PHOTO DETECTION DEVICE AND DISTANCE MEASURING SYSTEM

Abstract

Light sensing device. In one example, the light sensing device comprises a pixel layer, a first circuit layer, a second circuit layer, one or more first individual electrical connections between a photodiode located in the pixel layer and a first circuit located in the first circuit layer, and one or more second individual electrical connections between the first circuit and a second circuit located in the second circuit layer. The pixel layer, the first circuit layer, and the second circuit layer are stacked vertically.

Description

[Technical field]

[0001] The present disclosure relates to a photodetection device and a distance measuring system, and in particular to a photodetection device and a distance measuring system that can further improve performance. <QUERVERWEIS AUF VERWANDTE ANMELDUNGEN>

[0002] This application claims priority over Japanese priority patent application JP 2023-114929, filed on July 13, 2023, the entire contents of which are incorporated herein by reference. [State of the art]

[0003] In the past, distance measurement systems were developed that acquired distance images by arranging multiple SPADs (single-photon avalanche diodes) in an array and determining the distance to an object using the ToF (time-of-flight) method. For example, past distance measurement systems used a two-layer structure created by stacking a pixel layer on which the SPADs were arranged and a circuit layer on which distance measurement circuits were placed.

[0004] PTL 1 discloses an imaging device with a laminated structure in which a layer with a photoelectric conversion element and several layers with circuits are stacked. [Citation list][Patent literature]

[0005] [PTL 1] JP 2020-524943A [Summary of the invention][Technical problem]

[0006] In the two-layer photodetection device described above, however, all circuits are mounted on a single circuit layer, making it difficult to improve distance measurement performance, power consumption, chip size, etc., and thus creating a need to enhance its performance. It should be noted that in the imaging device mentioned above, disclosed in PTL 1, although circuits are arranged in multiple layers, so-called peripheral circuits are generally not provided, and the layers are not subdivided based on function.

[0007] The present disclosure was made in light of this situation, and it is desirable to further improve performance. [Solution to the problem]

[0008] According to one aspect of the present disclosure, a light-sensing device comprises: a pixel layer, a first circuit layer, and a second circuit layer. The pixel layer includes a pixel array, the pixel array comprising a photodiode configured to: detect photons and generate a first signal based on the detection of the photons. The first circuit layer comprises a first circuit configured to: receive the first signal via a first electrical connection and generate a second signal based on the first signal. The second circuit layer comprises a second circuit configured to: receive the second signal via a second electrical connection and generate distance data based on the second signal, the distance data indicating a distance between the light-sensing device and one or more objects.The first electrical connection is one or more individual electrical connections between the photodiode and the first circuit. The second electrical connection is one or more individual electrical connections between the first and second circuits, and the pixel layer, first circuit layer, and second circuit layer are stacked vertically together.

[0009] According to another aspect of the present disclosure, the pixel layer comprises a plurality of the photodiode, the first circuit layer comprises a plurality of the first circuit, and the second circuit layer comprises a plurality of the second circuit.

[0010] According to yet another aspect of the present disclosure, an electronic device comprises a light-sensing device. The light-sensing device comprises a pixel layer, a first circuit layer, and a second circuit layer. The pixel layer comprises a pixel array, the pixel array comprising a photodiode configured to: detect photons and generate a first signal based on the detection of the photons. The first circuit layer comprises a first circuit configured to: receive the first signal via a first electrical connection and generate a second signal based on the first signal.The second circuit layer comprises a second circuit configured to: receive the second signal via a second electrical connection, and generate distance data based on the second signal, where the distance data specifies a distance between the light-sensing device and one or more objects. The first electrical connection is one or more individual electrical connections between the photodiode and the first circuit. The second electrical connection is one or more individual electrical connections between the first and second circuits, and the pixel layer, the first circuit layer, and the second circuit layer are stacked vertically together. [Brief description of the drawings] [ Fig. 1] Fig. Figure 1 is a diagram that represents a configuration example of a first embodiment of a photodetection device to which the present technology is applied. [ Fig. 2] Fig. Figure 2 is a diagram showing a cross-sectional configuration example of the photodetection device in Fig. 1 represents. [ Fig. 3] Fig. Figure 3 is a diagram that shows a configuration example of a second embodiment of the photodetection device to which the present technology is applied. [ Fig. 4] Fig. Figure 4 is a diagram showing a cross-sectional configuration example of the photodetection device in Fig. 3 represents. [ Fig. 5] Fig. Figure 5 is a diagram that shows a configuration example of a third embodiment of the photodetection device to which the present technology is applied. [ Fig. 6] Fig. Figure 6 is a diagram showing a cross-sectional configuration example of the photodetection device in Fig. 5 represents. [ Fig. 7] Fig. Figure 7 is a cross-sectional view showing an example of a connection structure of connection pads via a Cu-Cu connection. [ Fig. 8] Fig. Figure 8 is a diagram that shows a configuration example of a fourth embodiment of the photodetection device to which the present technology is applied. [ Fig. 9] Fig. Figure 9 is a block diagram that represents a configuration example of a distance measurement system to which the present technology is applied. [Description of embodiments]

[0011] Specific embodiments to which the present technology is applied are described in detail below with reference to the drawings. First configuration example of a photodetection device

[0012] A first embodiment of a photodetection device to which the present technology is applied is described with reference to Fig. 1 and Fig. 2 described.

[0013] Fig. Figure 1 is a diagram representing a laminated structure of a photodetection device 11.

[0014] As in Fig. As shown in Figure 1, the photodetection device 11 has a three-layer structure in which a first semiconductor substrate 12, a second semiconductor substrate 13 and a third semiconductor substrate 14 are stacked.

[0015] The first semiconductor substrate 12 is a pixel layer comprising a pixel field 22 in which several SPADs 21 are arranged in an array. The SPAD 21 is a photon detection element with a pixel structure that uses avalanche multiplication to amplify electrons from an incident photon.

[0016] The second semiconductor substrate 13 is a circuit layer on which several pixel front-end (PFE) circuits 31 are arranged, corresponding to individual SPADs 21 of the first semiconductor substrate 12. The PFE circuit 31 is a pre-stage circuit configured by circuit elements required to receive high voltage under the pixel circuits provided for each SPAD 21 and to convert the analog signal output by the SPAD 21 in response to photon detection into a digital signal for output.

[0017] The third semiconductor substrate 14 is a circuit layer on which several distance sensing circuits 41 are arranged, corresponding to individual SPADs 21 of the first semiconductor substrate 12. The distance sensing circuit 41 is a subsequent stage circuit below the pixel circuits provided for each SPAD 21, which measures the distance based on the digital signal output by the PFE circuit 31.

[0018] Furthermore, in the photodetection device 11, each SPAD 21 and each PFE circuit 31 are electrically connected via a via 51, and each PFE circuit 31 and each distance measuring circuit 41 are electrically connected via a Cu-Cu connection 52. The via 51 is formed by filling a tiny hole, configured to extend through the first semiconductor substrate 12 and the second semiconductor substrate 13, with a metal that serves as a conductor. The Cu-Cu connection 52 is configured by bonding Cu pads formed on the respective bonding surfaces of the first semiconductor substrate 12 and the second semiconductor substrate 13.

[0019] Fig. Figure 2 is a diagram showing a cross-sectional configuration example of the photodetection device 11.

[0020] As in Fig. As shown in Figure 2, the photodetection device 11 is configured such that the first semiconductor substrate 12, on which the SPADs 21 are provided, the second semiconductor substrate 13, on which the PFE circuits 31 are provided, and the third semiconductor substrate 14, on which the distance measuring circuits 41 are provided, are stacked. The SPAD 21 and the PFE circuit 31 are then connected via the via 51, and the PFE circuit 31 and the distance measuring circuit 41 are connected via the Cu-Cu connection 52.

[0021] Since the photodetection device 11 has a configuration in which the PFE circuit 31, required to receive high voltage, is provided on the second semiconductor substrate 13 for each SPAD 21, the cathode wiring from the SPAD 21 to the PFE circuit 31 can be shortened. This allows the photodetection device 11 to reduce its cathode capacitance, which is important for the distance measurement performance (POS, etc.) and the power consumption of the SPAD 21.

[0022] For example, in the past, photodetection devices incorporating PFE circuits and distance sensing circuits in a single circuit layer required the integration of the PFE circuits necessary to receive high voltage to improve area efficiency, particularly when the SPAD pixel size was small. This also necessitated integrating the distance sensing circuits driven by low voltage. This resulted in a wiring layout where the cathode wiring extended from the SPAD to the PFE circuit, making it difficult to reduce cathode capacitance.

[0023] Since the photodetection device 11, in contrast, has a configuration in which the PFE circuits 31 and the distance sensing circuits 41 are provided in different circuit layers, the PFE circuit 31 can be arranged for each SPAD 21. Because of this, a wiring layout can be created in which the cathode wiring from the SPAD 21 to the PFE circuit 31 is shorter than before, and as a result, the cathode capacitance can be reduced. It should be noted that, since the distance sensing circuit 41 is configured to receive digital signals, even if the wiring from the PFE circuit 31 becomes long, the effect on its characteristics is minimal.

[0024] Additionally, the photodetection device 11 features a configuration in which the PFE circuits 31 and the distance measurement circuits 41 are provided in different circuit layers, thus increasing the number of counter bits provided per pixel and improving distance measurement accuracy. Furthermore, compared to a previous configuration in which the PFE circuits and distance measurement circuits were provided on a single circuit layer, the photodetection device 11 can achieve pixel miniaturization with the same performance. Second configuration example of a photodetection device

[0025] A second embodiment of the photodetection device to which the present technology is applied is described with reference to Fig. 3 and Fig. 4 described. It should be noted that in a photodetection device 11A, which is described in Fig. 3 and Fig. Figure 4 shows the components that correspond to those in the photodetection device 11. Fig. 1. They have in common, are designated with the same reference symbols, and a detailed description of them is omitted.

[0026] Fig. Figure 3 is a diagram illustrating the laminated structure of the photodetection device 11A.

[0027] As in Fig. As shown in Figure 3, the photodetection device 11A has the configuration that corresponds to that of the photodetection device 11 in Figure 3. Fig. 1 is common in that it is formed by a three-layer structure produced by stacking a first semiconductor substrate 12A on which the SPADs 21 are arranged in an array, a second semiconductor substrate 13A on which the PFE circuit 31 for each SPAD 21 is arranged, and a third semiconductor substrate 14A on which the distance measuring circuit 41 for each SPAD 21 is arranged.

[0028] Then the photodetection device 11A has a different configuration than the photodetection device 11 in Fig. 1, by having the photodetection device 11A edge circuits 61-1 and 61-2 arranged in the edge region of the second semiconductor substrate 13A, and edge circuits 61-3 and 61-4 arranged in the edge region of the third semiconductor substrate 14A.

[0029] This means that the photodetection device 11A is configured such that the edge circuits 61-1 to 61-4 are arranged to be distributed across the second semiconductor substrate 13A and the third semiconductor substrate 14A. For example, the edge circuits 61-1 and 61-2, which are arranged on the second semiconductor substrate 13A, and the edge circuits 61-3 and 61-4, which are arranged on the third semiconductor substrate 14A, are positioned so that they overlap when the photodetection device 11A is viewed from above. Of course, an arrangement in which the circuits do not overlap can also be assumed.

[0030] The edge circuits 61-1 and 61-2 are equipped with thick-film circuits such as a power-on reset circuit (PoR circuit), a voltage regulator circuit (LDO: Low Drop Out), a bias circuit, a temperature circuit, a circuit protection circuit and a decap circuit.

[0031] The edge circuits 61-3 and 61-4 are equipped with thin-film circuits such as a PLL (phase-locked loop) circuit, an interface circuit, a distance measuring circuit, and other digital circuits. It should be noted that the edge circuits 61-3 and 61-4 can be equipped with not only thin-film circuits, but also both thin-film and thick-film circuits.

[0032] Fig. Figure 4 is a diagram showing a connection diagram in a configuration in which a PoR circuit is mounted as the edge circuit 61-1 provided on the second semiconductor substrate 13A.

[0033] As in Fig. As shown in Figure 4, the edge circuits 61-1 and 61-2 are mounted on the second semiconductor substrate 13A. The third semiconductor substrate 14A is provided with connection pads 71-1 to 71-4 and also features an HV block 72, driven with high voltage, an MV block 73, driven with medium voltage, and an LV block 74, driven with low voltage, as the edge circuits 61-3 and 61-4.

[0034] The connection pads 71-1 to 71-4 are each connected to the edge circuit 61-1 via Cu-Cu connections 52a to 52d. An XCLR signal is input through connection pad 71-1, a high voltage VDDH is input through connection pad 71-2, a medium voltage VDDM is input through connection pad 71-3, and a low voltage VDDL is input through connection pad 71-4.

[0035] The HV block 72, the MV block 73, and the LV block 74 are each connected to the edge circuit 61-1 via Cu-Cu connections 52e to 52g. An XSHUTDOWN signal is input from the edge circuit 61-1 into the HV block 72, an XCLR_MV signal is input from the edge circuit 61-1 into the MV block 73, and an XCLR_LV signal is input from the edge circuit 61-1 into the LV block 74.

[0036] In the photodetection device 11A configured in this way, the chip size can be reduced by distributing the edge circuits 61 over the second semiconductor substrate 13A and the third semiconductor substrate 14A. Third configuration example of a photodetection device

[0037] A third embodiment of the photodetection device to which the present technology is applied is described with reference to Fig. 5 to Fig. 7 described. Furthermore, in a photodetection device 11B, which is described in Fig. 5 to Fig. Figure 7 shows the components that correspond to those in the photodetection device 11. Fig. 1 and the photodetection device 11A in Fig. 3 items are in common, are designated with the same reference symbols, and a detailed description is omitted.

[0038] Fig. Figure 5 is a diagram illustrating the laminated structure of the photodetection device 11B.

[0039] As in Fig. As shown in Figure 5, the photodetection device 11B has a configuration that is similar to that of the photodetection device 11 in Figure 5. Fig. 1 and the photodetection device 11A in Fig. 3 is characterized by a three-layer structure formed by stacking a first semiconductor substrate 12B on which the SPADs 21 are arranged in an array, a second semiconductor substrate 13B on which the PFE circuit 31 for each SPAD 21 is arranged, and a third semiconductor substrate 14B on which the distance measuring circuit 41 for each SPAD 21 is arranged. Furthermore, the photodetection device 11B has a configuration similar to that of the photodetection device 11A in Fig. 3 have in common that the edge circuits 61-1 and 61-2 are arranged in the edge region of the second semiconductor substrate 13B, and the edge circuits 61-3 and 61-4 are arranged in the edge region of the third semiconductor substrate 14B.

[0040] Then the photodetection device 11B has a different configuration than the photodetection device 11 in Fig. 1 and the photodetection device 11A in Fig. 3 by arranging multiple connection pads 81 along the edge of the second semiconductor substrate 13B, and multiple connection pads 82 along the edge of the third semiconductor substrate 14B. The multiple connection pads 81 provided on the second semiconductor substrate 13B and the multiple connection pads 82 provided on the third semiconductor substrate 14B are arranged to overlap when the photodetection device 11B is viewed from above.

[0041] Furthermore, in the photodetection device 11B, pads that are used together can be connected via the Cu-Cu connection 52 among the multiple connection pads 81 provided on the second semiconductor substrate 13B and the multiple connection pads 82 provided on the third semiconductor substrate 14B. In the Fig. In the example shown in Figure 5, the voltage supplied to the edge circuit 61-2 via a connection pad 81a and the voltage supplied to the edge circuit 61-4 via a connection pad 82a are a common voltage. Therefore, the connection pad 81a and the connection pad 82a are arranged in a position such that the pads overlap in the top view, and the connection pad 81a and the connection pad 82a are connected via the Cu-Cu connection 52.

[0042] Additionally, in the photodetection device 11B, a pad connected only to the edge circuit 61 of the second semiconductor substrate 13B can be arranged among the multiple connection pads 81 provided on the second semiconductor substrate 13B, and a pad connected only to the edge circuit 61 of the second semiconductor substrate 13B can be arranged among the multiple connection pads 82 provided on the second semiconductor substrate 13B, in positions that overlap each other in the top view. In the Fig. The 5 illustrated example includes a connection pad 81b, which is connected only to the edge circuit 61-1, and a connection pad 82b, which is connected only to the edge circuit 61-3, arranged in positions that overlap each other in the top view.

[0043] Therefore, by arranging the connection pads 81 and 82 in this way, the photodetection device 11B can reduce the number of connection pads 81 and 82 required, thereby reducing the chip size. Alternatively, even if the photodetection device 11B has a configuration in which the number of connection pads 81 and 82 does not affect the chip size, properties such as impedance reduction can be improved.

[0044] Fig. Figure 6 is a diagram showing a connection diagram in a configuration in which a PoR circuit is mounted as the edge circuit 61-1 provided on the second semiconductor substrate 13B.

[0045] As in Fig. As shown in Figure 6, the second semiconductor substrate 13B is provided with the connection pads 71-1 and 71-2 and also has the edge circuits 61-1 and 61-2 mounted on it. The third semiconductor substrate 14B is provided with connection pads 71-3 to 71-6 and comprises the HV block 72, which is driven with high voltage, the MV block 73, which is driven with medium voltage, and the LV block 74, which is driven with low voltage, as the edge circuits 61-3 and 61-4.

[0046] Connection pads 71-1 and 71-2 are directly connected to the edge circuit 61-1, and connection pads 71-3 to 71-6 are each connected to the edge circuits 61-1 via the Cu-Cu connections 52a to 52c. The XCLR signal is input through connection pad 71-1, the high voltage VDDH is input through connection pads 71-2 and 71-3, the medium voltage VDDM is input through connection pad 71-4, the low voltage VDDL is input through connection pad 71-5, and a test signal is input through connection pad 71-6.

[0047] The HV block 72, the MV block 73, and the LV block 74 are each connected to the edge circuit 61-1 via the Cu-Cu connections 52d to 52f. The XSHUTDOWN signal is input from the edge circuit 61-1 into the HV block 72, the XCLR_MV signal is input from the edge circuit 61-1 into the MV block 73, and the XCLR_LV signal is input from the edge circuit 61-1 into the LV block 74. Furthermore, the test signal is input into the LV block 74 of the photodetection device 11B via the connection pad 71-6.

[0048] In the photodetection device 11B, the connection pad 71-2 and the connection pad 71-3, which are used to input the high voltage VDDH, are connected via the Cu-Cu connection 52a.

[0049] In the photodetection device 11B, the interconnect pad 71-1, used to input a signal XCLR that is supplied only to the edge circuit 61-1, is provided on the second semiconductor substrate 13B, and the interconnect pad 71-6, used to input the test signal that is supplied only to the LV block 74, is provided on the third semiconductor substrate 14B. Therefore, the interconnect pad 71-1 and the interconnect pad 71-6 can be arranged in an overlapping position when the photodetection device 11A is viewed from above, similar to the interconnect pad 81b and the interconnect pad 82b, which are described with reference to Fig. 5 are described. It should be noted that the connection pad 71-6, which is used to input the test signal, is only used for testing the LV block 74 before the second semiconductor substrate 13B is stacked on top of the third semiconductor substrate 14B, and the pad is not used after the second semiconductor substrate 13B is stacked on top of the third semiconductor substrate 14B.

[0050] Additionally, the connection pad 81, which supplies a signal, power supply, GND, etc., which is used only on the second semiconductor substrate 13B, and the connection pad 82, which supplies a signal, power supply, GND, etc., which is used only on the third semiconductor substrate 14B, can be arranged in an overlapping position when the photodetection device 11A is viewed from above.

[0051] Fig. Figure 7 is a diagram showing a connection structure between connection pad 81a and connection pad 82a, which are connected via the Cu-Cu connection 52.

[0052] As in Fig. As shown in Figure 7, the photodetection device 11B has an opening for passing an external wire bond of the wiring on the connection pad 81a, extending to the connection pad 81a through the first semiconductor substrate 12B. The connection pad 81a and the Cu-Cu connection 52 are then connected via a through electrode 91, and the connection pad 82a and the Cu-Cu connection 52 are connected via a through electrode 92. Fourth configuration example of a photodetection device

[0053] With reference to Fig. Section 8 describes a fourth embodiment of a photodetection device to which the present technology is applied. Incidentally, in the photodetection device 11C, which is described in Fig. Figure 8 shows the components that correspond to those in the photodetection device 11. Fig. 1 and the photodetection device 11A in Fig. 3 things that are in common, are designated with the same reference symbols, and a detailed description of them is omitted.

[0054] As in Fig. As shown in Figure 8, a photodetection device 11C has a configuration that corresponds to that of the photodetection device 11 in Figure 8. Fig. 1 and the photodetection device 11A in Fig. 3 is characterized by a three-layer structure formed by stacking a first semiconductor substrate 12C on which the SPADs 21 are arranged in an array, a second semiconductor substrate 13C on which the PFE circuit 31 for each SPAD 21 is arranged, and a third semiconductor substrate 14C on which the distance measuring circuit 41 for each SPAD 21 is arranged. Furthermore, the photodetection device 11C has the configuration that is similar to that of the photodetection device 11A in Fig. 3 have in common that the edge circuits 61-1 and 61-2 are arranged in the edge region of the second semiconductor substrate 13C, and the edge circuits 61-3 and 61-4 are arranged in the edge region of the third semiconductor substrate 14C.

[0055] Then the photodetection device 11C has a different configuration than the photodetection device 11 in Fig. 1 and the photodetection device 11A in Fig. 3, by the photodetection device 11C having an ESD protection element (electrostatic discharge protection element) 62 which is arranged in the edge region of the first semiconductor substrate 12C. For example, the ESD protection element 62 is arranged in an empty region of the first semiconductor substrate 12C which overlaps the edge circuits 61-1 to 61-4 when the photodetection device 11C is viewed from above.

[0056] The ESD protection element 62 can be configured by a blind pixel provided with a surge current path (current path) through which an ESD surge current is caused to flow to protect the SPAD 21 from ESD. In particular, the surge current path of the ESD protection element 62 is configured such that the amount of current required to protect the SPAD 21 from the ESD surge voltage directed in the opposite direction to the SPAD 21 can flow.

[0057] The photodetection device 11C, configured in this way, can protect the SPAD 21 from ESD by having the ESD protection element 62.

[0058] Furthermore, due to a configuration in which the ESD protection element 62 is located in the edge region of the first semiconductor substrate 12C, the photodetection device 11C can reduce the chip size compared to a configuration in which the ESD protection element 62 is located, for example, on the second semiconductor substrate 13C or on the third semiconductor substrate 14C. In other words, the photodetection device 11C can effectively utilize the other empty region besides the pixel field 22 on the first semiconductor substrate 12C.

[0059] It should be noted that in the present embodiment the photodetection device 11 has been described with a three-layer structure, but it is sufficient if the photodetection device 11 is configured by a laminated structure in which at least the first semiconductor substrate 12, the second semiconductor substrate 13 and the third semiconductor substrate 14 are stacked, and the present technology can be applied to the photodetection device 11 with a laminated structure of three or more layers. <Konfigurationsbeispiel eines Entfernungsmesssystems>

[0060] Fig. Figure 9 is a block diagram that represents a configuration example of a distance measurement system to which the present technology is applied.

[0061] As in Fig.Figure 9 shows a distance measuring system 101 configured to include an illumination device 102 which illuminates a distance measuring object with irradiation laser light, a light receiving device 103 which receives reflected laser light reflected from the distance measuring object, and a control device 104 which controls the illumination device 102 and the light receiving device 103.

[0062] The illumination device 102 comprises a laser driver unit 111, a laser light source 112, and a diverting lens 113. When the laser driver unit 111 drives the laser light source 112 under the control of the control device 104, pulsed irradiation laser light is emitted from the laser light source 112, and the pulsed irradiation laser light is scattered by the diverting lens 113 and then emitted in the direction of the object to be measured.

[0063] The light receiving device 103 comprises a converging lens 121, an optical sensor 122, and a signal processing unit 123 (also referred to as a "signal processing circuit"). The pulsed reflected laser light reflected from the object to be measured is focused by the converging lens 121 onto the light receiving surface of the optical sensor 122, and the optical sensor 122 receives the pulsed reflected laser light pixel by pixel to output a signal that is subjected to signal processing in the signal processing unit 123 and then supplied to the control device 104.

[0064] The control device 104 controls the laser driver unit 111 to control the time at which the pulsed irradiation laser light is emitted and also measures the time until the pulsed reflected laser light is detected by the optical sensor 122, and can thereby measure the distance to the object to be measured.

[0065] Then, by applying the photodetection device 11 of each embodiment described above to the optical sensor 122, the distance measurement system 101 can, for example, further improve its distance measurement performance. <Kombinationsbeispiele einer Konfiguration>

[0066] It should be noted that the present technology can preferably be implemented in the following exemplary configurations. (1) Light detection device comprising: a pixel layer comprising a pixel field, the pixel field comprising a photodiode configured to: detect photons and generate a first signal based on the detection of the photons; a first circuit layer comprising a first circuit configured to: receive the first signal via a first electrical connection, and generate a second signal based on the first signal;and a second circuit layer comprising a second circuit configured to: receive the second signal via a second electrical connection, and generate distance data based on the second signal, wherein the distance data specifies a distance between the light sensing device and one or more objects, wherein the first electrical connection is one or more first individual electrical connections between the photodiode and the first circuit, wherein the second electrical connection is one or more second individual electrical connections between the first circuit and the second circuit, and wherein the pixel layer, the first circuit layer, and the second circuit layer are vertically stacked together. (2) Light detection device according to example (1), wherein the first circuit comprises one or more pixel front-end circuits (PFE circuits). (3) Light detection device according to example (2), wherein the second circuit comprises one or more distance measuring circuits. (4) Light detection device according to any one of examples (1) to (3), wherein the one or more first individual electrical connections are one or more vias. (5) Light detection device according to any one of examples (1) to (4), wherein the one or more first individual electrical connections are one or more metal-to-metal connections. (6) Light detection device according to example (5), wherein the one or more metal-metal connections are one or more copper-copper connections (Cu-Cu connections). (7) Light detection device according to any one of examples (1) to (6), wherein the one or more second individual electrical connections are one or more metal-to-metal connections. (8) Light detection device according to example (7), wherein the one or more metal-metal connections are one or more copper-copper connections (Cu-Cu connections). (9) Light detection device according to any one of examples (1) to (8), wherein the one or more second individual electrical connections are one or more vias. (10) Light detection device according to any one of examples (1) to (9), wherein the first circuit comprises one or more pixel front-end circuits (PFE circuits) and one or more peripheral circuits adjacent to the one or more PFE circuits. (11) Light detection device according to example (10), wherein the one or more peripheral circuits comprise some or all of a power-on reset (PoR) circuit, a voltage regulator circuit, a bias circuit, a temperature circuit, a circuit protection circuit and a decap circuit. (12) Light detection device according to any one of examples (1) to (11), wherein the second circuit comprises one or more distance measuring circuits and one or more peripheral circuits adjacent to the one or more distance measuring circuits. (13) Light detection device according to example (12), wherein the one or more peripheral circuits comprise some or all of a PLL (phase-locked loop) circuit, an interface circuit, a power-on reset (PoR) circuit, a voltage regulator circuit, a bias circuit, a temperature circuit, a circuit protection circuit and a decap circuit. (14) Light detection device according to any of examples (1) to (13) further comprising an electrostatic discharge element (ESD element). (15) Light detection device according to any one of examples (1) to (14), further comprising: a plurality of interconnect pads arranged along a region of a circumference of the first circuit layer. (16) Light detection device according to example (15), further comprising: a second plurality of connection pads arranged along a region of a circumference of the second circuit layer. (17) Light detection device according to example (16), further comprising: a metal-to-metal connection providing a third electrical connection between one of the second plurality of connection pads and one of the plurality of connection pads. (18) Light detection device according to example (17), wherein the metal-metal connection is a copper-copper (Cu-Cu) connection. (19) Light sensing device according to example (18), wherein the first circuit comprises one or more pixel front-end circuits (PFE circuits) and a first peripheral circuit adjacent to the one or more PFE circuits, and the first peripheral circuit is electrically connected to one of the plurality of connection pads, and wherein the second circuit comprises one or more distance sensing circuits and a second peripheral circuit adjacent to the one or more distance sensing circuits, and the second peripheral circuit is electrically connected to one of the second plurality of connection pads. (20) Light sensing device according to example (18), wherein the first circuit comprises one or more pixel front-end circuits (PFE circuits) and a first peripheral circuit adjacent to the one or more PFE circuits, and the first peripheral circuit is electrically connected to two or more of the plurality of connection pads, and wherein the second circuit comprises one or more distance sensing circuits and a second peripheral circuit adjacent to the one or more distance sensing circuits, and the second peripheral circuit is electrically connected to two or more of the second plurality of connection pads. (21) Light detection device according to example (18), wherein a first connection pad of the second plurality of connection pads is configured to provide a high voltage, wherein a second connection pad of the second plurality of connection pads is configured to provide a medium voltage, wherein a third connection pad of the second plurality of connection pads is configured to provide a low voltage, and wherein a fourth connection pad of the second plurality of connection pads is configured to provide a test voltage. (22) Light detection device according to example (17), wherein a first connection pad of the plurality of connection pads is configured to provide a high voltage, wherein a second connection pad of the plurality of connection pads is configured to provide a signal to a peripheral circuit. (23) Light detection device according to any one of examples (1) to (22), wherein the pixel layer has a first cross-sectional area, wherein the first circuit layer has a second cross-sectional area, wherein the second circuit layer has a third cross-sectional area, and wherein the first cross-sectional area, the second cross-sectional area and the third cross-sectional area are similar in shape and size. (24) Light detection device according to any one of examples (1) to (23), wherein the pixel layer comprises a plurality of the photodiode, wherein the first circuit layer comprises a plurality of the first circuit, and wherein the second circuit layer comprises a plurality of the second circuit. (25) Light detection device according to any one of examples (1) to (24), wherein the photodiode is a single-photon avalanche diode (SPAD). (26) Electronic device comprising: a light detection device comprising a pixel layer comprising a pixel field, the pixel field comprising a photodiode configured to: detect photons and generate a first signal based on the detection of the photons; a first circuit layer comprising a first circuit configured to: receive the first signal via a first electrical connection, and generate a second signal based on the first signal;and a second circuit layer comprising a second circuit configured to: receive the second signal via a second electrical connection, and generate distance data based on the second signal, wherein the distance data specifies a distance between the light sensing device and one or more objects, wherein the first electrical connection is one or more first individual electrical connections between the photodiode and the first circuit, wherein the second electrical connection is one or more second individual electrical connections between the first circuit and the second circuit, and wherein the pixel layer, the first circuit layer, and the second circuit layer are vertically stacked together. (27) Photodetection device comprising: a first semiconductor substrate on which photon detection elements are arranged in an array for capturing photons; a second semiconductor substrate on which pre-stage circuits are arranged for each of the photon detection elements, which convert analog signals output by the photon detection elements in response to photon detection into digital signals for output; and a third semiconductor substrate on which distance measurement circuits, measuring a distance based on the digital signals output by the pre-stage circuits, are arranged for each of the photon detection elements, wherein the photodetection device is formed by a laminated structure produced by stacking at least the first semiconductor substrate, the second semiconductor substrate and the third semiconductor substrate. (28) Photodetection device according to (27), wherein The preamplifier circuit is a circuit required to receive high voltage. (29) Photodetection device according to (27) or (28), wherein the photon detection elements and the pre-stage circuits are connected via vias, and the pre-stage circuits and the distance measurement circuits are connected via Cu-Cu connections. (30) Photodetection device according to one of (27) to (29), wherein a first edge circuit is arranged on the second semiconductor substrate in a border region around a region in which the pre-stage circuits are arranged, and a second edge circuit is arranged on the third semiconductor substrate in a border region around a region in which the distance measuring circuits are arranged. (31) Photodetection device according to (30), wherein an area in which the first boundary circuit is located, and an area in which the second boundary circuit is located, are positioned such that they overlap in the top view. (32) Photodetection device according to (30), wherein An area in which the first boundary circuit is located and an area in which the second boundary circuit is located are positioned without overlap in the top view. (33) Photodetection device according to (30), wherein a thick-film circuit is mounted as the first edge circuit, and only a thin-film circuit or both a thin-film circuit and a thick-film circuit are mounted as the second edge circuit. (34) Photodetection device according to one of (27) to (33), wherein several first interconnect pads are arranged along an edge of the second semiconductor substrate, and Several second connection pads are arranged along an edge of the third semiconductor substrate. (35) Photodetection device according to (34), in which Commonly used connection pads are connected to each other via a Cu-Cu connection among the multiple first connection pads and the multiple second connection pads. (36) Photodetection device according to (34) or (35), wherein a connection pad below the multiple first connection pads, which is connected only to the first edge circuit provided on the second semiconductor substrate, and a connection pad below the multiple second connection pads, which is connected only to the second edge circuit provided on the third semiconductor substrate, are arranged in positions that overlap in the top view. (37) Photodetection device according to one of (27) to (36), wherein On the first semiconductor substrate, an ESD protection element (electrostatic discharge protection element) is arranged to protect the photon detection elements from ESD in a different empty area than an area in which the photon detection elements are arranged in an array. (38) Distance measuring system, comprising: a lighting device that emits irradiated light; and a light receiving device that receives reflected light from the incident light, wherein The light receiving device includes: a photodetection device comprising: a first semiconductor substrate on which photon detection elements for capturing photons are arranged in an array, a second semiconductor substrate on which pre-stage circuits are arranged for each of the photon detection elements, which convert analog signals output by the photon detection elements in response to photon detection into digital signals in order to output the digital signals. a third semiconductor substrate on which distance measurement circuits, measuring a distance based on the digital signals output by the pre-stage circuits, are arranged for each of the photon detection elements, wherein the photodetection device is formed by a laminated structure produced by stacking at least the first semiconductor substrate, the second semiconductor substrate and the third semiconductor substrate.

[0067] It should be noted that the present embodiments are not limited to those described above and various modifications can be made without departing from the core of this disclosure. Furthermore, the effects described in this description are merely examples and are not limited; other effects may also exist. [List of reference symbols] 11 Photodetection device 12 First semiconductor substrate 13 Second semiconductor substrate 14 Third semiconductor substrate 21 Single-photon avalanche diode (SPAD) 22 pixel field 31-pixel front-end circuit (PFE circuit) 41 Distance measuring circuit 51 Through-hole plating 52 Copper-copper compound (Cu-Cu compound) 61 peripheral circuit 62 Electrostatic discharge protection element (ESD protection element) 71 Connection pad 72 High-voltage block (HV block) 73 Medium voltage block (MV block) 74 Low-voltage block (LV block) 81 and 82 connection pad 91 and 92 Through electrode 101 Distance measuring system 102 Lighting device 103 Light receiving device 104 Control device 111 Laser driver unit 112 Laser light source 113 Diverging lens 121 Converging lens 122 optical sensor 123 Signal processing circuit QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2023-114929

[0002] JP 2020-524943A

[0005]

Claims

[1] Light detection device comprising: a pixel layer comprising a pixel field, wherein the pixel field comprises a photodiode configured to: Capturing photons, and Generating an initial signal based on the detection of photons; a first circuit layer comprising a first circuit configured to: Receiving the first signal via an initial electrical connection, and Generating a second signal based on the first signal; and a second circuit layer comprising a second circuit configured to: Receiving the second signal via a second electrical connection, and Generating distance data based on the second signal, wherein the distance data specifies a distance between the light detection device and one or more objects, where the first electrical connection is one or more first individual electrical connections between the photodiode and the first circuit, wherein the second electrical connection is one or more second individual electrical connections between the first circuit and the second circuit, and where the pixel layer, the first circuit layer and the second circuit layer are stacked vertically together. [2] Light detection device according to claim 1, where the first circuit comprises one or more pixel front-end circuits (PFE circuits). [3] Light detection device according to claim 2, the second circuit comprises one or more distance measuring circuits. [4] Light detection device according to claim 1, where the one or more first individual electrical connections are one or more vias. [5] Light detection device according to claim 1, where one or more of the first individual electrical connections are one or more metal-to-metal connections. [6] Light detection device according to claim 5, where one or more metal-metal compounds are one or more copper-copper compounds (Cu-Cu compounds). [7] Light detection device according to claim 1, where one or more second individual electrical connections are one or more metal-to-metal connections. [8] Light detection device according to claim 7, where one or more metal-metal compounds are one or more copper-copper compounds (Cu-Cu compounds). [9] Light detection device according to claim 1, where one or more second individual electrical connections are one or more vias. [10] Light detection device according to claim 1, wherein the first circuit comprises one or more pixel front-end circuits (PFE circuits) and one or more peripheral circuits adjacent to the one or more PFE circuits. [11] Light detection device according to claim 10, wherein the one or more peripheral circuits include some or all of a power-on reset (PoR) circuit, a voltage regulator circuit, a bias circuit, a temperature circuit, a circuit protection circuit, and a decap circuit. [12] Light detection device according to claim 1, wherein the second circuit comprises one or more distance measuring circuits and one or more peripheral circuits adjacent to the one or more distance measuring circuits. [13] Light detection device according to claim 12, wherein the one or more peripheral circuits include some or all of a PLL (phase-locked loop) circuit, an interface circuit, a power-on reset (PoR) circuit, a voltage regulator circuit, a bias circuit, a temperature circuit, a circuit protection circuit, and a decap circuit. [14] Light detection device according to claim 1, which further comprises an electrostatic discharge element (ESD element). [15] Light detection device according to claim 1, further comprising: a multitude of interconnect pads arranged along a region of a circumference of the first circuit layer. [16] Light detection device according to claim 15, further comprising: a second set of interconnect pads arranged along a region of a circumference of the second circuit layer. [17] Light detection device according to claim 16, further comprising: a metal-to-metal connection that provides a third electrical connection between one of the second set of connection pads and one of the set of connection pads. [18] Light detection device according to claim 17, where the metal-metal compound is a copper-copper compound (Cu-Cu compound). [19] Light detection device according to claim 18, wherein the first circuit comprises one or more pixel front-end circuits (PFE circuits) and a first peripheral circuit adjacent to the one or more PFE circuits, and the first peripheral circuit is electrically connected to one of the plurality of interconnect pads, and wherein the second circuit comprises one or more distance measuring circuits and a second peripheral circuit adjacent to the one or more distance measuring circuits, and the second peripheral circuit is electrically connected to one of the second plurality of connection pads. [20] Light detection device according to claim 18, wherein the first circuit comprises one or more pixel front-end circuits (PFE circuits) and a first peripheral circuit adjacent to the one or more PFE circuits, and the first peripheral circuit is electrically connected to two or more of the plurality of interconnect pads, and wherein the second circuit comprises one or more distance measuring circuits and a second peripheral circuit adjacent to the one or more distance measuring circuits, and the second peripheral circuit is electrically connected to two or more of the second plurality of connection pads. [21] Light detection device according to claim 18, wherein a first connection pad of the second plurality of connection pads is configured to provide a high voltage, wherein a second connection pad of the second plurality of connection pads is configured to provide a medium voltage, wherein a third connection pad of the second plurality of connection pads is configured to provide a low voltage, and wherein a fourth connection pad of the second plurality of connection pads is configured to provide a test voltage. [22] Light detection device according to claim 17, wherein a first connection pad of the plurality of connection pads is configured to provide a high voltage, wherein a second connection pad of the plurality of connection pads is configured to provide a signal to a peripheral circuit. [23] Light detection device according to claim 1, wherein the pixel layer has a first cross-sectional area, wherein the first circuit layer has a second cross-sectional area, wherein the second circuit layer has a third cross-sectional area, and wherein the first cross-sectional area, the second cross-sectional area and the third cross-sectional area are similar in shape and size. [24] Light detection device according to claim 1, where the pixel layer comprises a multitude of the photodiode, wherein the first circuit layer comprises a plurality of the first circuit, and where the second circuit layer comprises a plurality of the second circuit. [25] Light detection device according to claim 1, where the photodiode is a single-photon avalanche diode (SPAD). [26] Electronic device comprising: a light detection device comprising: a pixel layer comprising a pixel field, wherein the pixel field comprises a photodiode configured to: Capturing photons, and Generating an initial signal based on the detection of photons; a first circuit layer comprising a first circuit configured to: Receiving the first signal via an initial electrical connection, and Generating a second signal based on the first signal; and a second circuit layer comprising a second circuit configured to: Receiving the second signal via a second electrical connection, and Generating distance data based on the second signal, wherein the distance data specifies a distance between the light detection device and one or more objects, where the first electrical connection is one or more first individual electrical connections between the photodiode and the first circuit, wherein the second electrical connection is one or more second individual electrical connections between the first circuit and the second circuit, and where the pixel layer, the first circuit layer and the second circuit layer are stacked vertically together.

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