Light detection device and semiconductor device

Abstract

Provided is a light detection device having a stack including a first substrate on which a light detection element is mounted and a second substrate on which a logic circuit for controlling the light detection element is mounted and which is stacked on the first substrate, wherein an inductor included in the logic circuit is provided on the reverse side of the second substrate from the first substrate.

Description

Photodetector and semiconductor device

[0001] This disclosure relates to a photodetector and a semiconductor device.

[0002] In recent years, in order to further miniaturize photodetectors, three-dimensional (layered) photodetectors have been proposed. An example of such a layered structure is the one disclosed in Patent Document 1 below. In the technology disclosed in Patent Document 1, miniaturization of the photodetector is achieved by stacking a sensor substrate on which a plurality of photodetectors are provided and a logic substrate on which transistors and the like that which constitute peripheral circuits are provided.

[0003] International Publication No. 2024 / 004876

[0004] In conventional optical detection devices, an inductor included in the peripheral circuitry is provided on the wiring layer on the sensor board side of the logic board. The magnetic flux generated by the inductor interferes with the light-shielding film provided on the sensor board, generating eddy currents and degrading the characteristics of the inductor. In order to suppress such interference, conventional technology has proposed providing slits in the light-shielding film. However, providing slits in the light-shielding film degrades the light-shielding function, increasing the likelihood of flare generation.

[0005] Therefore, this disclosure proposes a photodetector that can obtain desired inductor characteristics while suppressing the occurrence of flare.

[0006] According to this disclosure, a photodetector is provided, having a laminated structure including a first substrate on which a photodetector element is mounted, and a second substrate mounted on the first substrate and having a logic circuit for controlling the photodetector element, wherein an inductor included in the logic circuit is provided on the side of the second substrate opposite to the first substrate.

[0007] Furthermore, the present disclosure provides a semiconductor device having a laminated structure including a first substrate and a second substrate laminated on the first substrate, wherein an inductor is provided on the second substrate on the side opposite to the first substrate.

[0008] This is a block diagram showing a schematic configuration example of an electronic device equipped with an imaging device according to an embodiment of this disclosure. This is a block diagram showing a schematic configuration example of an imaging device according to an embodiment of this disclosure. This is a circuit diagram showing an example of pixel configuration according to an embodiment of this disclosure. This is a diagram showing an overview of an example of a stacked structure of an imaging device according to an embodiment of this disclosure. This is a diagram showing details of an example of a stacked structure of an imaging device according to a comparative example. This is an explanatory diagram for explaining the background of an embodiment of this disclosure. This is a diagram showing details of an example of a stacked structure of an imaging device according to a first embodiment of this disclosure. This is a diagram showing a cross-section when the imaging device is cut along the line B-B' shown in Figure 7A. This is an explanatory diagram (1) explaining the manufacturing method of an imaging device according to a first embodiment of this disclosure. This is an explanatory diagram (2) explaining the manufacturing method of an imaging device according to a first embodiment of this disclosure. This is a diagram showing details of an example of a stacked structure of an imaging device according to a second embodiment of this disclosure. This is an explanatory diagram (1) explaining the manufacturing method of an imaging device according to a second embodiment of this disclosure. This is an explanatory diagram (2) explaining the manufacturing method of an imaging device according to a second embodiment of this disclosure. This is a diagram showing details of an example of a stacked structure of an imaging device according to a modified example of the second embodiment of this disclosure. This is a diagram showing details of an example of a stacked structure of an imaging device according to a third embodiment of this disclosure. This is an explanatory diagram explaining the manufacturing method of an imaging device according to a third embodiment of this disclosure. This figure shows details of an example of a stacked structure of an imaging device according to Modification 1 of the third embodiment of this disclosure. This figure shows details of an example of a stacked structure of an imaging device according to Modification 2 of the third embodiment of this disclosure. This block diagram shows an example of a schematic functional configuration of a smartphone. This block diagram shows an example of a schematic configuration of a vehicle control system. This is an explanatory diagram showing an example of the installation positions of the external information detection unit and the imaging unit.

[0009] Preferred embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configuration will be denoted by the same reference numeral to avoid redundant explanation. In addition, in this specification and drawings, multiple components having substantially the same or similar functional configurations may be distinguished by adding a different alphabet after the same reference numeral. However, if there is no particular need to distinguish each of multiple components having substantially the same or similar functional configurations, only the same reference numeral will be used.

[0010] Furthermore, the drawings referenced in the following description are intended to illustrate and facilitate understanding of one embodiment of this disclosure, and for the sake of clarity, the shapes, dimensions, ratios, etc. shown in the drawings may differ from those of the actual product. In addition, the apparatus shown in the drawings may be modified in design as appropriate, taking into consideration the following description and known technology.

[0011] The descriptions of specific shapes in the following explanation do not refer only to geometrically defined shapes. More specifically, the descriptions of specific shapes in the following explanation include shapes that are similar to or have acceptable differences (errors and distortions) in the photodetector (semiconductor device), its manufacturing process, and its use and operation.

[0012] Furthermore, in the following descriptions of circuits (electrical connections), unless otherwise specified, "electrically connected" means connecting multiple elements in such a way that electricity (signals) can conduct through them. In addition, "electrically connected" in the following descriptions includes not only cases where multiple elements are directly and electrically connected, but also cases where they are indirectly and electrically connected through other elements.

[0013] The explanation will be given in the following order: 1. Background to the creation of the embodiments of this disclosure 1.1 Example of the configuration of an electronic device 1.2 Example of the configuration of an imaging device 1.3 Example of the configuration of a pixel 1.4 Example of the stacked structure of an imaging device 1.5 Example of the cross-sectional structure of an imaging device relating to a comparative example 1.6 Background 2. First embodiment 2.1 Detailed configuration 2.2 Manufacturing method 3. Second embodiment 3.1 Detailed configuration 3.2 Manufacturing method 3.3 Modification 4. Third embodiment 4.1 Detailed configuration 4.2 Manufacturing method 4.3 Modification 5. Summary 6. Application examples 6.1 Application example to a smartphone 6.2 Application example to a mobile device 7. Supplement

[0014] <<1. Background to the Creation of the Embodiments of the Disclosure>> <1.1 Example of Electronic Device Configuration> First, before describing the embodiments of the Disclosure, the background to the creation of the embodiments of the Disclosure will be explained. First, an electronic device on which an imaging device 100 (an example of a light detection device) according to an embodiment of the Disclosure may be mounted will be described with reference to Figure 1. Figure 1 is a block diagram showing a schematic configuration example of an electronic device 1000 on which an imaging device 100 according to an embodiment of the Disclosure is mounted. For example, the electronic device 1000 may be a digital camera or the like.

[0015] More specifically, as shown in Figure 1, the electronic device 1000 mainly comprises, for example, an imaging lens 1020, an imaging device 100, a storage unit 1030, and a processor 1040. The various functional parts of the electronic device 1000 will be described in detail below.

[0016] The imaging lens 1020 is an example of an optical system that focuses incident light and forms an image on the light-receiving surface of the imaging device 100. The light-receiving surface refers to the surface on which the multiple image sensors of the imaging device 100 are arranged. The imaging device 100 generates image data by photoelectric conversion of the incident light. The imaging device 100 also performs predetermined signal processing on the generated image data, such as noise reduction and white balance adjustment. An example of the configuration of the imaging device 100 will be described later.

[0017] The memory unit 1030 is composed of, for example, flash memory, DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), etc., and records image data and the like input from the imaging device 100.

[0018] The processor 1040 may include, for example, a CPU (Central Processing Unit) and an application processor that runs an operating system and various application software, as well as a GPU (Graphics Processing Unit) and a baseband processor. The processor 1040 performs various necessary processing on image data input from the imaging device 100 and image data read from the storage unit 1030, displays the data to the user, and transmits it externally via a predetermined network.

[0019] <1.2 Example of Imaging Device Configuration> Next, an example of the configuration of the imaging device 100 will be described with reference to Figure 2. Figure 2 is a block diagram showing a schematic configuration example of the imaging device 100 according to the embodiment of this disclosure. The imaging device 100 according to the embodiment of this disclosure may be a so-called back-illuminated type, where the incident surface is on the side opposite to the element formation surface of the semiconductor substrate (hereinafter referred to as the back surface), or it may be a so-called front-illuminated type, where the incident surface is on the front surface.

[0020] As shown in Figure 2, the imaging device 100 mainly comprises, for example, a pixel array unit 101, a vertical drive circuit 102, a column processing circuit 103, a horizontal drive circuit 104, a system control unit 105, a signal processing unit 108, and a data storage unit 109. In the following description, the vertical drive circuit 102, the column processing circuit 103, the horizontal drive circuit 104, the system control unit 105, the signal processing unit 108, and the data storage unit 109 are also referred to as peripheral circuits.

[0021] The pixel array section 101 has a configuration in which pixels 110, each having an image sensor that generates and stores an electric charge corresponding to the amount of light received, are arranged in a two-dimensional grid (hereinafter also referred to as array or matrix) in the row and column directions, i.e., in a matrix. Here, the row direction refers to the arrangement direction of the pixels 110 in a pixel row (horizontal direction in the drawing), and the column direction refers to the arrangement direction of the pixels 110 in a pixel column (vertical direction in the drawing). Details of specific circuit configuration examples of the pixels 110 will be described later.

[0022] In the pixel array section 101, pixel drive lines LD are wired along the row direction for each pixel row in the array of pixels, and vertical signal lines VSL are wired along the column direction for each pixel column. The pixel drive lines LD transmit drive signals for driving when reading signals from pixels. In Figure 2, the pixel drive lines LD are shown as individual wires, but this is not limited to individual wires. One end of each pixel drive line LD is connected to the output terminal corresponding to each row of the vertical drive circuit 102.

[0023] The vertical drive circuit 102 is composed of a shift register, an address decoder, and the like, and drives each pixel 110 of the pixel array 101 simultaneously or row by row. In other words, the vertical drive circuit 102, together with the system control unit 105 that controls the vertical drive circuit 102, constitutes a drive unit that controls the operation of each pixel 110 of the pixel array 101. The specific configuration of this vertical drive circuit 102 is not shown in the diagram, but generally it has two scanning systems: a read scanning system and a sweep scanning system.

[0024] The readout scanning system sequentially selects and scans the pixels 110 of the pixel array 101 row by row in order to read signals from the pixels 110. The signals read from the pixels 110 are analog signals. The sweep scanning system performs a sweep scan ahead of the readout scan performed by the readout scanning system by the exposure time.

[0025] This sweep scanning system resets the image sensor by sweeping away unwanted charges from the pixel 110 of the readout row. This sweep scanning system then performs what is known as an electronic shutter operation. Here, the electronic shutter operation refers to the operation of discarding the charge from the image sensor and starting a new exposure (starting to accumulate charge).

[0026] The signal read out by the readout scanning system corresponds to the amount of light received since the previous readout operation or electronic shutter operation. The period from the readout timing of the previous readout operation or the sweep timing of the electronic shutter operation to the readout timing of the current readout operation is the charge accumulation period (also called the exposure period) in pixel 110.

[0027] The signals output from each pixel 110 of the pixel row selected and scanned by the vertical drive circuit 102 are input to the column processing circuit 103 through each of the vertical signal lines VSL for each pixel column. The column processing circuit 103 performs predetermined signal processing on the signals output from each pixel 110 of the selected row through the vertical signal lines VSL for each pixel column of the pixel array unit 101, and temporarily holds the pixel signals after signal processing.

[0028] Specifically, the column processing circuit 103 performs at least noise reduction processing as signal processing, such as CDS (Correlated Double Sampling) processing or DDS (Double Data Sampling) processing. For example, CDS processing removes fixed pattern noise specific to the pixel 110, such as reset noise and threshold variations of the amplification transistors within the pixel. In addition, the column processing circuit 103 also has, for example, an AD (analog-to-digital) conversion function, which converts the analog pixel signals read from the image sensor into digital signals and outputs them.

[0029] The horizontal drive circuit 104 is composed of a shift register, an address decoder, and the like, and sequentially selects the readout circuits (hereinafter referred to as pixel circuits) corresponding to the pixel rows of the column processing circuit 103. Through this selective scanning by the horizontal drive circuit 104, the pixel signals processed for each pixel circuit in the column processing circuit 103 are output sequentially.

[0030] The system control unit 105 is composed of a timing generator and the like that generates various timing signals, and controls the vertical drive circuit 102, the column processing circuit 103, and the horizontal drive circuit 104, etc., based on the various timings generated by the timing generator.

[0031] The signal processing unit 108 has at least an arithmetic processing function and performs various signal processing, such as arithmetic processing, on the pixel signals output from the column processing circuit 103. The data storage unit 109 temporarily stores the data necessary for the signal processing performed by the signal processing unit 108.

[0032] Furthermore, the image data output from the signal processing unit 108 may be subjected to predetermined processing in, for example, a processor 1040 in an electronic device 1000 equipped with the imaging device 100, or transmitted to an external party via a predetermined network.

[0033] In the embodiments of this disclosure, the configuration of the imaging device 100 is not limited to the example shown in Figure 2.

[0034] <1.3 Example of Pixel Configuration> Next, with reference to Figure 3, a detailed description of a specific circuit configuration example of the pixel 110 will be given. Figure 3 is a circuit diagram showing an example of the configuration of a pixel 110 according to the embodiment of this disclosure. As shown in Figure 3, the pixel 110 mainly comprises a photodiode (image sensor) PD, a transfer transistor 111, a reset transistor 112, an amplification transistor 113, a selection transistor 114, and a floating diffusion layer FD.

[0035] The gate of the selection transistor 114 is electrically connected to the selection transistor drive line LD114 included in the pixel drive line LD, and the gate of the reset transistor 112 is electrically connected to the reset transistor drive line LD112 included in the pixel drive line LD. In addition, the gate of the transfer transistor 111 is electrically connected to the transfer transistor drive line LD111 included in the pixel drive line LD. Furthermore, the drain of the amplification transistor 113 is connected via the selection transistor 114 to the vertical signal line VSL, one end of which is connected to the column processing circuit 103.

[0036] In the following description, the reset transistor 112, the amplification transistor 113, and the selection transistor 114 are collectively referred to as the pixel circuit. The pixel circuit may include a floating diffusion layer FD and / or a transfer transistor 111.

[0037] The photodiode PD is an element that photoelectrically converts incident light. The transfer transistor 111 transfers charges generated in the photodiode PD. The floating diffusion FD accumulates the charges transferred by the transfer transistor 111. The amplification transistor 113 causes a pixel signal having a voltage value corresponding to the charges accumulated in the floating diffusion FD to appear on the vertical signal line VSL. The reset transistor 112 discharges the charges accumulated in the floating diffusion FD. The selection transistor 114 selects the pixel 110 to be read out.

[0038] An anode of the photodiode PD is grounded, and a cathode thereof is electrically connected to a source of the transfer transistor 111. A drain of the transfer transistor 111 is electrically connected to a source of the reset transistor 112 and a gate of the amplification transistor 113, and a node serving as these connection points constitutes the floating diffusion FD. Note that a drain of the reset transistor 112 is connected to a vertical reset input line (not shown).

[0039] A source of the amplification transistor 113 is connected to a vertical current supply line (not shown). A drain of the amplification transistor 113 is electrically connected to a source of the selection transistor 114, and a drain of the selection transistor 114 is electrically connected to the vertical signal line VSL.

[0040] The floating diffusion FD converts accumulated charges into a voltage having a voltage value corresponding to the amount of the charges. Note that the floating diffusion FD may be, for example, a capacitance to ground. Note that, in the embodiment of the present disclosure, the floating diffusion FD is not limited to being a capacitance to ground. For example, the floating diffusion FD may be a capacitance added by intentionally connecting a capacitor or the like to a node where the drain of the transfer transistor 111, the source of the reset transistor 112, and the gate of the amplification transistor 113 are connected to each other.

[0041] In the embodiment of the present disclosure, the circuit configuration of the pixel 110 is not limited to the example shown in FIG. 3. For example, in the embodiment of the present disclosure, the pixel 110 may include a plurality of photodiodes PD, or may further include other transistors (pixel transistors).

[0042] <1.4 Example of stacked structure of image pickup device> Next, an outline of an example of the stacked structure of the image pickup device 100 will be described with reference to FIG. 4. FIG. 4 is a diagram schematically showing an example of a stacked chip structure of the image pickup device 100 according to the embodiment of the present disclosure. As shown in FIG. 4, the image pickup device 100 has a stacked structure in which, for example, a substrate 121 called a CIS (CMOS Image Sensor) chip and a substrate 122 called a logic chip are stacked vertically. The CIS chip (substrate) 121 is, for example, a semiconductor chip including a pixel array unit 101 in which photodiodes PD are arranged, and the logic chip (substrate) 122 is, for example, for reading pixel signals as shown in FIG. 3, this is a semiconductor chip including a pixel circuit, a peripheral circuit for processing pixel signals as shown in FIG. 2, and the like. Note that in the embodiment of the present disclosure, the substrates 121 and 122 are not limited to being singulated semiconductor chips obtained by dicing a semiconductor wafer, and may be semiconductor wafers.

[0043] For bonding the two substrates 121 and 122, for example, so-called direct bonding can be used, in which the bonding surfaces of the two substrates are planarized and the two substrates are bonded together by atomic force. Alternatively, the embodiment of the present disclosure is not limited to this. For example, so-called Cu-Cu bonding, in which copper (Cu) electrode pads formed on the mutual bonding surfaces are bonded to each other, or bump bonding can also be used.

[0044] Furthermore, the two substrates 121 and 122 may be electrically connected to each other via a connecting portion such as a TSV (Through-Silicon Via) penetrating the semiconductor substrate, for example.

[0045] However, when Cu-Cu bonding or bump bonding is used to bond the two substrates 121 and 122, the two substrates are electrically connected to each other via the Cu-Cu bonding portion or the bump bonding portion.

[0046] In the embodiments of this disclosure, the stacked structure of the chip of the imaging device 100 is not limited to the example shown in Figure 4.

[0047] <1.5 Example of Cross-Sectional Structure of Imaging Device According to Comparative Example> Next, an example of the cross-sectional structure of the imaging device 100a according to the comparative example will be described with reference to Figure 5. Figure 5 is a cross-sectional view showing an example of the cross-sectional structure of the imaging device 100a according to the comparative example. Here, the comparative example refers to the imaging device 100a that the inventors had been studying before creating the embodiments of this disclosure.

[0048] As explained earlier, since the imaging device 100a has various functional blocks, multiple substrates and semiconductor chips equipped with different functional blocks are stacked and bonded together in the imaging device 100a. More specifically, in the imaging device 100a, semiconductor chips and semiconductor wafers stacked together, or semiconductor wafers with each other, or semiconductor chips with each other are electrically and physically bonded. Such a stacked structure enables high density and miniaturization of semiconductor devices, and furthermore, makes it possible to manufacture each substrate and each semiconductor chip equipped with different functional blocks using a manufacturing method suitable for each.

[0049] In this specification, a semiconductor chip refers to a chip obtained by cutting out a semiconductor wafer. Furthermore, in this specification, a substrate refers to a semiconductor wafer such as a silicon wafer, or a semiconductor chip obtained by cutting them out.

[0050] As shown in Figure 5, in the comparative example, the imaging device 100a has a stacked structure, and more specifically, a first substrate 200 and a second substrate 300 that are stacked and bonded together.

[0051] The first substrate 200 is, for example, a sensor substrate on which an image sensor is mounted that generates and outputs a pixel signal corresponding to the amount of incident light. More specifically, the first substrate 200 has a semiconductor substrate 210 and a wiring layer 230 provided on the surface 210a of the semiconductor substrate 210.

[0052] The semiconductor substrate 210 is provided with a photodiode PD, etc. The photodiode PD can generate an electric charge corresponding to the amount of light it receives and output it as a pixel signal. As shown in Figure 5, for example, a color filter (not shown) and an on-chip lens 502 are provided on the photodiode PD.

[0053] Furthermore, in the comparative example, as shown in Figure 5, a light-shielding film 500 made of a metallic material is provided on the back surface 210b located around the photodiode PD to prevent the occurrence of flare. Light incident on the imaging device 100a is incident on the photodiode PD and detected as a pixel signal. However, some of the light incident on the imaging device 100a may be reflected around the photodiode PD of the imaging device 100a and incident on the photodiode PD. When such light is detected by the photodiode PD, it may appear as unwanted flare (noise) in the image obtained by the imaging device 100a. Therefore, in order to prevent the occurrence of such flare, a light-shielding film 500 is provided around the photodiode PD. Furthermore, in the comparative example, the wiring layer 230 has an insulating film 236 and wiring 232.

[0054] Furthermore, the second substrate 300, which is bonded to the first substrate 200, is a logic board equipped with logic circuits that control a photodiode PD or perform predetermined signal processing, and specifically, the peripheral circuits described above are provided on it. More specifically, the second substrate 300 has a semiconductor substrate 310, a wiring layer 330 provided on the surface 310a of the semiconductor substrate 310, and a wiring layer 350 provided on the back surface 310b of the semiconductor substrate 310.

[0055] The semiconductor substrate 310 is provided with, for example, a transistor (not shown) included in a logic circuit electrically connected to the photodiode PD. Furthermore, in the comparative example, the semiconductor substrate 310 may have a TSV 314 penetrating the semiconductor substrate 310. Also in the comparative example, the wiring layer 330 has an insulating film 336 and wiring 332, and the wiring layer 350 has an insulating film 356 and wiring 352.

[0056] In the imaging device 100a, a Phase Locked Loop (PLL) circuit is provided as part of the peripheral circuitry to generate a reference clock signal used for control. Furthermore, the PLL circuit has an inductor that constitutes a loop filter. In the comparative example, as shown in Figure 5, the inductor 510 is provided in the wiring layer 330. Furthermore, in the comparative example, the inductor 510 has a large layout area, and for example, at least a small portion of it overlaps with the light-shielding film 500 located around the photodiode PD.

[0057] Thus, in the comparative example imaging device 100a, the imaging device 100a is miniaturized by stacking a first substrate 200 and a second substrate 300, each equipped with different functional blocks.

[0058] <1.6 Background> Next, with reference to Figure 6, the background to the inventor's creation of the embodiments of the present disclosure will be explained. Figure 6 is an explanatory diagram for explaining the background of the embodiments of the present disclosure.

[0059] In the comparative example, as explained earlier, the inductor 510 is superimposed on the light-shielding film 500. Also, in the comparative example, although there is a semiconductor substrate 210 between the inductor 510 and the light-shielding film 500, the distance between the inductor 510 and the light-shielding film 500 is close. Therefore, in the comparative example, as shown in Figure 6, the magnetic flux generated by the inductor 510 interferes with the light-shielding film 500, generating eddy currents. As a result of the generation of eddy currents in the comparative example, the Q value and oscillation frequency of the inductor 510 change, making it impossible to obtain the desired characteristics.

[0060] Therefore, in conventional technology, it has been proposed to reduce eddy currents by providing slits in the light-shielding film 500. However, providing slits in the light-shielding film 500 deteriorates the light-shielding function, which increases the likelihood of flare generation.

[0061] Therefore, in light of these circumstances, the inventors have created the embodiments of the present disclosure described below. According to the embodiments of the present disclosure, desired inductor characteristics can be obtained while suppressing the occurrence of flare. The details of the embodiments of the present disclosure created by the inventors will be described in order below.

[0062] <<2. First Embodiment>> <2.1 Detailed Configuration> First, an example of the cross-sectional structure of the imaging device 100 (an example of a light detection device) according to the first embodiment of the present disclosure will be described with reference to Figures 7A and 7B. Figure 7A is a cross-sectional view showing an example of the cross-sectional structure of the imaging device 100 according to this embodiment, and Figure 7B is a diagram showing the cross-section when the imaging device 100 is cut along the line B-B' shown in Figure 7A.

[0063] As shown in Figure 7A, in this embodiment as well as in the comparative example, the imaging device 100 has a stacked structure, and more specifically, a first substrate 200 and a second substrate 300 that are stacked and joined together.

[0064] The first substrate 200 is, for example, a sensor substrate on which an image sensor is mounted that generates and outputs a pixel signal corresponding to the amount of incident light. More specifically, the first substrate 200 has a semiconductor substrate (first semiconductor substrate) 210 and a wiring layer (first wiring layer) 230 provided on the surface 210a of the semiconductor substrate 210.

[0065] The semiconductor substrate 210 is formed from a semiconductor substrate made of, for example, silicon (Si), silicon carbide (SiC), silicon germanium (SiGe), etc. A photodiode (photodetector) PD is provided on the semiconductor substrate 210. The photodiode PD can generate an electric charge corresponding to the amount of light it receives and output it as a pixel signal. As shown in Figure 7A, a color filter (not shown) and an on-chip lens 502 are provided on the photodiode PD. The color filter is a filter that transmits light of a specific wavelength from the light incident on the imaging device 100. For example, the color filter can transmit red light, green light, or blue light. The color filter can be formed from a material in which a pigment or dye is dispersed in a transparent binder such as silicone. The on-chip lens 502 can focus the incident light onto the photodiode PD. The on-chip lens 502 can be formed from, for example, a styrene resin, an acrylic resin, a styrene-acrylic copolymer resin, or a siloxane resin.

[0066] Furthermore, in this embodiment, as shown in Figure 7A, a light-shielding film 500 made of a light-shielding metal material is provided on the back surface 210b located around the photodiode PD to prevent the generation of flare. The light-shielding film 500 can be formed from, for example, tungsten (W), copper (Cu), aluminum (Al), etc.

[0067] Furthermore, in this embodiment, the wiring layer 230 has an insulating film 236 and wiring 232. The insulating film 236 is, for example, silicon oxide (SiO ｘ ), silicon nitride (SiN ｘ ), silicon oxynitride (SiO ｘ N ｙ ), silicon oxycarbide (SiO ｘ C ｙ ), aluminum oxide (Al ｘ O ｙThe wiring 232 can be formed from, for example, tungsten (W), copper (Cu), titanium (Ti), tantalum (Ta), cobalt (Co), aluminum (Al), gold (Au), silver (Ag), polysilicon (poly-Si), etc.

[0068] Furthermore, in this embodiment, the wiring layer 230 may be electrically and physically connected (bonded) to the second substrate 300, for example, via an electrode 238 provided on the outermost surface, as will be described later.

[0069] Furthermore, the second substrate 300, which is bonded to the first substrate 200, is a logic board equipped with logic circuits that control a photodiode PD or perform predetermined signal processing, and specifically, the peripheral circuits described above are provided on it. More specifically, the second substrate 300 has a semiconductor substrate (second semiconductor substrate) 310, a wiring layer (second wiring layer) 330 provided on the surface 310a of the semiconductor substrate 310, and a wiring layer (third wiring layer) 350 provided on the back surface 310b of the semiconductor substrate 310.

[0070] The semiconductor substrate 310 is formed from a semiconductor substrate made of, for example, silicon, silicon carbide, or silicon germanium. The semiconductor substrate 310 is provided with transistors (not shown) and the like, which are included in a logic circuit electrically connected to the photodiode PD.

[0071] Furthermore, in this embodiment, the semiconductor substrate 310 may have a TSV (through-silicon) 314 that penetrates the semiconductor substrate 310. The TSV 314 can electrically connect the front surface 310a side and the back surface 310b side of the semiconductor substrate 310. In detail, the TSV 314 has a through-hole that penetrates the semiconductor substrate 310 and a metal film that covers the through-hole via an insulating film. The metal film can be formed from, for example, tungsten (W), copper (Cu), titanium (Ti), tantalum (Ta), polysilicon (poly-Si), etc.

[0072] In this embodiment, the wiring layer 330 includes an insulating film 336 and a wiring 332. The insulating film 336 can be formed of, for example, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, aluminum oxide, or the like. The wiring 332 can be formed of, for example, tungsten, copper, titanium, tantalum, cobalt, aluminum, gold, silver, polysilicon, or the like.

[0073] Furthermore, in this embodiment, an electrode 338 for electrically and physically connecting to the first substrate 200 is provided on the outermost surface of the wiring layer 330. That is, the electrode 338 is bonded to the above-mentioned electrode 238, whereby the wiring layer 230 of the first substrate 200 and the wiring layer 330 of the second substrate 300 can be electrically and physically connected (bonded). In this embodiment, the electrodes 238 and 338 can be formed of a metal material such as copper (Cu), for example. Note that in this embodiment, the bonding is not limited to the above-mentioned type, and may be bump bonding, for example.

[0074] Furthermore, in this embodiment, the wiring layer 350 includes an insulating film 356 and a wiring 352. The insulating film 356 can be formed of, for example, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, aluminum oxide, or the like. The wiring 352 can be formed of, for example, tungsten, copper, titanium, tantalum, cobalt, aluminum, gold, silver, polysilicon, or the like.

[0075] Furthermore, in this embodiment, as shown in FIG. 7A, unlike the comparative example, the inductor 510 is located on the opposite side of the surface (first surface) of the second substrate 300 facing the first substrate 200, in other words, on the surface (second surface) side, that is, on the back surface 310b of the semiconductor substrate 310. Specifically, in this embodiment, the inductor 510 has an electrode film formed of, for example, tungsten (W), copper (Cu), titanium (Ti), tantalum (Ta), cobalt (Co), aluminum (Al), or the like. Furthermore, in this embodiment, the electrode film is made of, for example, silicon oxide (SiO ｘ ), silicon nitride (SiN ｘ ), silicon oxynitride (SiOｘ N ｙ ), silicon oxycarbide (SiO ｘ C ｙ It is embedded in an insulating film made of the following:

[0076] Furthermore, in this embodiment, as shown in Figure 7B, the inductor 510 may be a planar coil made of an electrode film having a rectangular spiral pattern, for example. In addition, in this embodiment, as shown in Figure 7B, the inductor 510 may be electrically connected to the TSV 314. Since such an inductor 510 can be manufactured when processing the TSV 314 and wiring 352, the increase in manufacturing time of the imaging device 100 can be suppressed. In this embodiment, the planar shape of the inductor 510 is not limited to the shape shown in Figure 7B, and may be a circular spiral pattern or a polygonal spiral pattern (for example, an octagon, a hexagon, etc.).

[0077] Furthermore, in this embodiment, as shown in Figure 7A, at least a portion of the inductor 510 may be superimposed on the light-shielding film 500. In this embodiment, the light-shielding film 500 and the inductor 510 sandwich the first substrate 200 and the wiring layer 330 and semiconductor substrate 310 of the second substrate, and there is a sufficient distance between the light-shielding film 500 and the inductor 510. Therefore, according to this embodiment, the magnetic flux generated in the inductor 510 does not interfere with the light-shielding film 500, and the generation of eddy currents can be suppressed. As a result, according to this embodiment, the generation of eddy currents in the light-shielding film 500 can be suppressed, and the desired characteristics of the inductor 510 can be obtained. Furthermore, in this embodiment, since the generation of eddy currents in the light-shielding film 500 can be suppressed, it becomes unnecessary to provide slits in the light-shielding film 500, and as a result, the light-shielding function does not deteriorate, and the generation of flare can be suppressed. In addition, according to this embodiment, since slits are not provided in the light-shielding film 500, the increase in the manufacturing time of the imaging device 100 can be suppressed.

[0078] Furthermore, in this embodiment, since the photodiode PD and the inductor 510 are at a sufficient distance from each other, with the first substrate 200 and the wiring layer 330 and semiconductor substrate 310 of the second substrate in between, at least a portion of the inductor 510 may be superimposed on the photodiode PD.

[0079] Furthermore, in this embodiment, by providing the inductor 510 on the back surface 310b of the semiconductor substrate 310, the area of ​​the second substrate 300 can be reduced compared to the comparative example, making it possible to further miniaturize the imaging device 100.

[0080] In this embodiment, the imaging device 100 is not limited to the configuration shown in Figures 7A and 7B, but can be modified in various ways as will be described later.

[0081] <2.2 Manufacturing Method> Next, an example of a manufacturing method for the imaging device 100 according to this embodiment will be described with reference to Figures 8A and 8B. Figures 8A and 8B are explanatory diagrams illustrating the manufacturing method for the imaging device 100 according to this embodiment, and in detail correspond to the cross-sectional view in Figure 7A.

[0082] First, as shown in the upper part of Figure 8A, a wiring layer 330 is formed on the surface 310a of the semiconductor substrate 310, and a TSV 314 penetrating the semiconductor substrate 310 and wiring 352 on the back surface 310b are formed using etching or the like. Furthermore, as shown in the lower part of Figure 8A, an insulating film 356 is deposited on the back surface 310b of the semiconductor substrate 310.

[0083] Next, as shown in the upper part of Figure 8B, an inductor 510 is formed on the back surface 310b of the semiconductor substrate 310. Furthermore, as shown in the lower part of Figure 8B, an insulating film 356 is deposited so as to cover the inductor 510. Then, by bonding the second substrate 300 created in this way to the first substrate 200, the imaging device 100 can be manufactured.

[0084] In this embodiment, the method for manufacturing the imaging device 100 is not limited to the method shown in Figures 8A and 8B.

[0085] <<3. Second Embodiment>> <3.1 Detailed Configuration> Next, with reference to Figure 9, an example of the cross-sectional structure of the imaging device 100 according to the second embodiment of the present disclosure will be described. Figure 9 is a cross-sectional view showing an example of the cross-sectional structure of the imaging device 100 according to this embodiment. In the following description, points that are common with the first embodiment described above will be omitted from the explanation.

[0086] As shown in Figure 9, in this embodiment as well as in the first embodiment, the imaging device 100 has a stacked structure, and more specifically, a first substrate 200 and a second substrate 300 that are stacked and joined together. The first substrate 200 has a semiconductor substrate 210 and a wiring layer 230 provided on the surface 210a of the semiconductor substrate 210. Also in this embodiment as well, as shown in Figure 9, a light-shielding film 500 is provided on the back surface 210b located around the photodiode PD. Furthermore, in this embodiment as well, the wiring layer 230 has an insulating film 236 and wiring 232.

[0087] In this embodiment as well, the second substrate 300 includes a semiconductor substrate 310, a wiring layer 330 provided on the surface 310a of the semiconductor substrate 310, and a wiring layer 350 provided on the back surface 310b of the semiconductor substrate 310. Furthermore, in this embodiment as well, the semiconductor substrate 310 may have a TSV 314 penetrating the semiconductor substrate 310. In this embodiment as well, the wiring layer 330 has an insulating film 336 and wiring 332, and the wiring layer 350 has an insulating film 356 and wiring 352. Furthermore, in this embodiment as well, the wiring layer 230 of the first substrate 200 and the wiring layer 330 of the second substrate 300 are joined together.

[0088] Furthermore, in this embodiment, as shown in Figure 9, unlike the first embodiment, the inductor 510 is provided in a layer on the surface of the second substrate 300 that is opposite to the surface facing the first substrate 200, in other words, within the wiring layer 350 on the back surface 310b of the semiconductor substrate 310. Also, in this embodiment, the inductor 510 can be, for example, a three-dimensional spiral pattern within the insulating film 356 of the wiring layer 350. Since such an inductor 510 can be manufactured when processing the TSV 314 and wiring 352, the increase in manufacturing time of the imaging device 100 can be suppressed. In this embodiment, the shape of the inductor 510 is not limited to the shape shown in Figure 9, and may be, for example, a planar spiral pattern provided within the insulating film 356 of the wiring layer 350.

[0089] In this embodiment as well, as shown in Figure 9, at least a portion of the inductor 510 may be superimposed on the light-shielding film 500, or at least a portion of the inductor 510 may be superimposed on the photodiode PD.

[0090] In this embodiment, the light-shielding film 500 and the inductor 510 sandwich the first substrate 200, the wiring layer 330 of the second substrate 300, the semiconductor substrate 310, and a portion of the wiring layer 350, and there is a sufficient distance between the light-shielding film 500 and the inductor 510. Therefore, according to this embodiment, the magnetic flux generated by the inductor 510 does not interfere with the light-shielding film 500, and the generation of eddy currents can be suppressed. As a result, according to this embodiment, the generation of eddy currents in the light-shielding film 500 can be suppressed, and the desired characteristics of the inductor 510 can be obtained. Furthermore, in this embodiment as well, the generation of eddy currents in the light-shielding film 500 can be suppressed, so it is not necessary to provide slits in the light-shielding film 500, and as a result the light-shielding function does not deteriorate, and the generation of flare can be suppressed. In addition, according to this embodiment, since there are no slits in the light-shielding film 500, the increase in the manufacturing time of the imaging device 100 can be suppressed.

[0091] Furthermore, in this embodiment as well, by providing the inductor 510 within the wiring layer 350, the area of ​​the second substrate 300 can be reduced compared to the comparative example, making it possible to further miniaturize the imaging device 100.

[0092] In this embodiment, the imaging device 100 is not limited to the configuration shown in Figure 9, but can be modified in various ways as will be described later.

[0093] <3.2 Manufacturing Method> Next, an example of a manufacturing method for the imaging device 100 according to this embodiment will be described with reference to Figures 10A and 10B. Figures 10A and 10B are explanatory diagrams illustrating the manufacturing method for the imaging device 100 according to this embodiment, and in detail correspond to the cross-sectional view in Figure 9.

[0094] First, as shown in the upper part of Figure 10A, a wiring layer 330 is formed on the surface 310a of the semiconductor substrate 310, and a TSV 314 penetrating the semiconductor substrate 310 and wiring 352 on the back surface 310b are formed using etching or the like. Furthermore, as shown in the lower part of Figure 10A, an insulating film 356 is deposited on the back surface 310b of the semiconductor substrate 310.

[0095] Next, as shown in Figure 10B, an inductor 510 is formed on the insulating film 356 on the back surface 310b of the semiconductor substrate 310. Then, by bonding the second substrate 300 created in this way to the first substrate 200, the imaging device 100 can be manufactured.

[0096] In this embodiment, the method for manufacturing the imaging device 100 is not limited to the method shown in Figures 10A and 10B.

[0097] <3.3 Modified Examples> First, with reference to Figure 11, an example of the cross-sectional structure of the imaging device 100 according to a modified example of this embodiment will be described. Figure 11 is a cross-sectional view showing an example of the cross-sectional structure of the imaging device 100 according to a modified example of this embodiment. In the following description, points common to the first and second embodiments described above will be omitted from the explanation.

[0098] As shown in Figure 11, in this modified example, similar to the second embodiment, the imaging device 100 has a stacked structure, and more specifically, a first substrate 200 and a second substrate 300 that are stacked and joined together. The first substrate 200 has a semiconductor substrate 210 and a wiring layer 230 provided on the surface 210a of the semiconductor substrate 210. Also in this modified example, as shown in Figure 11, a light-shielding film 500 is provided on the back surface 210b located around the photodiode PD.

[0099] Furthermore, in this modified example, the second substrate 300 also includes a semiconductor substrate 310, a wiring layer 330 provided on the surface 310a of the semiconductor substrate 310, and a wiring layer 350 provided on the back surface 310b of the semiconductor substrate 310. Moreover, in this modified example, the semiconductor substrate 310 may also have a TSV 314 penetrating the semiconductor substrate 310.

[0100] In this modified example, unlike the second embodiment, as shown in Figure 11, the wiring layer 230 of the first substrate 200 and the wiring layer 350 of the second substrate 300 are joined together. Furthermore, in this modified example, as shown in Figure 11, the inductor 510 is provided in a layer on the surface of the second substrate 300 that is opposite to the surface facing the first substrate 200, in other words, within the wiring layer 330 on the surface 310a of the semiconductor substrate 310.

[0101] In this modified example, the light-shielding film 500 and the inductor 510 are sandwiched between the first substrate 200, the wiring layer 350 of the second substrate 300, the semiconductor substrate 310, and a portion of the wiring layer 330, and there is a sufficient distance between the light-shielding film 500 and the inductor 510. Therefore, according to this modified example, the magnetic flux generated by the inductor 510 can interfere with the light-shielding film 500, and the generation of eddy currents can be suppressed.

[0102] <<4. Third Embodiment>> <4.1 Detailed Configuration> Next, with reference to Figure 12, an example of the cross-sectional structure of the imaging device 100 according to the third embodiment of the present disclosure will be described. Figure 12 is a cross-sectional view showing an example of the cross-sectional structure of the imaging device 100 according to this embodiment. In the following description, points common to the first and second embodiments described above will be omitted from the explanation.

[0103] As shown in Figure 12, in this embodiment as well as in the first and second embodiments, the imaging device 100 has a stacked structure, and more specifically, a first substrate 200 and a second substrate 300 stacked and joined together. The first substrate 200 has a semiconductor substrate 210 and a wiring layer 230 provided on the surface 210a of the semiconductor substrate 210, and the wiring layer 230 has an insulating film 236 and wiring 232. Also in this embodiment as well, as shown in Figure 12, a light-shielding film 500 is provided on the back surface 210b located around the photodiode PD.

[0104] In this embodiment as well, the second substrate 300 includes a semiconductor substrate 310, a wiring layer 330 provided on the surface 310a of the semiconductor substrate 310, and a wiring layer 350 provided on the back surface 310b of the semiconductor substrate 310. Furthermore, in this embodiment as well, the semiconductor substrate 310 may have a TSV 314 penetrating the semiconductor substrate 310. In this embodiment as well, the wiring layer 330 has an insulating film 336 and wiring 332, and the wiring layer 350 has an insulating film 356 and wiring 352. Furthermore, in this embodiment as well, the wiring layer 230 of the first substrate 200 and the wiring layer 330 of the second substrate 300 are joined together.

[0105] Furthermore, in this embodiment, as shown in Figure 12, unlike the first and second embodiments, the third substrate 400 is provided on the surface of the second substrate 300 that is opposite to the surface facing the first substrate 200. In this embodiment, the third substrate 400 may be a semiconductor chip with a smaller area than the first substrate 200 and the second substrate 300, or it may be a semiconductor substrate (wafer) or semiconductor chip with the same area as the first substrate 200 and the second substrate 300. Furthermore, in this embodiment, the third substrate 400 may, for example, have a part of a logic circuit provided on it.

[0106] In this embodiment, the third substrate 400 includes a semiconductor substrate (third semiconductor substrate) 410 and a wiring layer (fourth wiring layer) 430 provided on the surface 410a of the semiconductor substrate 410. Furthermore, in this embodiment, the wiring layer 350 of the second substrate 300 and the wiring layer 430 of the third substrate 400 are joined together. In this embodiment, the joining of the wiring layer 350 of the second substrate 300 and the wiring layer 430 of the third substrate 400 can be by bonding using electrodes provided on the outermost surface of each (for example, Cu-Cu bonding) or bump bonding. In this embodiment, the wiring layer 450 includes an insulating film 456 and wiring 452. The insulating film 456 can be formed from, for example, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, aluminum oxide, etc. Furthermore, the wiring 452 can be formed from, for example, tungsten, copper, titanium, tantalum, cobalt, aluminum, gold, silver, polysilicon, etc.

[0107] Furthermore, in this embodiment, as shown in Figure 12, unlike the first and second embodiments, the inductor 510 is provided on the wiring layer 430 on the surface 410a of the semiconductor substrate 410. The shape of the inductor 510 may be, for example, a planar spiral pattern provided on the insulating film 436 of the wiring layer 430, or a three-dimensional spiral pattern within the insulating film 436 of the wiring layer 430. Since such an inductor 510 can be manufactured when processing the wiring 432, etc., it is possible to suppress an increase in the manufacturing time of the imaging device 100.

[0108] In this embodiment as well, as shown in Figure 12, at least a portion of the inductor 510 may be superimposed on the light-shielding film 500, or at least a portion of the inductor 510 may be superimposed on the photodiode PD.

[0109] In this embodiment, the light-shielding film 500 and the inductor 510 are sandwiched between the first substrate 200 and the second substrate 300, and there is a sufficient distance between the light-shielding film 500 and the inductor 510. Therefore, according to this embodiment, the magnetic flux generated by the inductor 510 does not interfere with the light-shielding film 500, and the generation of eddy currents can be suppressed. As a result, according to this embodiment, the generation of eddy currents in the light-shielding film 500 can be suppressed, and the desired characteristics of the inductor 510 can be obtained. Furthermore, in this embodiment as well, the generation of eddy currents in the light-shielding film 500 can be suppressed, so it is not necessary to provide slits in the light-shielding film 500, and as a result the light-shielding function does not deteriorate, and the generation of flare can be suppressed. In addition, according to this embodiment, since there are no slits in the light-shielding film 500, the increase in the manufacturing time of the imaging device 100 can be suppressed.

[0110] Furthermore, in this embodiment as well, by providing the inductor 510 on the wiring layer 430, the area of ​​the second substrate 300 can be reduced compared to the comparative example, making it possible to further miniaturize the imaging device 100.

[0111] In this embodiment, the imaging device 100 is not limited to the configuration shown in Figure 12, but can be modified in various ways as will be described later.

[0112] <4.2 Manufacturing Method> Next, an example of a manufacturing method for the imaging device 100 according to this embodiment will be described with reference to Figure 13. Figure 13 is an explanatory diagram illustrating the manufacturing method for the imaging device 100 according to this embodiment, and in detail corresponds to the cross-sectional view in Figure 12.

[0113] First, as shown in the upper part of Figure 13, a wiring layer 330 is formed on the surface 310a of the semiconductor substrate 310, and a TSV 314 penetrating the semiconductor substrate 310 and wiring 352 etc. are formed on the back surface 310b. Furthermore, an insulating film 356 is formed on the back surface 310b of the semiconductor substrate 310 to form a wiring layer 350.

[0114] Next, as shown in the lower part of Figure 13, a third substrate 400 on which an inductor 510 is formed is bonded to the insulating film 356 on the back surface 310b of the semiconductor substrate 310. Then, by bonding the second substrate 300 thus created to the first substrate 200, the imaging device 100 can be manufactured.

[0115] In this embodiment, the method for manufacturing the imaging device 100 is not limited to the method shown in Figure 13.

[0116] <4.3 Modifications> (Modification 1) Next, with reference to Figure 14, an example of the cross-sectional structure of the imaging device 100 according to Modification 1 of the third embodiment of this disclosure will be described. Figure 14 is a cross-sectional view showing an example of the cross-sectional structure of the imaging device 100 according to Modification 1 of this embodiment. In the following description, points common to the first to third embodiments described above will be omitted from the explanation.

[0117] As shown in Figure 14, in this modified example 1, similar to the third embodiment, the imaging device 100 has a stacked structure, and more specifically, a first substrate 200 and a second substrate 300 that are stacked and joined together. Furthermore, in this modified example 1, similar to the third embodiment, a third substrate 400 is provided on the surface of the second substrate 300 that is opposite to the surface facing the first substrate 200.

[0118] Furthermore, in this modified example 1, the first substrate 200 also includes a semiconductor substrate 210 and a wiring layer 230 provided on the surface 210a of the semiconductor substrate 210. In addition, in this modified example 1, a light-shielding film 500 is provided on the back surface 210b located around the photodiode PD.

[0119] Furthermore, in this modified example 1, the second substrate 300 includes a semiconductor substrate 310, a wiring layer 330 provided on the surface 310a of the semiconductor substrate 310, and a wiring layer 350 provided on the back surface 310b of the semiconductor substrate 310. Furthermore, in this modified example 1, the semiconductor substrate 310 may also have a TSV 314 penetrating the semiconductor substrate 310. Furthermore, in this modified example 1, the third substrate 400 includes a semiconductor substrate 410 and a wiring layer 430 provided on the surface 410a of the semiconductor substrate 410.

[0120] Furthermore, in this modified example 1, as shown in Figure 14, the inductor 510 is provided within the wiring layer 430 on the surface 310a of the semiconductor substrate 410. Also, in this modified example 1, unlike the third embodiment, the wiring layer 430 of the third substrate 400 is bonded to the wiring layer 330 of the second substrate 300.

[0121] In this modified example 1, the light-shielding film 500 and the inductor 510 are sandwiched between the first substrate 200, the second substrate 300, and a portion of the wiring layer 430 of the third substrate 400, and there is a sufficient distance between the light-shielding film 500 and the inductor 510. Therefore, according to this modified example 1, the magnetic flux generated by the inductor 510 can interfere with the light-shielding film 500, and the generation of eddy currents can be suppressed.

[0122] (Modification 2) Next, with reference to Figure 15, an example of the cross-sectional structure of the imaging device 100 according to Modification 2 of the third embodiment of the present disclosure will be described. Figure 15 is a cross-sectional view showing an example of the cross-sectional structure of the imaging device 100 according to Modification 2 of this embodiment. In the following description, points that are common to the first to third embodiments described above will be omitted from the explanation.

[0123] As shown in Figure 15, in this modified example 2, similar to the third embodiment, the imaging device 100 has a stacked structure, and more specifically, a first substrate 200 and a second substrate 300 that are stacked and joined together. Furthermore, in this modified example 2, similar to the third embodiment, a third substrate 400 is provided on the surface of the second substrate 300 that is opposite to the surface facing the first substrate 200.

[0124] More specifically, in this modified example 2, the first substrate 200 also has a semiconductor substrate 210 and a wiring layer 230 provided on the surface 210a of the semiconductor substrate 210. In addition, in this modified example 2, a light-shielding film 500 is provided on the back surface 210b located around the photodiode PD.

[0125] Furthermore, in this modified example 2, the second substrate 300 also includes a semiconductor substrate 310, a wiring layer 330 provided on the surface 310a of the semiconductor substrate 310, and a wiring layer 350 provided on the back surface 310b of the semiconductor substrate 310. Moreover, in this modified example 2, the semiconductor substrate 310 may also have a TSV 314 penetrating the semiconductor substrate 310.

[0126] However, in this modified example 2, unlike the third embodiment, the third substrate 400 has a semiconductor substrate 410, a wiring layer 430 provided on the surface 410a of the semiconductor substrate 410, and a wiring layer (fifth wiring layer) 450 provided on the back surface 410b of the semiconductor substrate 410. Also, in this modified example 2, as shown in Figure 15, the inductor 510 is provided in the wiring layer 430 on the surface 410a of the semiconductor substrate 410. Furthermore, in this modified example 2, unlike the third embodiment, the wiring layer 450 of the third substrate 400 is bonded to the wiring layer 330 of the second substrate 300.

[0127] In this modified example 2, the light-shielding film 500 and the inductor 510 are sandwiched between the wiring layer 450 of the first substrate 200, the second substrate 300, and the third substrate 400, as well as the semiconductor substrate 410, and there is a sufficient distance between the light-shielding film 500 and the inductor 510. Therefore, according to this modified example 2, the magnetic flux generated by the inductor 510 can interfere with the light-shielding film 500, and the generation of eddy currents can be suppressed.

[0128] <<5. Summary>> As described above, in each embodiment of the present disclosure, the light-shielding film 500 and the inductor 510 are sandwiched between at least the first substrate 200 and the wiring layer 330 and semiconductor substrate 310 of the second substrate, and there is a sufficient distance between the light-shielding film 500 and the inductor 510. Therefore, according to each embodiment of the present disclosure, the magnetic flux generated in the inductor 510 interferes with the light-shielding film 500 and the generation of eddy currents can be suppressed. As a result, according to each embodiment of the present disclosure, the generation of eddy currents in the light-shielding film 500 can be suppressed, and the desired characteristics of the inductor 510 can be obtained. Furthermore, in each embodiment of the present disclosure, since the generation of eddy currents in the light-shielding film 500 can be suppressed, it becomes unnecessary to provide slits in the light-shielding film 500, and as a result, the light-shielding function does not deteriorate and the generation of flare can be suppressed. In addition, according to each embodiment of the present disclosure, since slits are not provided in the light-shielding film 500, the increase in the manufacturing time of the imaging device 100 can be suppressed. Furthermore, in each embodiment of this disclosure, the area of ​​the second substrate 300 can be reduced compared to the comparative example, making it possible to further miniaturize the imaging device 100.

[0129] Furthermore, although the embodiments of the present disclosure have been described above as being applicable to an imaging device 100 that captures an image of the distribution of incident visible light, the embodiments of the present disclosure are not limited to such devices. For example, the embodiments of the present disclosure may be applied to an optical detection device applied to a distance measuring system. In addition, the embodiments of the present disclosure may be applied to imaging devices (physical quantity distribution detection devices) such as fingerprint detection sensors that capture an image of the distribution of incident amounts of infrared rays, X-rays, or particles, for example, or to fingerprint detection sensors that detect the distribution of other physical quantities such as pressure or capacitance and capture an image.

[0130] Furthermore, the technology of this disclosure may be applied not only to the imaging device 100, but also to various semiconductor devices.

[0131] Furthermore, the imaging device 100 according to the embodiment of this disclosure can be manufactured using methods, apparatus, and conditions commonly used in the manufacture of semiconductor devices. In other words, the imaging device 100 according to this embodiment can be manufactured using existing semiconductor device manufacturing processes.

[0132] Examples of the methods mentioned above include the PVD (Physical Vapor Deposition) method, the CVD (Chemical Vapor Deposition) method, and the ALD (Atomic Layer Deposition) method. Examples of PVD methods include vacuum deposition, electron beam (EB) deposition, various sputtering methods (magnetron sputtering, RF (Radio Frequency)-DC (Direct Current) coupled bias sputtering, ECR (Electron Cyclotron Resonance) sputtering, counter-target sputtering, high-frequency sputtering, etc.), ion plating, laser ablation, molecular beam epitaxy (MBE (Molecular Beam Epitaxy)), and laser transfer. Examples of CVD methods include plasma CVD, thermal CVD, metal-organic (MO) CVD, and optical CVD. Furthermore, other methods include electrolytic plating, electroless plating, spin coating, immersion, casting, microcontact printing, drop casting, various printing methods such as screen printing, inkjet printing, offset printing, gravure printing, and flexographic printing, as well as stamping, spraying, air doctor coater, blade coater, rod coater, knife coater, squeeze coater, reverse roll coater, transfer roll coater, gravure coater, kiss coater, cast coater, spray coater, slit orifice coater, and calender coater. In addition, patterning methods include shadow masking, laser transfer, chemical etching such as photolithography, physical etching using ultraviolet light or lasers, and nanoimprinting. Moreover, planarization techniques include CMP (Chemical Mechanical Polishing), laser planarization, and reflow.

[0133] <<6. Application Examples>> <6.1 Application Examples to Smartphones> The technology disclosed herein (this technology) can be applied to a variety of other products. For example, the technology disclosed herein may be applied to smartphones, etc. With reference to Figure 16, an example of the configuration of a smartphone 900 as an electronic device to which this technology is applied will be described. Figure 16 is a block diagram showing an example of a schematic functional configuration of a smartphone 900 to which the technology disclosed herein (this technology) can be applied.

[0134] As shown in Figure 16, the smartphone 900 includes a CPU (Central Processing Unit) 901, a ROM (Read Only Memory) 902, and a RAM (Random Access Memory) 903. The smartphone 900 also includes a storage device 904, a communication module 905, and a sensor module 907. Furthermore, the smartphone 900 includes an imaging device 100, a display device 910, a speaker 911, a microphone 912, an input device 913, and a bus 914. The smartphone 900 may also have a processing circuit such as a DSP (Digital Signal Processor) instead of, or together with, the CPU 901.

[0135] The CPU 901 functions as an arithmetic processing unit and control unit, controlling all or part of the operation of the smartphone 900 according to various programs recorded in the ROM 902, RAM 903, or storage device 904. The ROM 902 stores programs and calculation parameters used by the CPU 901. The RAM 903 temporarily stores programs used in the execution of the CPU 901 and parameters that change as appropriate during its execution. The CPU 901, ROM 902, and RAM 903 are interconnected by a bus 914. The storage device 904 is a data storage device configured as an example of the storage unit of the smartphone 900. The storage device 904 is composed of, for example, a magnetic storage device such as an HDD (Hard Disk Drive), a semiconductor storage device, or an optical storage device. This storage device 904 stores programs executed by the CPU 901, various data, and various data acquired from external sources.

[0136] The communication module 905 is a communication interface composed of, for example, a communication device for connecting to the communication network 906. The communication module 905 may be, for example, a communication card for wired or wireless LAN (Local Area Network), Bluetooth®, or WUSB (Wireless USB). Alternatively, the communication module 905 may be a router for optical communication, a router for ADSL (Asymmetric Digital Subscriber Line), or a modem for various types of communication. The communication module 905 transmits and receives signals, etc., to and from the Internet or other communication devices using a predetermined protocol such as TCP (Transmission Control Protocol) / IP (Internet Protocol). Furthermore, the communication network 906 connected to the communication module 905 is a network connected by wire or wireless means, such as the Internet, a home LAN, infrared communication, or satellite communication.

[0137] The sensor module 907 includes various sensors, such as motion sensors (e.g., acceleration sensors, gyroscopes, geomagnetic sensors, etc.), biometric information sensors (e.g., pulse sensors, blood pressure sensors, fingerprint sensors, etc.), or position sensors (e.g., GNSS (Global Navigation Satellite System) receivers, etc.).

[0138] The imaging device 100 is provided on the surface of the smartphone 900 and can image objects located on the back or front side of the smartphone 900. More specifically, the imaging device 100 can be configured to include the technology described herein (this technology) and an image sensor (not shown) and a signal processing circuit (not shown) that performs imaging signal processing on the signal photoelectrically converted by the image sensor. Furthermore, the imaging device 100 may further include an optical system mechanism (not shown) composed of an imaging lens, a zoom lens, and a focus lens, etc., and a drive system mechanism (not shown) that controls the operation of the optical system mechanism. The image sensor collects incident light from the object as an optical image, the signal processing circuit photoelectrically converts the formed optical image on a pixel-by-pixel basis, reads out the signal from each pixel as an imaging signal, and obtains an image by image processing.

[0139] The display device 910 is provided on the surface of the smartphone 900 and can be, for example, an LCD (Liquid Crystal Display) or an organic EL (Electroluminescence) display. The display device 910 can display an operation screen or captured images acquired by the imaging device 100 described above.

[0140] The speaker 911 can output, for example, call audio or audio associated with video content displayed by the display device 910 described above, to the user.

[0141] The microphone 912 can, for example, collect the user's voice during a call, voices including commands to activate functions of the smartphone 900, and sounds from the surrounding environment of the smartphone 900.

[0142] The input device 913 is a device operated by the user, such as a button, keyboard, touch panel, or mouse. The input device 913 includes an input control circuit that generates an input signal based on information entered by the user and outputs it to the CPU 901. By operating this input device 913, the user can input various types of data to the smartphone 900 or instruct it to perform processing operations.

[0143] The above shows an example configuration of the smartphone 900. Each of the above components may be made up of general-purpose materials, or it may be made up of hardware specialized for the function of each component. Such a configuration can be appropriately changed depending on the technological level at the time of implementation.

[0144] <6.2 Examples of Application to Mobile Devices> The technology relating to this disclosure (this technology) can be applied to various products. For example, the technology relating to this disclosure may be implemented as a device mounted on any type of mobile device such as automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility devices, airplanes, drones, ships, and robots.

[0145] Figure 17 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile control system to which the technology described herein may be applied.

[0146] The vehicle control system 12000 comprises a plurality of electronic control units connected via a communication network 12001. In the example shown in Figure 17, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. The functional configuration of the integrated control unit 12050 is shown in the figure, which includes a microcomputer 12051, an audio / image output unit 12052, and an in-vehicle network interface 12053.

[0147] The drivetrain control unit 12010 controls the operation of devices related to the vehicle's drivetrain according to various programs. For example, the drivetrain control unit 12010 functions as a control device for a drivetrain generating device that generates driving force for the vehicle, such as an internal combustion engine or a drive motor; a drivetrain transmission mechanism that transmits driving force to the wheels; a steering mechanism that adjusts the steering angle of the vehicle; and a braking device that generates braking force for the vehicle.

[0148] The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window system, or various lamps such as headlights, reverse lights, brake lights, turn signals, or fog lights. In this case, the body system control unit 12020 may receive radio waves transmitted from a portable device that replaces a key or signals from various switches. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock system, power window system, lamps, etc.

[0149] The external information detection unit 12030 detects information from outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the external information detection unit 12030. The external information detection unit 12030 causes the imaging unit 12031 to capture images of the outside of the vehicle and receives the captured images. Based on the received images, the external information detection unit 12030 may perform object detection processing such as detecting people, cars, obstacles, signs, or characters on the road surface, or distance detection processing.

[0150] The imaging unit 12031 is a light sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0151] The in-vehicle information detection unit 12040 detects information inside the vehicle. The in-vehicle information detection unit 12040 is connected to, for example, a driver status detection unit 12041 that detects the driver's state. The driver status detection unit 12041 includes, for example, a camera that captures images of the driver, and the in-vehicle information detection unit 12040 may calculate the driver's level of fatigue or concentration, or determine whether the driver is drowsy, based on the detection information input from the driver status detection unit 12041.

[0152] The microcomputer 12051 can calculate control target values ​​for the drive force generator, steering mechanism, or braking device based on information inside and outside the vehicle acquired by the external information detection unit 12030 or the internal information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing ADAS (Advanced Driver Assistance System) functions, including vehicle collision avoidance or impact mitigation, following driving based on distance between vehicles, maintaining vehicle speed, vehicle collision warning, or vehicle lane departure warning.

[0153] Furthermore, the microcomputer 12051 can perform cooperative control for purposes such as autonomous driving, where the vehicle drives autonomously without driver intervention, by controlling the drive force generating device, steering mechanism, or braking device, etc., based on information about the vehicle's surroundings acquired by the external information detection unit 12030 or the internal information detection unit 12040.

[0154] Furthermore, the microcomputer 12051 can output control commands to the body system control unit 12020 based on external information acquired by the external information detection unit 12030. For example, the microcomputer 12051 can control the headlights according to the position of a preceding or oncoming vehicle detected by the external information detection unit 12030, and perform coordinated control aimed at reducing glare, such as switching from high beams to low beams.

[0155] The audio-image output unit 12052 transmits at least one of audio and image output signals to an output device capable of visually or audibly notifying information to the vehicle's occupants or to those outside the vehicle. In the example shown in Figure 17, the output devices include an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an onboard display and a head-up display.

[0156] Figure 18 shows an example of the installation position of the imaging unit 12031.

[0157] In Figure 18, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0158] The imaging units 12101, 12102, 12103, 12104, and 12105 are installed, for example, on the front nose, side mirrors, rear bumper, back door, and the upper part of the windshield inside the vehicle 12100. The imaging unit 12101 installed on the front nose and the imaging unit 12105 installed on the upper part of the windshield inside the vehicle mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 installed on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 installed on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 installed on the upper part of the windshield inside the vehicle is mainly used for detecting preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, or lanes.

[0159] Figure 18 shows an example of the imaging range of imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of imaging unit 12101 located on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of imaging units 12102 and 12103 located on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of imaging unit 12104 located on the rear bumper or back door. For example, by superimposing the image data captured by imaging units 12101 to 12104, an overhead view image of the vehicle 12100 can be obtained.

[0160] At least one of the imaging units 12101 to 12104 may have a function for acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera consisting of multiple image sensors, or an image sensor having pixels for phase difference detection.

[0161] For example, the microcomputer 12051, based on distance information obtained from the imaging units 12101 to 12104, can determine the distance to each object within the imaging range 12111 to 12114 and the temporal change of this distance (relative speed to the vehicle 12100). In particular, it can extract the closest object on the vehicle 12100's path that is traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or more) as the preceding vehicle. Furthermore, the microcomputer 12051 can set a predetermined distance to be maintained before the preceding vehicle and perform automatic braking control (including follow-and-stop control) and automatic acceleration control (including follow-and-start control), etc. In this way, cooperative control aimed at autonomous driving, etc., that drives autonomously without driver operation, can be performed.

[0162] For example, the microcomputer 12051 can use distance information obtained from imaging units 12101 to 12104 to classify and extract three-dimensional object data related to three-dimensional objects, such as motorcycles, passenger cars, large vehicles, pedestrians, utility poles, and other three-dimensional objects, and use this data for automatic obstacle avoidance. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines the collision risk, which indicates the degree of risk of collision with each obstacle. If the collision risk is above a set value and there is a possibility of collision, the microcomputer 12051 can provide driving assistance to avoid collisions by outputting a warning to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or evasive steering via the drive system control unit 12010.

[0163] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared light. For example, the microcomputer 12051 can recognize pedestrians by determining whether or not pedestrians are present in the images captured by the imaging units 12101 to 12104. Such pedestrian recognition is performed, for example, by a procedure to extract feature points from the images captured by the imaging units 12101 to 12104 as infrared cameras, and a procedure to perform pattern matching on a series of feature points that indicate the contour of an object to determine whether or not it is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the imaging units 12101 to 12104 and recognizes a pedestrian, the audio-image output unit 12052 controls the display unit 12062 to superimpose a rectangular contour line for emphasis on the recognized pedestrian. The audio-image output unit 12052 may also control the display unit 12062 to display an icon indicating a pedestrian at a desired position.

[0164] The above describes an example of a vehicle control system to which the technology described herein may be applied. The technology described herein can be applied to, for example, the imaging unit 12031, among the configurations described above.

[0165] <<7. Supplementary Information>> Although preferred embodiments of the present disclosure have been described in detail above with reference to the attached drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that a person with ordinary skill in the art of the present disclosure may conceive of various modifications or alterations within the scope of the technical idea described in the claims, and these will naturally also be understood to fall within the technical scope of the present disclosure.

[0166] Furthermore, the effects described herein are merely descriptive or illustrative and not limiting. In other words, the technology relating to this disclosure may produce other effects that are obvious to those skilled in the art from the description herein, in addition to or instead of the effects described herein.

[0167] Furthermore, this technology can also take the following configurations: (1) A photodetector having a laminated structure including a first substrate on which a photodetector element is mounted, and a second substrate on which a logic circuit for controlling the photodetector element is mounted and laminated on the first substrate, wherein an inductor included in the logic circuit is provided on the side of the second substrate opposite to the first substrate. (2) The photodetector according to (1) above, wherein the first substrate has a first semiconductor substrate and a first wiring layer provided on the surface of the first semiconductor substrate, the first wiring layer includes an insulating film and wiring, and the first wiring layer is bonded to the second substrate. (3) The photodetector according to (2) above, wherein the inductor is provided on the second surface side of the second substrate, which is located opposite to the first surface facing the first substrate. (4) The photodetector according to (3) above, wherein the second substrate comprises a second semiconductor substrate, a second wiring layer provided on the surface of the second semiconductor substrate, and a third wiring layer provided on the back surface of the second semiconductor substrate, the second wiring layer and the third wiring layer include the insulating film and the wiring, and the inductor is provided on the back surface of the second semiconductor substrate. (5) The photodetector according to (4) above, wherein the first wiring layer and the second wiring layer are joined together. (6) The photodetector according to (5) above, wherein an electrode provided on the surface of the first wiring layer and an electrode provided on the surface of the second wiring layer are joined together. (7) The photodetector according to any one of (4) to (6) above, wherein the second substrate includes a through electrode penetrating the second semiconductor substrate. (8) The photodetector according to (2) above, wherein the inductor is provided in a layer provided on a second surface of the second substrate that is opposite to the first surface facing the first substrate. (9) The photodetector according to (8) above, wherein the second substrate comprises a second semiconductor substrate, a second wiring layer provided on the surface of the second semiconductor substrate, and a third wiring layer provided on the back surface of the second semiconductor substrate, and the inductor is provided in the third wiring layer.(10) The photodetector according to (9) above, wherein the first wiring layer and the second wiring layer are joined together. (11) The photodetector according to (8) above, wherein the second substrate comprises a second semiconductor substrate, a second wiring layer provided on the surface of the second semiconductor substrate, and a third wiring layer provided on the back surface of the second semiconductor substrate, and the inductor is provided in the second wiring layer. (12) The photodetector according to (11) above, wherein the first wiring layer and the third wiring layer are joined together. (13) The photodetector according to (2) above, wherein the inductor is provided on a third substrate laminated on a second surface of the second substrate that is opposite to the first surface facing the first substrate. (14) The photodetector according to (13), wherein the second substrate comprises a second semiconductor substrate, a second wiring layer provided on the surface of the second semiconductor substrate, and a third wiring layer provided on the back surface of the second semiconductor substrate, and the third substrate comprises a third semiconductor substrate and a fourth wiring layer provided on the surface of the third semiconductor substrate, and the inductor is provided on the fourth wiring layer. (15) The photodetector according to (14), wherein the third wiring layer and the fourth wiring layer are joined together. (16) The photodetector according to (14), wherein the second wiring layer and the fourth wiring layer are joined together. (17) The photodetector according to (14), further comprising a fifth wiring layer provided on the back surface of the third semiconductor substrate, wherein the second wiring layer and the fifth wiring layer are joined together. (18) The photodetector according to any one of (1) to (17) above, wherein the electrode film of the inductor contains at least one element selected from the group consisting of tungsten, copper, titanium, tantalum, cobalt, and aluminum. (19) The photodetector according to (18) above, wherein the electrode film is embedded in an insulating film made of silicon oxide, silicon nitride, silicon oxynitride, or silicon oxycarbide. (20) The photodetector according to any one of (1) to (19) above, wherein at least a portion of the inductor is superimposed on a light-shielding film provided around the photodetector element.(21) The photodetector according to any one of (13) to (17) above, wherein the first to third substrates are made of semiconductor chips or semiconductor wafers. (22) A semiconductor device having a laminated structure including a first substrate and a second substrate laminated on the first substrate, wherein an inductor is provided on the side of the second substrate opposite to the first substrate.

[0168] 100, 100a Imaging device 101 Pixel array section 102 Vertical drive circuit 103 Column processing circuit 104 Horizontal drive circuit 105 System control section 108 Signal processing section 109 Data storage section 110 Pixel 111 Transfer transistor 112 Reset transistor 113 Amplifier transistor 114 Selection transistor 121, 122 Substrate 200 First substrate 210, 310, 410 Semiconductor substrate 210a, 310a, 410a Front surface 210b, 310b, 410b Back surface 230, 330, 350, 430, 450 Wiring layer 232, 332, 352, 432, 452 Wiring 236, 336, 356, 436, 456 Insulating film 238, 338 Electrode 300 Second substrate 314 TSV 400 Third substrate 500 Light-shielding film 502 On-chip lens 510 Inductor

Claims

1. A photodetector having a laminated structure including a first substrate on which a photodetector element is mounted, and a second substrate on which a logic circuit for controlling the photodetector element is mounted and laminated on the first substrate, wherein an inductor included in the logic circuit is provided on the side of the second substrate opposite to the first substrate.

2. The photodetector according to claim 1, wherein the first substrate comprises a first semiconductor substrate and a first wiring layer provided on the surface of the first semiconductor substrate, the first wiring layer includes an insulating film and wiring, and the first wiring layer is bonded to the second substrate.

3. The photodetector according to claim 2, wherein the second substrate comprises a second semiconductor substrate, a second wiring layer provided on the surface of the second semiconductor substrate, and a third wiring layer provided on the back surface of the second semiconductor substrate, the second wiring layer and the third wiring layer include the insulating film and the wiring, the inductor is provided on the back surface of the second semiconductor substrate, and the first wiring layer and the second wiring layer are joined together.

4. The photodetector according to claim 3, wherein an electrode provided on the surface of the first wiring layer and an electrode provided on the surface of the second wiring layer are joined together.

5. The photodetector according to claim 3, wherein the second substrate includes a through-electrode penetrating the second semiconductor substrate.

6. The photodetector according to claim 2, wherein the second substrate comprises a second semiconductor substrate, a second wiring layer provided on the surface of the second semiconductor substrate, and a third wiring layer provided on the back surface of the second semiconductor substrate, the inductor is provided in the third wiring layer, and the first wiring layer and the second wiring layer are joined together.

7. The photodetector according to claim 2, wherein the second substrate comprises a second semiconductor substrate, a second wiring layer provided on the surface of the second semiconductor substrate, and a third wiring layer provided on the back surface of the second semiconductor substrate, the inductor is provided in the second wiring layer, and the first wiring layer and the third wiring layer are joined together.

8. The photodetector according to claim 2, wherein the inductor is provided on a third substrate laminated on a second surface of the second substrate located on the side opposite to the first surface facing the first substrate.

9. The photodetector according to claim 8, wherein the second substrate comprises a second semiconductor substrate, a second wiring layer provided on the surface of the second semiconductor substrate, and a third wiring layer provided on the back surface of the second semiconductor substrate, and the third substrate comprises a third semiconductor substrate and a fourth wiring layer provided on the surface of the third semiconductor substrate, and the inductor is provided on the fourth wiring layer.

10. The photodetector according to claim 9, wherein the third wiring layer and the fourth wiring layer are joined together.

11. The photodetector according to claim 9, wherein the second wiring layer and the fourth wiring layer are joined together.

12. The photodetector according to claim 9, further comprising a fifth wiring layer provided on the back surface of the third semiconductor substrate, wherein the second wiring layer and the fifth wiring layer are joined together.

13. The photodetector according to claim 1, wherein the electrode film of the inductor comprises at least one element selected from the group consisting of tungsten, copper, titanium, tantalum, cobalt, and aluminum.

14. The photodetector according to claim 13, wherein the electrode film is embedded in an insulating film made of silicon oxide, silicon nitride, silicon oxynitride, or silicon oxycarbide.

15. The photodetector according to claim 1, wherein at least a portion of the inductor is superimposed on a light-shielding film provided around the photodetector element.

16. A semiconductor device having a laminated structure including a first substrate and a second substrate laminated on the first substrate, wherein an inductor is provided on the second substrate on the side opposite to the first substrate.

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