increase the degree of integration by providing the DFE 70 on the circuit substrate 130. Therefore, considering the ease of wiring between the readout circuit unit 50 and the DFE 70, it is desirable to arrange the processing unit 52B on the circuit substrate 130.

[0151] As described above, in this embodiment, the functional blocks constituting the readout circuit unit 50 and the DFE 70 are distributed and arranged on appropriate circuit substrates 120 and 130, depending on the arrangement of the functional blocks 30A and 30B of the signal processing unit 30 on the circuit substrates 120 and 130. Therefore, according to this embodiment, while maintaining the waveform quality of the signal generated by the readout circuit unit 50, the degree of integration of the readout circuit unit 50 can be improved and its functionality can be enhanced. Furthermore, the ease of wiring between the readout circuit unit 50 and the DFE 70 can be improved.

[0152] Note that the configuration of the readout circuit unit 50 described in this embodiment is merely an example and is not limited thereto. The circuit substrates 120 and 130 on which the functional blocks constituting the readout circuit unit 50 are distributed can be appropriately selected based on the characteristics required of each circuit. When the readout circuit unit 50 includes a sense amplifier, since the sense amplifier is required to have small offset deviation, it is preferable to arrange relatively large components on the circuit substrate 120. From the perspectives of area conservation, power conservation, and high integration, other components are preferably formed of fine components and are preferably arranged on the circuit substrate 130.

[0153] [Sixth embodiment]

[0154] Will refer to Figure 15 A photoelectric conversion device according to a sixth embodiment of the present invention is described. Figure 15 Components identical to those of the photoelectric conversion apparatuses according to the first to third embodiments are denoted by the same reference numerals, and descriptions thereof will be omitted or simplified.

[0155] In this embodiment, description will be given of a configuration example of the TX 80. The configuration described in any of the first to fifth embodiments can be applied to other functional blocks of the photoelectric conversion apparatus.

[0156] For example Figure 15 As shown in FIG, TX 80 includes a processing unit 82 and an output unit 84. The input node of processing unit 82 is connected to the output node of DFE 70. The output node of processing unit 82 is connected to output unit 84. The output node of output unit 84 is also the output node of photoelectric conversion device 100.

[0157] The processing unit 82 is a block that performs predetermined processing such as serialization on the signal output from the DFE 70, and is required to have a small area from the viewpoint of low jitter and low skew. On the other hand, since the output unit 84 outputs a signal to the outside of the photoelectric conversion device 100, it is required to increase the driving capability, that is, increase the element size. From such a viewpoint, for example, Figure 15 As shown in , it is preferable to arrange the processing unit 82 on the circuit substrate 120, and to arrange the output unit 84 on the circuit substrate 130. By configuring the TX 80 in this manner, both good characteristics and improved integration can be achieved.

[0158] Furthermore, as described in the fifth embodiment, since it is desirable to arrange the DFE 70 on the circuit substrate 130 , it is desirable to arrange the processing unit 82 on the circuit substrate 130 in consideration of the ease of wiring between the DFE 70 and the processing unit 82 .

[0159] As described above, in this embodiment, the functional blocks constituting the TX 80 are distributed and arranged on appropriate circuit substrates 120 and 130, depending on the arrangement of the functional blocks 30A and 30B of the signal processing unit 30 on the circuit substrates 120 and 130. Therefore, according to this embodiment, it is possible to improve the degree of integration of the TX 80 while achieving excellent characteristics. Furthermore, it is possible to improve the ease of wiring between the DFE 70 and the TX 80.

[0160] Note that the configuration of the TX 80 described in this embodiment is merely an example, and the present invention is not limited thereto. The circuit substrates 120 and 130 to which the functional blocks constituting the TX 80 are distributed can be appropriately selected based on the characteristics required of each circuit. Generally, from the perspectives of area conservation, power saving, and high integration, it is desirable that the functional blocks constituting the TX 80, except for those constituting the output stage, be constructed from fine components, and preferably be arranged on the circuit substrate 130. It is preferable that the functional blocks constituting the output stage be constructed from relatively large, low-resistance components and arranged on the circuit substrate 120.

[0161] [Seventh embodiment]

[0162] Will refer to Figures 16 to 18 A photoelectric conversion device according to a seventh embodiment of the present invention is described. Figures 16 to 18 Components identical to those of the photoelectric conversion apparatuses according to the first to sixth embodiments are denoted by the same reference numerals, and description thereof will be omitted or simplified.

[0163] In this embodiment, an example of a specific cross-sectional structure of the photoelectric conversion device described in the above embodiment will be described.

[0164] Figures 16 to 18 1 is a schematic cross-sectional view illustrating an example configuration of a photoelectric conversion device comprising a stack of three substrates: a sensor substrate 110, a circuit substrate 120, and a circuit substrate 130. The sensor substrate 110 includes a semiconductor substrate 112 and an interconnect structure layer 114. The circuit substrate 120 includes a semiconductor substrate 122 and an interconnect structure layer 124. The circuit substrate 130 includes a semiconductor substrate 132 and an interconnect structure layer 134.

[0165] The sensor substrate 110 and the circuit substrate 120 are coupled in a face-to-back manner such that the front side of the semiconductor substrate 112 on which the interconnect structure layer 114 is disposed faces the front side of the semiconductor substrate 122 on which the interconnect structure layer 114 is disposed. The electrical connection between the sensor substrate 110 and the circuit substrate 120 can be achieved by metal bonding 140 between the top interconnect layers constituting the interconnect structure layers 114 and 124, respectively.

[0166] Circuit substrate 120 and circuit substrate 130 are bonded to each other in a face-to-face manner, such that the back side of semiconductor substrate 122 and the front side of semiconductor substrate 132, on which interconnect structure layer 134 is arranged, face each other. The bond between circuit substrate 120 and circuit substrate 130 can be formed by metal bonding 150, similar to the bond between sensor substrate 110 and circuit substrate 120. The electrical connection between circuit substrate 120 and circuit substrate 130 can be formed by connecting the uppermost interconnect layer constituting interconnect structure layer 134 and a through-electrode that penetrates semiconductor substrate 122 and is electrically connected to interconnect structure layer 124.

[0167] On the back side of the semiconductor substrate 112, an optical structure layer including a micro lens ML and a color filter layer (not shown) is arranged. Figures 16 to 18 The photoelectric conversion device shown in FIG is a so-called back-illuminated photoelectric conversion device. Note that the lamination pattern of the substrate, the bonding method, and the electrical connection are not limited to Figures 16 to 18 For example, the optical structure layer may be provided on the front side of the semiconductor substrate 112 to form a front-illuminated photoelectric conversion device.

[0168] like Figures 16 to 18 As shown in FIG, the interconnect structure layer 124 of the circuit substrate 120 may constitute at least a portion of the input interconnect 48I, the signal line 14A, and the output line 16 of the driver circuits 48A and 48B (see, for example, FIG. Figure 12 ). The interconnect structure layer 124 of the circuit substrate 120 may constitute at least a portion of the output interconnect 52AO of the receiving unit 52A, the input interconnect 84I and the output interconnect 84O of the output unit 84 (refer to, for example Figure 14 and Figure 15 The through-electrode penetrating the semiconductor substrate 122 may constitute a portion of the node B and the node C (see, for example, Figure 12 The interconnect structure layer 134 of the circuit substrate 130 may also include signal lines 14B (see, for example, Figure 12 ).

[0169] Figures 16 to 18 The configuration examples are different from each other in arrangement positions of pad electrodes used for wiring for electrical connection between the photoelectric conversion device and an external device.

[0170] exist Figure 16 In the configuration example shown in , all pad electrodes 116 are formed by an interconnect layer at the same level as the interconnect structure layer 114. With this configuration, when pad openings 118 that reach the pad electrodes 116 are formed in the semiconductor substrate 112 and the interconnect structure layer 114, the depths of the pad openings 118 can be made substantially the same. This facilitates metallization processing.

[0171] As described above, the voltage supplied to the sensor substrate 110 is a high voltage, and the circuit substrate 120 is provided with a circuit to which a fine process technology is applied. Figure 16 As shown, the voltage supplied from the pad electrode 116 is supplied only to the sensor substrate 110 , and thus it is possible to avoid application of a high voltage to the circuit provided on the circuit substrate 120 to which the micro-processing technology is applied.

[0172] exist Figure 17 In the configuration example shown in , a pad electrode 116 formed by the interconnect layer of the interconnect structure layer 114, a pad electrode 126 formed by the interconnect layer of the interconnect structure layer 124, and a pad electrode 136 formed by the interconnect layer of the interconnect structure layer 134 are provided. The pad openings 118, 128, 138 that expose the pad electrodes 116, 126, 136 have different depths. With this configuration, it is possible to reduce the wiring length from the pad electrodes to which the driving voltage is supplied to the circuits provided on each substrate, and to reduce the possibility of slowing down the circuit operation due to the propagation delay of the signal. In addition, the driving voltage corresponding to the elements provided on each substrate can be supplied from each pad electrode.

[0173] exist Figure 18 In the configuration example shown in FIG, pad electrodes 116 are formed from the interconnect layer of interconnect structure layer 114, and pad electrodes 126 are formed from the interconnect wiring layer of interconnect structure layer 124. Providing pad electrodes 116 for supplying voltage to sensor substrate 110 in interconnect structure layer 114 on the sensor substrate 110 side prevents high voltage from being applied to the circuits provided on circuit substrate 120, which utilizes microprocessing technology. Furthermore, since pad electrodes 126 for supplying voltage to circuit substrate 120 are provided in the interconnect layer of interconnect structure layer 124, the wiring length from the pad electrodes to the circuits provided on circuit substrate 120 can be reduced compared to providing pad electrodes in interconnect structure layer 114. Consequently, the possibility of slowing circuit operation due to signal propagation delays can be reduced. From the perspective of facilitating manufacturing processes, the pad electrodes for supplying voltage to circuit substrate 130 are formed in the same interconnect layer as the pad electrodes for supplying voltage to circuit substrate 120.

[0174] Note that the arrangement position of the pad electrode is not limited to the configuration example described in this embodiment and can be appropriately selected.

[0175] [Eighth embodiment]

[0176] Will refer to Figure 19 A light detection system according to an eighth embodiment of the present invention is described. Figure 19 1 is a block diagram showing a schematic configuration of a light detection system according to the present embodiment. In the present embodiment, a light detection sensor to which the photoelectric conversion apparatus 100 according to any of the first to seventh embodiments is applied will be described.

[0177] The photoelectric conversion device 100 described in the first to seventh embodiments can be applied to various optical detection systems. Examples of applicable optical detection systems include imaging systems such as digital still cameras, digital video cameras, surveillance cameras, copiers, fax machines, mobile phones, vehicle-mounted cameras, and observation satellites. The optical detection system also includes a camera module having an optical system such as a lens and an imaging device. Figure 19 A block diagram of a digital still camera is illustrated as one of them.

[0178] Figure 19 The light detection system 200 shown in FIG. 1 includes an imaging device 201, a lens 202 that forms an optical image of a subject on the imaging device 201, an aperture 204 that changes the amount of light passing through the lens 202, and a baffle 206 that protects the lens 202. The lens 202 and the aperture 204 form an optical system that focuses light on the imaging device 201. The imaging device 201 is the photoelectric conversion device 100 described in any of the first to seventh embodiments, and converts the optical image formed by the lens 202 into image data.

[0179] The light detection system 200 also includes a signal processing unit 208 that processes an output signal output from the imaging device 201. The signal processing unit 208 generates image data based on the digital signal output from the imaging device 201. In addition, the signal processing unit 208 performs various corrections and compressions as needed, and outputs the generated image data. The imaging device 201 may include an AD conversion unit that generates a digital signal to be processed by the signal processing unit 208. The AD conversion unit may be formed on a semiconductor layer (semiconductor substrate) on which the photon detection element of the imaging device 201 is formed, or may be formed on a semiconductor substrate different from the semiconductor layer on which the photon detection element of the imaging device 201 is formed. The signal processing unit 208 may be formed on the same semiconductor substrate as the imaging device 201.

[0180] The optical detection system 200 also includes a memory unit 210 for temporarily storing image data and an external interface unit (external I / F unit) 212 for communicating with an external computer or the like. Furthermore, the optical detection system 200 includes a storage medium 214, such as a semiconductor memory, for storing or reading image data, and a storage medium control interface unit (storage medium control I / F unit) 216 for storing or reading data on or from the storage medium 214. The storage medium 214 may be built into the optical detection system 200 or may be detachable. Communication between the storage medium control I / F unit 216 and the storage medium 214, as well as communication from the external I / F unit 212, can be performed wirelessly.

[0181] The light detection system 200 also includes a general control / operation unit 218 that performs various calculations and controls the entire digital still camera, and a timing generation unit 220 that outputs various timing signals to the imaging device 201 and the signal processing unit 208. Timing signals and the like may be input from the outside, and the light detection system 200 may include at least the imaging device 201 and the signal processing unit 208 that processes output signals from the imaging device 201. The timing generation unit 220 may be mounted on the imaging device 201. Furthermore, the general control / operation unit 218 and the timing generation unit 220 may be configured to perform part or all of the control functions of the imaging device 201.

[0182] The camera 201 outputs an imaging signal to the signal processing unit 208. The signal processing unit 208 performs predetermined signal processing on the imaging signal output from the camera 201 and outputs processed image data. The signal processing unit 208 generates an image using the imaging signal. The signal processing unit 208 may be configured to perform distance measurement calculations on the signal output from the camera 201.

[0183] As described above, according to the present embodiment, by configuring a light detection system using the photoelectric conversion device according to any of the first to seventh embodiments, a light detection system capable of acquiring a higher quality image can be realized.

[0184] [Ninth embodiment]

[0185] Will refer to Figure 20 A range image sensor according to a ninth embodiment of the present invention is described. Figure 20 1 is a block diagram showing a schematic configuration of a distance image sensor according to this embodiment. In this embodiment, a distance image sensor will be described as an example of a light detection system to which the photoelectric conversion device 100 according to any of the first to seventh embodiments is applied.

[0186] like Figure 20As shown in FIG, the distance image sensor 300 according to the present embodiment may include an optical system 302, a photoelectric conversion device 304, an image processing circuit 306, a monitor 308, and a memory 310. The distance image sensor 300 receives light (modulated light or pulsed light) emitted from a light source device 320 toward a subject 330 and reflected on the surface of the subject 330, and acquires a distance image corresponding to the distance to the subject 330.

[0187] The optical system 302 includes one or more lenses, and has a function of forming an image of image light (incident light) from a subject 330 on a light receiving surface (sensor unit) of the photoelectric conversion device 304 .

[0188] The photoelectric conversion device 304 is the photoelectric conversion device 100 described in any of the first to seventh embodiments, and has a function of generating a distance signal indicating the distance to the subject 330 based on image light from the subject 330, and supplying the generated distance signal to the image processing circuit 306.

[0189] The image processing circuit 306 has a function of performing image processing for constructing a distance image based on the distance signal supplied from the photoelectric conversion device 304 .

[0190] The monitor 308 has a function of displaying a distance image (image data) obtained by image processing in the image processing circuit 306. The memory 310 has a function of storing (recording) a distance image (image data) obtained by image processing in the image processing circuit 306.

[0191] As described above, according to this embodiment, by configuring a distance image sensor using a photoelectric conversion device according to any of the first to seventh embodiments, a distance image sensor capable of acquiring a distance image including distance information with higher precision can be realized in combination with improvements in the characteristics of the pixel 12.

[0192] [Tenth embodiment]

[0193] Will refer to Figure 21 An endoscopic surgery system according to a tenth embodiment of the present invention is described. Figure 21 1 is a schematic diagram showing a configuration example of an endoscopic surgery system according to this embodiment. In this embodiment, an endoscopic surgery system will be described as an example of a light detection system to which the photoelectric conversion device 100 according to any of the first to seventh embodiments is applied.

[0194] Figure 21 1 and 2. A state is shown in which an operator (surgeon) 460 performs surgery on a patient 472 on a bed 470 using the endoscopic surgery system 400.

[0195] like Figure 21 As shown in FIG, an endoscopic surgery system 400 according to this embodiment may include an endoscope 410, a surgical tool 420, and a cart 430 on which various devices used for endoscopic surgery are installed. A CCU (camera control unit) 432, a light source device 434, an input device 436, a processing tool control device 438, a display device 440, and the like may be installed on the cart 430.

[0196] The endoscope 410 includes a barrel 412 and a camera head 414 connected to the base end of the barrel 412. A region of the barrel 412 having a predetermined length from the front end is inserted into the body cavity of the patient 472. Figure 21 The endoscope 410 is shown as a so-called rigid scope having a rigid barrel 412 , but the endoscope 410 may also be configured as a so-called flexible scope having a flexible barrel. The endoscope 410 is held in a movable state by an arm 416 .

[0197] The front end of the lens barrel 412 is provided with an opening for the objective lens to fit in. A light source device 434 is connected to the endoscope 410, and light generated by the light source device 434 is guided to the front end of the lens barrel through a light guide extending inside the lens barrel 412, and is irradiated toward the observation object in the body cavity of the patient 472 through the objective lens. Note that the endoscope 410 can be a straight-view mirror, an oblique-view mirror, or a side-view mirror.

[0198] The camera head 414 includes an optical system and a photoelectric conversion device (not shown). Reflected light from the observation object (observation light) is focused onto the photoelectric conversion device by the optical system. The photoelectric conversion device performs photoelectric conversion on the observation light and generates an electrical signal corresponding to the observation light, that is, an image signal corresponding to the observed image. The photoelectric conversion device 100 described in any of the first to seventh embodiments can be used as the photoelectric conversion device. The image signal is transmitted to the CCU 432 as raw data.

[0199] The CCU 432 may be configured by a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit) or the like, and integrally controls the operations of the endoscope 410 and the display device 440. Furthermore, the CCU 432 receives an image signal from the camera head 414 and performs various types of image processing, such as development processing (demosaic processing), on the image signal for displaying an image based on the image signal.

[0200] The display device 440 displays an image based on the image signal subjected to image processing by the CCU 432 under the control of the CCU 432 .

[0201] The light source device 434 may be configured by, for example, a light source such as an LED (Light Emitting Diode), and supplies irradiation light to the endoscope 410 when imaging a surgical site or the like.

[0202] The input device 436 is an input interface for the endoscopic surgery system 400. The user can input various information and input instructions to the endoscopic surgery system 400 via the input device 436.

[0203] The treatment tool control device 438 controls the driving of the energy treatment tool 450 for tissue ablation, incision, blood vessel sealing, etc.

[0204] The light source device 434 that supplies irradiation light to the endoscope 410 when imaging the surgical site can be configured by, for example, a white light source configured by an LED, a laser light source, or a combination thereof. When the white light source is configured by a combination of RGB laser light sources, since the output intensity and output timing of each color (each wavelength) can be controlled with high precision, the white balance of the captured image can be adjusted in the light source device 434. In addition, in this case, it is also possible to capture images corresponding to each RGB in a time-division manner by irradiating the observation object with laser light from each RGB laser light source in a time-division manner and controlling the drive of the imaging element of the camera head 414 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter in the imaging element.

[0205] Furthermore, the light source device 434 can be controlled to change the intensity of the light output at predetermined intervals. By controlling the driving of the imaging element of the camera head 414 in synchronization with the timing of the light intensity change, images can be acquired and synthesized in a time-division manner, thereby generating images with a high dynamic range that are free of so-called blacked-out shadows and blown-out highlights.

[0206] The light source device 434 can be configured to supply light of a predetermined wavelength band corresponding to specific light observation. In specific light observation, for example, the wavelength dependence of the absorption of light in body tissue is utilized. Specifically, by illuminating light with a narrow band compared to the illuminating light (i.e., white light) during normal observation, predetermined tissues such as blood vessels injected into the surface layer of the mucosa can be photographed with high contrast. Alternatively, in specific light observation, fluorescence observation can be performed to obtain an image by illuminating the fluorescence generated by excitation light. In fluorescence observation, body tissue is irradiated with excitation light to observe fluorescence from the body tissue, or a reagent such as indocyanine green (ICG) is injected into the body tissue for local injection, and the body tissue is irradiated with excitation light corresponding to the fluorescence wavelength of the reagent to obtain a fluorescence image. The light source device 434 can be configured to supply narrowband light and / or excitation light corresponding to such specific light observation.

[0207] As described above, according to this embodiment, by configuring an endoscopic surgery system using the photoelectric conversion device according to any of the first to seventh embodiments, an endoscopic surgery system capable of acquiring higher quality images can be realized.

[0208] [Eleventh embodiment]

[0209] Will refer to Figures 22A to 24 A light detection system and a movable body according to an eleventh embodiment of the present invention are described. Figures 22A to 22C is a schematic diagram showing a configuration example of a movable body according to the present embodiment. Figure 23 is a block diagram showing a schematic configuration of a light detection system according to the present embodiment. Figure 24 In this embodiment, an application example of an in-vehicle camera as a light detection system to which the photoelectric conversion device 100 according to any of the first to seventh embodiments is applied will be described.

[0210] Figures 22A to 22C : is a schematic diagram showing a configuration example of a movable body (vehicle system) according to the present embodiment. Figures 22A to 22C There is shown a configuration of a vehicle 500 (vehicle) as an example of a vehicle system incorporating a light detection system to which the photoelectric conversion apparatus 100 according to any of the first to seventh embodiments is applied. Figure 22A is a schematic front view of a vehicle 500, Figure 22B is a schematic plan view of vehicle 500, and Figure 22C is a schematic rear view of a vehicle 500. Vehicle 500 includes a pair of photoelectric conversion devices 502 on the front. Photoelectric conversion devices 502 are photoelectric conversion devices 100 described in any of the first to fifth embodiments. Vehicle 500 includes an integrated circuit 503, an alarm device 512, and a main control unit 513.

[0211] Figure 231 is a block diagram illustrating an example configuration of a light detection system 501 mounted on a vehicle 500. The light detection system 501 includes a photoelectric conversion device 502, an image preprocessing unit 515, an integrated circuit 503, and an optical system 514. The photoelectric conversion device 502 is the photoelectric conversion device 100 described in any of the first to seventh embodiments. The optical system 514 forms an optical image of a subject on the photoelectric conversion device 502. The photoelectric conversion device 502 converts the optical image of the subject formed by the optical system 514 into an electrical signal. The image preprocessing unit 515 performs predetermined signal processing on the signal output from the photoelectric conversion device 502. The functions of the image preprocessing unit 515 may be incorporated into the photoelectric conversion device 502. At least two sets of optical systems 514, photoelectric conversion devices 502, and image preprocessing units 515 are provided in the light detection system 501, and the output from each set of image preprocessing units 515 is input to the integrated circuit 503.

[0212] Integrated circuit 503 is an integrated circuit for use in camera system applications and includes an image processing unit 504, an optical ranging unit 506, a parallax calculation unit 507, a subject recognition unit 508, and an abnormality detection unit 509. Image processing unit 504 processes the image signal output from image preprocessing unit 515. For example, image processing unit 504 performs image processing such as development processing and defect correction on the output signal of image preprocessing unit 515. Image processing unit 504 includes memory 505 for temporarily storing image signals. For example, the locations of known defective pixels in photoelectric conversion device 502 may be stored in memory 505.

[0213] The optical ranging unit 506 focuses on and measures the distance of a subject. The parallax calculation unit 507 calculates distance measurement information (distance information) based on the multiple image data (parallax images) acquired by the multiple photoelectric conversion devices 502. Each photoelectric conversion device 502 can have a configuration capable of acquiring various types of information, such as distance information. The subject recognition unit 508 recognizes subjects such as vehicles, roads, signs, or people. When an abnormality is detected in the photoelectric conversion device 502, the abnormality detection unit 509 notifies the main control unit 513 of the abnormality.

[0214] The integrated circuit 503 may be implemented by specially designed hardware, may be implemented by a software module, or may be implemented by a combination thereof. In addition, the integrated circuit 503 may be implemented by an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit), or may be implemented by a combination thereof.

[0215] The main control unit 513 integrally controls the operation of the light detection system 501, the vehicle sensor 510, the control unit 520, and the like. The vehicle 500 may not include the main control unit 513. In this case, the photoelectric conversion device 502, the vehicle sensor 510, and the control unit 520 transmit and receive control signals via a communication network. For example, the CAN standard may be used for transmission and reception of control signals.

[0216] The integrated circuit 503 has a function of receiving a control signal from the main control unit 513 or transmitting a control signal or a setting value to the photoelectric conversion device 502 through its own control unit.

[0217] The light detection system 501 is connected to the vehicle sensor 510 and can detect the driving status of the main vehicle, such as vehicle speed, yaw rate, and steering angle, the environment outside the main vehicle, and the status of other vehicles and obstacles. The vehicle sensor 510 also serves as a distance information acquisition unit that obtains distance information to the subject. In addition, the light detection system 501 is connected to the driving support control unit 511, which performs various driving support functions such as automatic steering, automatic driving, and collision avoidance. In particular, with respect to the collision judgment function, the driving support control unit 511 estimates a collision with another vehicle or obstacle based on the detection results of the light detection system 501 and the vehicle sensor 510. This allows for avoidance control when a collision is estimated and activation of safety devices when a collision occurs.

[0218] The light detection system 501 is also connected to an alarm device 512 that issues an alert to the driver based on the collision determination unit's results. For example, if the collision determination unit determines that the likelihood of a collision is high, the main control unit 513 controls the vehicle to avoid the collision and minimize damage by applying the brakes, returning the accelerator, or suppressing engine output. The alarm device 512 alerts the user by emitting an audible warning, displaying an alert message on the car navigation system's display screen or instrument panel, or vibrating the seatbelt or steering wheel.

[0219] In this embodiment, the light detection system 501 captures images of the surroundings (eg, the front or rear) of the vehicle. Figure 22B An example of the arrangement of the light detection system 501 is shown in the case where the light detection system 501 captures an image in front of a vehicle.

[0220] As described above, the photoelectric conversion device 502 is positioned in front of the vehicle 500. Specifically, it is preferred that the two photoelectric conversion devices 502 be positioned symmetrically with respect to the centerline of the vehicle 500's forward / backward direction or outer shape (e.g., the vehicle's width) as an axis of symmetry, in order to obtain distance information between the vehicle 500 and the subject being imaged and determine the likelihood of a collision. Furthermore, the photoelectric conversion device 502 is preferably positioned so as not to obstruct the driver's field of vision when visually recognizing conditions outside the vehicle 500 from the driver's seat. The warning device 512 is preferably positioned so as to be easily within the driver's field of vision.

[0221] Next, refer to Figure 24 The fault detection operation of the photoelectric conversion device 502 in the light detection system 501 is described. Figure 24 The failure detection operation of the photoelectric conversion device 502 is performed through steps S110 to S180 shown in FIG.

[0222] Step S110 is a step of performing settings at the start-up of the photoelectric conversion device 502. That is, settings for the operation of the photoelectric conversion device 502 are transmitted from the outside of the light detection system 501 (for example, the main control unit 513) or the inside of the light detection system 501, and the imaging operation and fault detection operation of the photoelectric conversion device 502 are started.

[0223] Next, in step S120, pixel signals are acquired from the effective pixels. In step S130, output values ​​from the fault detection pixels provided for fault detection are acquired. Similar to the effective pixels, the fault detection pixels may include photoelectric conversion elements. A predetermined voltage is written to the photoelectric conversion elements of the fault detection pixels. The fault detection pixels output signals corresponding to the voltage written to the photoelectric conversion elements. Note that steps S120 and S130 may be reversed.

[0224] Next, in step S140, the expected output value of the fault detection pixel and the actual output value from the fault detection pixel are classified. If, as a result of the classification in step S140, the expected output value matches the actual output value, processing proceeds to step S150, where it is determined that the imaging operation is proceeding normally, and the processing step proceeds to step S160. In step S160, the pixel signals of the scanned lines are sent to the memory 505 and temporarily stored. Thereafter, processing returns to step S120 to continue the fault detection operation. On the other hand, if, as a result of the classification in step S140, the expected output value does not match the actual output value, processing proceeds to step S170. In step S170, it is determined that an abnormality exists in the imaging operation, and an alarm is notified to the main control unit 513 or the alarm device 512. The alarm device 512 displays a message on the display unit indicating that an abnormality has been detected. Then, in step S180, the photoelectric conversion device 502 is stopped, and the operation of the light detection system 501 ends.

[0225] In this embodiment, an example of looping the flowchart for each run is described, but the flowchart may be looped for each of a plurality of runs, or the fault detection operation may be performed for each frame. The alarm of step S170 may be notified to the outside of the vehicle via a wireless network.

[0226] In addition, in this embodiment, the control of the present vehicle to prevent it from colliding with other vehicles has been described, but the present invention can also be applied to the control of the present vehicle following other vehicles and performing automatic driving, and the control of the vehicle performing automatic driving so as not to protrude from the lane, etc. In addition, the light detection system 501 is not limited to vehicles such as the present vehicle, and can be applied to other movable bodies (mobile devices) such as ships, aircraft, or industrial robots. In addition, the present invention is not limited to movable bodies, and can be widely applied to equipment that uses subject recognition, such as advanced road traffic systems (ITS: Intelligent Transport Systems), etc.

[0227] [Twelfth embodiment]

[0228] Will refer to Figure 25A and Figure 25B A light detection system according to a twelfth embodiment of the present invention is described. Figure 25A and Figure 25B 1 is a schematic diagram showing a configuration example of a light detection system according to this embodiment. In this embodiment, an application example of glasses (smart glasses) will be described as a light detection system to which the photoelectric conversion device 100 according to any of the first to seventh embodiments is applied.

[0229] Figure 25A1. A pair of glasses 600 (smart glasses) according to one application example is shown. The glasses 600 include a lens 601, a photoelectric conversion device 602, and a control device 603.

[0230] The photoelectric conversion device 602 is the photoelectric conversion device 100 described in any of the first to seventh embodiments, and is provided on the lens 601. One photoelectric conversion device 602 may be provided, or a plurality of photoelectric conversion devices may be provided. In the case of using a plurality of photoelectric conversion devices 602, a combination of a plurality of types of photoelectric conversion devices 602 may be used. The arrangement position of the photoelectric conversion device 602 is not limited to Figure 25A A display device (not shown) including a light emitting device such as an OLED or an LED may be provided on the back side of the lens 601.

[0231] The control device 603 serves as a power supply for supplying power to the photoelectric conversion device 602 and the display device. The control device 603 has a function of controlling the operation of the photoelectric conversion device 602 and the display device. The lens 601 may be provided with an optical system for focusing light on the photoelectric conversion device 602.

[0232] Figure 25B 1 and 2. Glasses 610 (smart glasses) according to another application example are shown. Glasses 610 include a lens 611 and a control device 612. The control device 612 may be mounted with a photoelectric conversion device (not shown) corresponding to the photoelectric conversion device 602 and a display device.

[0233] The lens 611 is provided with a photoelectric conversion device in the control device 612 and an optical system for projecting light from the display device, and an image is projected thereon. The control device 612 serves as a power supply for supplying power to the photoelectric conversion device and the display device, and has a function of controlling the operation of the photoelectric conversion device and the display device.

[0234] The control device 612 may also include a line-of-sight detection unit for detecting the wearer's line of sight. In this case, an infrared light emitting unit may be provided in the control device 612, and infrared light emitted from the infrared light emitting unit may be used to detect line of sight. Specifically, the infrared light emitting unit emits infrared light toward the eyeballs of the user viewing the displayed image. A captured image of the eyeball is obtained by detecting the reflected light from the eyeball of the emitted infrared light using a camera unit having a light-receiving element. By providing a reduction unit in the top view to reduce the amount of light transmitted from the infrared light emitting unit to the display unit, degradation of image quality can be reduced.

[0235] The line of sight of the user relative to the displayed image can be detected from a captured image of the eyeball obtained by capturing infrared light. Any known technology can be applied to line of sight detection using a captured image of the eyeball. As an example, a line of sight detection method based on a Purkinje image generated due to reflection of irradiated light on the cornea can be used. More specifically, a line of sight detection process based on a pupil-corneal reflection method is performed. The line of sight of the user can be detected by calculating a line of sight vector representing the orientation (rotation angle) of the eyeball based on an image of the pupil included in the captured image of the eyeball and the Purkinje image using the pupil-corneal reflection method.

[0236] The display device according to this embodiment may include a photoelectric conversion device having a light-receiving element, and may be configured to control the display image based on the line of sight information of the user from the photoelectric conversion device. Specifically, the display device determines a first observation area that the user is gazing at and a second observation area other than the first observation area based on the line of sight information. The first observation area and the second observation area may be determined by the control device of the display device, or may be determined by an external control device. In the case of determination by the external control device, the determination result is sent to the display device via communication. In the display area of ​​the display device, the display resolution of the first observation area may be controlled to be higher than the display resolution of the second observation area. That is, the resolution of the second observation area may be lower than the resolution of the first observation area.

[0237] The display area may include a first display area and a second display area different from the first display area, and an area with a high priority may be determined from the first display area and the second display area 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 an external control device. In the case of determination by an external control device, the determination result is sent to the display device via communication. The resolution of the high priority area may be controlled to be higher than the resolution of the area other than the high priority area. That is, the resolution of the area with a relatively low priority may be reduced.

[0238] Note that AI can be used to determine the first observation area or an area with high priority. The AI ​​can be a model configured to estimate the angle of sight and the distance to the target subject in front of the sight from the eye image using the image of the eyeball and the direction of the eyeball actually observing the image as teaching data. The AI ​​program can be included in the display device, the photoelectric conversion device, or an external device. If the external device has the program, the information can be sent to the display device via communication.

[0239] In the case of performing display control based on visual recognition detection, the present invention can be preferably applied to smart glasses that also include a photoelectric conversion device that captures external images. The smart glasses can display the captured external information in real time.

[0240] [Modification]

[0241] The present invention is not limited to the above-described embodiments, and various modifications are possible.

[0242] For example, an example in which a part of the configuration of any embodiment is added to another embodiment, or an example in which a part of the configuration of any embodiment is replaced with some of the configuration of another embodiment is also an embodiment of the present invention.

[0243] The circuit configuration of the pixel 12 is not limited to the above-described embodiment. For example, a switch such as a transistor may be provided between the photoelectric conversion element 22 and the quenching circuit 32, or between the photoelectric conversion element 22 and the signal processing unit 30, to control the electrical connection therebetween. Furthermore, a switch such as a transistor may be provided between a node supplied with a voltage VH and the quenching circuit 32, and / or between a node supplied with a voltage VL and the photoelectric conversion element 22, to control the electrical connection therebetween. Multiple photoelectric conversion elements 22 may be provided for one pixel 12.

[0244] In addition, in the above embodiment, a configuration using a counter circuit as the processing circuit 36 ​​has been described. However, a TDC (time-to-digital converter) and a memory may be used instead of the counter circuit. In this case, the TDC converts the generation timing of the pulse signal output from the waveform shaping circuit 34 into a digital signal. When measuring the timing of the pulse signal, a control pulse pREF (reference signal) is supplied from the vertical scanning circuit unit 40 to the TDC via the control line 14. The TDC obtains a signal as a digital signal when the input timing of the signal output from each pixel 12 is set relative to the reference control pulse pREF.

[0245] Although the photoelectric conversion device in which the sensor substrate 110 , the circuit substrate 120 , and the circuit substrate 130 are stacked in this order is described in the above embodiment, the stacking order of the circuit substrate 120 and the circuit substrate 130 may be reversed.

[0246] The present invention can also be implemented by supplying a program for implementing one or more functions of the above-described embodiments to a system or device via a network or storage medium, and having one or more processors in a computer of the system or device read and execute the program. Alternatively, the present invention can be implemented by a circuit (e.g., an ASIC) that implements one or more functions.

[0247] It should be noted that the above embodiments are only specific examples for implementing the present invention, and the technical scope of the present invention should not be interpreted in a limiting manner by these embodiments. That is, the present invention can be implemented in various forms without departing from the technical ideas or main features of the present invention.

[0248] The present invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, the appended claims should be accorded the full scope of the present invention.

[0249] This application claims priority based on Japanese Patent Application No. 2023-008010 filed on January 23, 2023, and Japanese Patent Application No. 2024-000212 filed on January 4, 2024, the entire contents of which are incorporated herein by reference.

[0250] [Reference Signs List]

[0251] 12 pixels

[0252] 20 photoelectric conversion units

[0253] 22 Photoelectric conversion element

[0254] 30 signal processing units

[0255] 30A and 30B function blocks

[0256] 40 vertical scanning circuit units

[0257] 50 readout circuit units

[0258] 60 horizontal scanning circuit units

[0259] 70DFE

[0260] 80TX

[0261] 90 control pulse generation unit

[0262] 100 Photoelectric Conversion Device

[0263] 110 sensor substrate

[0264] 120 and 130 circuit substrates

Claims

1. A photoelectric conversion device, configured by stacking at least a first substrate, a second substrate, and a third substrate, the photoelectric conversion device comprising: a plurality of pixels, each pixel including: a photoelectric conversion unit including an avalanche photodiode; and a signal processing unit configured to process a signal output from the photoelectric conversion unit, wherein the signal processing unit of each pixel of the plurality of pixels comprises: a quenching circuit connected to the avalanche photodiode; and a processing circuit configured to process a signal corresponding to the incidence of light on the avalanche photodiode, wherein the avalanche photodiode is arranged on the first substrate, wherein at least a portion of the quenching circuit is arranged on the second substrate, wherein at least a portion of the processing circuit is arranged on the third substrate, wherein each pixel of the plurality of pixels comprises a plurality of electrical connections between the second substrate and the third substrate, and Part of the plurality of electrical connections constitutes part of an input signal line to the processing circuit, and another part of the plurality of electrical connections constitutes part of an output signal line from the processing circuit.

2. The photoelectric conversion device according to claim 1, in, The signal processing unit for each pixel of the plurality of pixels further includes: a waveform shaping circuit connected to a connection node between the avalanche photodiode and the quenching circuit and configured to convert an analog signal output from the photoelectric conversion unit into a pulse signal; and A selection circuit is configured to select an output of the signal processed by the processing circuit.

3. The photoelectric conversion device according to claim 2, wherein At least a portion of the waveform shaping circuit and at least a portion of the selection circuit are arranged on the second substrate.

4. The photoelectric conversion device according to claim 3, wherein The waveform shaping circuit is connected to the processing circuit via the portion of the plurality of electrical connections.

5. The photoelectric conversion device according to claim 3 or 4, wherein The processing circuitry is connected to the selection circuitry via the other portion of the plurality of electrical connections.

6. The photoelectric conversion device according to any one of claims 3 to 5, wherein The processing circuit is connected to the quenching circuit via the other portion of the plurality of electrical connections.

7. The photoelectric conversion device according to any one of claims 2 to 6, further comprising: a scanning circuit unit configured to supply a control signal to the plurality of pixels in units of rows or columns, Wherein, the scanning circuit unit includes: a logic unit configured to generate signals for controlling the plurality of pixels; and a plurality of output units arranged corresponding to each of the plurality of rows or the plurality of columns, and each output unit being configured to supply a signal generated by the logic unit to pixels of a corresponding row or a corresponding column, and Wherein, each of the multiple output units includes: a first driving circuit disposed on the second substrate and configured to generate a signal for driving the selection circuit; and A second driving circuit is disposed on the third substrate and is configured to generate a signal for driving the processing circuit.

8. The photoelectric conversion device according to any one of claims 1 to 7, further comprising: a readout circuit unit configured to process signals output from the plurality of pixels, The readout circuit unit includes a plurality of receiving circuits arranged corresponding to a plurality of rows or a plurality of columns, and Wherein, each receiving circuit in the plurality of receiving circuits includes: a receiving unit disposed on the second substrate and configured to receive a signal output from pixels of a corresponding row or a corresponding column; and A processing unit is disposed on the third substrate and configured to process the signal output from the receiving unit. 9 . The photoelectric conversion device according to claim 8 , further comprising a signal processing circuit unit disposed on the third substrate and configured to perform digital signal processing on the signal output from the readout circuit unit.

10. The photoelectric conversion device according to any one of claims 1 to 9, further comprising: a transmitter circuit unit configured to output a signal based on the signal generated by the plurality of pixels to the outside, Wherein, the transmitter circuit unit includes: a processing unit disposed on the third substrate and configured to perform predetermined processing on a signal based on signals generated by the plurality of pixels; and An output unit is disposed on the second substrate and is configured to output the signal processed by the processing unit to the outside.

11. The photoelectric conversion device according to any one of claims 1 to 10, wherein The photoelectric conversion unit of each of the plurality of pixels includes a plurality of avalanche photodiodes.

12. The photoelectric conversion device according to claim 11, in, The signal processing unit of each of the plurality of pixels further includes a logic unit disposed on the second substrate and configured to perform a logic operation on a signal corresponding to the incidence of light on the plurality of avalanche photodiodes, and The logic unit is connected to the processing circuit via the portion of the plurality of electrical connections.

13. The photoelectric conversion device according to any one of claims 1 to 12, wherein The thickness of the gate insulating film of the transistor constituting the functional block arranged on the second substrate is thicker than the thickness of the gate insulating film of the transistor constituting the functional block arranged on the third substrate.

14. The photoelectric conversion device according to any one of claims 1 to 13, wherein A minimum channel length of transistors constituting the functional blocks arranged on the third substrate is shorter than a minimum channel length of transistors constituting the functional blocks arranged on the second substrate.

15. The photoelectric conversion device according to any one of claims 1 to 13, wherein The first substrate, the second substrate, and the third substrate are stacked in this order.

16. A photoelectric conversion device configured by stacking at least a first substrate, a second substrate, and a third substrate, the photoelectric conversion device comprising: a plurality of pixels arranged to form a plurality of rows and a plurality of columns, each pixel including: a photoelectric conversion unit including an avalanche photodiode; and a signal processing unit configured to process a signal output from the photoelectric conversion unit; and a plurality of output lines provided corresponding to the plurality of rows or the plurality of columns, and each output line being connected to pixels of a corresponding row or a corresponding column, wherein the signal processing unit of each pixel of the plurality of pixels comprises: an input node connected to the avalanche photodiode; a processing circuit configured to process a signal corresponding to the incidence of light on the avalanche photodiode; and an output node connected to the output line, wherein the avalanche photodiode is arranged on the first substrate, wherein the input node, the output node and the output line of the signal processing unit are arranged on the second substrate, and Wherein, at least a portion of the processing circuit is arranged on the third substrate.

17. The photoelectric conversion device according to claim 16, in, The signal processing unit of each pixel of the plurality of pixels further includes: a quenching circuit connected to the avalanche photodiode; a waveform shaping circuit connected to a connection node between the avalanche photodiode and the quenching circuit and configured to convert an analog signal output from the photoelectric conversion unit into a pulse signal; and a selection circuit configured to select output of the signal processed by the processing circuit to the output line, and At least a portion of the quenching circuit, at least a portion of the waveform shaping circuit, and at least a portion of the selection circuit are arranged on the second substrate.

18. The photoelectric conversion device according to any one of claims 1 to 17, further comprising a first pad electrode to which a power supply voltage to the first substrate is supplied, in, The first pad electrode is disposed on the first substrate.

19. The photoelectric conversion device according to claim 18, further comprising a second pad electrode to which a power supply voltage to the second substrate is supplied, in, The second pad electrode is disposed on the first substrate.

20. The photoelectric conversion device according to claim 18, further comprising a second pad electrode to which a power supply voltage to the second substrate is supplied, in, The second pad electrode is disposed on the second substrate.

21. The photoelectric conversion device according to any one of claims 18 to 20, further comprising a third pad electrode to which a power supply voltage to the third substrate is supplied, in, The third pad electrode is disposed on the first substrate.

22. The photoelectric conversion device according to any one of claims 18 to 20, further comprising a third pad electrode to which a power supply voltage to the third substrate is supplied, in, The third pad electrode is disposed on the second substrate.

23. The photoelectric conversion device according to any one of claims 18 to 20, further comprising a third pad electrode to which a power supply voltage to the third substrate is supplied, in, The third pad electrode is disposed on the third substrate.

24. A light detection system comprising: The photoelectric conversion device according to any one of claims 1 to 23; as well as A signal processing device is configured to process a signal output from the photoelectric conversion device.

25. The light detection system of claim 24, wherein: The signal processing device is configured to generate a distance image representing distance information to a subject based on the signal.

26. A movable body comprising: The photoelectric conversion device according to any one of claims 1 to 23; a distance information acquisition unit configured to acquire distance information to a subject from a parallax image based on a signal output from the photoelectric conversion device; as well as A control section is configured to control the movable body based on the distance information.

Images