Imaging device and camera system

Abstract

An imaging device 1 comprises: a first photoelectric conversion section 30 including a first photoelectric conversion film 32 that converts light into an electrical charge and a first pixel electrode 31 electrically connected to the first photoelectric conversion film 32; a second photoelectric conversion section 50 provided above the first photoelectric conversion section 30 and including a second photoelectric conversion film 52 that converts light into an electrical charge and a second pixel electrode 51a electrically connected to the second photoelectric conversion film 52; a via 60a passing through the first photoelectric conversion film 32 and electrically connected to the second pixel electrode 51a; and a structure 70 passing through the first photoelectric conversion film 32 and surrounding the first pixel electrode 31 in a plan view, wherein the structure 70 does not include the via 60a.

Description

Imaging device and camera system

[0001] The present disclosure relates to an imaging device and a camera system.

[0002] Patent Document 1 discloses a solid-state imaging device including a plurality of organic photoelectric conversion units that are stacked in the direction of light incidence and perform photoelectric conversion on light in different wavelength bands.

[0003] International Publication No. 2018 / 020902

[0004] In the above-described conventional technology, when a large load such as polishing is applied during the manufacturing process of the solid-state imaging device, there is a risk that the stacked photoelectric conversion sections may peel off, resulting in a problem of quality degradation.

[0005] Therefore, the present disclosure provides a high-quality imaging device and camera system.

[0006] An imaging device according to one aspect of the present disclosure comprises: a first photoelectric conversion unit including a first photoelectric conversion film that converts light into electric charges and a first pixel electrode electrically connected to the first photoelectric conversion film; a second photoelectric conversion unit including a second photoelectric conversion film that converts light into electric charges and a second pixel electrode electrically connected to the second photoelectric conversion film, the second photoelectric conversion unit being provided above the first photoelectric conversion unit; a first via that penetrates the first photoelectric conversion film and is electrically connected to the second pixel electrode; and a structure that penetrates the first photoelectric conversion film and surrounds the first pixel electrode in a planar view, the structure not including the first via.

[0007] A camera system according to one aspect of the present disclosure includes the imaging device according to the above aspect and an optical system that introduces light into the imaging device.

[0008] According to the present disclosure, a high-quality imaging device and camera system can be provided.

[0009] FIG. 1 is a diagram showing a configuration of an imaging device according to Embodiment 1. FIG. 2A is a cross-sectional view of a unit cell of the imaging device according to Embodiment 1. FIG. 2B is a cross-sectional view of a unit cell of the imaging device according to Embodiment 1. FIG. 3A is a cross-sectional view for explaining one step of a method for manufacturing the imaging device according to Embodiment 1. FIG. 3B is a cross-sectional view for explaining one step of a method for manufacturing the imaging device according to Embodiment 1. FIG. 3C is a cross-sectional view for explaining one step of a method for manufacturing the imaging device according to Embodiment 1. FIG. 3D is a cross-sectional view for explaining one step of a method for manufacturing the imaging device according to Embodiment 1. FIG. 3E is a cross-sectional view for explaining one step of a method for manufacturing the imaging device according to Embodiment 1. FIG. 3F is a cross-sectional view for explaining one step of a method for manufacturing the imaging device according to Embodiment 1. FIG. 3G is a cross-sectional view for explaining one step of a method for manufacturing the imaging device according to Embodiment 1. FIG. 3H is a cross-sectional view for explaining one step of a method for manufacturing the imaging device according to Embodiment 1. FIG. 3I is a cross-sectional view for explaining one step of a method for manufacturing the imaging device according to Embodiment 1. FIG. 3J is a cross-sectional view for explaining one step of a method for manufacturing the imaging device according to Embodiment 1. FIG. 3K is a cross-sectional view for explaining one step of a method for manufacturing the imaging device according to Embodiment 1. FIG. 3L is a cross-sectional view for explaining one step of a method for manufacturing the imaging device according to Embodiment 1. FIG. 4A is a cross-sectional view of a unit cell of an imaging device according to Modification 1 of Embodiment 1. FIG. 4B is a cross-sectional view of a unit cell of an imaging device according to Modification 1 of Embodiment 1. FIG. 5A is a cross-sectional view for explaining a step of a method for manufacturing an imaging device according to Modification 1 of Embodiment 1. FIG. 5B is a cross-sectional view for explaining a step of a method for manufacturing an imaging device according to Modification 1 of Embodiment 1. FIG. 6A is a cross-sectional view of a unit cell of an imaging device according to Modification 2 of Embodiment 1. FIG. 6B is a cross-sectional view of a unit cell of an imaging device according to Modification 2 of Embodiment 1. FIG. 7A is a cross-sectional view of a unit cell of an imaging device according to Modification 3 of Embodiment 1. FIG. 7B is a cross-sectional view of a unit cell of an imaging device according to Modification 3 of Embodiment 1. FIG. 8A is a cross-sectional view of a unit cell of an imaging device according to Modification 4 of Embodiment 1. FIG. 8B is a cross-sectional view of a unit cell of an imaging device according to Modification 4 of Embodiment 1.Fig. 8C is a cross-sectional view of a unit cell of an imaging device according to Variation 4 of Embodiment 1. Fig. 9A is a cross-sectional view of a unit cell of an imaging device according to Variation 5 of Embodiment 1. Fig. 9B is a cross-sectional view of a unit cell of an imaging device according to Variation 5 of Embodiment 1. Fig. 9C is a cross-sectional view of a unit cell of an imaging device according to Variation 5 of Embodiment 1. Fig. 9D is a cross-sectional view of a unit cell of an imaging device according to Variation 5 of Embodiment 1. Fig. 10 is a diagram showing the configuration of a camera system according to Embodiment 2.

[0010] (Summary of the present disclosure) An imaging device according to a first aspect of the present disclosure comprises a first photoelectric conversion unit including a first photoelectric conversion film that converts light into electric charges and a first pixel electrode electrically connected to the first photoelectric conversion film, a second photoelectric conversion unit including a second photoelectric conversion film that converts light into electric charges and a second pixel electrode electrically connected to the second photoelectric conversion film, and is provided above the first photoelectric conversion unit, a first via that penetrates the first photoelectric conversion film and is electrically connected to the second pixel electrode, and a structure that penetrates the first photoelectric conversion film and surrounds the first pixel electrode in a planar view, wherein the structure does not include the first via.

[0011] This structure can prevent peeling of the first photoelectric conversion film, thereby realizing a high-quality imaging device and improving the manufacturing yield of imaging devices.

[0012] An imaging device according to a second aspect of the present disclosure is the imaging device according to the first aspect, wherein the structure includes a material having electrical conductivity.

[0013] This allows the structure to be used as a power line, a signal line, or the like.

[0014] An imaging device according to a third aspect of the present disclosure is the imaging device according to the first or second aspect, wherein the structure contains the same material as the material contained in the first via.

[0015] This allows the structure to be formed in the same step as the formation of the first via.

[0016] An imaging device according to a fourth aspect of the present disclosure is the imaging device according to any one of the first to third aspects, wherein the structure includes a material having insulating properties.

[0017] This makes it possible to cut off the electrical connection between the first photoelectric conversion film and the structure. For example, it is no longer necessary to consider leakage to the first photoelectric conversion film, and the structure can be easily formed.

[0018] An imaging device according to a fifth aspect of the present disclosure is an imaging device according to any one of the first to fourth aspects, wherein the first photoelectric conversion unit includes a plurality of the first pixel electrodes, the first photoelectric conversion film includes a plurality of partial photoelectric conversion films that are completely separated from each other by the structure in a planar view, and the plurality of partial photoelectric conversion films are electrically connected in one-to-one correspondence to the plurality of first pixel electrodes.

[0019] This makes it possible to suppress interference such as charge transfer between adjacent pixels, and to suppress deterioration in image quality.

[0020] An imaging device according to a sixth aspect of the present disclosure is an imaging device according to any one of the first to fourth aspects, wherein the first photoelectric conversion section includes a plurality of the first pixel electrodes, the first photoelectric conversion film includes a plurality of partial photoelectric conversion films partitioned by the structure in a planar view, and a connecting portion connecting adjacent partial photoelectric conversion films, and the plurality of partial photoelectric conversion films are electrically connected in one-to-one correspondence to the plurality of first pixel electrodes.

[0021] This makes it possible to ensure conduction between pixels of a member that can be shared between pixels, such as a first counter electrode provided opposite the first pixel electrode.

[0022] An imaging device according to a seventh aspect of the present disclosure is an imaging device according to any one of the first to fourth and sixth aspects, wherein the structure has a plurality of partial walls separated from each other, and the plurality of partial walls are arranged in a ring shape in a planar view so as to surround the first pixel electrode.

[0023] This makes it possible to ensure conduction between pixels of a member that can be shared between pixels.

[0024] An imaging device according to an eighth aspect of the present disclosure is the imaging device according to the seventh aspect, wherein the plurality of partial walls surround at least half of the periphery of the first pixel electrode.

[0025] This can enhance the effect of suppressing peeling of the first photoelectric conversion film.

[0026] An imaging device according to a ninth aspect of the present disclosure is an imaging device according to the second or third aspect, wherein the second photoelectric conversion unit includes a shield electrode adjacent to the second pixel electrode, and the structure is electrically connected to the shield electrode.

[0027] This allows power to be supplied to the shield electrode via the structure.

[0028] An imaging device according to a tenth aspect of the present disclosure is an imaging device according to the second or third aspect, wherein the first photoelectric conversion unit includes a first opposing electrode that faces the first pixel electrode via the first photoelectric conversion film, and the structure is electrically connected to the first opposing electrode.

[0029] This allows power to be supplied to the first counter electrode through the structure.

[0030] An imaging device according to an eleventh aspect of the present disclosure is an imaging device according to any one of the first to tenth aspects, wherein the top surface of the structure and the top surface of the first via are located on the same plane.

[0031] This can improve the flatness of the second photoelectric conversion film provided above the structure and the first via.

[0032] An imaging device according to a twelfth aspect of the present disclosure is an imaging device according to any one of the first to eleventh aspects, wherein the first photoelectric conversion unit includes a first opposing electrode that faces the first pixel electrode via the first photoelectric conversion film, and the imaging device includes a second via that penetrates the second photoelectric conversion film and is electrically connected to the first opposing electrode.

[0033] This makes it possible to ensure power supply to the first opposing electrode without using a structure.

[0034] An imaging device according to a thirteenth aspect of the present disclosure is the imaging device according to the twelfth aspect, wherein the second photoelectric conversion section includes a second opposing electrode that faces the second pixel electrode via the second photoelectric conversion film, the imaging device includes wiring provided in the same layer as the second opposing electrode, and the second via is electrically connected to the wiring.

[0035] This allows the wiring layer for supplying power to the first opposing electrode to be formed in the same process as the second opposing electrode without using a structural body.

[0036] A camera system according to a fourteenth aspect of the present disclosure includes the imaging device according to any one of the first to thirteenth aspects, and an optical system that introduces light into the imaging device.

[0037] This makes it possible to obtain the same effects as those of the imaging devices according to the above-described aspects.

[0038] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0039] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, steps, and step order shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components not described in the independent claims are described as optional components.

[0040] Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. Therefore, for example, the scales of the figures do not necessarily match. Furthermore, in each figure, substantially the same components are given the same reference numerals, and redundant explanations are omitted or simplified.

[0041] Furthermore, in this specification, terms indicating the relationship between elements, such as parallel or perpendicular, terms indicating the shape of elements, such as rectangle, and numerical ranges are not expressions that only express a strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about a few percent.

[0042] Furthermore, in this specification, the terms "upward" and "downward" do not refer to the upward direction (vertically upward) and downward direction (vertically downward) in absolute spatial recognition, but are used as terms defined by a relative positional relationship based on the stacking order in the stacked configuration. In this specification, the direction in which the second photoelectric conversion film is located relative to the first photoelectric conversion film is considered to be "upward." Furthermore, the terms "upward" and "downward" are applied not only to cases in which two components are arranged with a gap between them and another component is present between the two components, but also to cases in which two components are arranged in close contact with each other and the two components are in contact with each other.

[0043] In addition, in this specification and drawings, the x-axis, y-axis, and z-axis represent the three axes of a three-dimensional Cartesian coordinate system. In each embodiment, the positive direction of the z-axis is defined as "upward," and the negative direction of the z-axis is defined as "downward." The z-axis is a direction perpendicular to the main surface of the photoelectric conversion film. In addition, in this specification, "planar view" refers to a view from a direction perpendicular to the main surface of the photoelectric conversion film, unless otherwise specified.

[0044] Furthermore, in this specification, ordinal numbers such as "first" and "second" do not refer to the number or order of components unless otherwise specified, but are used for the purpose of avoiding confusion and distinguishing between components of the same type.

[0045] First Embodiment First, an imaging device according to a first embodiment will be described.

[0046] Fig. 1 is a diagram showing the configuration of an image pickup device according to the present embodiment. As shown in Fig. 1, the image pickup device 1 includes a pixel array 2, a vertical scanning circuit 3, a horizontal signal readout circuit 4, a plurality of signal lines 5 and 6, and a horizontal signal common line 7. Although not shown, the image pickup device 1 also includes a control circuit that controls the vertical scanning circuit 3, the horizontal signal readout circuit 4, etc.

[0047] The pixel array 2 includes a plurality of unit cells 10 arranged in a matrix. The number of unit cells 10 arranged in the row direction (also called the horizontal direction) may be the same as or different from the number of unit cells 10 arranged in the column direction (also called the vertical direction). All of the unit cells 10 included in the pixel array 2 may be arranged in a single row (or a single column), and the imaging device 1 may be realized as a so-called line sensor.

[0048] 1, one unit cell 10 includes one first pixel electrode 31 and four second pixel electrodes 51a, 51b, 51c, and 51d. Note that in this specification, pixel electrodes and pixels correspond one-to-one. That is, one unit cell 10 includes one first pixel and four second pixels.

[0049] The first pixel and the second pixel are sensitive to different wavelength bands. For example, the first pixel is sensitive to at least a portion of the near-infrared light band from 800 nm to 2500 nm. The second pixel is sensitive to at least a portion of the visible light band from 380 nm to 800 nm. For example, the four second pixels correspond to an R pixel, two G pixels, and a B pixel arranged in a Bayer array. The first pixel and the second pixel may be sensitive to an ultraviolet light band of 380 nm or less or an infrared light band of 2500 nm or more. In this embodiment, the first pixel and the second pixel may be simply referred to as a "pixel" without distinction. The first pixel electrode and the second pixel electrode may also be simply referred to as a "pixel electrode."

[0050] In this embodiment, the unit cells 10 have the same configuration as each other. The specific configuration of the unit cells 10 will be described later.

[0051] The vertical scanning circuit 3, also called a row scanning circuit, is connected to each pixel via a signal line 5 provided corresponding to each row of the pixels. The vertical scanning circuit 3 drives the pixels row by row. Specifically, the vertical scanning circuit 3 supplies signals necessary for driving the pixels, such as a row selection signal and a reset signal, to the signal lines 5.

[0052] For example, the signal lines 5 include address signal lines to which row selection signals for selecting rows are supplied, and reset signal lines to which reset signals for resetting charges accumulated in pixels are supplied.

[0053] The horizontal signal readout circuit 4, also called a column scanning circuit, is connected to each pixel via a signal line 6 provided corresponding to each column of pixels. The signal line 6, also called a vertical signal line, is a signal line for reading out signal charges generated by photoelectric conversion in each pixel. Although not shown in FIG. 1 , the signal line 6 is provided with a column signal processing circuit that performs noise suppression signal processing, typified by correlated double sampling, and analog-to-digital conversion. The horizontal signal readout circuit 4 sequentially reads out signals from the column signal processing circuit to a horizontal signal common line 7.

[0054] Next, a specific cross-sectional configuration of the unit cell 10 will be described with reference to Figures 2A and 2B. Figures 2A and 2B are cross-sectional views of the unit cell 10 of the imaging device 1 according to this embodiment. Specifically, Figure 2A shows an x-z ​​cross section taken along line IIA-IIA in Figure 2B. Figure 2B shows an x-y cross section taken along line IIB-IIB in Figure 2A.

[0055] As shown in Figures 2A and 2B, the imaging device 1 includes a substrate 20, a first photoelectric conversion section 30, an interlayer insulating film 40, a second photoelectric conversion section 50, vias 60a, 60b, 60c and 60d, a structure 70, a protective film 80, and color filters 81a and 81b.

[0056] The substrate 20 includes a semiconductor substrate (not shown) and one or more interlayer insulating films stacked on the main surface of the semiconductor substrate. The semiconductor substrate is provided with a signal processing circuit for processing signal charges generated by photoelectric conversion in each of the first photoelectric conversion unit 30 and the second photoelectric conversion unit 50. The interlayer insulating film is provided with a plurality of vias, a plurality of wirings, a plurality of contact plugs, and the like for electrically connecting the signal processing circuit to the first photoelectric conversion unit 30 and the second photoelectric conversion unit 50. Note that FIG. 2A shows vias 22a and 22b, which are part of the plurality of vias, and wirings 23a and 23b, which are part of the plurality of wirings. The substrate 20 shown in FIG. 2A represents only the topmost layer of one or more interlayer insulating films stacked on the main surface of the semiconductor substrate.

[0057] A signal processing circuit is provided for each unit cell 10 or each pixel. The signal processing circuit includes a charge storage unit for storing signal charges generated by photoelectric conversion, and one or more transistors such as an amplification transistor, a selection transistor, and a reset transistor. The signal processing circuit may also include a capacitor for holding the signal charges.

[0058] The charge accumulation portion is an impurity region (also called a diffusion region) provided in a semiconductor substrate, as well as contact plugs, wiring, vias, etc. electrically connected to the impurity region. The semiconductor substrate is, for example, a p-type silicon (Si) substrate, and the impurity region is formed by adding n-type impurities such as phosphorus (P) by ion implantation or the like.

[0059] The transistor is, for example, a field effect transistor, and includes a plurality of impurity regions provided in a semiconductor substrate as a source and a drain, as well as a gate insulating film and a gate electrode. The gate electrode is formed using a conductive material such as polysilicon that has been given conductivity, but may also be formed using a metal material such as copper (Cu). The gate insulating film is formed using silicon oxide (SiO ２ The insulating film may have a single layer or a multilayer structure of an insulating film such as a silicon nitride (SiN) film.

[0060] As shown in Fig. 2A , the first photoelectric conversion unit 30 includes a first pixel electrode 31, a first photoelectric conversion film 32, and a first opposing electrode 33. Although not shown in Fig. 2A , the first photoelectric conversion unit 30 includes a plurality of first pixel electrodes 31. As indicated by the dashed lines in Fig. 1 , the plurality of first pixel electrodes 31 are arranged in a matrix.

[0061] The first pixel electrode 31 is electrically connected to the first photoelectric conversion film 32. The first pixel electrode 31 is formed using titanium nitride (TiN), tantalum nitride (TaN), indium tin oxide (ITO), or the like. The first pixel electrode 31 collects one of the charges of the electron-hole pairs generated in the first photoelectric conversion film 32 as a signal charge, and outputs the signal charge to a signal processing circuit provided on the substrate 20 through a via 21 (see FIG. 7A ). The via 21 is connected to the lower surface of the first pixel electrode 31.

[0062] One first pixel electrode 31 is provided for each unit cell 10, i.e., for each first pixel. The first pixel electrode 31 is, for example, a flat electrode having a rectangular shape in a plan view, with each side tilted at 45 degrees relative to the x-axis or y-axis. This allows the area of ​​the first pixel electrode 31 to be increased while avoiding contact with the wiring 23a, vias 22a, etc. The shape and arrangement of the first pixel electrode 31 are not limited to this. For example, the first pixel electrode 31 may be divided into multiple electrode pieces within one unit cell 10, with the vias 21 connected to each of the multiple electrode pieces.

[0063] The first photoelectric conversion film 32 is a film that converts light into electric charges. In this embodiment, the first photoelectric conversion film 32 is an organic photoelectric conversion film formed using an organic semiconductor material that is sensitive to the near-infrared light band. The first photoelectric conversion film 32 may also be formed using carbon nanotubes, quantum dots, inorganic materials, etc.

[0064] In the present embodiment, the first photoelectric conversion film 32 includes a plurality of partial photoelectric conversion films 32A that are completely separated from one another by structures 70 in a plan view. The plurality of partial photoelectric conversion films 32A correspond one-to-one to the plurality of first pixel electrodes 31 and are electrically connected to them. For example, as shown in FIG. 2B , in the first photoelectric conversion film 32, a rectangular area surrounded by structures 70 corresponds to one partial photoelectric conversion film 32A. Adjacent partial photoelectric conversion films 32A are not continuous with each other, and structures 70 exist between them.

[0065] The first photoelectric conversion film 32 may include, in addition to the film that mainly performs photoelectric conversion, one or more functional layers such as a charge blocking layer that blocks either holes or electrons and transmits the other, and a charge transport layer that assists in the movement of charges.

[0066] The first opposing electrode 33 faces the first pixel electrode 31 via the first photoelectric conversion film 32. The first opposing electrode 33 is translucent to at least a part of light in the wavelength band to which the first photoelectric conversion film 32 is sensitive. For example, the first opposing electrode 33 is a transparent electrode such as ITO. The first opposing electrode 33 collects the other charge of the electron-hole pairs generated in the first photoelectric conversion film 32.

[0067] In this embodiment, the first opposing electrode 33, like the first photoelectric conversion film 32, includes a plurality of partial opposing electrodes that are completely separated from one another by structures 70 in a planar view. The plurality of partial opposing electrodes correspond one-to-one to the plurality of first pixel electrodes 31. The size and shape of the partial opposing electrodes in a planar view are the same as those of the partial photoelectric conversion film 32A. Adjacent partial opposing electrodes are not continuous, with the structures 70 present between them.

[0068] The interlayer insulating film 40 is provided between the first photoelectric conversion section 30 and the second photoelectric conversion section 50. The interlayer insulating film 40 functions as a planarizing film that covers and planarizes the upper surface of the first photoelectric conversion section 30. The upper surface of the interlayer insulating film 40 is a flat surface. The interlayer insulating film 40 is, for example, a TEOS (tetraethyl orthosilicate) film, but it may also be made of SiO ２ The insulating film may have a single layer or a laminated structure of a film, a SiN film, a SiON film, or the like.

[0069] The second photoelectric conversion unit 50 includes second pixel electrodes 51a, 51b, 51c, and 51d, a second photoelectric conversion film 52, and a second opposing electrode 53. The second photoelectric conversion unit 50 is provided above the first photoelectric conversion unit 30. Although not shown in FIG. 2A , the second photoelectric conversion unit 50 includes a plurality of each of the second pixel electrodes 51a, 51b, 51c, and 51d.

[0070] The second pixel electrodes 51a, 51b, 51c, and 51d are each electrically connected to the second photoelectric conversion film 52. As shown in FIG. 1 , the second pixel electrodes 51a, 51b, 51c, and 51d are arranged in two rows and two columns and provided on the interlayer insulating film 40. The second pixel electrodes 51a, 51b, 51c, and 51d are translucent to at least a portion of light in the wavelength band to which the first photoelectric conversion film 32 is sensitive. For example, the second pixel electrodes 51a, 51b, 51c, and 51d are transparent electrodes such as ITO. The second pixel electrodes 51a, 51b, 51c, and 51d collect one charge of an electron-hole pair generated in the second photoelectric conversion film 52 as a signal charge and output the signal charge to a signal processing circuit via the vias 60a, 60b, 60c, and 60d.

[0071] The second pixel electrode 51a is provided for each unit cell 10, i.e., for each second pixel. The second pixel electrode 51a is, for example, a flat electrode having a rectangular shape in a plan view, but may be divided into multiple electrode pieces within one unit cell 10, and the via 60a may be connected to each of the multiple electrode pieces. The same may be true for the second pixel electrodes 51b, 51c, and 51d.

[0072] The second photoelectric conversion film 52 is a film that converts light into electric charges. In this embodiment, the second photoelectric conversion film 52 is an organic photoelectric conversion film formed using an organic semiconductor material that is sensitive to the visible light band. Note that the second photoelectric conversion film 52 may also be formed using carbon nanotubes, quantum dots, inorganic materials, etc.

[0073] In the present embodiment, the second photoelectric conversion film 52 is provided continuously across a plurality of unit cells 10. That is, the second photoelectric conversion film 52 is not separated or divided by the structures 70. The second photoelectric conversion film 52 is provided so as to cover the structures 70, that is, so as to overlap the structures 70 in a plan view.

[0074] The second photoelectric conversion film 52 may include, in addition to the film that mainly performs photoelectric conversion, one or more functional layers such as a charge blocking layer that blocks either holes or electrons and transmits the other, and a charge transport layer that assists in the movement of charges.

[0075] The second opposing electrode 53 faces the second pixel electrodes 51 a, 51 b, 51 c, and 51 d via the second photoelectric conversion film 52. The second opposing electrode 53 is translucent to at least part of light in the wavelength bands to which the first photoelectric conversion film 32 and the second photoelectric conversion film 52 are sensitive. For example, the second opposing electrode 53 is a transparent electrode such as ITO. The second opposing electrode 53 collects the other charge of the electron-hole pairs generated in the second photoelectric conversion film 52.

[0076] In the present embodiment, the second opposing electrode 53 is provided continuously across a plurality of unit cells 10, similar to the second photoelectric conversion film 52. That is, the second opposing electrode 53 is not separated or divided by the structures 70. The second opposing electrode 53 is provided so as to cover the structures 70, that is, so as to overlap the structures 70 in a plan view.

[0077] The vias 60a, 60b, 60c, and 60d are each an example of a first via that penetrates the first photoelectric conversion film 32 and is electrically connected to a corresponding second pixel electrode. The via 60a is electrically connected to the second pixel electrode 51a. The via 60b is electrically connected to the second pixel electrode 51b. The via 60c is electrically connected to the second pixel electrode 51c. The via 60d is electrically connected to the second pixel electrode 51d. The vias 60a, 60b, 60c, and 60d are formed using a conductive material such as Cu.

[0078] As shown in FIG. 2B , the vias 60a, 60b, 60c, and 60d are provided within an area surrounded by the structure 70. That is, the vias 60a, 60b, 60c, and 60d each penetrate a partial photoelectric conversion film 32A, which is a part of the first photoelectric conversion film 32. As shown in FIG. 2A , the upper surface of the via 60a is connected to the second pixel electrode 51a, and the lower surface of the via 60a is connected to the wiring 23a. The upper surface of the via 60b is connected to the second pixel electrode 51b, and the lower surface of the via 60b is connected to the wiring 23b. Although not shown in FIG. 2A , the vias 60c and 60d also have a similar configuration.

[0079] The sides of the vias 60a, 60b, 60c, and 60d are covered with insulating members 61a, 61b, 61c, and 61d, respectively, so as not to come into contact with the first photoelectric conversion film 32. The insulating members 61a, 61b, 61c, and 61d are formed using the same material as the interlayer insulating film 40. This ensures electrical insulation between the first photoelectric conversion film 32 and the vias 60a, 60b, 60c, and 60d, and makes it possible to suppress the inflow and outflow of charges to and from the first photoelectric conversion film 32.

[0080] The structure 70 penetrates the first photoelectric conversion film 32 and surrounds the first pixel electrode 31 in a planar view. Specifically, the structure 70 has a lattice shape in a planar view. The planar shape of the opening portion of the structure 70 is, for example, a square, but may also be a rectangle, a hexagon, an octagon, or the like. In other words, the planar shape of the structure 70 is not limited to a square lattice shape and may be a honeycomb lattice shape, or the like. The planar shape and size of the opening portion of the structure 70 are the same as the planar shape and size of the partial photoelectric conversion film 32A. The structure 70 does not include vias 60a, 60b, 60c, and 60d.

[0081] In this embodiment, the structure 70 includes a conductive material and an insulating material. Specifically, the structure 70 includes an insulating portion 71 and a conductive portion 72.

[0082] The insulating portion 71 is a portion formed using an insulating material, and is provided between the conductive portion 72 and the first photoelectric conversion film 32. The insulating portion 71 does not contain any conductive material. The insulating portion 71 covers the side surface of the conductive portion 72, and ensures electrical insulation between the conductive portion 72 and the first photoelectric conversion film 32. This makes it possible to suppress the inflow and outflow of charges to and from the first photoelectric conversion film 32.

[0083] The conductive portion 72 is a portion formed using a conductive material and has a lattice shape in a planar view. In this embodiment, the conductive portion 72 contains the same material as the vias 60a, 60b, 60c, and 60d. As will be described in detail later, the conductive portion 72 is formed in the same process as the vias 60a, 60b, 60c, and 60d. Therefore, the upper surface of the conductive portion 72 and the upper surfaces of the vias 60a, 60b, 60c, and 60d are located on the same plane. Specifically, the upper surface of the conductive portion 72, the upper surfaces of the vias 60a, 60b, 60c, and 60d, and the upper surface of the interlayer insulating film 40 are flush with each other.

[0084] In this embodiment, the conductive portion 72 is electrically floating. The conductive portion 72 is not used as a power line or a signal line for the imaging device 1. A reference potential such as ground potential (0 V) may be supplied to the conductive portion 72. Fixing the potential of the conductive portion 72 can prevent an unnecessary electric field from being applied to the first photoelectric conversion film 32, thereby suppressing a decrease in photoelectric conversion efficiency.

[0085] The protective film 80 is provided above the second photoelectric conversion section 50. The protective film 80 is made of SiO ２ The protective film 80 has a single layer or multilayer structure of an insulating film such as a silicon dioxide film, a silicon nitride film, a silicon oxynitride film, a silicon dioxide film, a silicon dioxide film, a silicon dioxide film, or a silicon oxynitride film. The protective film 80 is translucent to at least part of light in the wavelength band to which each of the first photoelectric conversion film 32 and the second photoelectric conversion film 52 has sensitivity. The protective film 80 does not necessarily have to be provided.

[0086] The color filters 81a and 81b have transmission bands corresponding to specific wavelength bands, allowing light in the transmission bands to pass through while suppressing the transmission of light outside the transmission bands. For example, the color filters 81a and 81b are each transmissive to at least a portion of the wavelength bands to which the first photoelectric conversion film 32 and the second photoelectric conversion film 52 are sensitive. For example, the color filter 81a has transmission bands for a green (G) wavelength band and a near-infrared wavelength band. The color filter 81b has transmission bands for a red (R) wavelength band and a near-infrared wavelength band. The color filters 81a and 81b are provided corresponding to the second pixel electrodes 51a and 51b, respectively. Although not shown in FIG. 2A , color filters corresponding to the second pixel electrodes 51c and 51d, respectively, are also provided. Microlenses may be provided on the top surface of each color filter. Note that the color filters 81a and 81b and other color filters may not be provided.

[0087] [Manufacturing Method] Next, a manufacturing method of the imaging device 1 according to this embodiment will be described with reference to Figures 3A to 3L. Figures 3A to 3L are cross-sectional views illustrating one step of the manufacturing method of the imaging device 1 according to this embodiment.

[0088] As shown in FIG. 3A , a substrate 20 is first prepared. The substrate 20 is formed with various transistors included in a signal processing circuit, as well as a multilayer wiring structure including contact plugs, vias, and wiring. The transistors and multilayer wiring structure can be formed using a typical silicon semiconductor process. A first pixel electrode 31 is formed on the upper surface of the prepared substrate 20. For example, the first pixel electrode 31 is formed by forming a metal film such as TiN by sputtering and then patterning it into a predetermined shape. At this time, the wiring 23 a and 23 b can also be formed simultaneously with the first pixel electrode 31. After the first pixel electrode 31 is formed, the upper surface of the substrate 20 including the first pixel electrode 31 is planarized by embedding the first pixel electrode 31 between adjacent first pixel electrodes 31.

[0089] 3B , a first photoelectric conversion film 32 is formed so as to cover the first pixel electrode 31. For example, the first photoelectric conversion film 32 is formed by forming a film of an organic photoelectric conversion material so as to cover the entire surface of the substrate 20 by a film formation method such as spin coating or vacuum deposition.

[0090] 3C, the first opposing electrode 33 is formed. For example, the first opposing electrode 33 is formed by forming ITO on the entire surface by sputtering.

[0091] 3D , portions of the first opposing electrode 33 and the first photoelectric conversion film 32 are removed to form contact holes 61h for exposing the wirings 23a and 23b, and through holes 71h for forming the structures 70. The removal of the portions of the first opposing electrode 33 and the first photoelectric conversion film 32 is performed by, for example, dry etching. The planar shape of the through holes 71h is the same as the planar shape of the structures 70. This allows the first photoelectric conversion film 32 and the first opposing electrode 33 to be patterned into a predetermined shape. In this embodiment, the first photoelectric conversion film 32 and the first opposing electrode 33 are both completely separated into multiple parts by the through holes 71h.

[0092] 3E, an interlayer insulating film 40 is formed so as to fill the contact holes 61h and the through holes 71h. For example, a SiO.sub.2 film is formed by plasma CVD (Chemical Vapor Deposition) or ALD (Atomic Layer Deposition). ２ Alternatively, an insulating material such as SiN is deposited to form the interlayer insulating film 40. The interlayer insulating film 40 may be formed thick in consideration of the fact that it will be thinned by polishing in a later process.

[0093] Next, as shown in FIG. 3F , a portion of the interlayer insulating film 40 is removed to form a via hole 60h for exposing the wirings 23a and 23b and a through hole 72h for forming the conductive portion 72 of the structure 70. The removal of the portion of the interlayer insulating film 40 is performed, for example, by dry etching. The planar shape of the through hole 72h is the same as the planar shape of the conductive portion 72 of the structure 70. The portion of the interlayer insulating film 40 that is embedded in the contact hole 61h shown in FIG. 3D and remains unremoved during the formation of the via hole 60h corresponds to the insulating members 61a, 61b, 61c, and 61d. The portion of the interlayer insulating film 40 that is embedded in the through hole 71h shown in FIG. 3D and remains unremoved during the formation of the through hole 72h corresponds to the insulating portion 71 of the structure 70.

[0094] 3G, a metal film 60 is formed to fill the via hole 60h and the through hole 72h. For example, the metal film 60 is formed by Cu plating. The portion of the metal film 60 that fills the via hole 60h becomes the vias 60a, 60b, 60c, and 60d. The portion of the metal film 60 that fills the through hole 72h becomes the conductive portion 72 of the structure 70.

[0095] 3H, the metal film 60 is polished by CMP (Chemical Mechanical Polishing) until the interlayer insulating film 40 is exposed. As a result, the upper surfaces of the interlayer insulating film 40, the vias 60a, 60b, 60c, and 60d, and the structure 70 become flush with each other.

[0096] Next, as shown in FIG. 3I, second pixel electrodes 51a and 51b connected to vias 60a and 60b are formed. For example, a transparent conductive film such as ITO is formed by sputtering, and then patterned into a predetermined shape to form second pixel electrodes 51a and 51b. Although not shown in FIG. 3I, second pixel electrodes 51c and 51d can also be formed at the same time.

[0097] 3J, a second photoelectric conversion film 52 is formed so as to cover the second pixel electrodes 51a, 51b, 51c, and 51d. For example, the second photoelectric conversion film 52 is formed by forming an organic photoelectric conversion material into a film by a film formation method such as spin coating or vacuum deposition so as to cover the entire surface of the substrate 20, and then patterning the film as necessary.

[0098] 3K, the second opposing electrode 53 is formed. For example, ITO is formed on the entire surface by sputtering, and then patterned as necessary to form the second opposing electrode 53.

[0099] Next, as shown in FIG. 3L, a protective film 80 is formed. For example, a SiO ２ Alternatively, the protective film 80 is formed by depositing an insulating material such as SiN.

[0100] Finally, the color filters 81 a and 81 d are formed, thereby manufacturing the imaging device 1 including the unit cell 10 shown in FIG. 2A. The above-described manufacturing method is merely an example, and each step may be modified as appropriate. For example, the steps of forming the protective film 80 and the color filters 81 a and 81 b may be omitted.

[0101] [Effects, etc.] Next, effects, etc. of the imaging device 1 according to this embodiment will be described.

[0102] As described with reference to FIGS. 3G and 3H , when forming vias 60 a, 60 b, 60 c, and 60 d, a polishing process using CMP is performed after the plating process to remove unnecessary metal film 60. In this polishing process, a force is applied to the first photoelectric conversion film 32 in the lateral direction of the substrate 20 (a direction parallel to the x-y plane). If the adhesion strength between the first photoelectric conversion film 32 and the interlayer insulating film (specifically, the top layer of the substrate 20) underlying the first photoelectric conversion film 32 is weak, the force generated in the polishing process may cause peeling of the first photoelectric conversion film 32. In particular, if the first photoelectric conversion film 32 is formed using an organic photoelectric conversion material, the weak adhesion strength makes peeling of the first photoelectric conversion film 32 more likely.

[0103] In contrast, the imaging device 1 according to this embodiment is provided with a structure 70 that penetrates the first photoelectric conversion film 32 and surrounds the first pixel electrode 31 in a planar view. The adhesion strength between the structure 70 and the underlying interlayer insulating film can be made higher than the adhesion strength between the first photoelectric conversion film 32 and the underlying interlayer insulating film. The structure 70 functions as an anchor, allowing the structure 70 to withstand the lateral force applied in the polishing process, thereby suppressing peeling of the first photoelectric conversion film 32. This makes it possible to realize a high-quality imaging device 1. Furthermore, the manufacturing yield of the imaging device 1 can be improved.

[0104] (Modification of Embodiment 1) Next, a description will be given of a modification of Embodiment 1. The following description will focus on the differences from Embodiment 1, and the description of commonalities will be omitted or simplified.

[0105] [Modification 1] First, a description will be given of Modification 1. Modification 1 differs from Embodiment 1 mainly in that the structure does not include a conductive material.

[0106] 4A and 4B are cross-sectional views of a unit cell 11 of an imaging device according to this modification. Specifically, Fig. 4A shows an x-z ​​cross section taken along line IVA-IVA in Fig. 4B. Fig. 4B shows an x-y cross section taken along line IVB-IVB in Fig. 4A.

[0107] 4A and 4B , the imaging device according to this modification includes a structure 170 instead of the structure 70 according to the first embodiment. The structure 170 does not include the conductive portion 72, and includes only an insulating material. Specifically, the structure 170 is part of the interlayer insulating film 40 and is an insulator.

[0108] Next, a method for manufacturing an image pickup device according to this modification will be described with reference to Figures 5A and 5B, each of which is a cross-sectional view illustrating one step in the method for manufacturing an image pickup device according to this modification.

[0109] In the manufacturing method of the imaging device according to this modification, the steps up to the formation of the interlayer insulating film 40 are the same as those in Embodiment 1. Specifically, as described with reference to Figures 3A to 3E, the steps are performed in the following order: formation of the first pixel electrode 31, formation of the first photoelectric conversion film 32, formation of the first opposing electrode 33, formation of the contact hole 61h and the through-hole 71h, and formation of the interlayer insulating film 40.

[0110] Next, as shown in Fig. 5A, a portion of the interlayer insulating film 40 is removed to form a via hole 60h for exposing the wirings 23a and 23b. Here, unlike in the first embodiment, the through hole 72h shown in Fig. 3F is not formed. That is, the interlayer insulating film 40 fills the through hole 71h shown in Fig. 3D, and the filled portion becomes a structure 170.

[0111] 5B, a metal film 60 is formed to fill the via hole 60h. For example, the metal film 60 is formed by Cu plating. The portions of the metal film 60 that fill the via hole 60h become vias 60a, 60b, 60c, and 60d.

[0112] The subsequent steps are the same as those in Embodiment 1. Specifically, as described with reference to Figures 3H to 3L, the steps are performed in the following order: polishing the metal film 60, forming the second pixel electrodes 51a, 51b, 51c, and 51d, forming the second photoelectric conversion film 52, forming the second opposing electrode 53, forming the protective film 80, and forming the color filters 81a and 81b. In this manner, an imaging device including the unit cell 11 shown in Figure 4A is manufactured.

[0113] In this modification, the structure 170 also functions as an anchor, allowing the structure 170 to withstand the lateral force applied in the polishing process and suppress peeling of the first photoelectric conversion film 32. This makes it possible to realize a high-quality imaging device. Furthermore, because the structure 170 is an insulator, there is no need to consider the inflow and outflow of charges to and from the first photoelectric conversion film 32, and the structure 170 can be easily formed.

[0114] [Modification 2] Next, a description will be given of Modification 2. Modification 2 differs from Embodiment 1 mainly in that the structure is used to feed power to the shield electrode.

[0115] 6A and 6B are cross-sectional views of a unit cell 12 of an imaging device according to this modification. Specifically, Fig. 6A shows an x-z ​​cross section taken along line VIA-VIA in Fig. 6B, and Fig. 6B shows an x-y cross section taken along line VIB-VIB in Fig. 6A.

[0116] As shown in FIGS. 6A and 6B, the imaging device according to this modification includes a shield electrode 54, a via 24, and a wiring 25 in addition to the configuration of the imaging device 1 according to the first embodiment.

[0117] As shown in FIG. 6B , the shield electrode 54 is disposed adjacent to the second pixel electrodes 51 a, 51 b, 51 c, and 51 d. Specifically, the shield electrode 54 is disposed in a grid pattern so as to collectively surround the second pixel electrodes 51 a, 51 b, 51 c, and 51 d in a plan view. The shield electrode 54 may be disposed so as to surround each of the second pixel electrodes 51 a, 51 b, 51 c, and 51 d individually. The shield electrode 54 does not need to completely surround the second pixel electrodes 51 a, 51 b, 51 c, and 51 d, and may be disposed partially. For example, the shield electrodes 54 may be disposed at intervals so that the grid-like lines are dashed or dotted.

[0118] The shield electrode 54 is translucent to at least a portion of light in the wavelength band to which the first photoelectric conversion film 32 is sensitive. For example, the shield electrode 54 is a transparent electrode such as ITO, and is formed using the same material as the second pixel electrodes 51 a, 51 b, 51 c, and 51 d. The shield electrode 54 can be formed simultaneously with the formation of the second pixel electrodes 51 a, 51 b, 51 c, and 51 d.

[0119] In this modification, as shown in FIG. 6A , the structure 70 is electrically connected to the shield electrode 54. Specifically, the upper surface of the conductive portion 72 of the structure 70 is in contact with the lower surface of the shield electrode 54. In addition, the via 24 is connected to the lower surface of the conductive portion 72 of the structure 70 via the wiring 25. A shield potential supplied from a peripheral circuit (not shown) of the imaging device is applied to the via 24. As a result, the shield potential is supplied to the shield electrode 54 via the via 24, the wiring 25, and the structure 70. The shield potential is a potential for suppressing the movement of charge across unit cells 12 or second pixels in the second photoelectric conversion film 52. The shield potential is, for example, 0 V, but is not limited to this.

[0120] As described above, in the imaging device according to this modification, the provision of the shield electrode 54 makes it possible to suppress the movement of charges across unit cells 12 or second pixels. This makes it possible to suppress deterioration in the quality of images obtained from the second pixels. Furthermore, since the structure 70 supplies power to the shield electrode 54, it is possible to achieve a more compact imaging device than when a dedicated wiring is provided.

[0121] [Modification 3] Next, a description will be given of Modification 3. Modification 3 differs from Modification 2 of Embodiment 1 mainly in that the structural body is used to feed power to the first counter electrode.

[0122] 7A and 7B are cross-sectional views of a unit cell 13 of an imaging device according to this modification. Specifically, Fig. 7A shows a yz cross section taken along line VIIA-VIIA in Fig. 7B. Fig. 7B shows an xy cross section taken along line VIIB-VIIB in Fig. 7A.

[0123] As shown in FIG. 7A, the imaging device according to this modification includes a voltage application wiring 55 and a via 73 instead of the shield electrode 54 according to the second modification of the first embodiment.

[0124] As shown in Fig. 7B , the voltage application wiring 55 has a lattice-shaped wiring portion 55a and an extension portion 55b extending inward from the wiring portion 55a. The shape of the wiring portion 55a is the same as that of the shield electrode 54 shown in Fig. 6B . The extension portion 55b starts from a part of the wiring portion 55a and extends so that its tip portion overlaps the first photoelectric conversion film 32 in a plan view. A via 73 is connected to the underside of the tip portion of the extension portion 55b. Note that multiple pairs of the extension portion 55b and the via 73 of the voltage application wiring 55 may be provided.

[0125] The voltage application wiring 55 is translucent to at least part of the light in the wavelength band to which the first photoelectric conversion film 32 is sensitive. For example, the voltage application wiring 55 is a transparent electrode such as ITO, and is formed using the same material as the second pixel electrodes 51 a, 51 b, 51 c, and 51 d. The voltage application wiring 55 can be formed simultaneously with the formation of the second pixel electrodes 51 a, 51 b, 51 c, and 51 d.

[0126] The via 73 penetrates the interlayer insulating film 40 and electrically connects the voltage application wiring 55 and the first opposing electrode 33. Specifically, the upper surface of the via 73 contacts the lower surface of the extension portion 55b of the voltage application wiring 55, and the lower surface of the via 73 contacts the upper surface of the first opposing electrode 33. The via 73 is formed using a conductive material such as Cu.

[0127] The via 73 is formed in the same process as the conductive portion 72 of the structure 70 and the vias 60a, 60b, 60c, and 60d (not shown in FIG. 7A ). For example, a via hole for the via 73 is formed simultaneously with the formation of the via hole 60h and the through-hole 72h shown in FIG. 3F . Due to the difference in etching rate between the first opposing electrode 33 and the interlayer insulating film 40, the first opposing electrode 33 can be used as an etching stopper layer to form the via hole for the via 73, and the upper surface of the first opposing electrode 33 can be exposed at the bottom of the via hole. The via 73 can then be formed by the plating process and polishing process described with reference to FIGS. 3G and 3H . Therefore, the upper surface of the via 73 is flush with the upper surface of the conductive portion 72 of the structure 70, the upper surfaces of the vias 60a, 60b, 60c, and 60d, and the upper surface of the interlayer insulating film 40.

[0128] In this modification, a potential to be applied to the first opposing electrode 33 is supplied to the conductive portion 72 of the structure 70 through the via 24 and the wiring 25. The first opposing electrode 33 is electrically connected to the conductive portion 72 through the conductive portion 72, the voltage application wiring 55, and the via 73, and therefore a desired potential is supplied to the first opposing electrode 33.

[0129] As described above, in the imaging device according to this modification, the structure 70 supplies power to the first opposing electrodes 33, thereby enabling the imaging device to be made smaller than when dedicated wiring is provided. Furthermore, even in the case where the first opposing electrodes 33 are completely separated for each unit cell 13, as in this modification, power can be supplied individually to the plurality of first opposing electrodes 33 with a simple configuration.

[0130] [Modification 4] Next, a description will be given of Modification 4. Modification 4 differs from Embodiment 1 mainly in that the structures are discontinuous.

[0131] 8A, 8B, and 8C are cross-sectional views of a unit cell 14 of an imaging device according to this modification. Specifically, FIG. 8A shows an x-z ​​cross section taken along line VIIIA-VIIIA in FIGS. 8B and 8C. FIG. 8B shows an x-y cross section taken along line VIIIB-VIIIB in FIG. 8A. FIG. 8C shows an x-y cross section taken along line VIIIC-VIIIC in FIG. 8A.

[0132] As shown in Fig. 8A , the imaging device according to this modification includes a structure 270 instead of the structure 70 according to embodiment 1. As shown in Fig. 8B , the structure 270 has a plurality of partial walls 271 that are separated from one another. The plurality of partial walls 271 are arranged in a ring shape so as to surround the first pixel electrode 31 in a plan view. That is, in the structure 270, a gap 272 is provided between adjacent partial walls 271.

[0133] The multiple partial walls 271 surround more than half of the periphery of the first pixel electrode 31. Specifically, in a plan view, when viewed 360° from the center of the first pixel electrode 31 as the starting point, the partial walls 271 are provided in a range of 180° or more. No gaps 272 are provided that continuously cover an area of ​​90° or more. This allows the structure 270 to effectively withstand forces in all directions that may be applied in the polishing process, and makes it possible to suppress peeling of the first photoelectric conversion film 32.

[0134] In this modification, the first pixel electrode 31 has a rectangular shape in a plan view, and partial walls 271 are provided corresponding to the four sides of the rectangle. When focusing on each side, the partial walls 271 are provided with a length equal to or greater than half the length of the corresponding side. In the example shown in Fig. 8B, no gaps 272 are provided on either the positive or negative side of the y axis, and one gap 272 is provided on each of the positive and negative sides of the x axis.

[0135] A portion of the first photoelectric conversion film 32 is provided in the gap 272. Specifically, as shown in FIG. 8B , the first photoelectric conversion film 32 includes a connecting portion 32B that connects adjacent partial photoelectric conversion films 32A to each other. The connecting portion 32B is a portion located on the line of the lattice-shaped structure 270. Furthermore, the partial photoelectric conversion film 32A is a portion partitioned by the structure 270 in plan view. Specifically, the partial photoelectric conversion film 32A is a portion provided in an opening of the lattice-shaped structure 270. The partial photoelectric conversion films 32A are electrically connected to the first pixel electrodes 31 in a one-to-one correspondence.

[0136] Similar to the first photoelectric conversion film 32, a portion of the first opposing electrode 33 is provided in the gap 272. Specifically, as shown in FIG. 8C , the first opposing electrode 33 includes a connecting portion 33B that connects adjacent partial opposing electrodes 33A to each other. The connecting portion 33B is a portion located on the line of the lattice-shaped structure 270. Furthermore, the partial opposing electrode 33A is a portion partitioned by the structure 270 in plan view. Specifically, the partial opposing electrode 33A is a portion provided in an opening of the lattice-shaped structure 270. The partial opposing electrodes 33A are arranged in one-to-one correspondence with the first pixel electrodes 31 and are opposed to each other.

[0137] The structure 270 according to this modification can be formed in the same manner as the structure 70 according to the first embodiment. The planar shapes of the contact hole 61h and the through hole 71h shown in FIG. 3D may be matched to the planar shapes of the structure 270. Furthermore, the planar shapes of the via hole 60h and the through hole 72h shown in FIG. 3F may be matched to the planar shapes of the conductive portion 72 of the structure 270. Note that in this modification, the structure 270 does not need to include the conductive portion 72. That is, the structure 270 may be an insulator, similar to the structure 170 according to the first modification.

[0138] As described above, in the imaging device according to this modification, the first opposing electrodes 33 are connected across adjacent unit cells 14. Therefore, electrical continuity between adjacent partial opposing electrodes 33A is ensured via the connecting portions 33B, eliminating the need to supply power to each partial opposing electrode 33A. This allows for easy power supply to the first opposing electrodes 33 with a simple configuration.

[0139] Next, a description will be given of Modification 5. Modification 5 differs from Embodiment 1 mainly in that it has a structure in which power is supplied to the first opposing electrode by using wiring provided in the same layer as the second opposing electrode.

[0140] 9A, 9B, 9C, and 9D are cross-sectional views of a unit cell 15 of an imaging device according to this modification. Specifically, FIG. 9A shows a yz cross section taken along line IXA-IXA in FIGS. 9B, 9C, and 9D. FIG. 9B shows an xy cross section taken along line IXB-IXB in FIG. 9A. FIG. 9C shows an xy cross section taken along line IXC-IXC in FIG. 9A. FIG. 9D shows an xy cross section taken along line IXD-IXD in FIG. 9A.

[0141] 9A , the imaging device according to this modification includes, in addition to the configuration of the imaging device 1 according to embodiment 1, wirings 56 and 57, vias 73 and 74, and an insulating member 82. The via 73 is similar to the via 73 according to modification 3, except that it is connected to wiring 57 instead of voltage application wiring 55.

[0142] The wiring 56 is provided in the same layer as the second opposing electrode 53. As shown in Fig. 9D, the wiring 56 and the second opposing electrode 53 are provided at a distance so as not to contact each other. A part of a protective film 80 made of an insulating material is provided between the wiring 56 and the second opposing electrode 53. A potential to be applied to the first opposing electrode 33 is supplied to the wiring 56.

[0143] The wiring 56 is translucent to at least part of light in the wavelength band to which each of the first photoelectric conversion film 32 and the second photoelectric conversion film 52 is sensitive. For example, the wiring 56 is a transparent electrode such as ITO, and is formed using the same material as the second opposing electrode 53. The wiring 56 can be formed simultaneously with the formation of the second opposing electrode 53.

[0144] The wiring 57 is translucent to at least part of light in the wavelength band to which the first photoelectric conversion film 32 is sensitive. For example, the wiring 57 is a transparent electrode such as ITO, and is formed using the same material as the second pixel electrodes 51 a, 51 b, 51 c, and 51 d. The wiring 57 can be formed simultaneously with the formation of the second pixel electrodes 51 a, 51 b, 51 c, and 51 d.

[0145] The via 74 penetrates the second photoelectric conversion film 52 and is electrically connected to the first opposing electrode 33. The via 74 is electrically connected to the wirings 56 and 57. Specifically, the upper surface of the via 74 contacts the lower surface of the wiring 56, and the lower surface of the via 74 contacts the upper surface of the wiring 57. The via 74 is formed using a conductive material such as Cu.

[0146] The side surfaces of the vias 74 are covered with insulating members 82 so as not to come into contact with the second photoelectric conversion film 52. The insulating members 82 are formed using the same material as the protective film 80. This ensures electrical insulation between the second photoelectric conversion film 52 and the vias 74, and makes it possible to suppress the inflow and outflow of charges to and from the second photoelectric conversion film 52. As can be seen by comparing Figures 9B and 9C, the vias 74 are provided in a position that overlaps the first opposing electrode 33 without overlapping the structure 70 in a plan view.

[0147] The via 74 can be formed in the same manner as the via 73. After forming the second photoelectric conversion film 52 shown in Fig. 3J, a via hole is formed by removing a part of the second photoelectric conversion film 52. The via hole is formed by filling the formed via hole with a metal material such as Cu.

[0148] In this modification, the first opposing electrode 33 is electrically connected to the wiring 56 through the via 73, the wiring 57, and the via 74. That is, a predetermined potential is applied to the first opposing electrode 33 through the wiring 56. Therefore, according to the imaging device of this modification, even if the first opposing electrodes 33 are completely separated for each unit cell 15, it is possible to individually supply power to the plurality of first opposing electrodes 33 with a simple configuration.

[0149] (Embodiment 2) Next, embodiment 2 will be described. Specifically, a camera system including an imaging device according to embodiment 1 or a modification thereof will be described. The following description will focus on differences from embodiment 1, and descriptions of commonalities will be omitted or simplified.

[0150] 10 is a diagram showing an example of a camera system 300 including an imaging device according to the present embodiment. Here, a camera system 300 including the imaging device 1 according to Embodiment 1 will be described. Note that the camera system 300 may include an imaging device according to any one of Variations 1 to 5 of Embodiment 1, instead of the imaging device 1.

[0151] As shown in FIG. 10, the camera system 300 includes a lens optical system 301 , the image capturing device 1 , a system controller 302 , and a camera signal processing circuit 303 .

[0152] The lens optical system 301 includes, for example, an autofocus lens, a zoom lens, and an aperture. The lens optical system 301 focuses light onto the imaging surface of the imaging device 1. Light that passes through the lens optical system 301 is incident on the second photoelectric conversion unit 50 and the first photoelectric conversion unit 30 from the protective film 80 side. The second photoelectric conversion film 52 and the first photoelectric conversion film 32 photoelectrically convert light of wavelength components to which they are each sensitive.

[0153] The system controller 302 controls the image capturing apparatus 1 and the camera signal processing circuit 303. The system controller 302 may be, for example, a microcomputer.

[0154] The camera signal processing circuit 303 functions as a signal processing circuit that processes signals generated by the imaging device 1 and outputs the signals as images or data. For example, the camera signal processing circuit 303 generates a near-infrared image based on signals from a plurality of first pixels, and generates a visible light image based on signals from a plurality of second pixels. The camera signal processing circuit 303 performs processes such as gamma correction, color interpolation, spatial interpolation, and white balance. The camera signal processing circuit 303 may be, for example, a DSP (Digital Signal Processor). The camera signal processing circuit 303 may also perform distance measurement based on the near-infrared image or the visible light image.

[0155] While imaging devices and camera systems according to one or more aspects have been described above based on embodiments, the present disclosure is not limited to these embodiments. As long as they do not deviate from the gist of the present disclosure, various modifications conceivable by those skilled in the art to the present embodiments and configurations constructed by combining components of different embodiments are also included within the scope of the present disclosure.

[0156] For example, although the above embodiment illustrates an example in which the unit cell 10 includes one first pixel and four second pixels, the unit cell 10 may include two first pixels and two second pixels, or may include one second pixel and multiple first pixels.

[0157] Furthermore, for example, the structures 70, 170, or 270 have been shown to surround each of the first pixel electrodes 31 individually, but may surround a plurality of first pixel electrodes 31 together.

[0158] Furthermore, for example, the first photoelectric conversion film 32 and the second photoelectric conversion film 52 may have sensitivity in the same wavelength band.

[0159] Furthermore, for example, the structure 70 or 270 may not include the insulating portion 71. That is, the structure 70 or 270 may include only the conductive portion 72.

[0160] Furthermore, various modifications, substitutions, additions, omissions, etc. can be made to the above-described embodiments within the scope of the claims or their equivalents.

[0161] The present disclosure can be used as a high-quality imaging device, and can be used in, for example, a camera or a distance measuring device.

[0162] REFERENCE SIGNS LIST 1 imaging device 2 pixel array 3 vertical scanning circuit 4 horizontal signal readout circuit 5, 6 signal line 7 horizontal signal common line 10, 11, 12, 13, 14, 15 unit cell 20 substrate 21, 22a, 22b, 24, 60a, 60b, 60c, 60d, 73, 74 via 23a, 23b, 25, 56, 57 wiring 30 first photoelectric conversion section 31 first pixel electrode 32 first photoelectric conversion film 32A partial photoelectric conversion film 32B, 33B connecting section 33 first opposing electrode 33A partial opposing electrode 40 interlayer insulating film 50 second photoelectric conversion section 51a, 51b, 51c, 51d second pixel electrode 52 second photoelectric conversion film 53 second opposing electrode 54 shield electrode 55 voltage application wiring 55a Wiring portion 55b Extension portion 60 Metal film 60h Via hole 61a, 61b, 61c, 61d, 82 Insulating member 61h Contact hole 70, 170, 270 Structure 71 Insulating portion 71h, 72h Through hole 72 Conductive portion 80 Protective film 81a, 81b Color filter 271 Partial wall 272 Gap 300 Camera system 301 Lens optical system 302 System controller 303 Camera signal processing circuit

Claims

1. An imaging device comprising: a first photoelectric conversion unit including a first photoelectric conversion film that converts light into electric charges and a first pixel electrode electrically connected to the first photoelectric conversion film; a second photoelectric conversion unit including a second photoelectric conversion film that converts light into electric charges and a second pixel electrode electrically connected to the second photoelectric conversion film, the second photoelectric conversion unit being provided above the first photoelectric conversion unit; a first via that penetrates the first photoelectric conversion film and is electrically connected to the second pixel electrode; and a structure that penetrates the first photoelectric conversion film and surrounds the first pixel electrode in a planar view, wherein the structure does not include the first via.

2. The imaging device according to claim 1, wherein the structure includes a conductive material.

3. The imaging device according to claim 1, wherein the structure contains the same material as the material contained in the first via.

4. The imaging device according to claim 1, wherein the structure includes an insulating material.

5. The imaging device described in claim 1, wherein the first photoelectric conversion unit includes a plurality of the first pixel electrodes, the first photoelectric conversion film includes a plurality of partial photoelectric conversion films that are completely separated from each other by the structure in a planar view, and the plurality of partial photoelectric conversion films are electrically connected in one-to-one correspondence to the plurality of first pixel electrodes.

6. The imaging device described in claim 1, wherein the first photoelectric conversion section includes a plurality of the first pixel electrodes, and the first photoelectric conversion film includes a plurality of partial photoelectric conversion films partitioned by the structure in a planar view and a connecting portion connecting adjacent partial photoelectric conversion films, and the plurality of partial photoelectric conversion films are electrically connected in one-to-one correspondence to the plurality of first pixel electrodes.

7. The imaging device according to claim 1, wherein the structure has a plurality of partial walls separated from one another, and the plurality of partial walls are arranged in a ring shape so as to surround the first pixel electrode in a plan view.

8. The imaging device according to claim 7, wherein the plurality of partial walls surround at least half of the periphery of the first pixel electrode.

9. The imaging device according to claim 2 or 3, wherein the second photoelectric conversion section includes a shield electrode adjacent to the second pixel electrode, and the structure is electrically connected to the shield electrode.

10. An imaging device as described in claim 2 or 3, wherein the first photoelectric conversion unit includes a first opposing electrode that faces the first pixel electrode via the first photoelectric conversion film, and the structure is electrically connected to the first opposing electrode.

11. The imaging device according to any one of claims 1 to 8, wherein the upper surface of the structure and the upper surface of the first via are located on the same plane.

12. An imaging device as described in any one of claims 1 to 8, wherein the first photoelectric conversion unit includes a first opposing electrode that faces the first pixel electrode via the first photoelectric conversion film, and the imaging device is provided with a second via that penetrates the second photoelectric conversion film and is electrically connected to the first opposing electrode.

13. The imaging device described in claim 12, wherein the second photoelectric conversion section includes a second opposing electrode that faces the second pixel electrode via the second photoelectric conversion film, the imaging device includes wiring provided in the same layer as the second opposing electrode, and the second via is electrically connected to the wiring.

14. A camera system comprising: an imaging device according to any one of claims 1 to 8; and an optical system that introduces light into the imaging device.

Images