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

Abstract

The invention discloses a photoelectric conversion apparatus, a photoelectric conversion system, a moving object, and equipment. The photoelectric conversion device includes: a pixel having an avalanche photodiode, a pixel circuit, and a signal processing circuit; and a control signal generation circuit for generating a first control signal controlling an operation of the pixel circuit and a second control signal controlling an operation of the signal processing circuit. A second circuit layer in which the signal processing circuit and the control signal generation circuit are arranged, a first circuit layer in which the pixel circuit is arranged, and a photodiode layer in which the avalanche photodiode, an output terminal of which is connected to the pixel circuit, are stacked together in this order; a control signal generation circuit is disposed in a peripheral region around a pixel region, and a first wiring is disposed on the first circuit layer, the first wiring being connected to the control signal generation circuit.

Description

Technical Field

[0001] The technology disclosed herein relates to a photoelectric conversion device, a photoelectric conversion system, a moving object, and equipment. Background Art

[0002] A photoelectric conversion device capable of detecting single-photon-level weak light using avalanche multiplication is known. US Patent Application Publication No. 2017 / 0186798 discloses a photoelectric conversion device in which a sensor chip having a plurality of pixels arranged therein and a circuit chip having a circuit for performing signal processing are electrically connected in a stacked structure.

[0003] It is disclosed that, in pixels inside a sensor chip of the photoelectric conversion device, an avalanche diode that causes charge avalanche multiplication is used as a conversion device.

[0004] Japanese Patent Laid-Open No. 2022-113123 proposes a configuration of a photoelectric conversion device having at least a three-layer structure including an avalanche photodiode.

[0005] However, in the structure of the photoelectric conversion device described in U.S. Patent Application Publication 2017 / 0186798 and Japanese Patent Application Laid-Open No. 2022-113123, there is room for studying microfabrication of circuits in a circuit layer stacked on a photodiode layer.

[0006] The technology of the present disclosure has been proposed in view of the above-mentioned problems, and an object thereof is to provide a technology for supporting microfabrication of a circuit in a photoelectric conversion device having at least a three-layer structure. Summary of the invention

[0007] According to some embodiments, a photoelectric conversion device includes: a pixel having an avalanche photodiode, a pixel circuit that performs processing using a signal output from the avalanche photodiode, and a signal processing circuit that performs processing using a signal output from the pixel circuit; and a control signal generating circuit that generates a first control signal for controlling the operation of the pixel circuit and a second control signal for controlling the operation of the signal processing circuit. A second circuit layer on which the signal processing circuit and the control signal generating circuit are arranged, a first circuit layer on which the pixel circuit is arranged, and a photodiode layer on which the avalanche photodiode is arranged are stacked together in this order, an output terminal of the avalanche photodiode is connected to the pixel circuit, a plurality of pixels are provided and arranged in a pixel region, the control signal generating circuit is arranged in a peripheral region provided around the pixel region, and a first wiring for supplying the first control signal to the pixel circuit is provided on the first circuit layer, the first wiring being connected to the control signal generating circuit in the peripheral region.

[0008] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of a photoelectric conversion device according to an embodiment.

[0010] Figure 2 is a schematic diagram of a photodiode layer in a photoelectric conversion device according to an embodiment.

[0011] Figure 3 is a schematic diagram of a first circuit layer in a photoelectric conversion device according to an embodiment.

[0012] Figure 4 is a schematic diagram of a second circuit layer in the photoelectric conversion device according to the embodiment.

[0013] Figure 5A and Figure 5B is a diagram schematically showing driving of a photodiode in a photoelectric conversion device according to the embodiment.

[0014] Figure 6 is a schematic diagram showing a circuit configuration of a photoelectric conversion device according to a first embodiment.

[0015] Figure 7 is a schematic diagram showing a circuit configuration of a photoelectric conversion device according to the prior art

[0016] Figure 8 is a schematic diagram showing a circuit configuration of a photoelectric conversion device according to a modification of the first embodiment.

[0017] Fig. 9 is a schematic diagram showing a circuit configuration of a photoelectric conversion device according to a second embodiment.

[0018] Fig.10 is a schematic diagram showing a circuit configuration of a photoelectric conversion device according to a third embodiment;

[0019] Fig.11 is a diagram showing a photoelectric conversion system according to a fourth embodiment.

[0020] Fig. 12A and Fig. 12B is a diagram showing a photoelectric conversion system and a moving body according to a fifth embodiment.

[0021] Fig.13 is a diagram showing a range image sensor according to a sixth embodiment.

[0022] Fig.14 is a diagram showing an endoscopic surgery system according to a seventh embodiment.

[0023] Fig.15A and Fig. 15B2 is a diagram showing smart glasses according to an eighth embodiment.

[0024] Fig.16A and Fig. 16B is a diagram showing electronic equipment according to a ninth embodiment.

[0025] Fig.17 is a diagram showing an X-ray CT apparatus according to a tenth embodiment.

[0026] Fig.18 is a diagram showing an apparatus according to an eleventh embodiment. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the technology according to the present disclosure will be described in detail based on the accompanying drawings. The following embodiments are intended to concretize the technical ideas of the present disclosure, but are not intended to limit the technology of the present disclosure. For the sake of clarity, the size or positional relationship of the components shown in the various drawings may be exaggerated. In the following description, the same configuration may be indicated by the same symbol, and their repeated description will be omitted in some cases.

[0028] In this specification, a plan view refers to an observation from a direction perpendicular to the light incident surface of the semiconductor layer. In addition, a cross-sectional view refers to an observation from a direction parallel to the light incident surface of the semiconductor layer. Note that when the light incident surface of the semiconductor layer is a rough surface from a microscopic perspective, the light incident surface of the semiconductor layer observed from a macroscopic perspective is used as a reference to define the plan view. The constituent elements of each embodiment may be added to another embodiment, or may be replaced with constituent elements of another embodiment. In addition, in some cases, the size or positional relationship of the components shown in the various drawings may be exaggerated for clarity.

[0029] The following embodiments relate to a photoelectric conversion device including a single photon avalanche diode (SPAD) that counts the number of photons incident on the avalanche photodiode in particular. The photoelectric conversion device includes at least an avalanche photodiode. In addition, in the photoelectric conversion device to be described in each of the following embodiments, the anode of the avalanche photodiode (APD) is set to a fixed potential, and a signal is extracted from the cathode side. Therefore, the first conductive semiconductor region having a charge with the same polarity as the signal charge as a majority carrier refers to an N-type semiconductor region. On the contrary, the second conductive semiconductor region having a charge with a different polarity from the signal charge as a majority carrier refers to a P-type semiconductor region.

[0030] Note that the following embodiments are also applicable to the case where the cathode of the APD is set to a fixed potential and a signal is extracted from the anode side. In this case, the first conductive type semiconductor region in which charges having the same polarity as the polarity of the signal charge are used as majority carriers refers to a P-type semiconductor region. On the contrary, the second conductive type semiconductor region in which charges having a polarity different from the polarity of the signal charge are used as majority carriers refers to an N-type semiconductor region. The following will describe the case in which one node of the APD is set to a fixed potential, but the potentials of the two nodes may fluctuate.

[0031] First, we will use Figures 1 to 5A and Figure 5B The configuration of the photoelectric conversion device common to the embodiments and the driving method thereof are described.

[0032] Figure 1 is a diagram showing an overall image of the photoelectric conversion device 100. The photoelectric conversion device 100 is configured with a first substrate 110, a second substrate 210, and a third substrate 310 stacked together. The first substrate 110 is also called a sensor chip, and has a pixel region 12 in which pixels having a photoelectric conversion unit are two-dimensionally arranged. In addition, a peripheral region 13 is provided between the pixel region 12 and the chip end of the photoelectric conversion device 100. The second substrate 210 is also called a pixel circuit chip, and has a pixel circuit region 22 in which a pixel control circuit that processes a signal from the photoelectric conversion unit is arranged. The third substrate 310 is also called a signal processing chip, and has a signal processing circuit region 32 in which a signal processing circuit that processes a signal from the pixel control circuit is arranged.

[0033] (First Substrate) Figure 2 1 is a configuration diagram of the first substrate 110. On the first substrate 110, a pixel region 12 is provided in which pixels 101 having a photoelectric conversion unit 102 including an avalanche photodiode (hereinafter referred to as APD) are two-dimensionally arranged. Note that the pixels 101 may also be one-dimensionally arranged in the pixel region 12. In addition, the details of the photoelectric conversion unit 102 will be described later.

[0034] The pixel 101 is used as a pixel generally used to form an image. However, when used in time of flight (TOF), the pixel 101 does not necessarily form an image. That is, the pixel 101 can also be used as an element for measuring the time and amount of light that light has arrived.

[0035] (Second Substrate) Figure 3 2 is a configuration diagram of the second substrate 210. The second substrate 210 has a pixel control circuit 201 and a vertical scanning circuit 202. The pixel circuit region 22 in which at least the pixel control circuit 201 is provided is arranged at the same Figure 2The pixel control circuit 201 is electrically connected to the photoelectric conversion unit 102 on the first substrate 110 through the connection wiring provided for each pixel. In addition, the pixel control circuit 201 is electrically connected to the signal processing circuit 301 on the third substrate 310 through the connection wiring. The pixel control circuit 201 serves as a pixel circuit that performs processing using a signal output from the photoelectric conversion unit 102 of the pixel. For example, the pixel control circuit 201 performs processing such as quenching operation of the avalanche photodiode of the photoelectric conversion unit 102 and waveform shaping of the signal output from the photoelectric conversion unit 102.

[0036] The vertical scanning circuit 202 receives a pixel control signal (also referred to as a pixel clock (PCLK)) supplied from a control signal generating circuit 302 on the third substrate 310, and supplies the pixel control signal to the corresponding pixel control circuit 201. Logic circuits such as a shift register and an address decoder are used for the vertical scanning circuit 202.

[0037] (Third Substrate) Figure 4 310 is a configuration diagram of the third substrate 310. The third substrate 310 has a signal processing circuit 301, a control signal generating circuit 302, a vertical scanning circuit 303, a horizontal scanning circuit 304, and a signal line 305. The signal processing circuit region 32 in which at least the signal processing circuit 301 is provided is arranged at the same Figure 2 The pixel region 12 and the pixel region 12 on the first substrate 110 are shown in FIG. Figure 3 The pixel circuit area 22 on the second substrate 210 is shown at an overlapping position.

[0038] The signal processing circuit 301 performs processing using the signal output from the pixel control circuit 201. For example, each signal processing circuit 301 has a counting circuit that counts the pulse signal output from the pixel control circuit 201 or a memory that holds the count value output from the counting circuit. The vertical scanning circuit 303 receives the control signal supplied from the control signal generating circuit 302, and supplies the control signal to each signal processing circuit 301. The horizontal scanning circuit 304 inputs a control pulse for sequentially selecting each column to the signal processing circuit 301 through the signal line 305 to read the signal from the signal processing circuit 301.

[0039] Note that the third substrate 310 may be provided with a processing circuit that performs image processing on the signal read out from the signal processing circuit 301 or performs processing such as noise reduction and white balance adjustment on the image data. In addition, when the photoelectric conversion device 100 is used as a distance measuring device, for example, a processing circuit that generates a histogram based on a time-to-digital converter (TDC) circuit or information derived from the TDC circuit and then performs distance calculation may be provided.

[0040] The histogram depicts the horizontal axis as time-related classes (bins) and the vertical axis as frequencies within each class. The frequency represents the number of times light is received during a specified light reception period. In addition, counts based on reflected light and ambient light coexist in the histogram. Therefore, by setting a specified threshold, counts based on the reflected light component and counts based on the ambient light component are separated. Using the light arrival time corresponding to the reflected light component, the distance between the distance measuring device and the object to be measured is calculated.

[0041] In addition, the third substrate 310 may be provided with a digital signal processor (DSP) that serves as a processing unit to execute a program stored in a memory and to perform various processes using a learning model created by machine learning. For example, the learning model is created by machine learning using a deep neural network (DNN). For example, a learning model may be designed based on parameters generated by inputting learning data into a prescribed machine learning model, wherein an input signal corresponding to an output from the pixel region 12 is associated with a label of the input signal. In addition, the prescribed machine learning model may also be a learning model using a multi-layer neural network.

[0042] The data output from the photoelectric conversion device 100 is input to an application processor (not shown) that processes a display or a user interface, etc. The application processor is configured using, for example, a central processing unit (CPU), etc., and performs an operating system or various application software, etc. The application processor may also be equipped with functions such as a graphics processing unit (GPU) or a baseband processor. The application processor may perform various processing on the input image data or the calculation result as needed, display it to the user, or transmit the information to an external cloud server via a prescribed network.

[0043] The network may include various networks such as the Internet, a wired local area network (LAN), a wireless LAN, a mobile communication network, and Bluetooth (TM). In addition, the transmission destination of the image data or the calculation result is not limited to the cloud server, but may include various information processing devices (systems) with communication functions such as a server operating alone, a file server storing and managing various data, and a communication terminal such as a mobile phone.

[0044] Figure 5A and Figure 5B Schematically shows the relationship between the operation of the APD of the photoelectric conversion unit 102 and the output signal. Figure 5AAs shown, in one pixel of the photoelectric conversion device 100, the APD 103 of the photoelectric conversion unit 102 is electrically connected to the quenching element 204 and the waveform shaping unit 205 of the pixel control circuit 201. Here, the input side of the waveform shaping unit 205 serves as a node A, and the output side thereof serves as a node B. Figure 5B Shows Figure 5A Example of waveform changes at node A and Figure 5A An example of the waveform change at Node B.

[0045] like Figure 5B As shown, between time t0 and time t1, Figure 5A A potential difference VH-VL is applied to the APD 103 in the quenching element 204. When a photon is incident on the APD 103 at time t1, avalanche multiplication occurs in the APD 103, which causes the avalanche multiplication current to flow to the quenching element 204. As a result, the voltage of the node A drops and exceeds the judgment threshold. Then, when the voltage drop amount further increases and the potential difference applied to the APD 103 decreases, the avalanche multiplication in the APD 103 stops at time t2, and the voltage level of the node A does not drop below at least a certain fixed value. Thereafter, between time t2 and time t3, a current flows to the node A to compensate for the voltage drop from the voltage VL, which causes the voltage of the node A to rise and exceed the judgment threshold. Then, at time t3, the node A stabilizes at the original potential level. At this time, the portion of the output waveform at the node A that exceeds a certain threshold is waveform-shaped by the waveform shaping unit 205, and then output as a signal from the node B.

[0046] First embodiment

[0047] Next, we will use Figure 6 A photoelectric conversion apparatus according to a first embodiment is described. Figure 6 1 is a block diagram showing a circuit example of the photoelectric conversion device 100 according to the present embodiment. Note that some constituent elements of the photoelectric conversion device 100 are omitted in the illustration.

[0048] like Figure 6 As shown, the photoelectric conversion device 100 includes a first substrate 110 used as a photodiode (PD) layer, a second substrate 210 used as a first circuit layer, and a third substrate 310 used as a second circuit layer. Therefore, in the photoelectric conversion device 100, the second circuit layer (third substrate 310), the first circuit layer (second substrate 210), and the photodiode layer (first substrate 110) are stacked together in this order. In addition, there is a side of the first substrate 110 that is used as a side on which light is incident on the photoelectric conversion device 100. In the pixel area 12 of the photoelectric conversion device 100, pixels 121, 122, 123, and 124 are arranged. Note that in Figure 6Four pixels are arranged in one direction, but pixels having the same configuration as those of these pixels are two-dimensionally arranged in the pixel area 12 .

[0049] like Figure 6 As shown, APDs 1211, 1221, 1231, and 1241 are respectively disposed in pixels 121, 122, 123, and 124 on the first substrate 110. In addition, on the second substrate 210, the pixels 121, 122, 123, and 124 include pixel control circuits 2011, 2012, 2013, and 2014, respectively. The pixel control circuits 2011, 2012, 2013, and 2014 perform operation control on the APDs 1211, 1221, 1231, and 1241, or perform signal processing on signals output from the APDs 1211, 1221, 1231, and 1241.

[0050] The second substrate 210 is used as a substrate for arranging elements such as a quenching element, which have higher pressure resistance than the elements arranged on the third substrate. Figure 6 , a wiring 2101 that supplies a control signal (PCLK) to the pixel control circuits 2011, 2012, 2013, and 2014 is provided on the second substrate 210. The wiring 2101 is provided on the second substrate 210 in the pixel region 12. The wiring 2101 serves as a first wiring that supplies a first control signal for controlling the operation of the pixel circuit to the pixel circuit.

[0051] In addition, buffers 1212 and 1232 are provided in pixels 121 and 123, respectively, and the buffers 1212 and 1232 perform timing adjustment and the like on the control signal transmitted by the wiring 2101. On the wiring 2101, the buffers 1212 and 1232 are provided at a fixed pitch corresponding to the pixel unit. However, on the wiring 2101, it is allowed to appropriately determine for which pixels the buffers are provided at a fixed pitch. In the present embodiment, the plurality of pixels include at least one pixel on which no buffer is provided on the wiring 2101 and at least one pixel on which a buffer is provided on the wiring 2101. In addition, the wiring 2101 is connected to the control signal generating circuit 302 on the third substrate 310 in the peripheral area 13.

[0052] The third substrate 310 is used as a substrate on which elements such as logic circuits of a counting circuit and a memory circuit, etc., which have lower withstand voltage than the elements arranged on the second substrate 210, are arranged. Figure 6, as an example, the control signal generating circuit 302 is provided in the peripheral region 13 on the third substrate 310. In addition, on the third substrate 310, the pixels 121, 122, 123, and 124 include signal processing circuits 3011, 3012, 3013, and 3014, respectively. The signal processing circuits 3011, 3012, 3013, and 3014 perform counting processing using signals output from the pixel control circuits 2011, 2012, 2013, and 2014.

[0053] Furthermore, a wiring 3101 for supplying a reset signal of a counting circuit to the signal processing circuits 3011, 3012, 3013, and 3014 is provided on the third substrate 310. Furthermore, a wiring 3102 for supplying an enable signal of a counting circuit to the signal processing circuits 3011, 3012, 3013, and 3014 is provided on the third substrate 310. Furthermore, a wiring 3103 for supplying a readout signal of a count value to the signal processing circuits 3011, 3012, 3013, and 3014 is provided on the third substrate 310. The wirings 3101, 3102, and 3103 function as second wirings for supplying a second control signal for controlling the operation of the signal processing circuits to the signal processing circuits.

[0054] In addition, in the pixel 121, buffers 1215, 1216, and 1217 are provided for performing timing adjustment and the like of control signals transmitted by the wirings 3101, 3102, and 3103. Similarly, in the pixel 123, buffers 1235, 1236, and 1237 are provided for performing timing adjustment and the like of control signals transmitted by the wirings 3101, 3102, and 3103. Note that it is allowed to appropriately determine for which pixels the buffers 1215, 1216, 1217, 1235, 1236, and 1237 are provided. In other words, on the third substrate 310, the pitches at which these respective buffers are provided may be different from each other.

[0055] Here, Figure 7 An example of a photoelectric conversion device 100c according to the prior art is shown. The photoelectric conversion device 100c includes a first substrate 110c, a second substrate 210c, and a third substrate 310c. In addition, pixels 121c, 122c, 123c, and 124c are arranged in a pixel region 12c of the photoelectric conversion device 100c. Note that Figure 7 Four pixels are arranged in one direction, but pixels having the same configuration as these pixels are two-dimensionally arranged in the pixel region 12c. In addition, a control signal generating circuit 302c is provided in the peripheral region 13c of the photoelectric conversion device 100c.

[0056] Pixels 121c, 122c, 123c, and 124c include APDs 1211c, 1221c, 1231c, and 1241c, pixel control circuits 2011c, 2012c, 2013c, and 2014c, and signal processing circuits 3011c, 3012c, 3013c, and 3014c, respectively. Note that Figure 7 The APD, pixel control circuit and signal processing circuit in Figure 6 The APD, pixel control circuit and signal processing circuit in the embodiment correspond to each other. In addition, the pixel 121c includes buffers 1212c, 1215c, 1216c and 1217c, and the pixel 123c includes buffers 1232c, 1235c, 1236c and 1237c. Figure 7 The buffers 1212c, 1215c, 1216c, 1217c, 1232c, 1235c, 1236c and 1237c in Figure 6 The buffers 1212, 1215, 1216, 1217, 1232, 1235, 1236 and 1237 correspond to each other.

[0057] In the photoelectric conversion device 100c, wiring 2101c for supplying control signals (PCLK) to pixel control circuits 2011c, 2012c, 2013c, and 2014c is provided on the third substrate 310c. Figure 6 Wirings 3101c, 3102c, and 3103c corresponding to the wirings 3101, 3102, and 3103 in FIG. 1 are provided on the third substrate 310c.

[0058] Therefore, on the third substrate 310c of the photoelectric conversion device 100c, the arrangement density of elements and wiring increases compared to the third substrate 310 of the photoelectric conversion device 100, which potentially reduces the number of elements that can be arranged in each pixel in the pixel area. In addition, in order to supply control signals to the pixel control circuits 2011c, 2012c, 2013c, and 2014c, it is necessary to provide wiring for transmitting signals between the third substrate 310c and the second substrate 210c in each pixel. Therefore, in the photoelectric conversion device 100c, the connection pitch between the third substrate 310c and the second substrate 210c becomes denser, which potentially reduces the number of elements that can be arranged in each pixel in the pixel area.

[0059] On the other hand, according to the photoelectric conversion device 100 of the present embodiment, the wiring 2101 for supplying signals to the pixel control circuits 2011, 2012, 2013, and 2014 provided on the second substrate 210 is provided on the second substrate 210, not on the third substrate 310. As described above, when the circuit that processes the signals from the APDs 1211, 1221, 1231, and 1241 is provided on the second substrate 210, the wiring that supplies the control signal to the circuit is not provided on the third substrate 310, but on the same second substrate 210. As a result, a larger area can be secured to provide wiring or elements or the like on the third substrate 310, and further microfabrication of the constituent elements of the third substrate 310 is achieved.

[0060] Modification 1

[0061] Next, a modification of the photoelectric conversion apparatus 100 according to the first embodiment will be described. Note that the same configurations as those of the above-described photoelectric conversion apparatus 100 will be denoted by the same symbols, and detailed descriptions thereof will be omitted below.

[0062] Figure 8 is a block diagram showing a circuit example of a photoelectric conversion device 150 according to this modification. Figure 8 Some components of the photoelectric conversion device 150 are omitted. Figure 8 As shown, on the first substrate 110 of the photoelectric conversion device 150, pixels 121, 122, 123, and 124 are arranged in the pixel area 12. In addition, the pixels 121, 122, 123, and 124 include APDs 1211, 1221, 1231, and 1241, respectively. A voltage Va is applied to anode terminals of the APDs 1211, 1221, 1231, and 1241. Cathode terminals of the APDs 1211, 1221, 1231, and 1241 are connected to metal oxide semiconductor field effect transistors (MOSFETs) 2011a, 2012a, 2013a, and 2014a used as quenching elements on the second substrate 210.

[0063] On the second substrate 210 of the photoelectric conversion device 150, MOSFETs 2011a, 2012a, 2013a, and 2014a constituting a pixel control circuit are provided in the pixel region 12. The drains of the MOSFETs 2011a, 2012a, 2013a, and 2014a are respectively connected to the cathode terminals of the APDs 1211, 1221, 1231, and 1241. In addition, a voltage Vdd is applied to the sources of the MOSFETs 2011a, 2012a, 2013a, and 2014a. The MOSFETs 2011a, 2012a, 2013a, and 2014a perform a quenching operation to suppress the voltage supplied to the APDs 1211, 1221, 1231, and 1241, thereby suppressing avalanche multiplication. Furthermore, in the pixel region 12 , processing circuits 2011 b , 2012 b , 2013 b , and 2014 b including a waveform shaping circuit that performs waveform shaping processing on signals output from the APDs 1211 , 1221 , 1231 , and 1241 are provided.

[0064] The APDs 1211, 1221, 1231, and 1241 generate charge pairs corresponding to incident light by photoelectric conversion. One of the two nodes of the APDs 1211, 1221, 1231, and 1241 is connected to a power line, through which a driving voltage Va (first voltage) is supplied. In addition, the other of the two nodes of the APDs 1211, 1221, 1231, and 1241 is connected to a power line, through which a driving voltage Vdd (second voltage) higher than the voltage Va supplied to the anode is supplied.

[0065] exist Figure 8 In the embodiment, one node of the APDs 1211, 1221, 1231, and 1241 is used as an anode terminal, and the other node thereof is used as a cathode terminal. A reverse bias voltage that enables the APDs 1211, 1221, 1231, and 1241 to perform avalanche multiplication is supplied to the anode terminal and the cathode terminal of the APDs 1211, 1221, 1231, and 1241. By creating a state in which such a voltage is supplied, the charge generated by the incident light causes avalanche multiplication, which results in the appearance of an avalanche current. Figure 8 In the embodiment, the cathode terminals used as the output terminals of the APDs 1211, 1221, 1231, and 1241 are connected to the MOSFETs 2011a, 2012a, 2013a, and 2014a constituting the pixel control circuit. However, the anode terminals of the APDs 1211, 1221, 1231, and 1241 may also be connected to the MOSFETs 2011a, 2012a, 2013a, and 2014a as the output terminals.

[0066] Note that there is a Geiger mode in which, when a reverse bias voltage is supplied, the APDs 1211, 1221, 1231, and 1241 operate with a voltage difference between the anode terminal and the cathode terminal greater than the breakdown voltage. In addition, there is a linear mode in which, when a reverse bias voltage is supplied, the APDs 1211, 1221, 1231, and 1241 operate with a voltage difference between the anode terminal and the cathode terminal close to or not greater than the breakdown voltage.

[0067] An APD operating in Geiger mode is called a SPAD. For example, the voltage Va is -30V and the voltage Vdd is 1V. APDs 1211, 1221, 1231, and 1241 can operate in a linear mode or a Geiger mode. In the case of a SPAD, the voltage difference becomes larger than that of an APD in a linear mode, which results in a significant withstand voltage effect. Therefore, APDs 1211, 1221, 1231, and 1241 are preferably used as SPADs.

[0068] Furthermore, on the second substrate 210, a wiring 2101 for supplying a control signal (PCLK) to the gates of the MOSFETs 2011a, 2012a, 2013a, and 2014a is provided in the peripheral region 13. Thus, the MOSFETs 2011a, 2012a, 2013a, and 2014a serving as quenching elements are controlled by the control signal supplied through the wiring 2101 to switch between a high resistance state and a low resistance state having a resistance value lower than that of the high resistance state.

[0069] On the third substrate 310, the control signal generating circuit 302 is provided in the peripheral region 13. In addition, on the third substrate 310, the pixels 121, 122, 123, and 124 respectively include counting circuits 3011a, 3012a, 3013a, and 3014a and memory circuits 3011b, 3012b, 3013b, and 3014b constituting a signal processing circuit. In addition, the counting circuit 3011a includes a trigger 3011f to perform counting processing on the signal output from the processing circuit 2011b. Note that the counting circuits 3012a, 3013a, and 3014a also include the same trigger as the trigger 3011f.

[0070] Furthermore, a wiring 3101 for supplying a reset signal to the counting circuits 3011a, 3012a, 3013a, and 3014a is provided on the third substrate 310. Furthermore, a wiring 3102 for supplying an enable signal to the counting circuits 3011a, 3012a, 3013a, and 3014a is provided on the third substrate 310. Furthermore, a wiring 3104 for supplying a write signal for writing the count value output from the counting circuits 3011a, 3012a, 3013a, and 3014a into the memory circuits 3011b, 3012b, 3013b, and 3014b is provided on the third substrate 310. Furthermore, a wiring 3103 for supplying a read signal of the count value to the memory circuits 3011b, 3012b, 3013b, and 3014b is provided on the third substrate 310. Wirings 3101, 3102, 3103, and 3104 function as second wirings for supplying a second control signal for controlling the operation of the signal processing circuit to the signal processing circuit.

[0071] In the pixel 121, buffers 1215, 1216, 1217, and 1218 are provided for performing timing adjustment and the like of control signals transmitted by the wirings 3101, 3102, 3103, and 3104. Similarly, in the pixel 123, buffers 1235, 1236, 1237, and 1238 are provided for performing timing adjustment and the like of control signals transmitted by the wirings 3101, 3102, 3103, and 3104. Note that it is allowed to appropriately determine for which pixels the buffers 1215, 1216, 1217, 1218, 1235, 1236, 1237, and 1238 are provided. In other words, on the third substrate 310, the pitches at which these respective buffers are provided may be different from each other.

[0072] According to the photoelectric conversion device 150 of the present modification, the wiring 2101 for supplying signals to the MOSFETs 2011a, 2012a, 2013a, and 2014a provided on the second substrate 210 is provided on the second substrate 210, rather than on the third substrate 310. As a result, a larger area can be ensured to provide wiring or elements or the like on the third substrate 310, and further microfabrication of constituent elements of the third substrate 310 is achieved.

[0073] Second embodiment

[0074] Next, we will use Fig. 9 A photoelectric conversion device according to a second embodiment is described. Note that the same configurations as those of the above-described embodiment will be denoted by the same symbols, and detailed descriptions thereof will be omitted below.

[0075] Fig. 9 is a block diagram showing a circuit example of the photoelectric conversion device 200 according to the present embodiment. Fig. 9 Some components of the photoelectric conversion device 200 are omitted. Fig. 9 As shown, the photoelectric conversion device 200 includes a first substrate 110 , a second substrate 210 , and a third substrate 310 .

[0076] On the first substrate 110, pixels 221 and 222 are provided in the pixel region 12. Note that a plurality of pixels having the same configuration as that of the pixels 221 and 222 are two-dimensionally arranged in the pixel region 12. However, the pixels 221 and 222 will be described, and descriptions of other pixels will be omitted below. The pixels 221 and 222 include APDs 1211 and 1221, pixel control circuits 2011 and 2012 connected to the APDs 1211 and 1221, and signal processing circuits 3011 and 3012 connected to the pixel control circuits 2011 and 2012, respectively.

[0077] In the peripheral area 13 on the second substrate 210, a wiring 2101 for supplying a control signal (PCLK) to the pixel control circuits 2011 and 2012 is provided. In addition, in the pixel area 12 on the second substrate 210, a buffer 2102 serving as a global buffer is provided, and the buffer 2102 performs timing adjustment on the transmission speed and the like of the control signal transmitted by the wiring 2101. In addition, in the pixel area 12 on the second substrate 210, a buffer 2103 serving as a local buffer is provided, and the buffer 2103 transmits the control signal transmitted via the buffer 2102 to the pixel control circuits 2011 and 2012. The buffer 2102 serves as a first buffer for outputting a first control signal to a plurality of groups, each group including at least two pixels among the plurality of pixels. In addition, the buffer 2103 serves as a second buffer for outputting a first control signal to the corresponding pixels included in the plurality of groups.

[0078] Furthermore, the control signal generating circuit 302 is provided in the peripheral region 13 on the third substrate 310. Furthermore, on the third substrate 310, the pixels 221 and 222 include signal processing circuits 3011 and 3012, respectively. Furthermore, wirings 3101, 3102, and 3103 are provided on the third substrate 310.

[0079] Furthermore, in this embodiment, a buffer 3105 serving as a global buffer is provided, which performs timing adjustment, etc., of the transmission speed of the signal transmitted by the wirings 3101, 3102, and 3103. Furthermore, a buffer 3106 serving as a local buffer is provided on the third substrate 310, and the buffer supplies the signal transmitted by the wirings 3101, 3102, and 3103 to the signal processing circuits 3011 and 3012.

[0080] Note that Fig. 9As shown, in the present embodiment, buffers 2102, 2103, 3105, and 3106 are provided for the groups of pixels 221 and 222. However, it is allowed to appropriately determine for which pixels these buffers are provided. In other words, on the second substrate 210 and the third substrate 310, the intervals at which these respective buffers are provided may be different from each other.

[0081] The farther the pixel is from the buffers 2102 and 3105, the greater the delay of the supply signal becomes. For this reason, if only the buffers 2102 and 3105 attempt to perform timing adjustment of the transmission speed of the signal, etc. for each pixel in the pixel area 12, the configuration of the buffers 2102 and 3105 may become complicated. Therefore, in the photoelectric conversion device 200 of the present embodiment, the buffers 2102, 2103, 3105, and 3106 are provided for the group of pixels 221 and 222. As a result, the burden of signal processing of the buffers 2102 and 3105 is dispersed, which makes it possible to reduce the delay of the control signal supplied to each pixel.

[0082] Furthermore, according to the photoelectric conversion device 200 of the present embodiment, the wiring 2101 for supplying signals to the pixel control circuits 2011 and 2012 provided on the second substrate 210 is provided on the second substrate 210, not on the third substrate 310. As described above, when the circuit that processes the signals from the APDs 1211 and 1221 is provided on the second substrate 210, the wiring that supplies the control signal to the circuit is not provided on the third substrate 310, but on the same second substrate 210. As a result, a larger area can be secured to provide wiring or elements, etc. on the third substrate 310, and further microfabrication of the constituent elements of the third substrate 310 is achieved.

[0083] Third embodiment

[0084] Next, we will use Fig.10 A photoelectric conversion device according to a third embodiment is described. Note that the same configurations as those of the above-described embodiment will be denoted by the same symbols, and detailed descriptions thereof will be omitted below.

[0085] Fig.10 is a block diagram showing a circuit example of the photoelectric conversion device 300 according to the present embodiment. Fig.10 Some components of the photoelectric conversion device 300 are omitted. Fig.10 As shown, the photoelectric conversion device 300 includes a first substrate 110 , a second substrate 210 , and a third substrate 310 .

[0086] On the first substrate 110, pixels 321, 322, 323, and 324 are provided in the pixel region 12. Note that a plurality of pixels having the same configuration as that of the pixels 321, 322, 323, and 324 are two-dimensionally arranged in the pixel region 12. However, the pixels 321, 322, 323, and 324 will be described, and description of other pixels will be omitted below. The pixels 321, 322, 323, and 324 include APDs 1211, 1221, 1231, and 1241, and pixel control circuits 2011, 2012, 2013, and 2014 connected to the APDs 1211, 1221, 1231, and 1241, respectively. Furthermore, the pixels 321 , 322 , 323 , and 324 include signal processing circuits 3011 , 3012 , 3013 , and 3014 connected to the pixel control circuits 2011 , 2012 , 2013 , and 2014 , respectively.

[0087] In the peripheral region 13 on the second substrate 210, a wiring 2101 is provided for supplying a control signal (PCLK) to the pixel control circuits 2011, 2012, 2013, and 2014. In addition, in the pixel region 12 on the second substrate 210, a buffer 2104 is provided as a global buffer, which performs timing adjustment on the transmission speed, etc. of the control signal transmitted by the wiring 2101. In addition, in the pixel region 12 on the second substrate 210, a buffer 2105 is provided as a local buffer, which transmits the control signal transmitted via the buffer 2104 to the pixel control circuits 2011 and 2012. Similarly, in the pixel region 12 on the second substrate 210, a buffer 2106 is provided as a global buffer, which performs timing adjustment on the transmission speed, etc. of the control signal output from the buffer 2104. Furthermore, in the pixel region 12 on the second substrate 210 , a buffer 2107 serving as a local buffer is provided, which transmits the control signal transmitted via the buffer 2106 to the pixel control circuits 2013 and 2014 .

[0088] In the present embodiment, buffers 2104, 2105, 2106 and 2107 are configured as combined logic circuits, each logic circuit including a pair of buffers and inverters. In addition, buffer 2107 has two pairs of buffers and inverters connected in series. Therefore, buffer 2104 used as a first buffer has a logic circuit that inverts the input first control signal. Therefore, the pulse waveform of the control signal transmitted by wiring 2101 is inverted by buffers 2104 and 2105, and then supplied to pixel control circuits 2011 and 2012. In addition, the control signal output from buffer 2104 is inverted by buffer 2106, and is further inverted twice by buffer 2107, and is supplied to pixel control circuits 2013 and 2014.

[0089] In the photoelectric conversion device 200 of the second embodiment, the buffers 2102 and 2103 are configured as positive logic circuits. Therefore, in the wiring 2101, the delay of the rise or fall of the pulse of the transmitted control signal accumulates, which leads to the possibility of deformation of the pulse waveform of the control signal. On the other hand, in the photoelectric conversion device 300 of the present embodiment, the delay of the rise and fall of the pulse of the control signal alternates whenever the control signal is inverted in the buffers 2104 and 2106. As a result, the buffers 2104 and 2106 can output the control signal without deforming the pulse waveform of the input control signal.

[0090] In the photoelectric conversion device 300, the control signal output from the control signal generation circuit 302 is inverted by the buffer 2104. Therefore, the signal is inverted again by the buffer 2105 and then supplied to the pixel control circuits 2011 and 2012. In addition, the control signal output from the buffer 2104 is inverted again by the buffer 2106. That is, the control signal output from the control signal generation circuit 302 becomes non-inverted. Therefore, the control signal output from the buffer 2106 is inverted twice by the buffer 2107 and then supplied to the pixel control circuits 2013 and 2014.

[0091] On the third substrate 310, the control signal generating circuit 302 is provided in the peripheral region 13. Also, on the third substrate 310, pixels 321, 322, 323, and 324 include signal processing circuits 3011, 3012, 3013, and 3014, respectively. Also, wirings 3101, 3102, and 3103 are provided on the third substrate 310.

[0092] Furthermore, in the present embodiment, buffers 3107 and 3109 are provided as global buffers which adjust the transmission speed and the like of the signals transmitted by the wirings 3101, 3102, and 3103. Furthermore, a buffer 3108 is provided on the third substrate 310 as a local buffer which supplies the signals transmitted by the wirings 3101, 3102, and 3103 to the signal processing circuits 3011 and 3012. Similarly, a buffer 3110 is provided as a local buffer which supplies the respective signals output from the buffer 3107 to the signal processing circuits 3013 and 3014.

[0093] Note that the inversion of the corresponding signals by buffers 3107, 3108, 3109 and 3110 is the same as the above-mentioned inversion of the control signal transmitted by the wiring 2101 by buffers 2104, 2105, 2106 and 2107, so its detailed description will be omitted here.

[0094] In addition, if Fig.10As shown, in this embodiment, buffers 3107 and 3108 are set for the group of pixels 321 and 322, and buffers 3109 and 3110 are set for the group of pixels 323 and 324. However, it is allowed to appropriately determine which pixels to set these buffers for. In other words, on the third substrate 310, the intervals at which these respective buffers are set may be different from each other.

[0095] According to the photoelectric conversion device 300 of this embodiment, buffers 3107 and 3108 are provided for the group of pixels 321 and 322, and buffers 3109 and 3110 are provided for the group of pixels 323 and 324. As a result, the burden of signal processing of the buffers 2104 and 3107 is dispersed, which makes it possible to reduce the delay of the control signal supplied to each pixel.

[0096] Furthermore, according to the photoelectric conversion device 300 of the present embodiment, the wiring 2101 for supplying signals to the pixel control circuits 2011, 2012, 2013, and 2014 provided on the second substrate 210 is provided on the second substrate 210, not on the third substrate 310. As described above, when the circuit that processes the signals from the APDs 1211, 1221, 1231, and 1241 is provided on the second substrate 210, the wiring that supplies the control signal to the circuit is not provided on the third substrate 310, but on the same second substrate 210. As a result, a larger area can be secured to provide wiring or elements or the like on the third substrate 310, and further microfabrication of the constituent elements of the third substrate 310 is achieved.

[0097] Fourth embodiment

[0098] Will use Fig.11 A photoelectric conversion system according to the present embodiment is described. Fig.11 is a block diagram showing a schematic configuration of a photoelectric conversion system according to the present embodiment.

[0099] The photoelectric conversion device described in the first embodiment to the third embodiment is applicable to various photoelectric conversion systems. The photoelectric conversion system includes at least the photoelectric conversion device according to the above-mentioned embodiment and a signal processing unit that processes a signal output from the photoelectric conversion device. Examples of equipment to which such a photoelectric conversion system can be applied include digital still cameras, digital cam encoders, monitoring cameras, copiers, fax machines, mobile phones, vehicle-mounted cameras, observation satellites, sensors, and measuring instruments. In addition, a camera module including an optical system such as a lens and an imaging device is also included in the equipment to which the photoelectric conversion system is applied. Fig.11 A block diagram of a digital still camera is shown as an example of these equipments.

[0100] Fig.11The photoelectric conversion system shown has an image pickup device 404 as an example of a photoelectric conversion device, a lens 402 for forming an optical image of a subject on the image pickup device 404, an aperture 403 for making the amount of light passing through the lens 402 variable, and a baffle 401 for protecting the lens 402. The lens 402 and the aperture 403 refer to an optical system that focuses light on the image pickup device 404. The image pickup device 404 refers to a photoelectric conversion device according to any of the above-described embodiments, and converts an optical image formed by the lens 402 into an electric signal.

[0101] The photoelectric conversion system also has a signal processing unit 407 serving as an image generating unit, and the signal processing unit 407 processes the output signal output from the image pickup device 404 to generate an image. The signal processing unit 407 performs various corrections and compressions as necessary, and outputs image data. The signal processing unit 407 may be formed on the same semiconductor substrate as the image pickup device 404, or may be formed on a semiconductor substrate different from the semiconductor substrate on which the image pickup device 404 is provided. In addition, the image pickup device 404 and the signal processing unit 407 may also be formed on the same semiconductor substrate.

[0102] The photoelectric conversion system also has a memory unit 410 for temporarily storing image data and an external interface unit (external I / F unit) 413 for communicating with an external computer or the like. In addition, the photoelectric conversion system has a recording medium 412 such as a semiconductor memory or the like for recording or reading image data, and a recording medium control interface unit (recording medium control I / F unit) 411 for recording or reading from the recording medium 412. Note that the recording medium 412 may be embedded in the photoelectric conversion system, or may be detachable.

[0103] Furthermore, the photoelectric conversion system has an overall control and calculation unit 409 that controls various calculations and the digital still camera as a whole, and a timing generation unit 408 that outputs various timing signals to the image pickup device 404 and the signal processing unit 407. Here, the timing signal and the like may be input from the outside, and the photoelectric conversion system may have at least only the image pickup device 404 and the signal processing unit 407 that processes an output signal output from the image pickup device 404.

[0104] The imaging device 404 outputs an imaging signal to the signal processing unit 407. The signal processing unit 407 applies prescribed signal processing to the imaging signal output from the imaging device 404, and outputs image data. The signal processing unit 407 generates an image using the imaging signal.

[0105] As described above, according to the present embodiment, a photoelectric conversion system to which the photoelectric conversion apparatus (imaging apparatus) according to any one of the above-described embodiments is applied can be realized.

[0106] Fifth embodiment

[0107] Will refer to Fig. 12A and Fig. 12B A photoelectric conversion system and a moving body according to the present embodiment are described. Fig. 12A is a diagram showing a configuration of a photoelectric conversion system according to the present embodiment, Fig. 12B is a diagram showing the configuration of a moving object according to the present embodiment.

[0108] Fig. 12A An example of a photoelectric conversion system related to a vehicle-mounted camera is shown. The photoelectric conversion system 500 includes a camera 510 to which the photoelectric conversion device described in any of the above-mentioned embodiments is applied. The photoelectric conversion system 500 has an image processing unit 512 that performs image processing on a plurality of image data acquired by the camera 510. In addition, the photoelectric conversion system 500 has a distance acquisition unit 516 that calculates the distance to the object and a collision judgment unit 518 that judges whether there is a possibility of collision based on the calculated distance. In this case, the distance acquisition unit 516 can acquire information related to the distance to the object based on ToF (time of flight), or can acquire the distance information using parallax information or the like. In addition, the distance acquisition unit 516 can acquire the distance information by combining the distance measurement based on ToF and the distance measurement based on the phase difference between pixels. In other words, the distance information is information related to parallax, defocus amount, or the distance to the object, etc. The collision judgment unit 518 can use any of these distance information to judge the possibility of collision. The distance information acquisition unit can be implemented by specially designed hardware, or can be implemented by a software module. Alternatively, the distance information acquisition unit may be implemented by an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit), etc., or a combination thereof.

[0109] The photoelectric conversion system 500 is connected to the vehicle information acquisition device 520, and is capable of acquiring vehicle information such as vehicle speed, yaw rate, and steering angle. In addition, the ECU 530 is connected to the photoelectric conversion system 500, and the ECU 530 is a control device that outputs a control signal for generating a braking force for the vehicle based on the judgment result of the collision judgment unit 518. In addition, the photoelectric conversion system 500 is also connected to the warning device 540, which issues a warning to the driver based on the judgment result of the collision judgment unit 518. For example, as a result of the judgment of the collision judgment unit 518, when it is found that the possibility of a collision is high, the ECU 530 performs vehicle control involving applying brakes, releasing the accelerator pedal, or suppressing engine output, etc., to avoid the collision and / or reduce damage. The warning device 540 issues a warning to the user by emitting an alarm sound, displaying a warning message on a screen of a car navigation system, etc., or vibrating a seat belt or a steering wheel, etc.

[0110] In the present embodiment, an image of the periphery of the vehicle such as the front or rear of the vehicle is picked up by the photoelectric conversion system 500 . Fig. 12B The photoelectric conversion system is shown when imaging the area in front of the vehicle (imaging range 550). The vehicle information acquisition device 520 sends a command to the photoelectric conversion system 500 or the imaging device 510. According to such a configuration, the accuracy of distance measurement can be further improved.

[0111] Although the above describes an example of controlling a vehicle to prevent a collision with another vehicle, the photoelectric conversion system can also be applied to: controlling automatic driving so that the vehicle follows other vehicles and controlling automatic driving so that the vehicle stays in a lane, etc. In addition, the photoelectric conversion system is not limited to vehicles such as motor vehicles, and can also be applied to mobile bodies (mobile devices) such as ships, airplanes, or industrial robots. The mobile body includes one or both of a driving force generating unit that generates a driving force mainly used for the movement of the mobile body and a rotating member mainly used for the movement of the mobile body. The driving force generating unit may be an engine or a motor, etc. The rotating member may be a tire, a wheel, a propeller of a ship, or a propeller of an aircraft, etc. In addition, in addition to mobile bodies, the photoelectric conversion system can be applied to a variety of devices that utilize object recognition, such as intelligent transportation systems (ITS), etc.

[0112] Sixth embodiment

[0113] Reference Fig.13 A photoelectric conversion system according to the present embodiment is described. Fig.13 : is a block diagram showing a configuration example of a distance image sensor as a photoelectric conversion system according to the present embodiment.

[0114] like Fig.13 As shown, the distance image sensor 601 is configured to include an optical system 607, a photoelectric conversion device 608, an image processing circuit 604, a monitor 605, and a memory 606. In addition, the distance image sensor 601 is capable of acquiring a distance image corresponding to the distance to the subject by receiving light (modulated light or pulsed light) emitted toward the subject from the light source device 609 and reflected by the surface of the object.

[0115] The optical system 607 is configured with one or more lenses, and guides image light (incident light) from a subject to the photoelectric conversion device 608 , and forms an image on a light receiving surface (sensor unit) of the photoelectric conversion device 608 .

[0116] The image processing circuit 604 performs image processing for constructing a distance image based on the distance signal supplied from the photoelectric conversion device 608. In addition, the distance image (image data) obtained by the image processing is supplied to the monitor 605 and displayed by the monitor 605, or supplied to the memory 606 and stored (recorded) in the memory 606.

[0117] With the distance image sensor 601 configured as described above, applying one of the above-described photoelectric conversion devices enables, for example, acquisition of a more accurate distance image due to improvement in distance measurement accuracy.

[0118] Seventh embodiment

[0119] Reference Fig.14 A photoelectric conversion system according to the present embodiment is described. Fig.14 : is a diagram showing an example of a schematic configuration of an endoscopic surgery system as a photoelectric conversion system according to the present embodiment.

[0120] Fig.14 The figure shows a situation where a technician (doctor) 731 is using an endoscopic surgery system 750 to perform surgery on a patient 732 on a bed 733. As shown in the figure, the endoscopic surgery system 750 is composed of an endoscope 700, a surgical instrument 710, and a cart 734 on which various devices for endoscopic surgery are installed.

[0121] The endoscope 700 is composed of a lens barrel 701, a region of a predetermined length from the distal end of which is to be inserted into a body cavity of a patient 732, and a camera 702 connected to the base end of the lens barrel 701. Although the illustrated example is characterized in that the endoscope 700 is configured as a so-called rigid scope having a rigid lens barrel 701, alternatively, the endoscope 700 may be configured as a so-called flexible scope having a flexible lens barrel.

[0122] At the distal end of the lens barrel 701, an opening for mounting an objective lens is provided. A light source device 703 is connected to the endoscope 700, and light generated by the light source device 703 is guided to the distal end of the lens barrel 701 through a light guide provided to extend inside the lens barrel, and is emitted toward an observation object inside the body cavity of the patient 732 via the objective lens. It should be noted that the endoscope 700 may be a forward-looking endoscope, an oblique-looking endoscope, or a side-looking endoscope.

[0123] The optical system and the photoelectric conversion device are arranged inside the camera 702, and the optical system collects the reflected light (observation light) from the observed object to the photoelectric conversion device. The observation light is photoelectrically converted by the photoelectric conversion device, and an electrical signal corresponding to the observation light is generated, or in other words, an image signal corresponding to the observed image is generated. As the photoelectric conversion device, the photoelectric conversion device according to any of the above-mentioned embodiments can be used. The image signal is transmitted to the camera control unit (CCU) 735 as raw (RAW) data.

[0124] The CCU 735 is composed of a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit) or the like, and comprehensively controls the operations of the endoscope 700 and the display device 736. In addition, the CCU 735 receives an image signal from the camera 702, and subjects the image signal to various image processing such as development processing (demosaicing) to display an image based on the image signal.

[0125] Under control exerted by the CCU 735, the display device 736 displays an image based on an image signal subjected to image processing by the CCU 735. The light source device 703 is constituted by a light source such as an LED (Light Emitting Diode) and supplies the endoscope 700 with irradiation light used when photographing a surgical site or the like.

[0126] The input device 737 is an input interface for the endoscopic surgery system 750. The user can input various information and input instructions to the endoscopic surgery system 750 via the input device 737.

[0127] The treatment tool control device 738 controls the drive of the energy treatment tool 712 for cauterizing or cutting tissue or sealing blood vessels, etc. The light source device 703 that supplies irradiation light to the endoscope 700 when photographing the surgical site can be composed of a white light source, which is composed of an LED, a laser light source, or a combination thereof. When the white light source is composed of 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 703. In addition, in this case, by irradiating the observed object with lasers from each RGB laser light source in a time-division manner and controlling the drive of the imaging element of the camera 702 in synchronization with the irradiation timing, images corresponding to each RGB can be captured in a time-division manner. According to this method, a color image can be obtained without setting a color filter for the imaging element.

[0128] In addition, the driving of the light source device 703 can be controlled so that the intensity of the output light changes at predetermined intervals. By controlling the driving of the imaging element of the camera 702 in synchronization with the timing of the light intensity change so as to acquire and synthesize images in a time-division manner, an image with a high dynamic range without so-called dark loss and highlight overflow can be generated.

[0129] In addition, the light source device 703 may be configured to be able to supply light in a predetermined wavelength band suitable for special light observation. In special light observation, for example, the wavelength dependence of the absorption of light by body tissue is utilized. Specifically, by irradiating light having a narrower band than the irradiation light (in other words, white light) during normal observation, predetermined tissues such as blood vessels of the surface portion of the mucosa are photographed with high contrast. Alternatively, in special light observation, fluorescence observation using fluorescence generated by irradiating excitation light to obtain an image may be performed. In fluorescence observation, body tissue may be irradiated with excitation light, and fluorescence from the body tissue may be observed, reagents such as indocyanine green (ICG) may be locally injected into body tissue, and body tissue may be irradiated with excitation light corresponding to the fluorescence wavelength of the reagent to obtain a fluorescent image, and the like. The light source device 703 may be configured to be able to supply narrowband light and / or excitation light suitable for such special light observation.

[0130] Eighth embodiment

[0131] Reference Fig.15A and Fig. 15B A photoelectric conversion system according to the present embodiment is described. Fig.15A Glasses 800 (smart glasses) are shown as a photoelectric conversion system according to the present embodiment. Glasses 800 have a photoelectric conversion device 802. The photoelectric conversion device 802 is a photoelectric conversion device according to any of the above-described embodiments. In addition, a display device including a light-emitting device such as an OLED or an LED may be provided on the rear surface side of the lens 801. There may be one or more photoelectric conversion devices 802. Alternatively, a plurality of types of photoelectric conversion devices may be used in combination. The arrangement position of the photoelectric conversion device 802 is not limited to Fig.15A Position shown.

[0132] The glasses 800 further include a control device 803. The control device 803 serves as a power source for supplying power to the above-mentioned photoelectric conversion device 802 and the display device. In addition, the control device 803 controls the operation of the photoelectric conversion device 802 and the display device. An optical system for collecting light to the photoelectric conversion device 802 is formed in the lens 801.

[0133] Fig. 15BGlasses 810 (smart glasses) according to an application example are shown. Glasses 810 include a control device 812, and the control device 812 is equipped with a photoelectric conversion device and a display device corresponding to the photoelectric conversion device 802. An optical system for projecting light emitted from the photoelectric conversion device and the display device inside the control device 812 is formed in a lens 811, and an image is projected onto the lens 811. The control device 812 is used as a power supply to power the photoelectric conversion device and the display device, and simultaneously controls the operation of the photoelectric conversion device and the display device. The control device may have a line of sight detection unit that detects the line of sight of the wearer. Infrared light can be used to detect the line of sight. The infrared light emitting unit emits infrared light to the eyes of the user who is looking at the displayed image. The picked-up image of the eye can be obtained by causing a camera unit including a light receiving element to detect the reflected light from the eye of the emitted infrared light. Providing a reduction component that reduces the light from the infrared light emitting unit to the display unit in the plan view can reduce the degradation of image quality.

[0134] The line of sight of the user relative to the displayed image can be detected from a picked-up image of the eye obtained by photographing with infrared light. Any known method can be applied to line of sight detection using a picked-up image of the eye. For example, a line of sight detection method based on a Purkinje image caused by reflection of irradiated light by the cornea can be used.

[0135] More specifically, a line of sight detection process based on the pupil-corneal reflection method is performed. Using the pupil-corneal reflection method, the line of sight of the user is detected by calculating a line of sight vector representing the orientation (rotation angle) of the eye based on the pupil image and Purkinje image included in the picked-up image of the eye. The display device according to the present embodiment may have a photoelectric conversion device including a light receiving element, and the display image of the display device may be controlled based on the user's line of sight information from the photoelectric conversion device.

[0136] Specifically, the display device determines a first field of view area that the user is paying attention to and a second field of view area other than the first field of view area based on the line of sight information. The first field of view area and the second field of view area can be determined by a control device of the display device, or an area determined by an external control device can be received as the first field of view area and the second field of view area. In the display area of ​​the display device, the display resolution of the first field of view area can be controlled to be higher than the display resolution of the second field of view area. In other words, the resolution of the second field of view area can be set to be lower than the resolution of the first field of view area.

[0137] In addition, the display area may have 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 an area determined by an external control device may be received as the first display area and the second display area. The resolution of the area with a high priority may be controlled to be higher than the resolution of the area other than the area with a high priority. In other words, the resolution of the area with a relatively low priority may be reduced.

[0138] It should be noted that AI (artificial intelligence) can be used to determine the first field of view area and the area with high priority. AI can be a model configured to use an image of the eye and the direction in which the eye is actually observing in the image as teacher data to estimate the angle of sight and the distance to the object in front of the sight based on the image of the eye. The AI ​​program can be included in a display device, a photoelectric conversion device, or an external device. When the external device includes an AI program, the inference result of the AI ​​is sent to the display device via communication.

[0139] The display control based on visual recognition and detection can be preferably applied to smart glasses which also include a photoelectric conversion device for capturing external images. The smart glasses can display the captured external information in real time.

[0140] Ninth embodiment

[0141] The above-described photoelectric conversion apparatus and photoelectric conversion system are applicable to, for example, electronic devices such as so-called smartphones and tablet computers.

[0142] Fig.16A and Fig. 16B is a diagram showing an example of an electronic device 900 in which a photoelectric conversion apparatus is mounted. Fig.16A The front surface side of the electronic device 900 is shown. Fig. 16B The rear surface side of the electronic device 900 is shown.

[0143] like Fig.16A As shown, a display 910 displaying an image is arranged at the center of the front surface of the electronic device 900. In addition, front cameras 921 and 922 using a photoelectric conversion device, an IR light source 930 emitting infrared light, and a visible light source 940 emitting visible light are arranged along the upper side of the front surface of the electronic device 900.

[0144] In addition, if Fig. 16B As shown, rear cameras 951 and 952 using a photoelectric conversion device, an IR light source 960 emitting infrared light, and a visible light source 970 emitting visible light are arranged along the upper side of the rear surface of the electronic device 900 .

[0145] In the electronic device 900 configured as described above, by applying the photoelectric conversion device as described above, for example, a higher quality image can be captured, and the distance to the subject can be measured with high accuracy. Note that the photoelectric conversion device can be applied to other electronic devices such as an infrared sensor, a distance measuring sensor using an active infrared light source, a security camera, and a personal authentication camera or a biometric camera. As a result, the accuracy and performance of such an electronic device can be improved.

[0146] Tenth embodiment

[0147] Fig.17 10 is a block diagram of an X-ray CT apparatus according to the present embodiment. The above-mentioned photoelectric conversion apparatus and the photoelectric conversion system can be applied to the detector of the X-ray CT apparatus. The X-ray CT apparatus 1000 according to the present embodiment includes an X-ray generating unit 1010, a wedge 1011, a collimator 1012, an X-ray detecting unit 1020, and a top plate 1030. In addition, the X-ray CT apparatus 1000 includes a rotating frame 1040, a high voltage generating device 1050, a data collecting device (DAS: Data Acquisition System) 1051, a signal processing unit 1052, a display unit 1053, and a control unit 1054.

[0148] The X-ray generating unit 1010 is constituted by, for example, a vacuum tube that generates X-rays. High voltage and filament current from the high voltage generating device 1050 are supplied to the vacuum tube of the X-ray generating unit 1010. When thermal electrons are radiated from the cathode (filament) toward the anode (target), X-rays are generated.

[0149] The wedge 1011 is a filter for adjusting the X-ray dose radiated from the X-ray generation unit 1010. The wedge 1011 attenuates the X-ray dose so that the X-ray radiated from the X-ray generation unit 1010 toward the object is distributed as predetermined. The collimator 1012 is composed of a lead plate or the like for narrowing the irradiation range of the X-ray that has passed through the wedge 1011. The X-ray generated by the X-ray generation unit 1010 is shaped into a cone beam shape via the collimator 1012 and radiated to the object on the top plate 1030.

[0150] The X-ray detection unit 1020 is configured by using the above-described photoelectric conversion device or photoelectric conversion system. The X-ray detection unit 1020 detects X-rays having passed through the object from the X-ray generation unit 1010 and outputs a signal corresponding to the X-ray dose to the DAS 1051 .

[0151] The rotating frame 1040 is annular and rotatable. The X-ray generation unit 1010 (wedge 1011 and collimator 1012) and the X-ray detection unit 1020 are arranged to face each other inside the rotating frame 1040. The X-ray generation unit 1010 and the X-ray detection unit 1020 can rotate together with the rotating frame 1040.

[0152] The high voltage generating device 1050 includes a boosting circuit, and outputs a high voltage to the X-ray generating unit 1010. The DAS 1051 includes an amplifier circuit and an A / D converter circuit, and outputs a signal from the X-ray detecting unit 1020 to the signal processing unit 1052 as digital data.

[0153] The signal processing unit 1052 includes a CPU (central processing unit), a ROM (read only memory) and a RAM (random access memory), and can perform image processing of digital data, etc. The display unit 1053 includes a flat display device, etc., and can display an X-ray image. The control unit 1054 includes a CPU, a ROM and a RAM, and controls the operation of the X-ray CT apparatus 1000 as a whole.

[0154] Eleventh Embodiment

[0155] Reference Fig.18 A photoelectric conversion system according to an eleventh embodiment is described. Fig.18 11 is a block diagram showing a schematic configuration of an imaging system SYS as a photoelectric conversion system according to the eleventh embodiment. The imaging system SYS includes at least a photoelectric conversion device according to any of the above-described embodiments and a signal processing unit that processes a signal output from the photoelectric conversion device.

[0156] The camera system SYS is an information terminal including a camera and a shooting function. The camera system SYS is constructed using a camera device IS. The camera device IS may also include a package PKG that accommodates a camera device IC. The package PKG may include a substrate that fixes the camera device IC and a cover body opposite to the camera device IC. The package PKG may include a connecting member connected to each other (a member that connects terminals provided on the substrate and terminals provided on the camera device IC). The camera device IS may install the camera device ICs to a common package PKG by arranging a plurality of camera device ICs side by side. Alternatively, the camera device IS may install the camera device IC and other semiconductor device ICs to a common package PKG by stacking the camera device IC and other semiconductor device ICs on top of each other.

[0157] The camera system SYS may include an optical system OU (optical device) that forms an image on the camera device IS. In addition, the camera system SYS may include at least any one of a control device CU, a processing device PU, a display device DU, and a storage device MU. The control device CU controls the camera device IS, and the processing device PU processes a signal obtained from the camera device IS. In addition, the display device DU displays an image obtained from the camera device IS, and the storage device MU stores the image obtained from the camera device IS.

[0158] Other embodiments

[0159] Although various devices have been described in the above embodiments, mechanical devices may be further provided. The mechanical devices in the camera may drive components of the optical system for the purpose of zooming, focusing, and shutter operation. Alternatively, the mechanical devices in the camera may move the photoelectric conversion device for vibration isolation.

[0160] In addition, the device may be a transport equipment such as a vehicle, a ship or an aircraft. The mechanical equipment in the transport equipment may be used as a mobile device. The device as the transport equipment is suitable as a device for transporting a photoelectric conversion device or a device for assisting and / or automating driving (operation) using a shooting function. The processing device for assisting and / or automating driving (operation) may perform processing for operating the mechanical device as a mobile device based on the information obtained by the photoelectric conversion device.

[0161] Without departing from the technical concept of the present invention, the above-mentioned embodiments may be appropriately modified. It should be understood that the contents disclosed in this specification include not only the contents described in this specification, but also all the contents that can be understood from this specification and from the drawings accompanying this specification. In addition, the disclosure of this specification includes a supplementary set of concepts described in this specification. In other words, assuming that this specification includes, for example, a description of "A is greater than B", it is assumed that this specification also discloses "A is not greater than B", even if the description of "A is not greater than B" is omitted. This is because the existence of the description to the effect that "A is greater than B" is premised on the fact that the case of "A is not greater than B" is considered.

[0162] In this specification, there may be cases where expressions such as "A or B", "at least one of A and B", "at least one of A and / or B", and "one or more than one of A and / or B" are used. In this case, all possible combinations of the listed items may be included unless otherwise explicitly defined. In other words, the above expressions are understood to disclose all cases including: cases including at least one A, cases including at least one B, and cases including both at least one A and at least one B. This logic also applies to combinations of three or more elements.

[0163] According to the technology of the present disclosure, in a photoelectric conversion device having at least a three-layer structure, a technology for supporting microfabrication of a circuit can be provided.

[0164] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A photoelectric conversion device, comprising: A pixel having an avalanche photodiode, a pixel circuit that performs processing using a signal output from the avalanche photodiode, and a signal processing circuit that performs processing using a signal output from the pixel circuit; as well as a control signal generating circuit for generating a first control signal for controlling the operation of the pixel circuit and a second control signal for controlling the operation of the signal processing circuit, The second circuit layer where the signal processing circuit and the control signal generating circuit are arranged, the first circuit layer where the pixel circuit is arranged, and the photodiode layer where the avalanche photodiode is arranged are stacked together in this order. The output terminal of the avalanche photodiode is connected to the pixel circuit, The pixels are provided in plurality and arranged in a pixel area, The control signal generating circuit is arranged in a peripheral area provided around the pixel area, and A first wiring for supplying the first control signal to the pixel circuit is provided on the first circuit layer, and the first wiring is connected to the control signal generating circuit in the peripheral region.

2. The photoelectric conversion device according to claim 1, wherein In the pixel region, buffers are arranged on the first wiring at a fixed pitch corresponding to a pixel unit.

3. The photoelectric conversion device according to claim 1, wherein The plurality of pixels include at least one pixel in which no buffer is provided on the first wiring and at least one pixel in which a buffer is provided on the first wiring.

4. The photoelectric conversion device according to claim 1, wherein In the pixel region, the first wiring is provided on the first circuit layer.

5. The photoelectric conversion device according to claim 1, wherein In the pixel region, a second wiring for supplying the second control signal to the signal processing circuit is provided on the second circuit layer.

6. The photoelectric conversion device according to claim 1, wherein The element arranged on the first circuit layer is an element having higher voltage resistance than the element arranged on the second circuit layer.

7. The photoelectric conversion device according to claim 1, wherein The pixel circuit includes a control circuit of the avalanche photodiode, and The signal processing circuit includes a counting circuit that performs counting processing on a signal output from the pixel circuit.

8. The photoelectric conversion device according to claim 1, wherein The pixel circuit includes a quenching element that performs a quenching operation on the avalanche photodiode and a waveform shaping circuit that performs a waveform shaping process on a signal output from the avalanche photodiode.

9. The photoelectric conversion device according to claim 8, wherein The quenching element is controlled by the first control signal to switch between a high resistance state and a low resistance state having a resistance value lower than that of the high resistance state.

10. The photoelectric conversion device according to claim 7, wherein The counting circuit includes a flip-flop that performs the counting process and a memory that holds a count value obtained by the counting process.

11. The photoelectric conversion device according to claim 1, wherein A first buffer and a second buffer are arranged on the first wiring, wherein the first buffer outputs the first control signal to a plurality of groups each including at least two pixels among the plurality of pixels, and the second buffer outputs the first control signal to corresponding pixels included in the plurality of groups.

12. The photoelectric conversion device according to claim 11, wherein The first buffer has a logic circuit that inverts a first control signal to be input.

13. A photoelectric conversion system comprising: The photoelectric conversion device according to any one of claims 1 to 12; as well as A signal processing unit is configured to generate an image using the signal output from the photoelectric conversion device.

14. A moving body having the photoelectric conversion device according to any one of claims 1 to 12, the moving body comprising: A control unit for controlling the movement of the moving body using the signal output from the photoelectric conversion device.

15. A device comprising the photoelectric conversion device according to any one of claims 1 to 12, the device further comprising at least any one of the following devices: An optical device, which corresponds to the photoelectric conversion device; A control device, which is used to control the photoelectric conversion device; a processing device for processing a signal output from the photoelectric conversion device; A display device, which is used to display the information obtained by the photoelectric conversion device; A storage device, used to store information obtained by the photoelectric conversion device; as well as A mechanical device for performing an operation based on information obtained by the photoelectric conversion device.

Images