Solid-state imaging device and electronic apparatus

Abstract

[Problem] Imaging is performed using a cooling element capable of responding to temperature fluctuations. [Solution] A solid-state imaging device includes a light-receiving element, a logic circuit, and a Peltier element. The light-receiving element is arranged in a two-dimensional array in a pixel array. The logic circuit processes a signal output from the light-receiving element. The Peltier element controls temperature based on a signal having a temperature characteristic output from the light-receiving element.

Description

Technical Field

[0001] This disclosure relates to solid-state imaging devices and electronic devices. Background Technology

[0002] Semiconductor devices are driven when receiving power, but heat is generated due to resistance or other factors, and the operation of the semiconductor device itself becomes unstable due to heat. For example, thermal noise may increase in flowing current. To solve this problem, it is conceivable to mount a Peltier element on the back of the semiconductor device to reduce the generation of thermal noise.

[0003] In solid-state imaging devices, there is a technique to improve image quality by mounting Peltier elements on the imaging sensor, but this is not controlled according to the element's temperature. While it's possible to reduce dark current in light-receiving elements such as photodiodes (PDs), avalanche photodiodes (APDs), or single-photon avalanche diodes (SPADs) by simply cooling them to avoid fluctuating errors, this approach struggles to respond to temperature fluctuations. Reference List Patent documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2016-162781 Patent Document 2: Japanese Patent Application Publication No. 2012-085324 Summary of the Invention The problem to be solved by the present invention

[0005] Therefore, a non-limiting problem to be solved by the embodiments of this disclosure is imaging using a cooling element capable of responding to temperature fluctuations. As a further non-limiting example, the problem to be solved by the embodiments of this disclosure may also be a problem corresponding to the effects described in the embodiments. That is, any problem corresponding to at least one effect described in the embodiments of this disclosure can be a problem to be solved by this disclosure. Problem Solution

[0006] According to an embodiment, the solid-state imaging device includes a light-receiving element, logic circuitry, and a Peltier element. The light-receiving element is arranged in a two-dimensional array within a pixel array. The logic circuitry processes signals output from the light-receiving element. The Peltier element controls the temperature based on a temperature-dependent signal output from the light-receiving element.

[0007] The pixel array can be disposed in a first layer, the logic circuit can be disposed in a second layer, and the Peltier element can be disposed in a third layer, wherein the second layer is arranged to contact the first layer, and the third layer is arranged to contact the second layer.

[0008] The Peltier element can acquire the temperature-sensitive signal via the second layer.

[0009] The second and third layers can be connected by interlocking metal wiring, and the Peltier element can acquire the temperature-characteristic signal via the interlocking and interconnected metal wiring.

[0010] The first layer and the third layer can be electrically connected through a through-hole electrode passing through the second layer, and the Peltier element can acquire the temperature-characteristic signal via the through-hole electrode.

[0011] The third layer can be electrically connected to the first or second layer via external bonding.

[0012] The pixel array may include: a first pixel that includes the light-receiving element and receives light; and a second pixel that includes the light-receiving element, receives light, and outputs the temperature-characteristic signal from the light-receiving element, and the Peltier element controls the temperature based on the temperature-characteristic signal output from the second pixel.

[0013] The Peltier element is configured for each segmented region of the pixel array, and at least one second pixel can be configured for each said region.

[0014] The Peltier element and the region can be rectangular.

[0015] For each of the regions, a second pixel may be set near the center of that region.

[0016] The Peltier element and the region can be hexagonal.

[0017] For the region in question, at least one second pixel may be positioned near the center of the region.

[0018] The signal with temperature characteristics can be a signal related to dark current.

[0019] The signal with temperature characteristics can be a signal related to the dark count rate.

[0020] The signal with temperature characteristics can be a signal output via a thermistor.

[0021] According to an embodiment, the electronic device includes a light receiving element, logic circuitry, and a Peltier element. The logic circuitry processes signals output from the light receiving element. The Peltier element controls the temperature based on a temperature-dependent signal output from the light receiving element.

[0022] It may further include a light-emitting module for illuminating a target, and the Peltier element may be positioned for each location receiving light illuminating each light-emitting element in the light-emitting module.

[0023] The light receiving element can be arranged in a two-dimensional array in the pixel array. The pixel array can include: a first pixel, which includes the light receiving element and receives light, and a second pixel, which includes the light receiving element, receives light, and outputs the signal with temperature characteristics from the light receiving element. The second pixel is arranged relative to the Peltier element at a position corresponding to the position of each light-emitting element in the light-emitting module. Attached Figure Description

[0024] Figure 1 This is a schematic diagram illustrating a portion of a solid-state imaging apparatus according to an embodiment. Figure 2 This is a schematic diagram illustrating a portion of a solid-state imaging apparatus according to an embodiment. Figure 3 This is a schematic diagram illustrating a portion of a solid-state imaging apparatus according to an embodiment. Figure 4 This is a schematic diagram illustrating a portion of a solid-state imaging apparatus according to an embodiment. Figure 5 This is a schematic cross-sectional view illustrating a portion of a solid-state imaging apparatus according to an embodiment. Figure 6 This is a schematic cross-sectional view illustrating a portion of a solid-state imaging apparatus according to an embodiment. Figure 7 This is a schematic cross-sectional view illustrating a portion of a solid-state imaging apparatus according to an embodiment. Figure 8 This is a schematic cross-sectional view illustrating a portion of a solid-state imaging apparatus according to an embodiment. Figure 9 This is a schematic cross-sectional view illustrating a portion of a solid-state imaging apparatus according to an embodiment. Figure 10 This is a schematic top view illustrating a portion of a solid-state imaging apparatus according to an embodiment. Figure 11 This is a schematic top view illustrating a portion of a solid-state imaging apparatus according to an embodiment. Figure 12 This is a schematic top view illustrating a portion of a solid-state imaging apparatus according to an embodiment. Figure 13 This is a schematic top view illustrating a portion of a solid-state imaging apparatus according to an embodiment. Figure 14This is a schematic top view illustrating a portion of a solid-state imaging apparatus according to an embodiment. Figure 15 This is a schematic diagram illustrating a portion of a distance measuring device according to an embodiment. Figure 16 This is a schematic diagram illustrating a light-emitting module according to an embodiment. Figure 17 This is a circuit diagram illustrating a schematic example of a temperature characteristic signal output circuit from a second pixel according to an embodiment. Figure 18 This is a circuit diagram illustrating a schematic example of a temperature characteristic signal output circuit from a second pixel according to an embodiment. Figure 19 This is a diagram illustrating a schematic construction example of a solid-state imaging device according to an embodiment. Figure 20 This is a diagram illustrating a schematic construction example of a solid-state imaging device according to an embodiment. Figure 21 This is a diagram illustrating a schematic construction example of a solid-state imaging device according to an embodiment. Figure 22 This is a diagram illustrating a schematic construction example of a solid-state imaging device according to an embodiment. Figure 23 This is a diagram illustrating a schematic construction example of a solid-state imaging device according to an embodiment. Figure 24 This is a diagram illustrating a schematic construction example of a solid-state imaging device according to an embodiment. Detailed Implementation

[0025] Embodiments of this disclosure will now be described with reference to the accompanying drawings. The drawings are for illustrative purposes, and the shapes, dimensions, or proportions of the components in the actual device need not be the same as those shown in the drawings. Furthermore, since the drawings have been simplified, other constructions for implementation besides those shown in the drawings are appropriately included.

[0026] The embodiments in this disclosure are primarily applicable to image sensors, solid-state imaging devices, electronic devices, etc., including light-receiving sensors. The image sensor can be driven by a global shutter or a rolling shutter, or it can be driven in the case of including various event detection pixels. Furthermore, since the forms other than the driving of Peltier elements are similar to the driving of general image sensors, detailed descriptions will be omitted.

[0027] The forms in this disclosure are described in the following order. 1. Example of substrate construction 2. Cross-sectional arrangement of Peltier elements 3. Top surface arrangement of Peltier elements 4. Example of a temperature characteristic signal output circuit 5. Example of image sensor construction

[0028] <1. Example of substrate construction>

[0029] Non-limiting examples of the construction of a substrate for a solid-state imaging device according to this disclosure will be described. For example, a solid-state imaging device can be formed by bonding multiple semiconductor layers using appropriate means. Each of these multiple semiconductor layers includes a light-receiving element, logic circuitry, a Peltier element, or a combination thereof.

[0030] (First Embodiment)

[0031] Figure 1 This is a diagram illustrating a non-limiting example of the construction of multiple semiconductor layers according to an embodiment. The upper figure shows the construction of the semiconductor substrate forming the solid-state imaging device 1, and the lower figure shows the mutually separated layers of the semiconductor substrate. The solid-state imaging device 1 is a device that receives light incident from above the figure and generates information.

[0032] As shown in the figure above, the solid-state imaging device 1 includes at least a first layer 30, a second layer 32, and a third layer 34. Furthermore, the solid-state imaging device 1 may also include various necessary circuits for driving, controlling, etc., of the solid-state imaging device 1. For example, the solid-state imaging device 1 may include light-receiving pixels that receive light in the visible light band and acquire image information, video information, etc.; or alternatively or additionally, it may include light-receiving pixels that receive light in the infrared or ultraviolet band and acquire information with specific characteristics in each band.

[0033] The first layer 30 includes a pixel array 10. The pixel array 10 is a region where light-receiving pixels, including light-receiving elements, are arranged. The pixel array 10 may include light-receiving pixels arranged in a two-dimensional array in a continuous manner in a first direction and a second direction intersecting the first direction. Note that arrangements of light-receiving pixels other than this arrangement are not excluded. The pixel array 10 may include light-receiving pixels with any arrangement capable of acquiring appropriate information.

[0034] The second layer 32 includes logic circuitry 12. Logic circuitry 12 is a circuit that receives signals acquired by light-receiving pixels arranged in the pixel array 10 and performs appropriate signal processing or image processing. Logic circuitry 12 may include not only digital circuitry but also analog circuitry (e.g., an analog-to-digital converter (AD converter)) for generating signals input to the digital circuitry. As another example, in the pixel circuitry of the light-receiving pixels included in the pixel array 10, the analog signal output by the light-receiving pixels can be converted into a digital signal and input to logic circuitry 12.

[0035] The third layer 34 includes a Peltier element 14. The Peltier element 14 is a component used to regulate (especially cool) the temperature of the pixel array 10 and / or the logic circuit 12. For example, the Peltier element 14 may be configured to engage and contact the logic circuit 12, thereby cooling areas of the logic circuit 12 and the pixel array 10. The Peltier element 14 regulates the temperature based on a temperature-dependent signal from the signals output from the light-receiving elements in the light-receiving pixels included in the pixel array 10.

[0036] In the following, in this disclosure, unless otherwise stated, the third direction in the drawings that intersects with the first and second directions and is a downward direction will be referred to as the downward direction. That is to say, it can be said that the second layer 32 is formed as the lower layer of the first layer 30, and the third layer 34 is formed as the lower layer of the second layer 32.

[0037] As shown more clearly in the figure below, the first layer 30 may include a pixel array 10, the second layer 32 may include logic circuitry 12, and the third layer 34 may include Peltier elements 14. Depending on the specific circumstances, necessary constructions not shown in the figure may be formed in appropriate layers or other layers.

[0038] The first layer 30 is arranged to contact the upper surface of the second layer 32, and the third layer 34 is arranged to contact the lower surface of the second layer 32. Depending on the specific situation, the three layers are electrically connected between each other through conductor wiring or semiconductor wiring.

[0039] Furthermore, the solid-state imaging device 1 can be formed by bonding together three semiconductor substrates, each separately forming a first layer 30, a second layer 32, and a third layer 34. The bonding method is as follows: depending on the specific circumstances, the layers are electrically connected by means such as microbumps or vias. The bonding of the layers can be performed by any means such as chip-on-chip (CoC), chip-on-wafer (CoW), or wafer-on-wafer (WoW).

[0040] For example, electrical connections between layers can be achieved through wiring or bonding; in the case of conductors, metallic materials such as Ag, Cu, Al, Au, Ti, or W or their alloys are used, or in the case of semiconductors, polycrystalline silicon is used. These connection areas are also appropriately connected to wiring, circuits, etc. in each layer via similar conductors or semiconductors.

[0041] As shown in this embodiment, the solid-state imaging device 1 may have a three-layer structure, which includes a pixel array 10, a logic circuit 12, and a Peltier element 14, respectively.

[0042] (Second Embodiment)

[0043] Figure 2 This is a diagram illustrating a non-limiting example of the construction of multiple semiconductor layers according to an embodiment. The solid-state imaging device 1 may have a two-layer construction including a first layer 30 and a second layer 32, but not all three layers. As an example, the solid-state imaging device 1 may have a pixel array 10 and logic circuitry 12 formed in the first layer 30, and a Peltier element 14 formed in the second layer 32.

[0044] Note that in Figure 2 In this configuration, the Peltier element 14 is arranged in the lower layers of both the pixel array 10 and the logic circuit 12, but its arrangement is not limited to this. Figure 4 Similarly, the Peltier element 14 can be placed in the lower layer of the pixel array 10 where temperature fluctuations are particularly large, and in contact with the first layer 30.

[0045] (Third Embodiment)

[0046] Figure 3 This is a diagram illustrating a non-limiting example of the construction of multiple semiconductor layers according to an embodiment. As another example of a second embodiment, the solid-state imaging device 1 may have the following configuration: a pixel array 10 is formed in a first layer 30, and logic circuitry 12 and Peltier elements 14 are formed in a second layer 32.

[0047] In this case, similar to the case described above, the Peltier element 14 is preferably disposed in the lower layer so as to at least contact the area of ​​the pixel array 10 disposed in the first layer 30.

[0048] Note that the arrangement in a double-layer structure is not limited to the two embodiments described above. For example, as... Figure 4 As shown, the logic circuit 12 can be arranged to span the first layer 30 and the second layer 32.

[0049] <2. Cross-sectional arrangement of Peltier elements>

[0050] The cross-sectional arrangement of the Peltier element will be described. Here, the cross-sectional arrangement of the Peltier element refers to the arrangement of the Peltier element in a cross-section that includes a light-receiving region (e.g., the photoelectric conversion region included in a light-receiving pixel), a wiring region where various wirings and circuits are arranged, and a region including the Peltier element.

[0051] Each cross-section represents, for example, along... Figure 1 The image shows a portion of a cross-section taken from line AA. Furthermore, the following section will primarily describe the three-layer case, but a similar implementation also applies to the two-layer case. Additionally, the number of light-receiving pixels for a single Peltier element 14, the number of transistors in the Peltier element, the proportions of these numbers, the layer thickness ratio, etc., can be appropriately determined based on the environment and intended use.

[0052] It should be noted that in this disclosure, the description will focus primarily on the input of the signal to the Peltier element 14 and the arrangement of the Peltier element 14. That is to say, for other configurations, any configuration that can be adjusted within a range without causing inconsistencies with other aspects can be used.

[0053] (Fourth Embodiment)

[0054] Figure 5 This is a schematic cross-sectional view illustrating a non-limiting construction of each semiconductor layer of the solid-state imaging device 1 according to an embodiment. The pixel array 10 formed in the first layer 30 includes light-receiving pixels arranged in a two-dimensional array. Each light-receiving pixel is isolated by an insulating film 304 and includes an on-chip lens (hereinafter referred to as OCL 300), a filter 302, and a photoelectric conversion region 306.

[0055] Note that appropriate components not shown in the figure are suitable for the connection of various terminals, wiring, etc. In addition, for example, the figure shows the size, arrangement, number, etc. of the first conductor type region 344 or the second conductor type region 346 relative to the photoelectric conversion region 306 in an easily understandable manner, but the size relationship, positional relationship, etc. are not limited to the size relationship, positional relationship, etc. shown in the figure.

[0056] For example, OCL 300 is a focusing lens disposed on the upper surface of the substrate of the first layer 30 for each light-receiving pixel or, in another example, for multiple light-receiving pixels. OCL 300 is configured to efficiently focus light onto the photoelectric conversion region 306 in each pixel.

[0057] Filter 302 is a filter that limits the frequency band of light received in each light-receiving pixel or limits the polarization state of light, etc. For example, filter 302 may be a color filter that appropriately allows light in each RGB band to pass through. However, filter 302 is not limited to this, and depending on the application, filter 302 may have various transmission and absorption properties.

[0058] The insulating film 304 is a film that separates the individual light-receiving pixels. The insulating film 304 essentially comprises an insulator, but any construction can be used as long as carriers are not allowed to pass between adjacent photoelectric conversion regions 306, and a conductor can be used in a portion of the insulating film 304. For example, the insulating film 304 may be coated with a thin metal film in the region contacting the photoelectric conversion region 306 to reflect incident light to the photoelectric conversion region 306, thereby improving photoelectric conversion efficiency, and may also have a thin metal film formed inside the insulating film 304.

[0059] The photoelectric conversion region 306 is the region that converts the light incident on each light-receiving pixel into an analog signal. The photoelectric conversion region 306 converts the light converged by the OCL 300 and passed through the filter 302 into an analog signal (e.g., current) and outputs the analog signal.

[0060] The signal output from the photoelectric conversion region 306 is properly processed by the pixel circuit formed by wiring 310, etc., and propagated to the second layer 32 via the junction 312 and junction 320.

[0061] The insulating layer 308 is an insulating region used to insulate the photoelectric conversion area 306, the wiring 310 and the junction 312 from each other, but it does not insulate the parts where electrical connections are required.

[0062] Wiring 310 is a wiring for transmitting signals or forming circuitry for performing signal processing. Wiring 310 may be formed, for example, using conductors or semiconductors. The analog signal output from the photoelectric conversion region 306 is transmitted to the junction 312 via wiring 310.

[0063] Note that the analog signal output from the photoelectric conversion region 306 can be converted into a digital signal through wiring 310 and output from the junction 312; or, the analog signal propagated through the junction 312 can be converted into a digital signal in the second layer 32.

[0064] The signal acquired through photoelectric conversion in the photoelectric conversion region 306 is propagated via the junction 320 to the logic circuit 12 in the second layer 32. The logic circuit 12 is formed, for example, by an insulating layer 322 and wiring 324. The logic circuit 12 performs logical operations on the signal acquired from the junction 320 and outputs the result appropriately to other components inside the solid-state imaging device 1 or to the outside of the solid-state imaging device 1.

[0065] When the acquired signal is an analog signal, the logic circuit 12 can convert the analog signal into a digital signal through the ADC included in the logic circuit 12 and perform various logic operations.

[0066] The second layer 32 and the third layer 34 are electrically connected via junction 326 and junction 340. The second layer 32 can also propagate the output of the first layer 30 to the third layer 34 via wiring 324, junction 326 and junction 340, as a path different from that of logic circuit 12.

[0067] The third layer 34 includes an insulating film 342, a first conductor-type region 344, a second conductor-type region 346, an electrode 348, and an insulating film 350. The Peltier element 14 is formed by a path connecting the first conductor-type region 344, the second conductor-type region 346, and the electrode 348.

[0068] For example, the first conductor-type region 344 can be an n-type conductive region, and in this case, the second conductor-type region 346 can be a p-type conductive region. Alternatively, the first conductor-type region 344 can be a p-type conductive region, and in this case, the second conductor-type region 346 can be an n-type conductive region. Note that in the third layer 34, regions other than those constructed such as the first conductor-type region 344 and the second conductor-type region 346 can have the following form: these regions are insulated by an insulating film in a manner similar to that of the first layer 30 and the second layer 32.

[0069] Insulating films 342 and 350 are formed, for example, using ceramic materials. Depending on the direction of the current flowing through the Peltier element 14, the Peltier element 14 absorbs heat from the second layer 32 and dissipates heat downwards as shown in the figure. The temperature regulation of heat absorption and dissipation of the Peltier element 14 is controlled by the magnitude of the current flowing through it.

[0070] By allowing an appropriate current to flow through the Peltier element 14, heat can be absorbed from the second layer 32 and the first layer 30, and the temperature of each element can be controlled. The Peltier element 14 can be controlled to a suitable temperature by allowing a current based on a temperature-dependent signal from the photoreceiving element to flow through wiring 310, junction 312, junction 320, wiring 324, junction 326, and junction 340. In other words, the Peltier element 14 can achieve suitable temperature control in real time by receiving feedback from the first layer 30 and the second layer 32, which takes into account the effect of the Peltier element 14's own temperature control.

[0071] exist Figure 5 In its construction, the Peltier element 14 can achieve appropriate temperature control by acquiring a signal with temperature characteristics from the first layer 30 via the second layer 32.

[0072] Specifically, the second layer 32 and the third layer 34 are connected by bonding conductor wiring or semiconductor wiring to each other using metal electrodes called junction 326 and junction 340, and the Peltier element 14 can allow a temperature-dependent current from the first layer 30 to flow through the wiring connected by the junction.

[0073] For example, the temperature-dependent signal output from the first layer 30 is a signal related to the dark current in the light-receiving pixel. Typically, the dark current from the photoelectric conversion region increases with increasing temperature. Therefore, by allowing a current based on the dark current from the light-receiving pixel to flow through the Peltier element 14, high-precision temperature control of the first layer 30 can be performed.

[0074] The Peltier element 14 receives a signal related to the dark current output from the light-receiving pixel from the first layer 30, which is electrically connected via the second layer 32, for example, by amplifying the current obtained from the dark current. Appropriate temperature control can be achieved in any of the first layer 30, the second layer 32, and the third layer 34 by controlling the dark current to a suitable value and allowing the dark current to flow through the Peltier element 14.

[0075] As described above, according to this embodiment, the current related to the dark current output from the light-receiving pixel formed in the first layer 30 can be passed through the Peltier element 14 formed in the third layer 34 via the second layer 32, thereby enabling appropriate temperature control of the first layer 30.

[0076] The general imaging element for acquiring video signals has been described above, but a similar construction can also be used for imaging elements such as photon counting cameras, for example, imaging elements with an APD or SPAD as a light receiving element. For example, in the case of performing temperature control on the APD or SPAD element, a similar effect can be obtained by acquiring the dark count rate (DCR) and inputting a current based on that signal into the Peltier element 14.

[0077] By receiving feedback from the first layer 30 (particularly from the light-receiving element), the Peltier element 14 can not only easily cool the device but also control its temperature, preventing instability in the temperature of the light-receiving element and pixel circuitry. Therefore, the solid-state imaging device 1 can also make the signal-to-noise ratio (SNR) of the output signal more stable.

[0078] (Fifth Embodiment)

[0079] Figure 6 This is a schematic cross-sectional view illustrating a non-limiting configuration of each semiconductor layer of the solid-state imaging device 1 according to an embodiment. The solid-state imaging device 1 may also include a fourth layer 36, which contacts the lower surface of the third layer 34. The fourth layer 36 is arranged to improve the heat dissipation efficiency of the Peltier element 14.

[0080] For example, the fourth layer 36 can be a layer with a water-cooling mechanism. In the case of a water-cooling mechanism, the fourth layer 36 has a suitable heat-absorbing layer and a path that allows refrigerant to flow. The heat-absorbing layer is arranged to be in direct or indirect contact with the heat dissipation portion of the Peltier element 14 and absorbs the heat dissipated from the Peltier element 14 through the refrigerant to achieve appropriate temperature control.

[0081] Furthermore, the fourth layer 36 is not limited to water cooling, but may include mechanisms that use other refrigerants such as gas or oil for cooling.

[0082] Furthermore, the fourth layer 36 can be a layer with an air cooling mechanism. When including an air cooling mechanism, the fourth layer 36 can be designed to increase the contact area between the gas used as the air cooling medium and the heat dissipation area, and to expand the range of contact with air by using a material with high thermal conductivity such as Al or Cu. For example, in a manner similar to a conventional air-cooled module, multiple plate-like materials can be arranged such that their surfaces do not contact each other and are in direct or indirect contact with the heat dissipation area of ​​the Peltier element 14.

[0083] In addition, a fan may be included to facilitate heat dissipation from the highly thermally conductive material.

[0084] As described above, the solid-state imaging device 1 may include a fourth layer 36 to facilitate heat dissipation, which is in contact with the third layer 34 on which the Peltier element 14 is disposed. With this structure, the solid-state imaging device 1 can further improve temperature control accuracy.

[0085] (Sixth Embodiment)

[0086] Figure 7 This is a schematic cross-sectional view illustrating a non-limiting configuration of each semiconductor layer of the solid-state imaging device 1 according to an embodiment. In the above embodiment, a signal from the first layer 30 is output to the Peltier element 14 via a junction between the second layer 32 and the third layer 34, but the connection between the first layer 30 and the third layer 34 can also be achieved through a via through the second layer 32. The solid-state imaging device 1 may include an electrode 314, a via electrode 328, and a junction 352.

[0087] Electrode 314 forms a region for electrically connecting the first layer 30 and the second layer 32. Joint 352 forms a region for electrically connecting the second layer 32 and the third layer 34.

[0088] The via electrode 328 is an electrode formed to pass through the second layer 32. The via electrode 328 is formed by filling a via hole, which is formed in a manner similar to a conventional via hole, with a conductor such as Cu. A temperature-dependent signal (e.g., dark current output from the first layer 30) propagates to the Peltier element 14 via the via electrode 328. In other words, the Peltier element 14 acquires a temperature-dependent signal from the first layer 30 via the via electrode 328.

[0089] As described above, this can be achieved as long as the signal with temperature characteristics is properly output to the Peltier element 14, regardless of the path in the second layer 32 or the bonding method in the second layer 32.

[0090] exist Figures 5 to 7In the form shown, a Peltier element is set for pixels belonging to a specific region; that is, one Peltier element is set for each region, but this is not a limitation. For example, a Peltier element could also be set for all pixels belonging to pixel array 10.

[0091] (Seventh Embodiment)

[0092] Figure 8 This is an exemplary cross-sectional view showing a non-limiting construction of each semiconductor layer of the solid-state imaging apparatus 1 according to an embodiment. In the above embodiments, each semiconductor layer transmits and receives signals via junctions included within the layer or via via-hole electrodes, but this is not limited thereto.

[0093] For example, the second layer 32 and the third layer 34 can be used for inputting and outputting signals to the Peltier element 14 outside the semiconductor layer. As shown, the second layer 32 and the third layer 34 respectively include connecting electrodes 330 and 354, which are electrodes used to output signals to the outside of the semiconductor layer. Inputting and outputting signals with temperature characteristics can be achieved by electrically connecting the connecting electrodes 330 and 354 using connecting conductor 356.

[0094] The connecting electrode 330 and the connecting conductor 356, as well as the connecting electrode 354 and the connecting conductor 356, can be connected via external bonding to the semiconductor layer. That is, the third layer 34 is electrically connected to the second layer 32 via the connecting conductor 356 in an external bonding manner.

[0095] Figure 9 This is a schematic cross-sectional view illustrating a non-limiting construction of each semiconductor layer of a solid-state imaging apparatus 1 according to another example of this embodiment. As shown, the first layer 30 and the third layer 34 can be electrically connected via an external bonding. In this case, a signal with temperature characteristics can propagate from the first layer 30 to the third layer 34 without passing through the second layer 32.

[0096] As mentioned above, the input and output of signals with temperature characteristics can be achieved using wires located outside the semiconductor layer rather than inside it. For the portions where wires are connected by bonding, appropriate sealing treatments, such as injection molding, can be applied.

[0097] Note that in Figure 8 and Figure 9 In the form shown, a Peltier element is provided for all pixels belonging to the entire pixel array 10, but this is not a limitation. As in the embodiment described above, a Peltier element can be provided for each region. In this case, temperature control of each region can be achieved by properly arranging wiring and wires connected together to transmit dark currents, etc., representing the temperature of each region.

[0098] <3. Top surface arrangement of Peltier elements>

[0099] Next, the description will be based on several accompanying figures, starting from the top surface (i.e. Figure 1 The arrangement of Peltier elements is observed from the top side of the drawing.

[0100] (Eighth Embodiment)

[0101] Figure 10 This is a top view schematically illustrating a portion of the solid-state imaging apparatus 1 according to an embodiment, and is a non-limiting example. Figures 10 to 14 It shows from Figure 1 A view of the solid-state imaging device 1 as seen from the top (i.e., from the upper surface of the first layer 30). The dashed area represents the area where the Peltier element 14 is arranged in a layer different from the first layer 30 (e.g., the third layer 34).

[0102] As described above, in the pixel array 10, light-receiving pixels with light-receiving elements are arranged in a two-dimensional array. These light-receiving pixels may include a first pixel 100 and a second pixel 102.

[0103] The first pixel 100 is a pixel in the pixel array 10 that acquires light (which, depending on the specific circumstances, includes electromagnetic waves outside the visible light band; this also applies hereinafter) corresponding to the information acquired by the solid-state imaging device 1, and generates a signal for forming the information acquired by the solid-state imaging device 1. For example, the first pixel 100 receives light in the visible light band and generates a signal related to the image and video information acquired by the solid-state imaging device 1.

[0104] The second pixel 102 in the pixel array 10 acquires light corresponding to the information acquired by the solid-state imaging device 1 and generates a signal for forming that information; simultaneously, it also acquires and outputs a signal with temperature characteristics from its light-receiving element. The signal output from the second pixel 102 propagates to the Peltier element 14, where appropriate temperature control is performed. In the figure, the shaded pixels represent the second pixel 102.

[0105] For example, a Peltier element 14 is provided for each segmented region of the pixel array 10. The Peltier element 14 can perform temperature control (e.g., cooling) for each segmented region. To perform this temperature control, the Peltier element 14 obtains a signal with temperature characteristics from a second pixel 102 disposed in that region. At least one second pixel 102 is disposed in each region, such that the appropriate signal for each region propagates to the Peltier element 14.

[0106] For example, the segmented region can be a rectangular region, and in this case, the shape of the Peltier element 14 can also be rectangular depending on the region.

[0107] like Figure 10 As shown, a second pixel 102 can be placed near the center of the area where the Peltier element 14 is positioned. The area near the center of the segmented region is highly likely to have the statistically average temperature characteristics of that region. Therefore, by placing the second pixel 102 near the center, the Peltier element 14 can perform appropriate temperature control.

[0108] Note that, as another non-limiting example, Figure 11 As shown, the second pixel 102 does not necessarily need to be located near the center of each region, and can be located at the ends of the regions. For example, in appropriate cases, such as when it is difficult to propagate temperature-sensitive signals from pixels near the center of a region due to limitations in the pixel circuitry, as in this example, the second pixel 102 can be located away from the center. Even in this case, the Peltier element 14 can still achieve appropriate temperature control for each region.

[0109] (Ninth Embodiment)

[0110] In the above embodiments, a second pixel 102 is set for each region, but it is not limited to this. For example, multiple second pixels 102 can be set for each region.

[0111] Figure 12 This is a top view schematically illustrating a portion of the solid-state imaging apparatus 1 according to an embodiment, and is a non-limiting example. Note that the illustration of the first pixel 100 is omitted in the following figures. As shown in this figure, two (or more) second pixels 102 may be provided for each region where the Peltier element 14 is provided.

[0112] By referencing a temperature-sensitive signal from a second pixel 102 located at a position separate from each other in each region, the Peltier element 14 can more accurately obtain the temperature state of the light-receiving element in each region. Therefore, the Peltier element 14 can perform temperature control more precisely.

[0113] The Peltier element 14 can implement temperature control of the light-receiving pixel based on statistical scores (e.g., the average or median of temperature-characteristic signals output from multiple second pixels 102). Furthermore, by providing multiple second pixels 102 for each region, higher-precision temperature control can be performed, for example, even when the dark current, which is a temperature-characteristic signal, is small.

[0114] (Tenth Embodiment)

[0115] In each of the above embodiments, the Peltier element 14 and the region corresponding to the Peltier element 14 are rectangular in shape, but are not limited to this. The Peltier element 14 and the region corresponding to the Peltier element 14 can have various other shapes.

[0116] Figure 13 This is a top view of a non-limiting example of a portion of the solid-state imaging apparatus 1 according to an embodiment. For example, the Peltier element 14 has a hexagonal shape, and the pixel array 10 may be in a form in which temperature control is received from the Peltier element 14 in a region corresponding to the shape.

[0117] exist Figure 13 In this configuration, two second pixels 102 are arranged for each Peltier element 14, meaning two second pixels 102 are arranged in each region. However, as mentioned above, this is not a limitation. For example, one second pixel 102 may be provided for each Peltier element 14, or three or more second pixels 102 may be provided for each Peltier element 14. Furthermore, as long as a signal with temperature characteristics can be properly transmitted, the second pixels 102 do not need to be arranged near the center of the region.

[0118] In this way, the Peltier element 14 can have various shapes and can be arranged, for example, based on the area or shape of the layout, in order to properly cool the light receiving element.

[0119] (Eleventh Embodiment)

[0120] A more specific example will be used to illustrate the corresponding arrangement of the Peltier element 14 and the second pixel 102 described above. Figures 14 to 16 The position of the Peltier element 14 is used to illustrate this embodiment and a non-limiting application example.

[0121] The arrangement of the Peltier element 14 and the second pixel 102 can be as follows: Figure 14 The arrangement shown is used in... Figure 15 The distance measuring device 2 shown is useful in this case.

[0122] The distance measuring device 2 is a schematic diagram illustrating a distance measuring device as at least a part of a distance measuring system using the solid-state imaging device 1 according to an embodiment. The distance measuring device 2 may include the solid-state imaging device 1 and the light-emitting module 20.

[0123] The light-emitting module 20 is a module (or device) with a light-emitting element. In the distance measuring device 2, the light emitted by the light-emitting module 20 toward the target (e.g., light in the infrared band) is reflected by the target, and the reflected light is received by the solid-state imaging device 1, thereby measuring the distance to the target using time-of-flight (ToF).

[0124] When the distance measuring device 2 includes a solid-state imaging device 1 and a light-emitting module 20, the positions of the light-receiving elements in the pixel array 10 and the positions of the light-emitting elements in the light-emitting module 20 can be correlated with each other. For example, the positions of the light-emitting pixels in the light-emitting pixel array of the light-emitting module 20 and the positions of the light-receiving elements in the light-receiving pixel array of the pixel array 10 can have an approximate one-to-many correspondence (this does not exclude one-to-one correspondence, many-to-one correspondence, or many-to-many correspondence).

[0125] In other words, the relative positions of the light-receiving elements in the light-receiving pixel array of the pixel array 10 and the relative positions of the light-emitting elements in the light-emitting pixel array of the light-emitting module 20 can be correlated. By making this correlation, the distance measuring device 2 can properly receive light by activating the light-receiving pixels corresponding to the positions of the light-emitting pixels, and can also reduce power consumption and extend the lifespan of the light-receiving elements.

[0126] Figure 16 This is an exemplary diagram showing the positions of light-emitting elements in a light-emitting pixel array. For example, as shown, light-emitting element 200 is arranged in the light-emitting pixel array of light-emitting module 20. This arrangement is used, for example, when using light-emitting elements such as VCSELs.

[0127] In the case of light-emitting elements with this arrangement, by means of... Figure 14 The Peltier elements 14 are arranged as shown, and each region of the light-receiving pixel that receives light from the light-emitting element can be provided with Peltier elements 14. This arrangement of Peltier elements 14 allows for localized temperature control of the light-receiving pixel's temperature variation caused by the emission of light from a single light-emitting element.

[0128] Furthermore, the second pixel 102 can be arranged in Figure 14 The position of the light-receiving element is shown. This arrangement is based on the following method: when a light-emitting element in the light-emitting module 20 emits light, the second pixel 102 is positioned at the corresponding position of the light-receiving element in the pixel array 10. By activating the first pixel 100 and the second pixel 102 in the area to which the second pixel 102 belongs at the moment the light-emitting element emits light, the distance measuring device 2 obtains an appropriate Time of Flight (ToF).

[0129] Then, by performing temperature control based on the temperature-characteristic signal in the second pixel 102 via the Peltier element 14, more precise local temperature control can be achieved. In particular, with proper construction of the pixel array 10 and the light-emitting module 20, the second pixel 102 ideally receives light from the light-emitting element 200, thus, a temperature-characteristic signal is desired to be acquired in the light-receiving pixel located at the corresponding position in the pixel array 10.

[0130] Note that the arrangement of the second pixel 102 in the pixel array 10 can be appropriately modified according to the configuration of the distance measuring device 2. Depending on the configuration of the distance measuring device 2, the light-emitting pixel and the light-receiving pixel may have a horizontally symmetrical relationship, a vertically symmetrical relationship, or a horizontally and vertically symmetrical relationship. In this case, a similar effect can be achieved by appropriately arranging the position of the second pixel 102 in the pixel array 10 according to the correspondence with the corresponding configuration, for example, arranging the second pixel 102 in a horizontally symmetrical position, a vertically symmetrical position, or a vertically and horizontally symmetrical position.

[0131] In this way, when the apparatus according to the above embodiments is used as the light receiving side of the distance measuring device, by arranging the second pixel 102 in an appropriate position, a signal with temperature characteristics from the light receiving pixel that may be heated can be output to the Peltier element 14, and higher precision temperature control can be achieved.

[0132] As described above, local temperature control can be performed by providing a Peltier element 14 for each region to which multiple pixels belong in the pixel array 10. Therefore, compared to temperature control of the entire pixel array 10, it is possible to effectively cool the light-receiving pixels with higher temperatures and reduce power consumption.

[0133] <4. Example of a temperature characteristic signal output circuit>

[0134] A non-limiting example of a circuit for outputting a signal with temperature characteristics will be described with reference to the second pixel 102, which operates as a temperature monitor.

[0135] (Twelfth Embodiment)

[0136] Figure 17 This is a diagram illustrating a non-limiting example of a circuit that outputs a temperature-characteristic signal from the second pixel 102 according to an embodiment. Hereinafter, it is assumed that Idark is the dark current, i.e., the current flowing through the light-emitting element P in a state where no light (photons) is received, and Iout is the current flowing through the Peltier element 14.

[0137] The first pixel 100 and the second pixel 102 can have the same structure except for the output circuit. That is, the pixel circuit and light-emitting element P in the illustrated second pixel 102 can have the same structure as the pixel circuit and light-emitting element P in the first pixel 100.

[0138] For example, the light-emitting element P is connected between the cathode-side power line Vcathod and the anode-side power line Vanode, and the pixel circuit that processes the signal output from the light-emitting element P can have a path to transmit the signal to the floating diffusion region via a transmission transistor. Furthermore, in the case of a global shutter type, each pixel circuit may include a memory. The anode side of the light-emitting element P is appropriately connected to the pixel circuit including these elements.

[0139] On the other hand, the circuit that outputs a signal with temperature characteristics appropriately outputs the dark current Idark output from the anode or the anode potential that varies according to the dark current Idark to the terminals of the Peltier element 14. For example, in the above embodiment, the output to the current terminals of the Peltier element 14 is achieved via the junction 326, the through-hole electrode 328, the connecting electrode 330, the connecting electrode 316, etc.

[0140] A circuit that outputs a signal with temperature characteristics can, for example, include a current mirror as shown in the figure. Figure 17 In this process, a current-sink current mirror, composed of n-type MOSFETs, outputs a signal with temperature characteristics to the Peltier element 14.

[0141] For example, the Peltier element 14 is positioned between the positive-side power supply line Vdd and the negative-side power supply line Vss. Gain can be applied to the current mirror based on the operating characteristics of the Peltier element 14. In this case, for example, the output current Iout = the gain of the current mirror g × the dark current Idark.

[0142] The figure illustrates a current sink, but by further using a current mirror including a p-type MOSFET, a signal with temperature characteristics can also be output from a current-source current mirror to the Peltier element 14. Furthermore, n-type and p-type current mirrors can be optionally interchanged, and in both current sink and current source configurations, the output circuit can be constructed using any conductivity type.

[0143] By appropriately setting the gain of the current mirror, the dark current from the second pixel 102 is converted into a current for temperature control of the Peltier element 14 and input to the Peltier element 14, thereby enabling proper temperature control.

[0144] In this way, as a non-limiting example, the solid-state imaging device 1 can realize the output of a signal for performing temperature control in the Peltier element 14 by the output current of the second pixel 102, which operates as a temperature monitor.

[0145] (Thirteenth Embodiment)

[0146] Figure 18This is a diagram illustrating a non-limiting example of a circuit according to an embodiment for outputting a signal having temperature characteristics from a second pixel 102. (See diagram for example.) Figure 18 As shown, the output current Iout can be generated using a source follower circuit (emitter follower circuit).

[0147] and Figure 17 Compared to the current mirror shown, the impedance effect of the circuit that outputs a signal with temperature characteristics can be reduced, thereby decreasing the impact on the signal output to the pixel circuit (i.e., the image). In this circuit, the output current Iout = V+ / R1. By appropriately setting the value of resistor R1, the output current Iout can be set to a current value suitable for temperature control of the Peltier element 14.

[0148] Furthermore, as another example, an amplifier can also be included on the side of the second pixel 102. For instance, an amplifier can be included in the circuit stage before the comparator stage of the output circuit, and the potential of the anode of the light-emitting element P is amplified by the amplifier and input to the comparator. Thus, the magnitude of the output current Iout can be appropriately controlled.

[0149] Note that in the above embodiments, the light-emitting element P is, for example, a photodiode, but it could also be a SPAD, etc., which measures in units of photons as described above. In this case, a similar circuit configuration can be obtained by including a general-purpose output circuit for appropriately converting the dark count rate, etc., into a current value.

[0150] In the case of temperature control of the Peltier element 14 based on the outputs of multiple second pixels 102, the current value can also be determined by connecting the signals obtained from the multiple second pixels 102 using the output circuit in parallel or series. However, this is not limited to this, and the outputs of these output circuits can also be used as outputs to the Peltier element 14 by circuitry for appropriate statistical processing.

[0151] In addition, in addition to Figure 17 and Figure 18 In the case of the configuration, the solid-state imaging device 1 only needs to include circuitry for appropriately outputting a signal with temperature characteristics based on dark current, etc.

[0152] Furthermore, in each of the above embodiments, examples of outputting dark current, etc., from the second pixel 102, which serves as a temperature monitor, have been described, but this is not a limitation. For example, a thermistor may be included in the first layer 30 or the second layer 32, and the output signal from the thermistor may also be used as a circuit for outputting a signal with temperature characteristics. Of course, the thermistor may also be included in the second pixel 102.

[0153] For example, the thermistor is an NTC thermistor, but this is not a limitation, and PTC or CTR thermistors can also be used. When using a PTC thermistor, the solid-state imaging device 1 can be implemented by outputting to the Peltier circuit 14 through a circuit that inverts the magnitude relationship of the signal output as a signal with temperature characteristics; or, it can also be implemented by... Figure 17 and Figure 18 In contrast, the input and output terminals of the Peltier element 14 are interchanged.

[0154] In addition, the solid-state imaging device 1 can also acquire signals with temperature characteristics in various forms, such as using thermocouples and band gap reference (BGR) circuits.

[0155] <5. Example of Image Sensor Construction>

[0156] Examples of image sensor construction will be described with reference to each of the above embodiments. Note that these are merely non-limiting examples, and at least some of them may be combined or substituted without departing from the spirit of this disclosure.

[0157] (Fourteenth Embodiment)

[0158] Figure 19 This is a block diagram illustrating a non-limiting example of the construction of a solid-state imaging apparatus 1 according to an embodiment. The first layer 30 may include a first pixel 100 and a second pixel 102. The second layer 32 may include a readout circuit 120 and an output circuit 122. The third layer 34 may include a Peltier element 14.

[0159] The readout circuit 120 is a circuit that reads out signals based on the received light intensity output from the first pixel 100 and the second pixel 102 and performs subsequent processing.

[0160] The output circuit 122 is a circuit that converts the temperature-sensitive signal output from the second pixel 102 into an appropriate current and outputs the current to the Peltier element 14.

[0161] The first pixel 100 and the second pixel 102 included in the first layer 30 output signals acquired through photoelectric conversion to the readout circuit 120 included in the second layer 32. The readout circuit 120 generates information desired by the solid-state imaging device 1, such as video information and image information, based on the output signals.

[0162] For example, the second pixel 102 in the first layer 30 can output the dark current acquired at a time when no light is received to the output circuit 122 included in the second layer 32. Note that, without using the dark current, the second pixel 102 can output a signal with temperature characteristics acquired at an appropriate time to the output circuit 122. This also applies below to other cases besides dark current.

[0163] The output circuit 122 generates a current suitable for temperature control of the Peltier element 14 based on the input signal and outputs this current to the Peltier element 14 included in the third layer 34. Thus, the Peltier element 14 can achieve temperature control based on the input current.

[0164] (Fifteenth Embodiment)

[0165] Figure 20 This is a block diagram illustrating a non-limiting example of a solid-state imaging apparatus 1 according to an embodiment. The first layer 30 may include a first pixel 100, a second pixel 102, and an output circuit 122. The second layer 32 may include a readout circuit 120. The third layer 34 may include a Peltier element 14.

[0166] The first pixel 100 and the second pixel 102 included in the first layer 30 output signals acquired through photoelectric conversion to the readout circuit 120 included in the second layer 32. The readout circuit 120 generates information desired by the solid-state imaging device 1, such as video information and image information, based on the output signals.

[0167] For example, the second pixel 102 included in the first layer 30 will output the dark current acquired when no light is received to the output circuit 122 included in the first layer 30.

[0168] The output circuit 122 generates a current suitable for temperature control of the Peltier element 14 based on the input signal, and outputs the current to the Peltier element 14 through, for example, a via electrode 328 formed through the second layer 32. Thus, the Peltier element 14 can achieve temperature control based on the input current.

[0169] (Sixteenth Embodiment)

[0170] Figure 21 This is a block diagram illustrating a non-limiting example of a solid-state imaging apparatus 1 according to an embodiment. The first layer 30 may include a first pixel 100. The second layer 32 may include a readout circuit 120, a monitoring circuit 124, and an output circuit 122. The third layer 34 may include a Peltier element 14.

[0171] The first pixel 100 included in the first layer 30 outputs the signal acquired through photoelectric conversion to the readout circuit 120 included in the second layer 32. The readout circuit 120 generates the information to be acquired in the solid-state imaging device 1, such as video information and image information, based on the output signal.

[0172] The monitoring circuit 124 included in the second layer 32 generates a signal with temperature characteristics. The monitoring circuit 124 may be, for example, a circuit including a BGR circuit or a thermistor. Furthermore, the monitoring circuit 124 may be located near the boundary between the first layer 30 and the second layer 32.

[0173] The monitoring circuit 124 outputs the generated signal with temperature characteristics to the output circuit 122 included in the second layer 32.

[0174] The output circuit 122 generates a current suitable for temperature control of the Peltier element 14 based on the input signal, and outputs this current to the Peltier element 14 included in the third layer 34. Thus, the Peltier element 14 can achieve temperature control based on the input current.

[0175] (Seventeenth Embodiment)

[0176] Figure 22 This is a block diagram illustrating a non-limiting example of a solid-state imaging apparatus 1 according to an embodiment. The first layer 30 may include a first pixel 100, a second pixel 102, a readout circuit 120, and an output circuit 122. The second layer 32 may include a Peltier element 14.

[0177] The first pixel 100 and the second pixel 102 included in the first layer 30 output signals acquired through photoelectric conversion to the readout circuit 120 included in the first layer 30. The readout circuit 120 generates information desired by the solid-state imaging device 1, such as video information and image information, based on the output signals.

[0178] For example, the second pixel 102 included in the first layer 30 will output the dark current acquired when no light is received to the output circuit 122 included in the first layer 30.

[0179] The output circuit 122 generates a current suitable for temperature control of the Peltier element 14 based on the input signal, and outputs this current to the Peltier element 14 included in the second layer 32. Thus, the Peltier element 14 can achieve temperature control based on the input current.

[0180] (Eighteenth Embodiment)

[0181] Figure 23This is a block diagram illustrating a non-limiting example of a solid-state imaging apparatus 1 according to an embodiment. The first layer 30 may include a first pixel 100 and a second pixel 102. The second layer 32 may include a readout circuit 120, an output circuit 122, and a Peltier element 14.

[0182] The first pixel 100 and the second pixel 102 included in the first layer 30 output signals acquired through photoelectric conversion to the readout circuit 120 included in the second layer 32. The readout circuit 120 generates information desired by the solid-state imaging device 1, such as video information and image information, based on the output signals.

[0183] For example, the second pixel 102 included in the first layer 30 will output the dark current acquired when no light is received to the output circuit 122 included in the second layer 32.

[0184] The output circuit 122 generates a current suitable for temperature control of the Peltier element 14 based on the input signal, and outputs this current to the Peltier element 14 included in the second layer 32. Thus, the Peltier element 14 can achieve temperature control based on the input current.

[0185] (Nineteenth Embodiment)

[0186] Figure 24 This is a block diagram illustrating a non-limiting example of a solid-state imaging apparatus 1 according to an embodiment. The first layer 30 may include a first pixel 100. The second layer 32 may include a readout circuit 120, a monitoring circuit 124, an output circuit 122, and a Peltier element 14.

[0187] The first pixel 100 in the first layer 30 outputs the signal acquired through photoelectric conversion to the readout circuit 120 in the second layer 32. The readout circuit 120 generates the information desired by the solid-state imaging device 1, such as video information and image information, based on the output signal.

[0188] The monitoring circuit 124 included in the second layer 32 generates a signal with temperature characteristics. The monitoring circuit 124 may be, for example, a circuit including a BGR circuit or a thermistor. Furthermore, the monitoring circuit 124 may be located near the boundary between the first layer 30 and the second layer 32.

[0189] The monitoring circuit 124 outputs the generated signal with temperature characteristics to the output circuit 122 included in the second layer 32.

[0190] The output circuit 122 generates a current suitable for temperature control of the Peltier element 14 based on the input signal, and outputs this current to the Peltier element 14 included in the second layer 32. Thus, the Peltier element 14 can achieve temperature control based on the input current.

[0191] Alternatively, the monitoring circuit 124 can be included in the first layer 30.

[0192] As described above, according to various embodiments of this disclosure, the Peltier element 14 can perform temperature control applicable to the light-receiving pixel and the region adjacent to the light-receiving pixel. This circuit configuration is applicable to various circuit configurations because it does not require significant layout changes to the circuitry in a general image sensor.

[0193] The above embodiments may also take the following forms.

[0194] (1) A solid-state imaging device, comprising: The light receiving element is arranged in a two-dimensional array within the pixel array; Logic circuitry that processes signals output from the optical receiving element; and A Peltier element that controls temperature based on a temperature-sensitive signal output from the light-receiving element.

[0195] (2) The solid-state imaging device according to (1), The pixel array is located in the first layer. The logic circuit is disposed in the second layer, which is arranged to contact the first layer, and The Peltier element is disposed in the third layer, which is arranged to contact the second layer.

[0196] (3) The solid-state imaging device according to (2), The Peltier element acquires the temperature-sensitive signal via the second layer.

[0197] (4) The solid-state imaging device according to (3), The second and third layers are connected by interlocking metal wiring. The Peltier element acquires the temperature-sensitive signal via interconnected and joined metal wiring.

[0198] (5) The solid-state imaging device according to (3), The first layer and the third layer are electrically connected through a through-hole electrode passing through the second layer, and The Peltier element acquires the temperature-sensitive signal via the through-hole electrode.

[0199] (6) The solid-state imaging device according to (2), The third layer is electrically connected to the first layer or the second layer via an external bonding.

[0200] (7) The solid-state imaging apparatus according to any one of (1) to (6), The pixel array includes: The first pixel includes the light-receiving element and receives light; and The second pixel includes the light-receiving element, receives light, and outputs the signal with temperature characteristics from the light-receiving element. The Peltier element controls the temperature based on the temperature-sensitive signal output from the second pixel.

[0201] (8) The solid-state imaging device according to (7), The Peltier element is configured for each segmented region of the pixel array, and At least one second pixel is provided for each of the regions.

[0202] (9) The solid-state imaging device according to (8), The Peltier element and the region are rectangular.

[0203] (10) The solid-state imaging device according to (9), Specifically, for each region, a second pixel is set near the center of that region.

[0204] (11) The solid-state imaging device according to (8), The Peltier element and the region are hexagonal.

[0205] (12) The solid-state imaging device according to (11), In each of the regions, at least one second pixel is disposed near the center of the region.

[0206] (13) The solid-state imaging apparatus according to any one of (1) to (12), The signal with temperature characteristics is a signal related to dark current.

[0207] (14) The solid-state imaging apparatus according to any one of (1) to (12), The signal with temperature characteristics is a signal related to the dark count rate.

[0208] (15) The solid-state imaging apparatus according to any one of (1) to (12), The signal with temperature characteristics is a signal output via a thermistor.

[0209] (16) An electronic device comprising: Optical receiving element; Logic circuitry that processes signals output from the optical receiving element; and A Peltier element that controls temperature based on a temperature-sensitive signal output from the light-receiving element.

[0210] (17) The electronic device according to (16), The pixel array is located in the first layer. The logic circuit is disposed in the second layer, which is arranged to contact the first layer, and The Peltier element is disposed in the third layer, which is arranged to contact the second layer.

[0211] (18) The electronic device according to (17), The Peltier element acquires the temperature-sensitive signal via the second layer.

[0212] (19) The electronic device according to (18), The second and third layers are connected by interlocking metal wiring. The Peltier element acquires the temperature-sensitive signal via interconnected and joined metal wiring.

[0213] (20) The electronic device according to (18), The first layer and the third layer are electrically connected through a through-hole electrode passing through the second layer, and The Peltier element acquires the temperature-sensitive signal via the through-hole electrode.

[0214] (21) The electronic device according to (17), The third layer is electrically connected to the first layer or the second layer via an external bonding.

[0215] (22) The electronic device according to any one of (16) to (21), The pixel array includes: The first pixel includes the light-receiving element and receives light; and The second pixel includes the light-receiving element, receives light, and outputs the signal with temperature characteristics from the light-receiving element. The Peltier element controls the temperature based on the temperature-sensitive signal output from the second pixel.

[0216] (23) The electronic device according to (22), The Peltier element is configured for each segmented region of the pixel array, and At least one second pixel is provided for each of the regions.

[0217] (24) The electronic device according to (23), The Peltier element and the region are rectangular.

[0218] (25) The electronic device according to (24), Specifically, for each region, a second pixel is set near the center of that region.

[0219] (26) The electronic device according to (25), In each of the regions, at least one second pixel is disposed near the center of the region.

[0220] (27) The electronic device according to any one of (16) to (24), The signal with temperature characteristics is a signal related to dark current.

[0221] (28) The electronic device according to any one of (16) to (24), The signal with temperature characteristics is a signal related to the dark count rate.

[0222] (29) The electronic device according to any one of (16) to (24), The signal with temperature characteristics is a signal output via a thermistor.

[0223] (30) The electronic device according to any one of (16) to (27) further comprises: The light-emitting module is used to illuminate the target. The Peltier element is positioned at each location that receives light from each light-emitting element in the light-emitting module.

[0224] (31) The electronic device described in (30) of reference (22), The light receiving elements are arranged in a two-dimensional array within the pixel array, and The second pixel is positioned relative to the Peltier element at a position corresponding to the position of each light-emitting element in the light-emitting module.

[0225] This disclosure is not limited to the embodiments described above, and includes various conceivable modifications, and the effects of this disclosure are not limited to those described above. The constituent elements in the various embodiments can be appropriately combined and applied. That is, various additions, changes, and partial deletions can be made without departing from the concept and spirit of this disclosure derived from the claims and their equivalents. List of reference numerals

[0226] 1 Solid-state imaging device 10-pixel array 100 First pixel 102 Second pixel P Light-emitting element Resistors R0 and R1 12 Logic Circuits 120 Readout Circuit 122 Output Circuit 124 Monitoring Circuit 14 Peltier elements 30 First Floor 300 OCL 302 filter 304 insulating film 306 Photoelectric Conversion Region 308 insulation layer 310 wiring 312 Joint 314 electrode 316 Connecting Electrodes 32 Second layer 320 Joint 322 Insulation Layer 324 wiring 326 Joint 328 Through-hole Electrode 330 Connecting Electrode 34 Third layer 340 Joint 342 Insulating Film 344 First Conductor Type Region 346 Second Conductor Type Region 348 electrode 350 insulating film 352 Joint 354 Connecting Electrodes 356 Connecting conductor 36 Fourth Floor 2 Distance measuring device 20 Light-emitting modules 200 light-emitting elements

Claims

1. A solid-state imaging device, comprising: The light receiving element is arranged in a two-dimensional array within the pixel array; A logic circuit that processes the signal output from the optical receiving element; as well as A Peltier element that controls temperature based on a temperature-sensitive signal output from the light-receiving element.

2. The solid-state imaging device according to claim 1, in, The pixel array is disposed in the first layer. The logic circuit is disposed in the second layer, which is arranged to contact the first layer, and The Peltier element is disposed in the third layer, which is arranged to contact the second layer.

3. The solid-state imaging device according to claim 2, in, The Peltier element acquires the temperature-sensitive signal via the second layer.

4. The solid-state imaging device according to claim 3, in, The second and third layers are connected by interlocking metal wiring, and The Peltier element acquires the temperature-sensitive signal via interconnected and joined metal wiring.

5. The solid-state imaging device according to claim 3, in, The first layer and the third layer are electrically connected through a through-hole electrode passing through the second layer, and The Peltier element acquires the temperature-sensitive signal via the through-hole electrode.

6. The solid-state imaging device according to claim 2, in, The third layer is electrically connected to the first or second layer via an external bonding.

7. The solid-state imaging device according to claim 1, in, The pixel array includes: The first pixel includes the light-receiving element and receives light; and The second pixel includes the light-receiving element, receives light, and outputs the signal with temperature characteristics from the light-receiving element. The Peltier element controls the temperature based on the temperature-sensitive signal output from the second pixel.

8. The solid-state imaging device according to claim 7, in, The Peltier element is positioned for each segmented region of the pixel array, and At least one second pixel is provided for each of the regions.

9. The solid-state imaging device according to claim 8, in, The Peltier element and the region are rectangular.

10. The solid-state imaging device according to claim 9, in, For each of the regions, a second pixel is set near the center of that region.

11. The solid-state imaging device according to claim 8, in, The Peltier element and the region are hexagonal.

12. The solid-state imaging device according to claim 11, in, For each of the regions, at least one second pixel is disposed near the center of the region.

13. The solid-state imaging device according to claim 1, in, The signal with temperature characteristics is a signal related to dark current.

14. The solid-state imaging device according to claim 1, in, The signal with temperature characteristics is a signal related to the dark count rate.

15. The solid-state imaging device according to claim 1, in, The signal with temperature characteristics is a signal output via a thermistor.

16. An electronic device comprising: Optical receiving element; A logic circuit that processes the signal output from the optical receiving element; as well as A Peltier element that controls temperature based on a temperature-sensitive signal output from the light-receiving element.

17. The electronic device of claim 16, further comprising a light-emitting module for illuminating a target with light. in, The Peltier element is positioned for each location receiving light from each light-emitting element in the light-emitting module.

18. The electronic device according to claim 17, in, The light receiving elements are arranged in a two-dimensional array within the pixel array. The pixel array includes: The first pixel includes the light-receiving element and receives light, and The second pixel includes the light-receiving element, receives light, and outputs the signal with temperature characteristics from the light-receiving element. The second pixel is positioned relative to the Peltier element at a position corresponding to the position of each light-emitting element in the light-emitting module.

Images