Light receiving device

Abstract

A light-receiving device includes a first chip having a pixel region in which a sensor pixel is provided, a second chip including a processing circuit that signal-processes a sensor signal output from the sensor pixel, the second chip being stacked on the first chip, and a first alignment mark provided in the pixel region of the first chip and corresponding to a second alignment mark provided in the second chip.

Description

Technical Field

[0001] This invention relates to an optical receiving device. Background Technology

[0002] In recent years, as a technique for further miniaturizing the structure of light receiving devices such as camera devices, a technique has been proposed in which pixel arrays and signal processing circuits or storage circuits are formed on separate chips and bonded together in a chip state (see Patent Document 1).

[0003] During bonding, chip alignment is achieved, for example, by detecting alignment marks set on each chip. Therefore, by controlling the position of each chip so that the alignment marks on each chip have a predetermined positional relationship, the positional relationship between the chips can be controlled with high precision.

[0004] [List of cited references]

[0005] Patent documents

[0006] Patent Document 1: International Publication No. WO2019 / 087764 Summary of the Invention

[0007] As described above, in such a stacked optical receiver, it is desirable to further miniaturize the size of the optical receiver. Therefore, it is desirable to arrange alignment marks, which do not contribute to the function of the optical receiver and are used for alignment, in an efficient layout to avoid increasing the size of the optical receiver.

[0008] Therefore, it is desirable to provide a light receiving device in which alignment marks can be set in a more efficient layout.

[0009] A light receiving device according to an embodiment of the present invention includes: a first chip having a pixel region and a sensor pixel disposed in the pixel region; a second chip including a processing circuit for processing a sensor signal output from the sensor pixel, and the second chip being stacked on the first chip; and a first alignment mark disposed in the pixel region of the first chip and corresponding to a second alignment mark disposed in the second chip.

[0010] In the light receiving device described above according to an embodiment of the present invention, a first chip has a pixel region provided with sensor pixels, and a second chip includes a processing circuit for processing sensor signals output from the sensor pixels. The first chip and the second chip are aligned and stacked using a first alignment mark provided in the pixel region of the first chip and a second alignment mark provided in the second chip. This allows for a more efficient layout of alignment marks, for example, when stacking chips together, in the light receiving device. Attached Figure Description

[0011] Figure 1 This is a longitudinal cross-sectional view of the overall structure of the optical receiving device to which the present invention is applicable.

[0012] Figure 2 This is a longitudinal sectional view used to illustrate the outline of the first alignment mark and the second alignment mark according to the first embodiment of the present invention.

[0013] Figure 3A This is a schematic perspective view of a specific example of a first chip and a second chip to be joined together.

[0014] Figure 3B This is a schematic perspective view of a specific example of a first chip and a second chip to be joined together.

[0015] Figure 4 This is a plan view of an example layout of the first alignment mark in the first chip and the second alignment mark in the second chip.

[0016] Figure 5A This is a schematic diagram illustrating a construction example of the first alignment mark and the second alignment mark according to the first embodiment of the present invention.

[0017] Figure 5B This is a schematic diagram illustrating an example of the construction of a first alignment mark and a second alignment mark according to a first embodiment of the present invention.

[0018] Figure 6A This is a schematic diagram illustrating a variation in the planar shape of the first alignment mark and the second alignment mark according to a first embodiment of the present invention.

[0019] Figure 6B This is a schematic diagram illustrating a variation in the planar shape of the first alignment mark and the second alignment mark according to a first embodiment of the present invention.

[0020] Figure 6C This is a schematic diagram illustrating a variation in the planar shape of the first alignment mark and the second alignment mark according to a first embodiment of the present invention.

[0021] Figure 7This is a longitudinal sectional view used to illustrate the outline of the first alignment mark and the second alignment mark according to the second embodiment of the present invention.

[0022] Figure 8 This is a longitudinal sectional view used to illustrate the outline of the first alignment mark and the second alignment mark according to the second embodiment of the present invention.

[0023] Figure 9 This is a schematic diagram showing an example of the construction of a first alignment mark and a second alignment mark overlapping on a wiring layer according to a second embodiment of the present invention.

[0024] Figure 10 This is a schematic diagram of a wiring layer construction example according to a modified embodiment of the second embodiment of the present invention.

[0025] Figure 11 This is a schematic diagram of a construction example of a first alignment mark and a second alignment mark according to a variation of the second embodiment of the present invention.

[0026] Figure 12 This is a block diagram illustrating a schematic example of the construction of a camera system including a light receiving device according to an embodiment of the present invention.

[0027] Figure 13 It is a flowchart illustrating the camera operation process in a camera system.

[0028] Figure 14 This is a block diagram illustrating a schematic example of the construction of a vehicle control system.

[0029] Figure 15 This is an example diagram used to illustrate the placement of the vehicle exterior information detection unit and the camera unit.

[0030] Figure 16 This is a diagram illustrating an example of the schematic construction of an endoscopic surgical system.

[0031] Figure 17 This is a block diagram illustrating an example of the functional structure of a camera head and a camera control unit (CCU). Detailed Implementation

[0032] Hereinafter, some embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below provide specific examples of the present invention, and the technology of the present invention is not limited to these aspects. Furthermore, the positions, dimensions, aspect ratios, etc., of the various constituent elements of the present invention are not limited to those shown in the various drawings.

[0033] It should be noted that the explanations are given in the following order.

[0034] 1. First Embodiment

[0035] 1.1. Example of the structure of an optical receiving device

[0036] 1.2. Example of constructing alignment marks

[0037] 1.3. Variations in the shape of the alignment mark

[0038] 2. Second Embodiment

[0039] 2.1. Example of constructing alignment marks

[0040] 2.2. Variation Example

[0041] 3. Application Examples

[0042] <1. First Embodiment>

[0043] (1.1. Example of optical receiving device construction)

[0044] First, refer to Figure 1 The overall structure of the optical receiving device 1 to which the present invention is applicable is described. Figure 1 This is a longitudinal cross-sectional view of the overall structure of the optical receiving device 1.

[0045] like Figure 1 As shown, the light receiving device 1 is, for example, a back-illuminated CMOS (Complementary Metal-Oxide-Semiconductor) image sensor. The light receiving device 1 includes, for example, a stacked structure of a first chip 10 and a second chip 20.

[0046] It should be noted that in this specification, the term "chip" includes a wafer having multiple semiconductor devices formed on it and individual wafers (chips) obtained by cutting the wafer for each semiconductor device. That is, the light receiving device 1 may be a light receiving device in which wafers are stacked together, wafers are stacked together, or chips are stacked together.

[0047] The first chip 10 has a photoelectric conversion function and outputs a sensor signal based on the amount of light received. Specifically, the first chip 10 has a pixel region 50 in which multiple sensor pixels 51 are arranged in a matrix in a two-dimensional manner. The first chip 10 performs photoelectric conversion on the light received in each sensor pixel 51 and outputs a sensor signal based on the charge generated by the photoelectric conversion to the second chip 20.

[0048] The first chip 10 is formed by stacking multiple wiring layers 110 on a semiconductor substrate 100. The first chip 10 is stacked on the second chip 20 such that the multiple wiring layers 110 face each other with the multiple wiring layers 210 of the second chip 20. In the first chip 10, the main surface on the opposite side of the main surface facing the second chip 20 is used as a light receiving surface.

[0049] The semiconductor substrate 100 is, for example, a substrate made of a semiconductor such as Si (silicon). In the semiconductor substrate 100, a photodiode (PD) is provided for each sensor pixel 51.

[0050] The multilayer wiring layer 110 includes, for example, electrodes 111, contacts 113, wiring layers 115, and interlayer insulating films 117.

[0051] Electrode 111 is disposed on semiconductor substrate 100 and functions as an electrode for transistors, etc. Electrode 111 may be made of, for example, polycrystalline silicon. Contact portion 113 is configured to penetrate interlayer insulating film 117 in the film thickness direction and electrically connect electrode 111 and wiring layer 115 to each other. For example, contact portion 113 may be made of metal such as W (tungsten), Ti (titanium), or Ta (tantalum) or a compound of any of these metals. Interlayer insulating film 117 electrically separates electrode 111, contact portion 113, wiring layer 115, etc. from each other. For example, interlayer insulating film 117 may be made of SiO2 (silicon dioxide) or SiN (silicon nitride). Wiring layer 115 outputs the charge extracted from photodiodes disposed for each sensor pixel 51 and the sensor signal based on the charge to processing circuits, etc. For example, wiring layer 115 may be made of metal such as Cu (copper) or Al (aluminum).

[0052] Additionally, the first chip 10 is provided with a connection hole 121. The connection hole 121 is configured to penetrate the semiconductor substrate 100 and a portion of the multilayer wiring layer 110, and expose the pad electrode 122 disposed in the multilayer wiring layer 110. The pad electrode 122 is made of, for example, Al (aluminum) and serves as an external connection terminal for signal input and output to the outside.

[0053] The second chip 20 includes a processing circuit that processes the sensor signals output from the first chip 10. Specifically, the second chip 20 is provided with multiple MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors). The second chip 20 processes the sensor signals output from the first chip 10 using the processing circuit including the multiple MOSFETs.

[0054] To increase the theoretical yield of the number of chips that can be formed from a single wafer, the second chip 20, including the processing circuitry for signal processing of sensor signals, is made smaller. On the other hand, in the first chip 10, the size of the pixel region 50, including the sensor pixel 51 for receiving incident light, is designed based on optical specifications. Therefore, the planar area of ​​the second chip 20 can be smaller than the planar area of ​​the first chip 10.

[0055] The second chip 20 is formed by stacking multiple wiring layers 210 on a semiconductor substrate 200. The second chip 20 is stacked on the first chip 10 such that the multiple wiring layers 210 face each other with the multiple wiring layers 110 of the first chip 10.

[0056] The multilayer wiring layer 210 includes, for example, electrodes 211, contacts 213, wiring layers 215, and interlayer insulating films 217.

[0057] Electrode 211 is disposed on semiconductor substrate 200 and serves as the electrode for multiple MOSFETs. Electrode 211 may be made of, for example, polysilicon. Contact 213 is configured to penetrate interlayer insulating film 217 in the film thickness direction and electrically connect electrode 211 and wiring layer 215 to each other. For example, contact 213 may be made of metal such as W (tungsten), Ti (titanium), or Ta (tantalum), or a compound of any of these metals. Interlayer insulating film 217 electrically separates electrode 211, contact 213, wiring layer 215, etc. from each other. Interlayer insulating film 217 may be made of, for example, SiO2 (silicon dioxide) or SiN (silicon nitride). Wiring layer 215 electrically connects multiple MOSFETs that form a processing circuit for signal processing of sensor signals to each other. For example, wiring layer 215 may be made of metal such as Cu (copper) or Al (aluminum).

[0058] The first chip 10 and the second chip 20 can be electrically connected to each other via a metal bonding structure 123, such as a Cu-Cu bond. The metal bonding structure 123 is formed by bringing the exposed metal electrodes on the opposing surfaces of both the multilayer wiring layer 110 and the multilayer wiring layer 210 into contact, and then bonding the metal electrodes together through heat treatment or the like. It should be noted that the first chip 10 and the second chip 20 can also be electrically connected to each other via a through electrode disposed between the multilayer wiring layer 110 and the multilayer wiring layer 210.

[0059] For example, a protective layer 31, an inter-pixel separation film 32, a color filter 33, and an on-chip lens 34 are provided on the main surface (i.e., the light receiving surface) of the first chip 10 on the side opposite to the main surface stacked on the second chip 20.

[0060] A protective layer 31 is disposed on the light-receiving surface side of the semiconductor substrate 100 of the first chip 10, and is used to protect the semiconductor substrate 100 on which the photodiode is disposed from the influence of the external environment. The protective layer 31 can be made of, for example, SiO2 (silicon dioxide) or SiN (silicon nitride).

[0061] An inter-pixel separation film 32 is disposed on the light-receiving surface side of the semiconductor substrate 100 of the first chip 10 to suppress crosstalk between sensor pixels 51. Specifically, the inter-pixel separation film 32 can be disposed between the individual sensor pixels 51 using a light-shielding material such as W (tungsten).

[0062] The color filters 33 are, for example, red (R) filters, green (G) filters, blue (B) filters, or white (W) filters. For example, the color filters 33 are arranged in a regular array for each sensor pixel 51, such as a Bayer array. Therefore, the light receiving device 1 can obtain sensor signals of various colors corresponding to the color array of the color filters 33 in each sensor pixel 51.

[0063] The on-chip lens 34 is disposed on the light-receiving surface side of the first chip 10 for each sensor pixel 51. Each on-chip lens 34 focuses the incident light onto a photodiode disposed for each sensor pixel 51. The shape of the on-chip lens 34 can be appropriately designed according to the size of the sensor pixel 51. For example, the on-chip lens 34 can be made of a transparent organic resin such as acrylic resin or can be made of SiO2 (silicon dioxide).

[0064] An insulating layer 41 and a support substrate 40 are provided on the main surface of the second chip 20 on the side opposite to the main surface of the first chip 10.

[0065] An embedded insulating layer 41 is disposed on the main surface of the second chip 20 on the side opposite to the main surface stacked on the first chip 10, thereby embedding the second chip 20. The second chip 20 is embedded in the embedded insulating layer 41, thereby protecting it from the influence of the external environment. Furthermore, by embedding the second chip 20, which has a smaller planar area than the first chip 10, into the embedded insulating layer 41, the main surface of the second chip 20 on the side opposite to the main surface stacked on the first chip 10 can be planarized. The embedded insulating layer 41 can be made of, for example, an organic resin or an inorganic insulator such as SiO2 (silicon dioxide) or SiN (silicon nitride).

[0066] A support substrate 40 is disposed on the main surface of the embedded insulating layer 41, opposite to the main surface stacked on the second chip 20. The support substrate 40 supports the stack of the first chip 10 and the second chip 20 to maintain the rigidity and strength of the entire light receiving device 1. The support substrate 40 can be, for example, a resin substrate, a glass substrate, a quartz substrate, a silicon substrate, etc.

[0067] (1.2. Example of constructing alignment marks)

[0068] Next, refer to Figures 2 to 4 An example of the construction of the alignment mark set in the light receiving device 1 according to the first embodiment is described. Figure 2 This is a longitudinal sectional view illustrating the outline of the first alignment mark 119 and the second alignment mark 219 according to the first embodiment. Figure 3A and Figure 3B This is a schematic perspective view of a specific example of a first chip 10 and a second chip 20 to be joined together. Figure 4 This is a plan view of an example configuration of the first alignment mark 119 in the first chip 10 and the second alignment mark 219 in the second chip 20.

[0069] As described above, the optical receiving device 1 includes, for example, a stacked structure of a first chip 10 and a second chip 20. Therefore, the manufacturing process of the optical receiving device 1 includes a process of bonding the first chip 10 and the second chip 20 together. In the step of bonding the first chip 10 and the second chip 20 together, it is crucial to precisely control the bonding positions of the first chip 10 and the second chip 20 in order to achieve the alignment of the wiring layers 115 and 215 or the metal bonding structure 123 in each chip.

[0070] Therefore, as Figure 2 As shown, in the optical receiving device 1, alignment marks for alignment are provided in both the first chip 10 and the second chip 20. Specifically, the first alignment mark 119 is provided in the multilayer wiring layer 110 of the first chip 10, and the second alignment mark 219 is provided in the multilayer wiring layer 210 of the second chip 20. During the bonding process of the first chip 10 and the second chip 20, the positional relationship between the first chip 10 and the second chip 20 on the plane can be controlled by detecting the first alignment mark 119 and the second alignment mark 219 using a detection light DL. For example, the detection of the first alignment mark 119 and the second alignment mark 219 can be performed by detecting the reflected light of the detection light DL by the first alignment mark 119 and the second alignment mark 219.

[0071] The first alignment mark 119 and the second alignment mark 219 can be made of a metallic material such as Al (aluminum). To further improve alignment accuracy, the first alignment mark 119 and the second alignment mark 219 can be respectively disposed on the mating surface side of the multilayer wiring layer 110 and the mating surface side of the multilayer wiring layer 210.

[0072] In the light receiving device 1 according to this embodiment, by providing a first alignment mark 119 within the pixel region 50 of the first chip 10, the chip area of ​​the first chip 10 can be used more effectively. Furthermore, in the light receiving device 1 according to this embodiment, the bonding position of the second chip 20 relative to the first chip 10 can be controlled more flexibly.

[0073] For example, such as Figure 3A As shown, when a first wafer 11 (corresponding to the first chip 10) having a plurality of semiconductor devices 11A and a second wafer 21 (corresponding to the second chip 20) having a plurality of semiconductor devices 21A are to be bonded together, a first alignment mark 119 and a second alignment mark 219 are respectively provided on the first wafer 11 and the second wafer 21. Therefore, even after the first wafer 11 and the second wafer 21 are cut into individual wafers to form a stack comprising semiconductor devices 11A and semiconductor devices 21A, the first alignment mark 119 and the second alignment mark 219 are not retained in each of the stacks comprising semiconductor devices 11A and semiconductor devices 21A.

[0074] On the other hand, for example, such as Figure 3B As shown, when semiconductor devices 22A and 23A (corresponding to the second chip 20), which have been cut into individual wafers, are to be bonded to semiconductor device 11A (corresponding to the first chip 10) formed on the first wafer 11, a first alignment mark 119 and a second alignment mark 219 are respectively provided on semiconductor device 11A and semiconductor devices 22A and 23A. Therefore, even after the first wafer 11 is cut into individual wafers to form a stack comprising semiconductor device 11A and semiconductor devices 22A and 23A, the first alignment mark 119 and the second alignment mark 219 will be retained in each of the stacks comprising semiconductor device 11A and semiconductor devices 22A and 23A.

[0075] Here, if the first alignment mark 119 is not provided within the pixel region 50 of the semiconductor device 11A (corresponding to the first chip 10), the area for the first alignment mark 119 needs to be separately provided in the semiconductor device 11A. In this case, the size of the semiconductor device 11A becomes larger. In addition, if the first alignment mark 119 is not provided within the pixel region 50 of the semiconductor device 11A, the size of the semiconductor device 11A differs from that of the semiconductor devices 22A and 23A (corresponding to the second chip 20) after they have been cut into individual pieces, which may lead to an inappropriate bonding position of the second chip 20 relative to the first chip 10.

[0076] In the light receiving device 1 according to this embodiment, by providing the first alignment mark 119 within the pixel region 50 of the first chip 10, the first alignment mark 119 and the second alignment mark 219 can be arranged more effectively. Therefore, in the light receiving device 1, the bonding position of the second chip 20 relative to the first chip 10 and the size of the second chip 20 can be changed more flexibly. Furthermore, in the light receiving device 1, multiple second chips 20, each including processing circuits with different functions, can be bonded to appropriate positions on the first chip 10 for their respective functions.

[0077] It should be noted that, Figure 1 and Figure 2 In the light receiving device 1 shown, photodiodes are provided for each sensor pixel 51 in the pixel region 50 of the first chip 10. Therefore, in order to detect the first alignment mark 119 and the second alignment mark 219 with higher accuracy, the detection light DL can, for example, be incident from the semiconductor substrate 200 side of the second chip 20. In addition, in this case, in order to prevent the detection light DL from being unintentionally reflected or scattered, it is preferable that the wiring layer 215 and components such as transistors are not provided in the multilayer wiring layer 210 and the semiconductor substrate 200 in the region where the first alignment mark 119 and the second alignment mark 219 are provided.

[0078] For example, such as Figure 4 As shown, when two second chips 20 with different functions are bonded to a first chip 10, for example, at least two or more first alignment marks 119 and at least two or more second alignment marks 219 may be provided in the first chip 10 and the second chip 20. In this case, at least one of the two or more first alignment marks 119 and at least one of the two or more second alignment marks 219 are provided within the pixel region 50. Therefore, according to the light receiving device 1 of this embodiment, the first alignment marks 119 and the second alignment marks 219 can be provided at multiple locations, which can further improve the alignment accuracy between the first chip 10 and the second chip 20.

[0079] It should be noted that when the planar shape of the first chip 10 and the second chip 20 is rectangular, the first alignment mark 119 and the second alignment mark 219 can be provided at least at the two corners of the rectangular shape of the second chip 20. In this case, the first alignment mark 119 and the second alignment mark 219 can effectively improve the alignment accuracy between the first chip 10 and the second chip 20 even in fewer locations.

[0080] Furthermore, when the planar shape of both the first chip 10 and the second chip 20 is rectangular, the first alignment mark 119 and the second alignment mark 219 can be provided at least at the four corners of the rectangular shape of the second chip 20. In this case, the first alignment mark 119 and the second alignment mark 219 can further improve the alignment accuracy between the first chip 10 and the second chip 20.

[0081] Next, refer to Figure 5A and Figure 5B The specific planar shapes of the first alignment mark 119 and the second alignment mark 219 are described. Figure 5A and Figure 5B This is a schematic diagram illustrating an example of the construction of the first alignment mark 119 and the second alignment mark 219. It should be noted that... Figure 5A and Figure 5B The planar shapes of the first alignment mark 119 and the second alignment mark 219 are shown in a plan view taken from the stacking direction of the light receiving device 1.

[0082] like Figure 5A As shown, the planar shapes of the first alignment mark 119 and the second alignment mark 219 can be set to corresponding shapes that enable alignment on a plane. Specifically, the first alignment mark 119 can have a rectangular shape, and the second alignment mark 219 can have a rectangular frame shape surrounding the first alignment mark 119.

[0083] Based on this planar shape, the alignment mark 119 and the alignment mark 219 can be measured in two mutually orthogonal directions. Figure 5A The spacing between the first alignment mark 119 and the second alignment mark 219 in the two mutually orthogonal directions (i.e., the vertical and horizontal directions) is controlled to a predetermined value. Therefore, by controlling the spacing between the first alignment mark 119 and the second alignment mark 219 in the two mutually orthogonal directions (i.e., the vertical and horizontal directions) to a predetermined value, the first chip 10 and the second chip 20 can have a predetermined positional relationship.

[0084] It should be noted that the planar shapes of the first alignment mark 119 and the second alignment mark 219 are interchangeable. That is, the second alignment mark 219 may have a rectangular shape, and the first alignment mark 119 may have a rectangular frame shape surrounding the second alignment mark 219.

[0085] In addition, such as Figure 5B As shown, the first alignment mark 119 and the second alignment mark 219 can have a planar shape formed by arranging a plurality of conductor layers 619 extending in parallel in the same direction.

[0086] Multiple conductor layers 619 extending in parallel along the same direction constitute a so-called wire grid; therefore, the conductor layers 619 can act as polarizers. Specifically, the conductor layers 619 can reflect linearly polarized light vibrating in a direction parallel to the extension direction and allow linearly polarized light vibrating in a direction orthogonal to the extension direction to pass through. Therefore, by using linearly polarized light vibrating in a direction parallel to the extension direction of the conductor layers 619 as the detection light DL, the first alignment mark 119 and the second alignment mark 219, each composed of multiple conductor layers 619, can reflect the detection light DL as if they were formed from a single film (i.e., a solid film) of a metallic material such as Al (aluminum).

[0087] The first alignment mark 119 and the second alignment mark 219 are each composed of multiple conductor layers 619, which allows for a reduction in pattern density. This enables the light receiving device 1 to suppress the reflection of light by the first alignment mark 119 and the second alignment mark 219. Therefore, the light receiving device 1 can suppress the increase of background noise in the sensor pixels 51 in the area where the first alignment mark 119 and the second alignment mark 219 are provided.

[0088] To further reduce the influence of the first alignment mark 119 and the second alignment mark 219 on the sensor pixel 51, the repeating pitch pa used to set the conductor layer 619 is preferably equal to or less than the size of the sensor pixel 51. For example, the repeating pitch pa used to set the conductor layer 619 is preferably equal to or less than 5 μm. It should be noted that the repeating pitch pa used to set the conductor layer 619 can be uniform or non-uniform.

[0089] Here, the size of sensor pixel 51 refers to the size (length of one side) of the smallest repeating pattern of the pixel capable of reading the charge obtained through photoelectric conversion in the photodiode. For example, if the smallest repeating pattern of sensor pixel 51 is a square shape, the size of sensor pixel 51 can be the length of one side of that square shape. Alternatively, if the smallest repeating pattern of sensor pixel 51 is a rectangle, the size of sensor pixel 51 can be the length of the shorter side of that rectangle.

[0090] (1.3. Variations in the shape of the alignment mark)

[0091] Next, refer to Figures 6A to 6C A description is given of the variations in the planar shape of the first alignment mark 119 and the second alignment mark 219.

[0092] Figures 6A to 6C This is a schematic diagram illustrating a variation in the planar shape of the first alignment mark 119 and the second alignment mark 219. It should be noted that... Figures 6A to 6C The planar shapes of the first alignment mark 119 and the second alignment mark 219 are shown in a plan view taken from the stacking direction of the light receiving device 1.

[0093] like Figure 6A As shown, the first alignment mark 119 may have a shape in which the four corner vertices have been removed from a rectangular frame shape and the four sides are separated from each other. The second alignment mark 219 may have a frame shape surrounding the first alignment mark 119. Based on this planar shape, it is possible to measure the alignment of both the first alignment mark 119 and the second alignment mark 219 in two mutually orthogonal directions at the edges of their frame shapes. Figure 6A The intervals in the vertical and horizontal directions.

[0094] like Figure 6B As shown, the first alignment mark 119 may have five rectangular shapes arranged at positions corresponding to the vertices and center of a square. The second alignment mark 219 may have: a polygonal shape that includes the central rectangular shape of the first alignment mark 119 and extends in a cross shape between the four rectangular shapes of the first alignment mark 119; and a frame shape surrounding the four rectangular shapes of the first alignment mark 119. Based on this planar shape, it is possible to measure the relationship between the first alignment mark 119 and the second alignment mark 219 in two mutually orthogonal directions between the five rectangular shapes of the first alignment mark 119 and the polygonal shape or frame shape of the second alignment mark 219. Figure 6B The intervals in the vertical and horizontal directions.

[0095] like Figure 6CAs shown, the first alignment mark 119 may have a cross shape composed of two mutually orthogonal straight lines. The second alignment mark 219 may have four rectangular shapes arranged at the position enclosed by the two straight lines contained in the cross shape of the first alignment mark 119. Based on this planar shape, it is possible to measure the alignment of both the first alignment mark 119 and the second alignment mark 219 in two mutually orthogonal directions between their cross shape and the four rectangular shapes. Figure 6C The intervals in the vertical and horizontal directions.

[0096] Therefore, even in Figures 6A to 6C In the planar shape shown, the spacing between the first alignment mark 119 and the second alignment mark 219 in two mutually orthogonal directions (i.e., the up and down direction and the left and right direction) can be controlled to a predetermined value, which enables the first chip 10 and the second chip 20 to have a predetermined positional relationship.

[0097] Figures 6A to 6C The first alignment mark 119 and the second alignment mark 219 shown can also be... Figure 5B It is constructed using multiple conductor layers 619 extending in parallel along the same direction. Furthermore, even in Figures 6A to 6C In this context, the planar shapes of the first alignment mark 119 and the second alignment mark 219 are also interchangeable.

[0098] <2. Second Embodiment>

[0099] (2.1. Example of constructing alignment marks)

[0100] Next, refer to Figures 7 to 9 A description of a construction example of an alignment mark set in an optical receiving device 1 according to the second embodiment is given. Figure 7 and Figure 8 This is a longitudinal sectional view used to illustrate the outline of the first alignment mark 129 and the second alignment mark 229 according to the second embodiment. Figure 9 This is a schematic diagram showing an example of the construction of the first alignment mark 129 and the second alignment mark 229 overlapping on the wiring layer 115. It should be noted that... Figure 9 The planar shapes of the first alignment mark 129 and the second alignment mark 229 are shown in a plan view taken from the stacking direction of the light receiving device 1.

[0101] exist Figure 7 and Figure 8 In the light receiving device 1 shown, the first alignment mark 129 is disposed in the pixel region 50 of the first chip 10; therefore, in the region where the first alignment mark 129 and the second alignment mark 229 are disposed, the first chip 10 (i.e., the multilayer wiring layer 110 and the semiconductor substrate 100) is disposed, a photodiode and the wiring layer 115 are disposed.

[0102] In addition, in order to make more efficient use of the chip area in the second chip 20, it is desirable that the second chip 20 (i.e., the multilayer wiring layer 210 and the semiconductor substrate 200) in the region where the first alignment mark 119 and the second alignment mark 219 are provided, as in other regions, also have wiring layers 215 and components such as transistors provided.

[0103] Furthermore, when semiconductor substrates 100 and 200 are thinned by grinding or the like, the areas without wiring layers 115 and 215 have lower strength, making them easier to grind. Therefore, if areas with wiring layers 115 and 215 and areas without wiring layers 115 and 215 coexist, thinning semiconductor substrates 100 and 200 while maintaining planarity increases the manufacturing difficulty. Therefore, it is desirable that the second chip 20 in the area where the first alignment mark 119 and the second alignment mark 219 are located, as in other areas, has wiring layers 215 and components such as transistors.

[0104] Therefore, in the second embodiment, it is preferable that the detection light DL passes through the wiring layer 115 disposed in the multilayer wiring layer 110. Figure 7 ) or wiring layer 215 located in multilayer wiring layer 210 ( Figure 8 ), and is reflected by the first alignment mark 129 and the second alignment mark 229.

[0105] Therefore, in the second embodiment, as Figure 9 As shown, wiring layers 115 and 215 in the region where the first alignment mark 129 and the second alignment mark 229 are provided extend in parallel in the same direction. For example, wiring layers 115 and 215 can be made of metals such as Cu (copper) or Al (aluminum).

[0106] Multiple wiring layers 115 and 215 extending parallel to each other in the same direction constitute a so-called wire grid, thus enabling wiring layers 115 and 215 to function as polarizers. Specifically, these wiring layers 115 and 215 can reflect linearly polarized light vibrating in a direction parallel to the extension direction and allow linearly polarized light vibrating in a direction orthogonal to the extension direction to pass through. Therefore, by using linearly polarized light vibrating in a direction perpendicular to the extension direction of wiring layers 115 and 215 for detection light DL, the detection light DL can pass through wiring layers 115 and 215 and be reflected by the first alignment mark 129 and the second alignment mark 229 located on the inner side in the illumination direction.

[0107] The arrangement pitch of the plurality of wiring layers 115 and 215 extending in parallel along the same direction can be appropriately selected, for example, according to the wavelength of the light used for detection light DL. Specifically, the arrangement pitch of wiring layers 115 and 215 can be selected such that the detection light DL, which is linearly polarized light vibrating in a direction perpendicular to the extension direction of wiring layers 115 and 215, can more effectively pass through wiring layers 115 and 215.

[0108] Similar to the first embodiment, the planar shapes of the first alignment mark 129 and the second alignment mark 229 can be configured as corresponding shapes capable of achieving alignment on a plane. Specifically, the first alignment mark 129 can have a rectangular shape, and the second alignment mark 229 can have a rectangular frame shape surrounding the first alignment mark 129. The materials and construction of the first alignment mark 129 and the second alignment mark 229 are substantially the same as in the first embodiment, and will not be described in detail here.

[0109] It should be noted that the planar shapes of the first alignment mark 129 and the second alignment mark 229 are interchangeable. That is, the second alignment mark 229 may have a rectangular shape, and the first alignment mark 129 may have a rectangular frame shape surrounding the second alignment mark 229.

[0110] (2.2. Variation)

[0111] Next, refer to Figure 10 and Figure 11 A description of a variation of the second embodiment is given. Figure 10 This is a schematic diagram of the construction example of wiring layers 115 and 215 according to a modified example of the second embodiment. Figure 11 This is a schematic diagram of a construction example of the first alignment mark 129 and the second alignment mark 229.

[0112] like Figure 10 and Figure 11 As shown, in a variation of the second embodiment, the first alignment mark 129 and the second alignment mark 229, as well as the wiring layer 115 and wiring layer 215 in the region where the first alignment mark 129 and the second alignment mark 229 are provided, can be configured as wire grid structures extending in mutually orthogonal directions.

[0113] Specifically, such as Figure 10 As shown, wiring layer 115 disposed in multilayer wiring layer 110 and wiring layer 215 disposed in multilayer wiring layer 210 can be configured to be parallel to each other along a first direction ( Figure 10 Wiring extending in the Y direction (as in the diagram). Additionally, as... Figure 11As shown, the first alignment mark 129 and the second alignment mark 229 can have multiple parallel alignment marks arranged along a second direction orthogonal to the first direction. Figure 11 The planar shape is formed by a conductor layer 629 extending in the X direction.

[0114] According to the above structure, wiring layers 115 and 215, as well as the first alignment mark 129 and the second alignment mark 229, can function as polarizers. Therefore, wiring layers 115 and 215 can reflect linearly polarized light vibrating in the Y direction and allow linearly polarized light vibrating in the X direction to pass through. Additionally, the first alignment mark 129 and the second alignment mark 229 can reflect linearly polarized light vibrating in the X direction and allow linearly polarized light vibrating in the Y direction to pass through.

[0115] Therefore, by using linearly polarized light vibrating in the X direction as the detection light DL for the first alignment mark 129 and the second alignment mark 229, the detection light DL is allowed to pass through the wiring layer 115 and the wiring layer 215 and be reflected by the first alignment mark 129 and the second alignment mark 229. Accordingly, in the light receiving device 1 of the modified embodiment according to the second embodiment, the detection light DL can detect the first alignment mark 129 and the second alignment mark 229 without being reflected or scattered by the wiring layer 115 and the wiring layer 215, which are disposed in a manner overlapping the first alignment mark 129 and the second alignment mark 229.

[0116] Furthermore, it can reduce the possibility that linearly polarized light that has passed through the first alignment mark 129 and the second alignment mark 229 will be reflected by the wiring layer 115 or wiring layer 215 located inside the first alignment mark 129 and the second alignment mark 229. Therefore, in the light receiving device 1 of the modified embodiment according to the second embodiment, by suppressing the reflection of the detection light DL inside the light receiving device 1, noise during detection can be reduced.

[0117] For example, wiring layers 115 and 215 can be made of metals such as Cu (copper) or Al (aluminum). From the viewpoint of suppressing reflection of reflected light on sensor pixel 51, the arrangement pitch pw of wiring layers 115 and 215 is preferably equal to or less than the size of sensor pixel 51, and specifically, preferably equal to or less than 5 μm. Furthermore, when near-infrared light is used as the detection light DL, from the viewpoint of further improving the characteristics of the polarizer, the arrangement pitch pw of wiring layers 115 and 215 is preferably equal to or less than 1 μm, which is the wavelength of near-infrared light.

[0118] For example, the conductor layer 629 included in the first alignment mark 129 and the second alignment mark 229 can be made of a metallic material such as Al (aluminum). Preferably, the repeating pitch pa of the conductor layer 629 included in the first alignment mark 129 and the second alignment mark 229 is equal to or less than the size of the sensor pixel 51 in order to suppress the reflection of incident light on the sensor pixel 51.

[0119] It should be noted that, as described in the first embodiment, the size of sensor pixel 51 refers to the size (length of one side) of the smallest repeating pattern of pixels capable of reading the charge obtained through photoelectric conversion in the photodiode.

[0120] <3. Application Examples>

[0121] The following reference Figures 12 to 17 An application example of the optical receiving device 1 according to an embodiment of the present invention is given.

[0122] (Application in camera systems)

[0123] First, refer to Figure 12 and Figure 13 The application of the optical receiving device 1 according to an embodiment of the present invention in a camera system is described. Figure 12 This is a block diagram illustrating a schematic example of the construction of a camera system 900 including a light receiving device 1 according to an embodiment of the present invention. Figure 13 This is a flowchart illustrating the camera operation process in the camera system 900.

[0124] like Figure 12 As shown, examples of the camera system 900 include: camera devices such as digital cameras or camcorders; and portable terminal devices with camera functions such as smartphones or tablets.

[0125] For example, the camera system 900 includes a lens group 941, a shutter 942, a light receiving device 1 according to an embodiment of the present invention, a DSP (digital signal processing) circuit 943, a frame memory 944, a display unit 945, a storage unit 946, an operation unit 947, and a power supply unit 948. In the camera system 900, the light receiving device 1, the DSP circuit 943, the frame memory 944, the display unit 945, the storage unit 946, the operation unit 947, and the power supply unit 948 are interconnected via a bus 949.

[0126] The light receiving device 1 receives incident light that has passed through the lens group 941 and the shutter 942, and outputs a sensor signal (i.e., image data) corresponding to the received light. The DSP circuit 943 is a signal processing circuit that processes the image data output from the light receiving device 1. The frame memory 944 temporarily stores the image data processed by the DSP circuit 943 in frames. For example, the display unit 945 includes a panel-type display device such as a liquid crystal panel or an organic EL (electroluminescent) panel, and displays the image data processed by the DSP circuit 943. The storage unit 946 includes a recording medium such as a semiconductor memory or a hard disk, and records the image data output from the light receiving device 1 or the image data processed by the DSP circuit 943. The operation unit 947 issues operation commands for various functions of the camera system 900 based on user operations. The power supply unit 948 includes various power supplies for providing power to the operation of the light receiving device 1, the DSP circuit 943, the frame memory 944, the display unit 945, the storage unit 946, and the operation unit 947.

[0127] Next, the operation process of the camera system 900 will be explained.

[0128] like Figure 13 As shown, the user instructs the start of optical reception by manipulating the operation unit 947 (step S101). Therefore, the operation unit 947 sends an optical reception command to the optical receiving device 1 (step S102). Upon receiving the optical reception command, the optical receiving device 1 begins optical reception using a predetermined method (step S103).

[0129] Next, the light receiving device 1 outputs image data corresponding to the received light to the DSP circuit 943. The DSP circuit 943 performs predetermined signal processing (e.g., noise reduction processing) on ​​the image data output from the light receiving device 1 (step S104). The DSP circuit 943 causes the frame memory 944 to retain the image data that has undergone predetermined signal processing. Thereafter, the frame memory 944 stores the image data in the storage unit 946 (step S105). In this way, the operation of the camera system 900 is performed.

[0130] (Application in mobile body control systems)

[0131] The technology of this invention (the technology) can be applied to a variety of products. For example, the technology of this invention can be applied to devices installed on any type of mobile body such as automobiles, electric vehicles, hybrid vehicles, motorcycles, bicycles, personal motor vehicles, airplanes, unmanned aerial vehicles, ships, robots, etc.

[0132] Figure 14This is a block diagram illustrating a schematic construction example of a vehicle control system, which serves as an example of a mobile body control system to which the technology of the present invention can be applied.

[0133] The vehicle control system 12000 includes multiple electronic control units interconnected via a communication network 12001. Figure 14 In the example shown, the vehicle control system 12000 includes a drive system control unit 12010, a main system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and a comprehensive control unit 12050. Furthermore, as part of the functional structure of the comprehensive control unit 12050, a microcomputer 12051, an audio / image output unit 12052, and an in-vehicle network interface (I / F) 12053 are shown.

[0134] The drive system control unit 12010 controls the operation of equipment related to the vehicle's drive system according to various programs. For example, the drive system control unit 12010 functions as a control device for equipment such as: a drive force generating device for generating vehicle driving force, such as an internal combustion engine or drive motor; a drive force transmission mechanism for transmitting driving force to the wheels; a steering mechanism for adjusting the vehicle's steering angle; and a braking device for generating vehicle braking force.

[0135] The main system control unit 12020 controls the operation of various devices installed on the vehicle body according to various programs. For example, the main system control unit 12020 functions as a control device for devices such as: keyless entry systems; smart key systems; power windows; or various lights such as headlights, reversing lights, brake lights, turn signals, or fog lights. In this case, radio waves transmitted from a portable device or signals from various switches, used in place of a key, can be input to the main system control unit 12020. The main system control unit 12020 receives these radio wave or signal inputs and controls the vehicle's door locking devices, power windows, lights, etc.

[0136] The exterior information detection unit 12030 detects external information of the vehicle equipped with the vehicle control system 12000. For example, the exterior information detection unit 12030 is connected to the camera unit 12031. The exterior information detection unit 12030 causes the camera unit 12031 to capture images of the exterior of the vehicle and receives the captured images. The exterior information detection unit 12030 can perform object detection processing or distance detection processing based on the received images, such as for people, vehicles, obstacles, signs, and text on the road.

[0137] The camera unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The camera unit 12031 can output the electrical signal as an image or as ranging information. Furthermore, the light received by the camera unit 12031 can be visible light or non-visible light such as infrared light.

[0138] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, the in-vehicle information detection unit 12040 is connected to a driver state detection unit 12041 for detecting the driver's state. For example, the driver state detection unit 12041 includes a camera for capturing images of the driver. Based on the detection information input from the driver state detection unit 12041, the in-vehicle information detection unit 12040 can calculate the driver's fatigue level or the driver's concentration level, or it can determine whether the driver is dozing off.

[0139] For example, based on information about the vehicle's interior and exterior obtained by the external information detection unit 12030 or the internal information detection unit 12040, the microcomputer 12051 can calculate target control values ​​for the drive force generating device, steering mechanism, or braking device, and output control commands to the drive system control unit 12010. For instance, the microcomputer 12051 can perform coordinated control aimed at implementing ADAS (Advanced Driver Assistance System) functions, including collision avoidance or mitigation, distance-based following, constant speed control, collision warning, and lane departure warning.

[0140] Furthermore, based on information about the vehicle's surroundings obtained by the external information detection unit 12030 or the internal information detection unit 12040, the microcomputer 12051 can perform coordinated control, such as autonomous driving, which aims to enable the vehicle to drive autonomously without relying on the driver's operation, by controlling the drive force generating device, steering mechanism, braking device, etc.

[0141] Furthermore, based on the information about the exterior of the vehicle obtained by the exterior information detection unit 12030, the microcomputer 12051 can output control commands to the main system control unit 12020. For example, based on the position of the vehicle in front or oncoming vehicle detected by the exterior information detection unit 12030, the microcomputer 12051 can control the headlights to perform coordinated control aimed at preventing glare, such as switching from high beams to low beams.

[0142] The sound / image output unit 12052 sends an output signal of at least one of sound and image to an output device capable of visually or audibly notifying vehicle occupants or external to the vehicle. Figure 14 In the example, an audio speaker 12061, a display unit 12062, and a dashboard 12063 are illustrated as output devices. For example, the display unit 12062 may include at least one of an onboard display and a head-up display.

[0143] Figure 15 This is a diagram showing an example of the installation position of the camera unit 12031.

[0144] exist Figure 15 In the vehicle 12100, camera units 12101, 12102, 12103, 12104 and 12105 are camera units 12031.

[0145] For example, camera units 12101, 12102, 12103, 12104, and 12105 are arranged at positions such as the front nose, side mirrors, rear bumper, trunk lid, and upper part of the windshield inside the vehicle 12100. Camera unit 12101 at the front nose and camera unit 12105 at the upper part of the windshield inside the vehicle primarily acquire images of the front of the vehicle 12100. Camera units 12102 and 12103 at the side mirrors primarily acquire images of the sides of the vehicle 12100. Camera unit 12104 at the rear bumper or trunk lid primarily acquires images of the rear of the vehicle 12100. The front images acquired by camera units 12101 and 12105 are mainly used to detect vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc., ahead.

[0146] Incidentally, Figure 15 Examples of the shooting ranges of camera units 12101 to 12104 are shown. Camera range 12111 represents the shooting range of camera unit 12101 located at the front nose. Camera ranges 12112 and 12113 represent the shooting ranges of camera units 12102 and 12103 located at the side mirrors, respectively. Camera range 12114 represents the shooting range of camera unit 12104 located at the rear bumper or trunk lid. For example, by superimposing the image data captured by camera units 12101 to 12104, a top-view image of vehicle 12100 can be obtained.

[0147] At least one of the camera units 12101 to 12104 may have the function of acquiring distance information. For example, at least one of the camera units 12101 to 12104 may be a stereo camera including multiple imaging elements, or may be an imaging element having pixels for phase difference detection.

[0148] For example, based on distance information obtained from cameras 12101 to 12104, microcomputer 12051 can calculate the distance to each three-dimensional object within the camera range 12111 to 12114 and how that distance changes over time (relative speed to vehicle 12100). This allows it to identify three-dimensional objects as those closest to the vehicle, particularly those on the vehicle 12100's path, and those traveling in approximately the same direction as vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, microcomputer 12051 can set a pre-determined distance from the vehicle and perform automatic braking control (including follow-stop control), automatic acceleration control (including follow-start control), etc. In this way, coordinated control aimed at achieving autonomous driving, where the vehicle can operate independently of the driver, can be executed.

[0149] For example, based on distance information obtained from cameras 12101 to 12104, microcomputer 12051 can classify three-dimensional object data into three-dimensional object data such as two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, and utility poles, and then extract the three-dimensional object data and use the extracted data to automatically avoid obstacles. For example, microcomputer 12051 distinguishes obstacles around vehicle 12100 into obstacles that can be visually identified by the driver of vehicle 12100 and obstacles that are difficult to visually identify. Then, microcomputer 12051 determines the collision risk, which represents the degree of danger of colliding with each obstacle, and when the collision risk is equal to or higher than a set value and there is a possibility of collision, microcomputer 12051 can output a warning to the driver via audio speaker 12061 or display unit 12062, or can perform forced deceleration or evasive steering via drive system control unit 12010, thereby providing driving assistance for collision avoidance.

[0150] At least one of the camera units 12101 to 12104 can be an infrared camera for detecting infrared light. For example, the microcomputer 12051 can identify a pedestrian by determining whether a pedestrian exists in the images captured by the camera units 12101 to 12104. For example, this pedestrian identification is performed through the following process: extracting feature points from the images captured by the camera units 12101 to 12104, which are infrared cameras; and performing pattern matching processing on a series of feature points used to represent the outline of an object to determine whether the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian exists in the images captured by the camera units 12101 to 12104 and thus identifies the pedestrian, the sound / image output unit 12052 can control the display unit 12062 to display a rectangular outline for emphasis overlaid on the identified pedestrian. The sound / image output unit 12052 can also control the display unit 12062 to display an icon or the like representing a pedestrian at a desired location.

[0151] The above has described an example of a mobile body control system to which the technology of the present invention is applicable. The technology of the present invention can be applied to the camera unit 12031 in the configuration described above. According to the technology of the present invention, the size of the camera unit 12031 can be further miniaturized, which makes it easier to implement its mounting on a mobile body.

[0152] (Application in endoscopic surgical systems)

[0153] The technology of this invention (the technology) can be applied to various products. For example, the technology of this invention can be applied to endoscopic surgical systems.

[0154] Figure 16 This is a diagram illustrating an example of a schematic construction of an endoscopic surgical system to which the technology of the present invention (the present technology) can be applied.

[0155] exist Figure 16 The image shows a surgeon (doctor) 11131 performing surgery on a patient 11132 on a bed 11133 using an endoscopic surgery system 11000. As shown, the endoscopic surgery system 11000 includes: an endoscope 11100; other surgical instruments 11110 such as a pneumoperitoneum tube 11111 and an energy delivery device 11112; a support arm device 11120 for supporting the endoscope 11100; and a trolley 11200 equipped with various devices for endoscopic surgery.

[0156] Endoscope 11100 includes: a tube 11101, a region of which, measured distally, has a predetermined length, inserted into a body cavity of a patient 11132; and a camera head 11102, which is connected to the base of the tube 11101. In the example shown in the figure, an endoscope 11100 is illustrated as a so-called rigid endoscope comprising a rigid tube 11101. However, endoscope 11100 can also be configured as a so-called flexible endoscope comprising a flexible tube.

[0157] The endoscope tube 11101 has an opening at its distal end into which the objective lens is inserted. A light source device 11203 is connected to the endoscope 11100, allowing light generated by the light source device 11203 to be guided to the distal end of the endoscope tube via a light guide extending inside the tube 11101, and then directed through the objective lens toward the object being observed within the body cavity of the patient 11132. It should be noted that the endoscope 11100 can be a direct-viewing endoscope, or it can be an oblique-viewing endoscope or a side-viewing endoscope.

[0158] An optical system and an image sensor are housed inside the camera head 11102. The optical system focuses reflected light (observation light) from the object being observed onto the image sensor. The image sensor performs photoelectric conversion on the observation light to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. The image signal is transmitted to the CCU 11201 as RAW (raw) data.

[0159] The CCU 11201 includes a central processing unit (CPU) or a graphics processing unit (GPU), and comprehensively controls the operation of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives image signals from the camera head 11102 and performs various image processing operations, such as image processing (de-mosaicing), on the image signals to display an image based on those signals.

[0160] The display device 11202 displays an image based on the image signal that has been processed by the CCU 11201 under the control of the CCU 11201.

[0161] For example, the light source device 11203 includes a light source such as a light-emitting diode (LED) and is capable of supplying illumination light for imaging surgical sites to the endoscope 11100.

[0162] Input device 11204 is an input interface for endoscopic surgical system 11000. Users can input various information and commands into endoscopic surgical system 11000 via input device 11204. For example, users can input commands to change the imaging conditions of endoscope 11100 (type of illumination light, magnification, focal length, etc.).

[0163] The treatment device control unit 11205 controls the operation of the energy treatment device 11112 used for tissue cauterization or incision, or sealing of blood vessels. The pneumoperitoneum device 11206 injects gas into the patient's body cavity 11132 via the pneumoperitoneum tube 11111 to inflate the cavity, ensuring the field of vision of the endoscope 11100 and ensuring the surgeon's working space. The recorder 11207 is a device capable of recording various information related to the surgery. The printer 11208 is a device capable of printing various information related to the surgery in various forms such as text, images, and charts.

[0164] Furthermore, the light source device 11203, which supplies illumination light for imaging the surgical site to the endoscope 11100, may include, for example, an LED, a laser light source, or a white light source composed of a combination thereof. When the white light source is composed of a combination of RGB (red, green, and blue) laser light sources, the output intensity and timing of each color (wavelength) can be controlled with high precision, allowing the light source device 11203 to adjust the white balance of the captured image. Moreover, in this case, by time-divisionally illuminating the object of observation with lasers from each of the RGB laser light sources and controlling the driving of the imaging element of the camera head 11102 in sync with the illumination timing, images corresponding to each of the RGB elements can be captured in a time-division manner. According to this method, color images can be obtained even when a color filter is not provided in the imaging element.

[0165] Furthermore, the drive of the light source device 11203 can be controlled so that the intensity of the light to be output changes at predetermined time intervals. By controlling the drive of the imaging element of the camera head 11102 in time sequence with the change in light intensity, images can be acquired in a time-division manner and synthesized to generate high dynamic range images without underexposure or overexposure.

[0166] Furthermore, the light source device 11203 can be configured to supply light in a predetermined wavelength band corresponding to special light observation. In special light observation, for example, a so-called narrow-band light observation (narrow-band imaging) can be performed, wherein, utilizing the wavelength dependence of light absorption in body tissue, a predetermined tissue, such as blood vessels in the mucosal surface, is photographed with high contrast by irradiating light with a narrow band compared to the illumination light used in ordinary observation (i.e., white light). Furthermore, in special light observation, for example, fluorescence observation can be performed to obtain an image using fluorescence generated by irradiating excitation light. In fluorescence observation, for example, fluorescence from body tissue can be observed by irradiating excitation light onto the body tissue (autofluorescence observation), or a fluorescence image can be obtained by locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the body tissue with excitation light corresponding to the fluorescence wavelength of the reagent. The light source device 11203 can be configured to supply narrow-band light and / or excitation light corresponding to this special light observation.

[0167] Figure 17 It shows Figure 16 A block diagram illustrating an example of the functional configuration of the camera head 11102 and CCU 11201.

[0168] Camera head 11102 includes a lens unit 11401, an image capturing unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. Camera head 11102 and CCU 11201 are communicatively connected to each other via a transmission cable 11400.

[0169] The lens section 11401 is an optical system disposed at the connection point with the lens barrel 11101. Observation light received from the distal end of the lens barrel 11101 is guided to the camera head 11102 and incident on the lens section 11401. The lens section 11401 includes a combination of multiple lenses, including a zoom lens and a focusing lens.

[0170] The camera unit 11402 is composed of camera elements. The camera elements used to construct the camera unit 11402 can be a single element (so-called single-plate type) or multiple elements (so-called multi-plate type). When the camera unit 11402 is multi-plate type, for example, image signals corresponding to each of the RGB values ​​are generated by each camera element, and a color image can be obtained by synthesizing the image signals. Furthermore, the camera unit 11402 may include a pair of camera elements, which are used to acquire right-eye image signals and left-eye image signals corresponding to three-dimensional (3D) display, respectively. By performing 3D display, the surgeon 11131 can more accurately grasp the depth of body tissues in the surgical site. Furthermore, when the camera unit 11402 is multi-plate type, multiple systems of lens units 11401 can be provided corresponding to each camera element.

[0171] Furthermore, the camera unit 11402 does not necessarily have to be located in the camera head 11102. For example, the camera unit 11402 can be located inside the lens barrel 11101 and immediately behind the objective lens.

[0172] The drive unit 11403 includes an actuator, and the zoom lens and focusing lens of the lens unit 11401 are moved a predetermined distance along the optical axis under the control of the camera head control unit 11405. As a result, the magnification and focus of the image captured by the imaging unit 11402 can be appropriately adjusted.

[0173] The communication unit 11404 includes communication devices for transmitting various information to and receiving various information from the CCU 11201. The communication unit 11404 transmits image signals acquired from the camera unit 11402 as RAW data to the CCU 11201 via the transmission cable 11400.

[0174] Furthermore, the communication unit 11404 receives control signals from the CCU 11201 for controlling the drive of the camera head 11102, and supplies these control signals to the camera head control unit 11405. The control signals include information related to imaging conditions, such as: information specifying the frame rate of the captured image; information specifying the exposure value during imaging; and / or information specifying the magnification and focus of the captured image, etc.

[0175] It should be noted that the aforementioned imaging conditions, such as frame rate, exposure value, magnification, and focus, can be appropriately specified by the user, or can be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the endoscope 11100 is equipped with so-called automatic exposure (AE), automatic focus (AF), and automatic white balance (AWB) functions.

[0176] The camera head control unit 11405 controls the drive of the camera head 11102 based on the control signal received from the CCU 11201 via the communication unit 11404.

[0177] The communication unit 11411 includes a communication device for transmitting various information to and receiving various information from the camera head 11102. The communication unit 11411 receives image signals transmitted from the camera head 11102 via the transmission cable 11400.

[0178] In addition, the communication unit 11411 transmits control signals for controlling the camera head 11102 to the camera head 11102. Image signals and control signals can be transmitted via electrical communication, optical communication, etc.

[0179] The image processing unit 11412 performs various image processing operations on the image signal transmitted from the camera head 11102 as RAW data.

[0180] The control unit 11413 performs various controls related to imaging the surgical site, etc., through the endoscope 11100 and displaying the images obtained by imaging the surgical site, etc. For example, the control unit 11413 generates control signals for controlling the drive of the camera head 11102.

[0181] Furthermore, the control unit 11413 uses image signals that have undergone image processing by the image processing unit 11412 to cause the display device 11202 to display the captured image reflecting the surgical site, etc. In this case, the control unit 11413 can identify various objects in the captured image by using various image recognition techniques. For example, the control unit 11413 detects the edge shape and / or color of objects contained in the captured image, thereby being able to identify surgical instruments such as forceps, specific body parts, bleeding, fog when the energy treatment device 11112 is used, etc. When the display device 11202 displays the captured image, the control unit 11413 can use the recognition results to cause the display device 11202 to overlay various surgical support information on the image of the surgical site. By overlaying and presenting the surgical support information to the surgeon 11131, the workload of the surgeon 11131 can be reduced, and the surgeon 11131 can perform the surgery reliably.

[0182] The transmission cable 11400 that connects the camera head 11102 and CCU 11201 to each other is an electrical signal cable corresponding to electrical signal communication, an optical fiber corresponding to optical communication, or a composite cable thereof.

[0183] Here, in the example shown in the attached figure, communication is performed in a wired manner using transmission cable 11400, but communication between camera head 11102 and CCU 11201 can also be performed wirelessly.

[0184] An example of an endoscopic surgical system to which the technology of the present invention is applicable has been described above. The technology of the present invention is applicable to the imaging unit 11402 disposed in the camera head 11102 of the endoscope 11100 in the configuration described above. According to the technology of the present invention, the size of the imaging unit 11402 can be further miniaturized, and the size of the camera head 11102 of the endoscope 11100 can be further miniaturized, thereby reducing the burden on the patient 11132.

[0185] The technology of the present invention has been described above with reference to the first and second embodiments and variations. However, the technology of the present invention is not limited to the above embodiments, and can be modified in various ways.

[0186] The light receiving device to which the technology of this invention is applicable is not limited to CMOS image sensors. Examples of light receiving devices to which the technology of this invention is applicable include ToF (Time of Flight) ranging sensors and infrared image sensors.

[0187] Furthermore, the constructions and operations described in the various embodiments are not necessarily essential to the construction and operation of the present invention. For example, among the constituent elements of the various embodiments, those not described in the independent claims that represent the superior concept of the present invention should be understood as any optional constituent elements.

[0188] The terms used in this specification and the appended claims shall be interpreted as “non-limiting” terms. For example, the terms “comprising” or “including” shall be interpreted as “not limited to those contained herein”. The term “having” shall be interpreted as “not limited to those having herein”.

[0189] The terminology used in this specification is for ease of explanation only, and includes terms not intended to limit construction and operation. For example, terms such as "right," "left," "upper," and "lower" indicate directions only in the referenced figures. Similarly, the terms "inner" and "outer" simply indicate directions toward and away from the center of the element of interest, respectively. This also applies to similar terms and terms serving the same purpose.

[0190] It should be noted that the technology of the present invention can have the following configuration. The technology of the present invention with the following configuration can have alignment marks provided within the pixel area for bonding chips together. This allows the light receiving device to use the chip area more efficiently, thus further miniaturizing the size of the light receiving device. The effects achieved by the technology of the present invention are not necessarily limited to those described herein, but may also include any effects described in the disclosure of the present invention.

[0191] (1) An optical receiving device, comprising:

[0192] The first chip has a pixel area in which sensor pixels are disposed;

[0193] A second chip includes signal processing circuitry for processing sensor signals output from the sensor pixels, and the second chip is stacked on top of the first chip; and

[0194] A first alignment mark is disposed in the pixel region of the first chip and corresponds to a second alignment mark disposed in the second chip.

[0195] (2) The optical receiving device according to (1), wherein,

[0196] The first alignment mark and the second alignment mark are respectively disposed on the bonding surface side of the first chip and the bonding surface side of the second chip.

[0197] (3) The optical receiving device according to (2), wherein,

[0198] In the first chip and / or the second chip, in the area on the opposite side of the bonding surface that overlaps with the first alignment mark or the second alignment mark, a wiring or semiconductor element is provided.

[0199] (4) The optical receiving device according to any one of (1) to (3), wherein,

[0200] The wiring in the first chip or the second chip located in the area overlapping with the first alignment mark or the second alignment mark is configured to extend in the same direction.

[0201] (5) The optical receiving device according to (4), wherein,

[0202] The wiring extending in the same direction is arranged with repeating pitches smaller than the pixel size of the sensor pixel.

[0203] (6) The optical receiving device according to any one of (1) to (5), wherein,

[0204] The planar shape of the first alignment mark and / or the second alignment mark is rectangular.

[0205] (7) The optical receiving device according to (6), wherein,

[0206] The first alignment mark and / or the second alignment mark are formed by arranging multiple conductor layers that extend in parallel along the same direction.

[0207] (8) The optical receiving device according to (7), wherein,

[0208] The conductor layer is arranged with repeating pitches smaller than the pixel size of the sensor pixel.

[0209] (9) The optical receiving device according to any one of (1) to (8), wherein,

[0210] The wiring disposed in the region overlapping with the first alignment mark or the second alignment mark is configured to extend along a first direction, and

[0211] The first alignment mark and the second alignment mark are arranged by arranging a plurality of conductor layers that extend in parallel along a second direction orthogonal to the first direction.

[0212] (10) The optical receiving device according to any one of (1) to (9), wherein,

[0213] The first alignment mark and the second alignment mark are positioned in an area where the first alignment mark and the second alignment mark overlap each other in the planar view of the pixel area.

[0214] (11) The optical receiving device according to any one of (1) to (10), wherein,

[0215] The first alignment mark and the second alignment mark have corresponding planar shapes.

[0216] (12) The optical receiving device according to any one of (1) to (11), wherein,

[0217] The planar area of ​​the second chip is smaller than that of the first chip.

[0218] (13) The optical receiving device according to any one of (1) to (12), wherein

[0219] The second chip has a rectangular shape, and

[0220] The second alignment mark is set at least at each corner of the rectangle.

[0221] (14) The optical receiving device according to any one of (1) to (13), wherein

[0222] Both the first chip and the second chip are formed by stacking multiple wiring layers on a semiconductor substrate, and

[0223] The first chip and the second chip are stacked such that the multilayer wiring layers of the first chip and the multilayer wiring layers of the second chip face each other.

[0224] This application claims priority to Japanese patent application JP2020-000191, filed with the Japan Patent Office on January 6, 2020, the entire contents of which are incorporated herein by reference.

[0225] Those skilled in the art should understand that various modifications, combinations, sub-combinations, and alterations can be made according to design requirements and other factors, as long as they fall within the protection scope of the appended claims or their equivalents.

Claims

1. An optical receiving device, comprising: The first chip has a pixel area in which sensor pixels are disposed; The second chip includes a processing circuit that performs signal processing on the sensor signal output from the sensor pixel, and the second chip is stacked on the first chip. and A first alignment mark is disposed in the pixel region of the first chip and corresponds to a second alignment mark disposed in the second chip. In this configuration, the wiring in the first chip or the second chip located in the area overlapping with the first alignment mark or the second alignment mark is configured to extend in the same direction. The wiring extending in the same direction is arranged with repeating pitches smaller than the pixel size of the sensor pixel.

2. The optical receiving device according to claim 1, wherein, The first alignment mark and the second alignment mark are respectively disposed on the bonding surface side of the first chip and the bonding surface side of the second chip.

3. The optical receiving device according to claim 2, wherein, In the first chip and / or the second chip, in the area on the opposite side of the bonding surface that overlaps with the first alignment mark or the second alignment mark, a wiring or semiconductor element is provided.

4. The optical receiving device according to claim 1, wherein, The planar shape of the first alignment mark and / or the second alignment mark is rectangular.

5. The optical receiving device according to claim 4, wherein, The first alignment mark and / or the second alignment mark are formed by arranging multiple conductor layers that extend in parallel along the same direction.

6. The optical receiving device according to claim 5, wherein, The conductor layer is arranged with repeating pitches smaller than the pixel size of the sensor pixel.

7. The optical receiving device according to claim 1, wherein, The wiring disposed in the region overlapping with the first alignment mark or the second alignment mark is configured to extend along a first direction, and The first alignment mark and the second alignment mark are arranged by arranging a plurality of conductor layers that extend in parallel along a second direction orthogonal to the first direction.

8. The optical receiving device according to claim 1, wherein, The first alignment mark and the second alignment mark are positioned in an area where the first alignment mark and the second alignment mark overlap each other in the planar view of the pixel area.

9. The optical receiving device according to claim 1, wherein, The first alignment mark and the second alignment mark have corresponding planar shapes.

10. The optical receiving device according to claim 1, wherein, The planar area of ​​the second chip is smaller than that of the first chip.

11. The optical receiving device according to claim 1, wherein, The second chip has a rectangular shape, and The second alignment mark is set at least at each corner of the rectangle.

12. The optical receiving device according to any one of claims 1 to 11, wherein, Both the first chip and the second chip are formed by stacking multiple wiring layers on a semiconductor substrate, and The first chip and the second chip are stacked such that the multilayer wiring layers of the first chip and the multilayer wiring layers of the second chip face each other.

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