Imaging device

Abstract

An image capture device according to an aspect of the present disclosure is provided with: at least one first pixel electrode; at least one second pixel electrode spaced apart from the at least one first pixel electrode; a photoelectric converter including a photoelectric conversion layer continuously covering the upper surface of the at least one first pixel electrode and the upper surface of the at least one second pixel electrode; a first counter-electrode positioned over the photoelectric converter and opposing the at least one first pixel electrode; and a second counter-electrode positioned over the photoelectric converter, spaced apart from the first counter-electrode, and opposing the at least one second pixel electrode. A first portion of the upper surface of the photoelectric converter in an inter-electrode region between the first counter-electrode and the second counter-electrode in plan view is recessed more than a second portion of the upper surface of the photoelectric converter in an overlap region overlapping the first counter-electrode or the second counter-electrode in plan view.

Description

[Technical field]

[0001] The present disclosure relates to an imaging device. [Background technology]

[0002] In imaging devices such as CMOS (Complementary Metal Oxide Semiconductor) image sensors, a structure has been proposed in which a photoelectric conversion film formed of an organic material is used for the photoelectric conversion section. For example, Patent Document 1 discloses that for a photoelectric conversion element configured by sandwiching a photoelectric conversion film between an upper electrode and a lower electrode, the upper electrode is patterned to be formed for each pixel. It is disclosed that this reduces dark current by individually applying a voltage to the upper electrode for each pixel.

[0003] Patent Document 2 discloses a technique for varying the sensitivity of each pixel by applying individual voltages to upper electrodes electrically isolated between pixels. Patent Document 3 discloses a technique for forming a pattern of a photoelectric conversion film using a first shadow mask, and then forming a pattern of an ITO (Indium Tin Oxide) electrode using a second shadow mask. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5533046 [Patent Document 2] JP 2019-54499 A [Patent Document 3] Patent No. 5946132 Summary of the Invention [Problem to be solved by the invention]

[0005] When the number of pixels of an imaging device is increased, the area of ​​the upper electrode becomes larger. This causes a voltage drop in the upper electrode, and shading due to potential variations in the surface of the upper electrode may occur. Even in this case, the potential variations in the surface of the upper electrode can be suppressed by patterning the upper electrode for each row or column of pixels or for each pixel. In this way, patterning the upper electrode of the photoelectric conversion element is effective in improving the characteristics of the imaging element.

[0006] However, when a shadow mask is used as disclosed in Patent Document 3, there is a problem that contaminants (contamination) adhering to the shadow mask adhere to the surface of the photoelectric conversion layer when the shadow mask is replaced, resulting in a decrease in the yield of the element. Furthermore, with the small pixel size on the order of microns used in image sensors, patterning with a shadow mask is difficult.

[0007] For this reason, when finely patterning the counter electrode laminated on the photoelectric conversion film, patterning by an etching process used in semiconductors is preferable. However, when the counter electrode located above the adjacent pixel electrodes is removed by etching, the photoelectric conversion film exposed by removing the counter electrode receives damage to the surface by etching, or absorbs moisture or impurities due to exposure to the atmosphere after the process. For this reason, there is a problem that a leakage current occurs between the adjacent counter electrodes through the surface of the photoelectric conversion film.

[0008] Therefore, the present disclosure provides an imaging device in which leakage current between adjacent opposing electrodes is reduced. [Means for solving the problem]

[0009] An imaging device according to an embodiment of the present disclosure includes at least one first pixel electrode, at least one second pixel electrode spaced apart from the at least one first pixel electrode, a photoelectric conversion unit including a photoelectric conversion layer continuously covering an upper surface of the at least one first pixel electrode and an upper surface of the at least one second pixel electrode, a first counter electrode located above the photoelectric conversion unit and facing the at least one first pixel electrode, and a second counter electrode located above the photoelectric conversion unit, spaced apart from the first counter electrode, and facing the at least one second pixel electrode. A first portion of the upper surface of the photoelectric conversion unit in an inter-electrode region between the first counter electrode and the second counter electrode in a plan view is recessed more than a second portion of the upper surface of the photoelectric conversion unit in an overlap region overlapping the first counter electrode or the second counter electrode in a plan view. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide an imaging device in which leakage current between adjacent opposing electrodes is reduced. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view showing a light detection section according to a first comparative example. [Diagram 2] FIG. 2 is a cross-sectional view showing a light detection section according to Comparative Example 2. As shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view showing a light detection section according to Comparative Example 3. As shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view showing a light detection section according to Comparative Example 4. As shown in FIG. [Diagram 5] FIG. 5 is a cross-sectional view showing a light detection unit according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a light detection unit according to the second embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a light detection unit according to the third embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing a light detection unit according to the fourth embodiment. [Figure 9]FIG. 9 is a top view showing a counter electrode, a pixel electrode, and an electrode terminal of an imaging device according to a fifth embodiment. [Figure 10] FIG. 10 is a top view showing a counter electrode, a pixel electrode, and an electrode terminal of an imaging device according to a sixth embodiment. [Figure 11] FIG. 11 is a top view showing a counter electrode, a pixel electrode, and an electrode terminal of an imaging device according to a seventh embodiment. [Figure 12] FIG. 12 is a top view showing a counter electrode, a pixel electrode, and an electrode terminal of an imaging device according to an eighth embodiment. [Figure 13] FIG. 13 is a circuit diagram showing a circuit configuration of an imaging device according to an embodiment. [Figure 14] FIG. 14 is a cross-sectional view of a unit pixel cell in an imaging device according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (Summary of the Disclosure) An imaging device according to an embodiment of the present disclosure includes at least one first pixel electrode, at least one second pixel electrode spaced apart from the at least one first pixel electrode, a photoelectric conversion unit including a photoelectric conversion layer continuously covering an upper surface of the at least one first pixel electrode and an upper surface of the at least one second pixel electrode, a first counter electrode located above the photoelectric conversion unit and facing the at least one first pixel electrode, and a second counter electrode located above the photoelectric conversion unit, spaced apart from the first counter electrode, and facing the at least one second pixel electrode. A first portion of the upper surface of the photoelectric conversion unit in an inter-electrode region between the first counter electrode and the second counter electrode in a plan view is recessed more than a second portion of the upper surface of the photoelectric conversion unit in an overlap region overlapping the first counter electrode or the second counter electrode in a plan view.

[0013] As a result, the upper surface of the photoelectric conversion unit in the inter-electrode region is recessed, which suppresses leakage current flowing between the opposing electrodes, thereby making it possible to provide an imaging device in which leakage current between adjacent opposing electrodes is reduced.

[0014] Furthermore, for example, the film thickness of the photoelectric conversion portion in the inter-electrode region may be smaller than the film thickness of the photoelectric conversion portion in the overlap region.

[0015] This allows the upper surface of the photoelectric conversion unit in the interelectrode region to be easily recessed by reducing the film thickness of the photoelectric conversion unit in the interelectrode region. For example, after forming a photoelectric conversion unit with excellent film quality and a uniform film thickness on a flat upper surface such as an interlayer insulating layer, the surface layer of the photoelectric conversion unit is partially removed, allowing the upper surface of the photoelectric conversion unit in the interelectrode region to be easily recessed. Therefore, the function of the photoelectric conversion unit can be effectively exerted while reducing the leakage current between adjacent opposing electrodes.

[0016] Furthermore, for example, the thickness of the photoelectric conversion layer in the inter-electrode region may be smaller than the thickness of the photoelectric conversion layer in the overlap region.

[0017] As a result, for example, after forming a photoelectric conversion layer with excellent film quality and uniform thickness, the upper surface of the photoelectric conversion section in the inter-electrode region can be easily recessed by partially removing the surface portion of the photoelectric conversion layer, thereby improving the photoelectric conversion function and reducing the leakage current between adjacent opposing electrodes.

[0018] Also, for example, the distance between the first opposing electrode and the second opposing electrode may be smaller than the distance between the at least one first pixel electrode and the at least one second pixel electrode.

[0019] This allows the photoelectric conversion region, where the counter electrode and pixel electrode overlap and where photoelectric conversion takes place, to be separated from the edge of the counter electrode, which prevents damage caused by etching from reaching the photoelectric conversion region and suppresses deterioration of the photoelectric conversion function.

[0020] Also, for example, an end face of the first opposing electrode may have a forward tapered shape or a shape perpendicular to the upper surface of the first opposing electrode, and an end face of the second opposing electrode may have a forward tapered shape or a shape perpendicular to the upper surface of the second opposing electrode.

[0021] This makes it more difficult for etching damage caused by etching gas, oxygen, moisture, etc. to reach the photoelectric conversion region, compared to when the end face of the counter electrode is inversely tapered, and therefore deterioration of the photoelectric conversion function can be suppressed.

[0022] Also, for example, the photoelectric conversion unit may further include an auxiliary layer located between the photoelectric conversion layer and the first opposing electrode and the second opposing electrode, and a portion of the auxiliary layer that overlaps with the first opposing electrode in a planar view may be separated from a portion of the auxiliary layer that overlaps with the second opposing electrode in a planar view.

[0023] This allows the auxiliary layer to further enhance the photoelectric conversion function, and since the auxiliary layer is separated, leakage current through the auxiliary layer can be reduced.

[0024] Also, for example, an imaging device according to one aspect of the present disclosure may further include a sealing layer containing a metal oxide or a metal nitride continuously covering an upper surface of the first opposing electrode and an upper surface of the second opposing electrode, and the sealing layer may be in contact with the photoelectric conversion layer in the inter-electrode region.

[0025] This makes it possible for the sealing layer to prevent oxygen, moisture, and the like from reaching the photoelectric conversion layer from the outside, thereby making it possible to suppress deterioration of the photoelectric conversion function.

[0026] Furthermore, for example, the sealing layer may be in contact with the upper surface and end surface of the first opposing electrode and the upper surface and end surface of the second opposing electrode.

[0027] Thus, by providing the sealing layer in the inter-electrode region, the leakage current between the opposing electrodes can be further reduced.

[0028] Also, for example, the at least one first pixel electrode may include a plurality of first pixel electrodes, and the at least one second pixel electrode may include a plurality of second pixel electrodes.

[0029] Moreover, for example, the liquid crystal display may further include a first pixel electrode group including the plurality of first pixel electrodes and a second pixel electrode group including the plurality of second pixel electrodes, wherein in the first pixel electrode group, the plurality of first pixel electrodes are arranged along a first direction, and in the second pixel electrode group, the plurality of second pixel electrodes are arranged along the first direction, the first pixel electrode group and the second pixel electrode group are arranged side by side along a second direction perpendicular to the first direction, the first opposing electrode has an elongated shape extending along the first direction and covers the first pixel electrode group, and the second opposing electrode has an elongated shape extending along the first direction and covers the second pixel electrode group.

[0030] This makes it possible to provide an opposing electrode for each row or column, for example, so that potential variations can be suppressed and shading correction can be easily performed.

[0031] Also, for example, the distance between two adjacent first pixel electrodes among the plurality of first pixel electrodes along the first direction may be smaller than the distance between each of the plurality of first pixel electrodes and a corresponding second pixel electrode among the plurality of second pixel electrodes that is adjacent to each of the plurality of first pixel electrodes in the second direction.

[0032] This makes it possible to ensure a wide inter-electrode region, thereby suppressing film breakage in the protective film caused by a depression in the upper surface of the photoelectric conversion section, thereby improving the protection performance of the photoelectric conversion section.

[0033] Also, for example, in the first pixel electrode group, the plurality of first pixel electrodes may be arranged along the first direction and the second direction, and in the second pixel electrode group, the plurality of second pixel electrodes may be arranged along the first direction and the second direction.

[0034] This allows multiple rows or columns of pixel electrodes to be covered collectively by one counter electrode, thereby reducing the number of counter electrodes. By reducing the number of counter electrodes, the number of inter-electrode regions also decreases, and the number of recesses provided on the upper surface of the photoelectric conversion unit also decreases. This reduces the possibility of the protective film being torn due to the recesses on the upper surface of the photoelectric conversion unit, thereby improving the protection performance of the photoelectric conversion unit.

[0035] Hereinafter, the embodiment will be specifically described with reference to the drawings.

[0036] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component arrangements and connection forms, steps, and order of steps 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 that are not described in the independent claims are described as optional components.

[0037] In addition, each figure is a schematic diagram and is not necessarily illustrated precisely. Therefore, for example, the scales in each figure do not necessarily match. In addition, in each figure, substantially the same configurations are given the same reference numerals, and duplicated explanations are omitted or simplified.

[0038] Furthermore, in this specification, terms indicating the relationship between elements, such as uniform or equal, terms indicating the shape of elements, such as trapezoid or triangle, and numerical ranges are not expressions that only express a strict meaning, but are expressions that include a substantially equivalent range, for example, a difference of about a few percent.

[0039] In this specification, the terms "upper" and "lower" do not refer to the upper direction (vertically upward) and lower direction (vertically downward) in absolute spatial recognition, but are used as terms defined by a relative positional relationship based on the stacking order in a stacked configuration. The terms "upper" and "lower" are applied not only to the case where two components are arranged with a gap between them and another component exists between the two components, but also to the case where two components are arranged closely together and are in contact with each other.

[0040] (Embodiment) First, the structure of a light detection unit included in the imaging device according to the embodiment will be described.

[0041] [1. Comparative example of cross-sectional structure] Hereinafter, a specific cross-sectional structure of a photodetector of an imaging device according to a comparative example will be described with reference to FIGS.

[0042] [1-1. Comparative Example 1] Fig. 1 is a cross-sectional view showing a photodetection section of an imaging device according to Comparative Example 1. As shown in Fig. 1, the photodetection section 100 includes a plurality of pixel electrodes 101, a photoelectric conversion layer 102, and a counter electrode 103. The photodetection section 100 is provided on an insulating layer 104. The insulating layer 104 is provided with a plurality of connection wirings 105. In addition, a protective film 106, an insulating film 107, and an insulating film 108 are provided so as to cover the photodetection section 100.

[0043] Each of the pixel electrodes 101 is an electrode for collecting signal charges generated in the photoelectric conversion layer 102. The pixel electrodes 101 are made of a conductive material such as a metal, a metal oxide, a metal nitride, or conductive polysilicon. Examples of metals include aluminum, silver, copper, titanium, and tungsten. Examples of metal nitrides include titanium nitride and tantalum nitride. Conductive polysilicon is polysilicon to which impurities have been added to provide conductivity.

[0044] The multiple pixel electrodes 101 are arranged at a distance from each other. For example, as shown in Fig. 1, the first pixel electrode 101a and the second pixel electrode 101b are arranged at a predetermined distance from each other without contacting each other. The first pixel electrode 101a and the second pixel electrode 101b are two pixel electrodes adjacent to each other among the multiple pixel electrodes 101.

[0045] The photoelectric conversion layer 102 generates electron-hole pairs therein when irradiated with light. The electron-hole pairs are separated into electrons and holes by an electric field applied to the photoelectric conversion layer 102, and each of them moves to the pixel electrode 101 side or the counter electrode 103 side. Either the holes or the electrons that have moved to the pixel electrode 101 side are collected by the pixel electrode 101 as signal charges and supplied to a charge detection circuit (not shown) via the connection wiring 105.

[0046] The photoelectric conversion layer 102 is formed using a known photoelectric conversion material. The photoelectric conversion material is, for example, an organic material, but may be an inorganic material. As the inorganic photoelectric conversion material, hydrogenated amorphous silicon, a compound semiconductor material, a metal oxide semiconductor material, etc. can be used. An example of the compound semiconductor material is CdSe. An example of the metal oxide semiconductor material is ZnO.

[0047] When the photoelectric conversion material is an organic material, the molecular design of the photoelectric conversion material can be performed relatively freely so as to obtain desired photoelectric conversion characteristics. When the photoelectric conversion material is an organic material, the photoelectric conversion layer 102 having excellent planarization properties can be easily formed by a coating process using a solution containing the photoelectric conversion material. The organic semiconductor material can be formed by, for example, a vacuum deposition method or a coating method.

[0048] When an organic semiconductor material is used as the photoelectric conversion material, the photoelectric conversion layer 102 may be composed of a laminated film of a donor material and an acceptor material, or may be composed of a mixed film of these materials. The structure of the laminated film of the donor material and the acceptor material is called a heterojunction type. The structure of the mixed film of the donor material and the acceptor material is called a bulk heterojunction type.

[0049] The p-type semiconductor of an organic compound is a donor organic semiconductor, and is mainly represented by a hole-transporting organic compound, which is an organic compound that has a property of easily donating electrons. Specifically, the p-type semiconductor of an organic compound is an organic compound that has a smaller ionization potential when two organic materials are used in contact with each other. Therefore, any organic compound that has electron-donating properties can be used as the donor organic semiconductor. For example, the donor organic semiconductor can be a triarylamine compound, a benzidine compound, a pyrazoline compound, a styrylamine compound, a hydrazone compound, a triphenylmethane compound, a carbazole compound, a polysilane compound, a thiophene compound, a phthalocyanine compound, a cyanine compound, a merocyanine compound, an oxonol compound, a polyamine compound, an indole compound, a pyrrole compound, a pyrazole compound, a polyarylene compound, a metal complex having a condensed aromatic carbon ring compound or a nitrogen-containing heterocyclic compound as a ligand, or the like. The condensed aromatic carbon ring compound may be, for example, a naphthalene derivative, an anthracene derivative, a phenanthrene derivative, a tetracene derivative, a pyrene derivative, a perylene derivative, or a fluoranthene derivative, etc. In addition to these, any organic compound having a smaller ionization potential than the organic compound used as the acceptor organic semiconductor may be used as the donor organic semiconductor.

[0050] The n-type semiconductor of an organic compound is an acceptor organic semiconductor, which is mainly represented by an electron transporting organic compound and refers to an organic compound that has a property of easily accepting electrons. Specifically, the n-type semiconductor of an organic compound refers to the organic compound that has a larger electron affinity when two organic compounds are used in contact with each other. Therefore, any organic compound that has electron accepting properties can be used as the acceptor organic compound. For example, the acceptor organic compound can be a fullerene, a fullerene derivative, a condensed aromatic carbon ring compound, a polyarylene compound, a fluorene compound, a cyclopentadiene compound, a silyl compound, or a metal complex having a nitrogen-containing heterocyclic compound as a ligand. Alternatively, the acceptor organic compound can be a metal complex having a 5- or 7-membered heterocyclic compound containing a nitrogen atom, an oxygen atom, or a sulfur atom as a ligand. Examples of 5- or 7-membered heterocyclic compounds containing a nitrogen atom, an oxygen atom, or a sulfur atom include pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, quinoxaline, quinazoline, phthalazine, cinnoline, isoquinoline, pteridine, acridine, phenazine, phenanthroline, tetrazole, pyrazole, imidazole, thiazole, oxazole, indazole, benzimidazole, benzotriazole, benzoxazole, benzothiazole, carbazole, purine, triazolopyridazine, triazolopyrimidine, tetrazaindene, oxadiazole, imidazopyridine, pyrrolidine, pyrrolopyridine, thiadiazolopyridine, dibenzazepine, or tribenzazepine. Not limited to these, as described above, any organic compound having a larger electron affinity than the organic compound used as the donor organic compound can be used as the acceptor organic semiconductor.

[0051] The photoelectric conversion layer 102 is included in a photoelectric conversion section that continuously covers the upper surfaces of the plurality of pixel electrodes 101. The photoelectric conversion section is a layer located between the plurality of pixel electrodes 101 and the counter electrode 103. In the example shown in FIG. 1, the photoelectric conversion section has a single-layer structure consisting of only the photoelectric conversion layer 102. In other words, the photoelectric conversion layer 102 is the photoelectric conversion section itself having a single-layer structure. The photoelectric conversion section may have a laminated structure including one or more layers other than the photoelectric conversion layer 102. The one or more layers other than the photoelectric conversion layer 102 include an electron blocking layer, an electron injection layer, an electron transport layer, a hole blocking layer, a hole injection layer, or a hole transport layer.

[0052] In addition, "continuous" means that it is not physically separated. For example, as shown in Fig. 1, the photoelectric conversion layer 102 continuously covers the upper surface of the first pixel electrode 101a and the upper surface of the second pixel electrode 101b. The photoelectric conversion layer 102 is not physically separated in the region between the first pixel electrode 101a and the second pixel electrode 101b.

[0053] Moreover, the film thickness of the photoelectric conversion layer 102 is uniform within the plane. That is, the film thickness of the photoelectric conversion layer 102 in the region directly above the pixel electrodes 101 is equal to the film thickness of the photoelectric conversion layer 102 in the region between the two pixel electrodes 101. The photoelectric conversion layer 102 is formed in the shape of a flat sheet covering the multiple pixel electrodes 101.

[0054] The counter electrode 103 collects charges of the opposite polarity to the signal charges collected by the pixel electrodes 101. A predetermined voltage is applied to the counter electrode 103. This generates a potential difference between the counter electrode 103 and the multiple pixel electrodes 101, and an electric field is applied to the photoelectric conversion layer 102. The counter electrode 103 collects charges that, of the holes and electrons generated in the photoelectric conversion layer 102, move toward the counter electrode 103 due to the electric field.

[0055] The counter electrode 103 is located above the photoelectric conversion layer 102 and faces the pixel electrodes 101. The material of the counter electrode 103 is a transparent conductive oxide or a conductive polymer. Examples of the transparent conductive oxide include ITO, IZO (indium zinc oxide), AZO (aluminum-doped zinc oxide), FTO (florine-doped tin oxide), SnO2, TiO2, and ZnO2. One or more transparent conductive oxides selected from these are used as the material of the counter electrode 103. Examples of the conductive polymer include PEDOT / PSS (poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonic acid)). The conductive polymer may be obtained by dispersing metal particles, transparent conductive oxide particles, or the like in a polymer material. The counter electrode 103 may also be a thin metal film that is thin enough to transmit light.

[0056] In Comparative Example 1, the counter electrode 103 is provided so as to cover the entire upper surface of the photoelectric conversion layer 102. The counter electrode 103, like the photoelectric conversion layer 102, continuously covers the upper surface of each of the multiple pixel electrodes 101. In other words, the counter electrode 103 is not physically separated and covers the upper surface of the photoelectric conversion layer 102 with a uniform film thickness. The counter electrode 103 is not provided for each pixel electrode 101, but is a common electrode provided in common to the multiple pixel electrodes 101.

[0057] The insulating layer 104 is an insulating layer formed above a substrate (not shown). For example, a transistor included in a signal processing circuit that processes a signal charge generated by the photodetector 100 is formed on the substrate. The insulating layer 104 has a single layer structure or a multilayer structure of, for example, tetraethyl orthosilicate (TEOS), a silicon oxide film, or a silicon nitride film, but is not particularly limited thereto.

[0058] The connection wiring 105 is provided for each pixel electrode 101. The connection wiring 105 is a part of the wiring that electrically connects the corresponding pixel electrode 101 and the signal processing circuit. The connection wiring 105 is made of a conductive material such as a metal, a metal oxide, a metal nitride, or conductive polysilicon.

[0059] The protective film 106 is an example of a sealing layer provided to prevent the photoelectric conversion layer 102 from coming into contact with air and moisture. The material of the protective film 106 is, for example, an insulating material having a sufficiently low moisture transmittance and a high light transmittance. Specifically, the protective film 106 contains a metal oxide or nitride. The protective film 106 is, for example, an aluminum oxide film.

[0060] The protective film 106 is provided above the counter electrode 103. Specifically, the protective film 106 is provided so as to cover the entire upper surface of the counter electrode 103. Similar to the photoelectric conversion layer 102, the protective film 106 continuously covers the upper surfaces of the multiple pixel electrodes 101. In other words, the protective film 106 is not physically separated, and covers the upper surface of the counter electrode 103 with a uniform film thickness.

[0061] The insulating film 107, like the protective film 106, is provided to prevent the photoelectric conversion layer 102 from coming into contact with air and moisture. The insulating film 107 is made of, for example, an insulating material having low moisture transmittance and high light transmittance. The insulating film 107 is, for example, a silicon oxide film, a silicon nitride film, or a silicon oxynitride film.

[0062] The insulating film 107 is provided above the protective film 106. Specifically, the insulating film 107 is provided so as to cover the entire upper surface of the protective film 106. The insulating film 107 continuously covers the upper surfaces of the plurality of pixel electrodes 101, similar to the photoelectric conversion layer 102. In other words, the insulating film 107 is not physically separated, and covers the upper surface of the protective film 106 with a uniform thickness.

[0063] The insulating film 108 is a planarizing film having a flat upper surface. The insulating film 108 is made of a light-transmitting material, such as tetraethyl orthosilicate (TEOS).

[0064] The insulating film 108 is provided above the insulating film 107. Specifically, the insulating film 108 is provided so as to cover the entire upper surface of the insulating film 107. Similar to the photoelectric conversion layer 102, the insulating film 108 continuously covers the upper surfaces of the multiple pixel electrodes 101. In other words, the insulating film 108 is not physically separated, and covers the upper surface of the insulating film 107 with a uniform film thickness.

[0065] It should be noted that the imaging device does not necessarily need to include at least one of the protective film 106, the insulating film 107, and the insulating film .

[0066] In this way, in the imaging device according to Comparative Example 1, the counter electrode 103 is not separated. Therefore, as described above, there is a problem of shading due to the effect of a voltage drop in the counter electrode 103.

[0067] [1-2. Comparative Example 2] Next, Comparative Example 2 will be described with reference to Fig. 2. Below, the differences from Comparative Example 1 will be mainly described, and the description of commonalities will be omitted or simplified.

[0068] Fig. 2 is a cross-sectional view showing a photodetector of an imaging device according to Comparative Example 2. As shown in Fig. 2, the photodetector 110 according to Comparative Example 2 is different from the photodetector 100 according to Comparative Example 1 in that it includes a plurality of counter electrodes 113 instead of the counter electrode 103.

[0069] The multiple counter electrodes 113 are disposed at a distance from each other. For example, as shown in FIG. 2, the first counter electrode 113a and the second counter electrode 113b are disposed at a predetermined distance from each other without contacting each other. The first counter electrode 113a and the second counter electrode 113b are two counter electrodes adjacent to each other among the multiple counter electrodes 113. The first counter electrode 113a faces the first pixel electrode 101a. The second counter electrode 113b faces the second pixel electrode 101b.

[0070] Each of the plurality of counter electrodes 113 collects electric charges of the opposite polarity to the signal electric charges collected by the opposing pixel electrodes 101. The counter electrodes 113 are provided, for example, for each pixel electrode group including the plurality of pixel electrodes 101. Specifically, in a plan view, the counter electrodes 113 have an elongated shape extending along a first direction. The plurality of counter electrodes 113 are arranged along a second direction perpendicular to the first direction. In the cross section shown in FIG. 2, the first direction is the depth direction of the paper, and the second direction is the left-right direction of the paper. Specific examples of the plan view shapes and plan layouts of the plurality of counter electrodes 113 and the plurality of pixel electrodes 101 will be described later.

[0071] The end face of the counter electrode 113 according to Comparative Example 2 is forward tapered. Forward tapered means that the normal direction of the end face is obliquely upward. That is, as shown in FIG. 2, the cross-sectional shape of the counter electrode 113 is a trapezoid whose lower base is longer than its upper base. For example, the upper surface of the counter electrode 113 is smaller than the lower surface of the counter electrode 113. The lower base and the lower surface are the sides and surfaces of the counter electrode 113 on the photoelectric conversion layer 102 side. The upper base and the upper surface are the sides and surfaces of the counter electrode 113 on the opposite side to the photoelectric conversion layer 102.

[0072] Since the end face is forward tapered, etching damage caused by etching gas, oxygen, moisture, etc. is less likely to reach the photoelectric conversion region compared to when the end face is reverse tapered. Therefore, deterioration of the photoelectric conversion function can be suppressed. The photoelectric conversion region is a region of the photoelectric conversion layer 102 where the pixel electrode 101 and the counter electrode 113 overlap in a planar view. In Comparative Example 2, since the pixel electrode 101 is smaller than the counter electrode 113, the photoelectric conversion region corresponds to a portion of the photoelectric conversion layer 102 that overlaps with the pixel electrode 101 in a planar view.

[0073] Moreover, the inter-electrode distance between adjacent counter electrodes 113 is smaller than the inter-electrode distance between adjacent pixel electrodes 101. The inter-electrode distance between adjacent counter electrodes 113 is represented by b in Figures 9 to 11, which will be described later. Similarly, the inter-electrode distance between adjacent pixel electrodes 101 is represented by a in Figures 9 to 11.

[0074] For example, the inter-electrode distance between the first opposing electrode 113a and the second opposing electrode 113b is smaller than the inter-electrode distance between the first pixel electrode 101a and the second pixel electrode 101b. The inter-electrode distance means the shortest distance between adjacent opposing electrodes 113 or pixel electrodes 101. For example, the inter-electrode distance between the first opposing electrode 113a and the second opposing electrode 113b is the distance between the lower end of the end face of the first opposing electrode 113a and the lower end of the end face of the second opposing electrode 113b. The inter-electrode distance may be the distance between the center of the end face of the first opposing electrode 113a and the center of the end face of the second opposing electrode 113b.

[0075] Since the distance between adjacent counter electrodes 113 is small, the photoelectric conversion region in the photoelectric conversion layer 102 can be separated from the end of the counter electrode 113. This makes it possible to prevent etching damage from reaching the photoelectric conversion region, and thus to suppress deterioration of the photoelectric conversion function.

[0076] 2 illustrates an overlapping region 201 that overlaps with the counter electrode 113 in a plan view, and an interelectrode region 202 that is a region between two adjacent counter electrodes 113. For example, the overlapping region 201 is a region that overlaps with the first counter electrode 113a or the second counter electrode 113b in a plan view. The interelectrode region 202 is a region between the first counter electrode 113a and the second counter electrode 113b in a plan view.

[0077] Specifically, overlapping region 201 is a region that overlaps with the lower surface of counter electrode 113 in a plan view. Inter-electrode region 202 is a region between the contours of the lower surfaces of two adjacent counter electrodes 113 in a plan view. Note that overlapping region 201 and inter-electrode region 202 may be determined based on the upper surface of counter electrode 113. Alternatively, overlapping region 201 and inter-electrode region 202 may be determined based on the center line of the end surface of counter electrode 113.

[0078] As can be seen in comparison with Comparative Example 1, in Comparative Example 2, the multiple counter electrodes 113 are separated from one another. Specifically, in plan view, the counter electrodes 113 are not provided in the interelectrode regions 202.

[0079] The multiple counter electrodes 113 are formed by patterning the counter electrode 103 according to Comparative Example 1. Specifically, after forming the flat sheet-like counter electrode 103, the portions of the counter electrode 103 located in the inter-electrode regions 202 are removed by photolithography and etching to form the multiple counter electrodes 113 spaced apart from one another.

[0080] At this time, by making the end face of the resist pattern used as an etching mask forward tapered, it is possible to make the end face of the counter electrode 103 forward tapered. The cross-sectional shape of the resist pattern is, for example, a trapezoid, but it may also be a triangle.

[0081] As described above, in the imaging device according to Comparative Example 2, since the counter electrodes 113 are arranged apart from each other, the effect of shading can be suppressed. On the other hand, when the counter electrodes 113 are patterned, the surface of the photoelectric conversion layer 102 in the inter-electrode region 202 is damaged by etching. In addition, moisture or impurities are adsorbed on the surface of the photoelectric conversion layer 102 in the inter-electrode region 202. Due to the effects of such damage or impurities, the surface portion of the photoelectric conversion layer 102 can become a path for a leak current between adjacent counter electrodes 113. Therefore, the imaging device according to Comparative Example 2 has a problem in that the leak current cannot be suppressed.

[0082] In Comparative Example 2 and Comparative Examples and Examples described later, since there is an interelectrode region 202 where the counter electrode 113 is not provided, the protective film 106 continuously covers the upper surfaces of the multiple counter electrodes 113, and is provided in contact with the photoelectric conversion layer 102 in the interelectrode region 202. As shown in FIG. 2, the protective film 106 and the insulating film 107 are provided so as to follow the unevenness caused by the presence or absence of the counter electrode 113. Since the protective film 106 and the insulating film 107 have a uniform thickness, the upper surface of the insulating film 107 forms unevenness equivalent to the unevenness caused by the presence or absence of the counter electrode 113. The insulating film 108 is provided so as to fill the unevenness on the upper surface of the insulating film 107, and flattens the upper surface. Therefore, the thickness of the insulating film 108 is different between the overlap region 201 and the interelectrode region 202. Specifically, the thickness of the insulating film 108 in the overlap region 201 is smaller than the thickness of the insulating film 108 in the interelectrode region 202.

[0083] [1-3. Comparative Example 3] Next, Comparative Example 3 will be described with reference to Fig. 3. In the following, differences from Comparative Example 2 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0084] Fig. 3 is a cross-sectional view showing a photodetector of an imaging device according to Comparative Example 3. As shown in Fig. 3, the photodetector 120 according to Comparative Example 3 is different from the photodetector 110 according to Comparative Example 2 in that it includes a plurality of photoelectric conversion layers 122 instead of the photoelectric conversion layer 102.

[0085] The multiple photoelectric conversion layers 122 are arranged at a distance from each other. For example, as shown in FIG. 3, the first photoelectric conversion layer 122a and the second photoelectric conversion layer 122b are arranged at a predetermined distance from each other without contacting each other. The first photoelectric conversion layer 122a and the second photoelectric conversion layer 122b are two photoelectric conversion layers adjacent to each other among the multiple photoelectric conversion layers 122. The first photoelectric conversion layer 122a is located between the first pixel electrode 101a and the first counter electrode 113a. The second photoelectric conversion layer 122b is located between the second pixel electrode 101b and the second counter electrode 113b.

[0086] As can be seen by comparison with Comparative Example 2, in Comparative Example 3, the photoelectric conversion layer 122 is separated for each counter electrode 113. Specifically, in a plan view, the photoelectric conversion layer 122 is not provided in the inter-electrode region 202.

[0087] The multiple photoelectric conversion layers 122 are formed by patterning the photoelectric conversion layer 102 according to Comparative Example 2. Specifically, after forming the flat sheet-like photoelectric conversion layer 102 and the counter electrode 103 in order, the counter electrode 103 and the photoelectric conversion layer 102 in the inter-electrode region 202 are removed by photolithography and etching to form multiple spaced apart photoelectric conversion layers 122. That is, the counter electrode 103 and the photoelectric conversion layer 102 are successively etched using the same resist pattern as a mask, whereby the photoelectric conversion layers 122 separated for each counter electrode 113 are formed.

[0088] As described above, in the imaging device according to Comparative Example 3, similarly to Comparative Example 2, the counter electrodes 113 are arranged apart from each other, so that the effect of shading can be suppressed. On the other hand, when the photoelectric conversion layer 122 is patterned, the surface of the insulating layer 104 in the interelectrode region 202 is damaged by etching. In addition, moisture or impurities are adsorbed on the surface of the insulating layer 104 in the interelectrode region 202. Due to the effects of such damage or impurities, the surface portion of the insulating layer 104 can become a path for leakage current between adjacent pixel electrodes 101. Therefore, the imaging device according to Comparative Example 3 has a problem that leakage current between pixel electrodes cannot be suppressed.

[0089] [1-4. Comparative Example 4] Next, Comparative Example 4 will be described with reference to Fig. 4. In the following, differences from Comparative Example 3 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0090] Fig. 4 is a cross-sectional view showing a light detection unit of an imaging device according to Comparative Example 4. As shown in Fig. 4, the imaging device according to Comparative Example 4 differs from the imaging device according to Comparative Example 3 in that it additionally includes a shield electrode 139 and a plurality of connection wires 135.

[0091] The shield electrode 139 is provided around the pixel electrodes 101, and a predetermined voltage is applied to the shield electrode 139. For example, the shield electrode 139 is formed in a lattice shape so as to surround each of the pixel electrodes 101 arranged two-dimensionally in a plan view. By applying an appropriate voltage to the shield electrode 139, a lateral electric field can be generated in the photoelectric conversion layer 122. This makes it possible to suppress the lateral movement of signal charges in the photoelectric conversion layer 122.

[0092] The shield electrode 139 is made of a conductive material such as a metal, a metal oxide, a metal nitride, or conductive polysilicon. The shield electrode 139 is made of, for example, copper. The material of the shield electrode 139 may be the same as the material of the pixel electrode 101.

[0093] The multiple connection wirings 135 are part of wiring for supplying a voltage to be applied to the shield electrode 139. The multiple connection wirings 135 are made of the same material as the connection wirings 105, for example, a conductive material such as a metal, a metal oxide, a metal nitride, or conductive polysilicon.

[0094] When the shield electrode 139 is provided so as to surround the pixel electrode 101, as shown in FIG. 4, the shield electrode 139 is also present in the inter-electrode region 202 and is exposed from the upper surface of the insulating layer 104.

[0095] In this case, during patterning of the photoelectric conversion layer 122, the shield electrode 139 exposed in the inter-electrode region 202 is exposed to the etching gas and oxidized. The oxidized shield electrode 139 loses its conductivity and becomes insulated, and does not adequately perform its shielding function. Furthermore, during etching, the metal material contained in the shield electrode 139 may scatter and form a path for leakage current. Thus, the imaging device according to Comparative Example 4 also has the problem that leakage current cannot be suppressed.

[0096] [2. Example of cross-sectional structure] Next, a specific cross-sectional structure of the photodetector of the imaging device according to the embodiment will be described with reference to Fig. 5 to Fig. 8. In the following, the differences from the above-mentioned Comparative Examples 1 to 4 will be mainly described, and the description of the commonalities will be omitted or simplified.

[0097] [2-1. Example 1] Fig. 5 is a cross-sectional view showing a photodetector of the imaging device according to Example 1. As shown in Fig. 5, the photodetector 300 according to Example 1 is different from the photodetector 110 according to Comparative Example 2 in that it includes a photoelectric conversion layer 302 instead of the photoelectric conversion layer 102.

[0098] The photoelectric conversion layer 302, like the photoelectric conversion layer 102, continuously covers the upper surfaces of the plurality of pixel electrodes 101. That is, the photoelectric conversion layer 302 is provided in both the overlap region 201 and the inter-electrode region 202.

[0099] In Example 1, the thickness of the photoelectric conversion layer 302 is not uniform. Specifically, the thickness of the photoelectric conversion layer 302 in the interelectrode region 202 is smaller than the thickness of the photoelectric conversion layer 302 in the overlap region 201. As shown in FIG. 5, the photoelectric conversion layer 302 includes an overlapping portion 302a located in the overlap region 201 and a non-overlapping portion 302c located in the interelectrode region 202. The thickness of the non-overlapping portion 302c is smaller than the thickness of the overlapping portion 302a. For example, the difference between the thickness of the non-overlapping portion 302c and the thickness of the overlapping portion 302a is 5 nm or more. Specifically, the difference between the lower end of the counter electrode 113 and the upper surface of the non-overlapping portion 302c is 5 nm or more. This makes it possible to suppress the generation of a tunnel current between the lower end of the counter electrode 113 and the upper surface of the non-overlapping portion 302c, thereby reducing the leak current.

[0100] The thickness of the non-overlapping portion 302c may be 2 / 3 or less, half or less, or 1 / 3 or less of the thickness of the overlapping portion 302a. As an example, the thickness of the overlapping portion 302a is 500 nm, and the thickness of the non-overlapping portion 302c is 300 nm. The lower limit of the thickness of the non-overlapping portion 302c is, for example, 5 nm.

[0101] The lower surface of the photoelectric conversion layer 302 is flat. That is, the upper surfaces of the pixel electrodes 101 and the uppermost surface of the insulating layer 104 are flush with each other to form a flat surface. The photoelectric conversion layer 302 is provided so as to contact and cover the flat surface. Since the lower surface of the photoelectric conversion layer 302 is flat, unevenness can be formed on the upper surface of the photoelectric conversion layer 302 due to the difference in film thickness of the photoelectric conversion layer 302. Specifically, the upper surface of the photoelectric conversion layer 302 in the inter-electrode region 202 is recessed below the upper surface of the photoelectric conversion layer 302 in the overlap region 201. That is, the upper surface of the non-overlapping portion 302c is located lower than the upper surface of the overlapping portion 302a.

[0102] The photoelectric conversion layer 302 is formed by partially removing the surface layer of the photoelectric conversion layer 102 according to Comparative Example 2. Specifically, after forming the flat sheet-like photoelectric conversion layer 102 and the counter electrode 103 in order, the photoelectric conversion layer 302 is formed by removing only the surface layer of the counter electrode 103 located in the interelectrode region 202 and the surface layer of the photoelectric conversion layer 102 located in the interelectrode region 202 by photolithography and etching. That is, the etching of the counter electrode 103 and the etching of the photoelectric conversion layer 102 are performed successively using the same resist pattern as a mask. At this time, the portion of the photoelectric conversion layer 102 located in the interelectrode region 202 is not completely removed, but is left with a predetermined film thickness. As a result, the photoelectric conversion layer 302 with a small film thickness and a concave upper surface is formed in the interelectrode region 202.

[0103] As described above, in the imaging device according to the first embodiment, the upper surface of the photoelectric conversion layer 302 in the inter-electrode region 202 is recessed, so that the leakage current flowing along the upper surface is suppressed. Therefore, the leakage current between the adjacent counter electrodes 113 can be reduced.

[0104] Moreover, the photoelectric conversion layer 302 having a recessed upper surface can be formed by using, as a mask, the same resist pattern as that used for patterning the counter electrode 113. In other words, since no dedicated resist pattern is required for forming the photoelectric conversion layer 302, the photoelectric conversion layer 302 can be easily formed.

[0105] In the first embodiment, since the photoelectric conversion layer 302 is also present in the inter-electrode region 202, the protective film 106 continuously covers the upper surface of each of the multiple counter electrodes 113 and is in contact with the photoelectric conversion layer 302 in the inter-electrode region 202. The protective film 106 is in contact with the upper surface and end surface of each of the multiple counter electrodes 113. By covering the end surfaces of the counter electrodes 113 with the insulating protective film 106, the leakage current between the counter electrodes 113 can be further suppressed.

[0106] The protective film 106 is formed along the steps due to the presence or absence of the counter electrode 113, and is therefore formed using a method with high film-covering properties. For example, the protective film 106 is formed using an atomic layer deposition (ALD) method or a chemical vapor deposition method. The improved film-covering properties can further suppress the leakage current.

[0107] The lower surface of the photoelectric conversion layer 302 does not have to be flat. For example, the lower surface of the photoelectric conversion layer 302 may have a step due to the pixel electrode 101. The height of the step is, for example, in the range of several nm to 20 nm. The upper surface of each of the multiple pixel electrodes 101 may be located above the uppermost surface of the insulating layer 104. For example, the multiple pixel electrodes 101 may be provided on the flat uppermost surface of the insulating layer 104, and the spaces between the pixel electrodes 101 may not be filled with an insulating layer.

[0108] 2-2. Example 2 Next, a second embodiment will be described with reference to Fig. 6. In the following, differences from the first embodiment will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0109] Fig. 6 is a cross-sectional view showing a light detection unit of an imaging device according to Example 2. As shown in Fig. 6, the imaging device according to Example 2 is different from the imaging device according to Example 1 in that it additionally includes a shield electrode 139 and a plurality of connection wires 135. The shield electrode 139 and the connection wires 135 are the same as those in Comparative Example 4.

[0110] In Example 2, similarly to Example 1, a photoelectric conversion layer 302 is provided in the inter-electrode region 202. That is, the upper surface of the shield electrode 139 is covered with the photoelectric conversion layer 302. The upper surface of the shield electrode 139 is not exposed when the counter electrode 113 is patterned and the photoelectric conversion layer 302 is partially removed, and remains covered with the photoelectric conversion layer 302. Therefore, both the oxidation of the shield electrode 139 and the generation of a path for a leak current, as shown in Comparative Example 4, are suppressed.

[0111] In addition, since the photoelectric conversion layer 302 is also provided in the inter-electrode region 202, the signal charge generated in one overlapping portion 302a can move to the adjacent overlapping portion 302a via the non-overlapping portion 302c. In the second embodiment, the shield electrode 139 is provided, so that the lateral movement of the signal charge can be suppressed, and thus the occurrence of color mixing due to the mixing of the signal charges can be suppressed.

[0112] 2-3. Example 3 Next, a third embodiment will be described with reference to Fig. 7. In the following, differences from the first embodiment will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0113] Fig. 7 is a cross-sectional view showing a photodetector of an imaging device according to Example 3. As shown in Fig. 7, the photodetector 310 according to Example 3 is different from the photodetector 300 according to Example 1 in that an auxiliary layer 312 is newly provided.

[0114] The auxiliary layer 312 is included in a photoelectric conversion unit located between the plurality of pixel electrodes 101 and the plurality of counter electrodes 113. In the third embodiment, the photoelectric conversion unit is configured by the auxiliary layer 312 and the photoelectric conversion layer 302. The auxiliary layer 312 is, for example, a charge blocking layer that suppresses the transmission of the signal charge collected by the pixel electrode 101. When the signal charge is a hole, the auxiliary layer 312 is a hole blocking layer that suppresses the transmission of the hole and transmits the electron. When the signal charge is an electron, the auxiliary layer 312 is an electron blocking layer that suppresses the transmission of the electron and transmits the hole. The auxiliary layer 312 may be a hole injection layer, a hole transport layer, an electron injection layer, or an electron transport layer.

[0115] 7, the auxiliary layer 312 is provided for each counter electrode 113. For example, the auxiliary layer 312 is separated into a portion 312a overlapping the first counter electrode 113a and a portion 312b overlapping the second counter electrode 113b in a plan view. In other words, the auxiliary layer 312 is not provided in the inter-electrode region 202.

[0116] The auxiliary layer 312 separated for each counter electrode 113 is formed by continuously etching the auxiliary layer 312 using the same resist pattern as a mask following the patterning of the counter electrode 113. In other words, since no dedicated resist pattern is required to separate the auxiliary layer 312, the auxiliary layer 312 can be easily separated.

[0117] The auxiliary layer 312 is formed using a material with lower insulating properties than the photoelectric conversion layer 302. For this reason, when the auxiliary layer 312 is provided continuously between a plurality of counter electrodes 113, the auxiliary layer 312 itself is likely to become a path for leakage current. In contrast, in Example 3, the auxiliary layer 312 is separated, so that the leakage current through the auxiliary layer 312 can be reduced.

[0118] In the third embodiment, the photodetector 310 may include the photoelectric conversion layer 102 instead of the photoelectric conversion layer 302. That is, the photoelectric conversion layer included in the photodetector 310 may have the same film thickness in the inter-electrode region 202 and the overlap region 201.

[0119] Furthermore, auxiliary layer 312 may remain with a predetermined thickness in inter-electrode region 202 without being completely removed. That is, similar to photoelectric conversion layer 302, auxiliary layer 312 may have a smaller thickness in the inter-electrode region 202 than in the overlap region 201.

[0120] 2-4. Example 4 Next, a fourth embodiment will be described with reference to Fig. 8. In the following, differences from the first embodiment will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0121] Fig. 8 is a cross-sectional view showing a photodetector of an imaging device according to Example 4. As shown in Fig. 8, the photodetector 320 according to Example 4 includes a photoelectric conversion layer 322 instead of the photoelectric conversion layer 302 of the photodetector 300 according to Example 1. Moreover, the photodetector 320 is provided so as to cover an insulating layer 324 instead of the insulating layer 104.

[0122] The insulating layer 324 does not have a flat top surface. As shown in FIG. 8, a recess 324c is formed in the inter-electrode region 202 on the top surface of the insulating layer 324. The recess 324c is formed, for example, by removing a surface portion of the insulating layer 104, the top surface of which is flattened, located in the inter-electrode region 202, by photolithography and etching. Alternatively, the recess 324c may be between adjacent pixel electrodes 101. A plurality of pixel electrodes 101 may be formed on the flattened top surface of the insulating layer 104, and the space between adjacent pixel electrodes 101 may be used as the recess 324c.

[0123] The photoelectric conversion layer 322 is provided with a uniform thickness along the inner surface of the recess 324c. Specifically, the thickness of the overlapping portion 322a of the photoelectric conversion layer 322 is equal to the thickness of the non-overlapping portion 322c. As a result, the upper surface of the photoelectric conversion layer 322 in the inter-electrode region 202 is recessed further than the upper surface of the photoelectric conversion layer 322 in the overlapping region 201.

[0124] In the imaging device according to the fourth embodiment, the upper surface of the photoelectric conversion layer 322 in the inter-electrode region 202 is recessed, so that the leakage current flowing along the upper surface is suppressed. Therefore, the leakage current between the adjacent counter electrodes 113 can be reduced.

[0125] In the third and fourth embodiments, the shield electrode 139 and the connection wiring 135 may also be provided.

[0126] [3. Plane layout] Next, examples of planar layouts of counter electrodes and pixel electrodes will be described with reference to Figures 9 to 12. Examples 5 to 8 described below can be applied as planar layouts to any of Examples 1 to 4 described above.

[0127] [3-1. Example 5] First, the fifth embodiment will be described with reference to FIG.

[0128] Fig. 9 is a top view showing a counter electrode, a pixel electrode, and an electrode terminal of an imaging device according to Example 5. As shown in Fig. 9, in the imaging device according to Example 5, a plurality of pixel electrodes 101 are arranged two-dimensionally in a plan view. The pixel electrodes 101 are arranged at equal intervals in each of the x-axis direction and the y-axis direction. In the example shown in Fig. 9, the inter-electrode distance between adjacent pixel electrodes 101 is represented by a.

[0129] The x-axis and y-axis are two axes perpendicular to each other. The x-axis direction is an example of a first direction in which the pixel electrodes 101 are arranged. The y-axis direction is an example of a second direction perpendicular to the first direction. The xy plane is a plane parallel to the substrate of the imaging device. For example, the top surface of the insulating layer 104 shown in FIG. 5 is parallel to the xy plane.

[0130] 9 includes a plurality of pixel electrodes 101 arranged along the x-axis direction. The plurality of pixel electrode groups 401 are arranged along the y-axis direction. The number of pixel electrodes 101 included in the pixel electrode group 401, i.e., the number of pixel electrodes 101 arranged along the x-axis direction, may be only one and is not particularly limited. The number of pixel electrode groups 401 arranged along the y-axis direction is not particularly limited as long as it is a plurality.

[0131] The plurality of counter electrodes 113 have an elongated shape extending along the x-axis direction. The counter electrodes 113 cover the pixel electrode groups 401. Specifically, the counter electrodes 113 are provided for each pixel electrode group 401.

[0132] Here, a description will be given of the relationship between the planar layout according to the fifth embodiment and the cross-sectional structures according to the first to fourth embodiments. Specifically, the cross section taken along line VV shown in Fig. 9 corresponds to the cross-sectional views shown in Figs. 5 to 8.

[0133] For example, a plurality of first pixel electrodes 101a are arranged in the x-axis direction and are included in a first pixel electrode group 401a. The first counter electrode 113a has an elongated shape extending along the x-axis direction and covers the first pixel electrode group 401a.

[0134] A plurality of second pixel electrodes 101b are arranged in the x-axis direction and are included in the second pixel electrode group 401b. The second counter electrode 113b has an elongated shape extending along the x-axis direction and covers the second pixel electrode group 401b. The first pixel electrode group 401a and the second pixel electrode group 401b are pixel electrode groups adjacent to each other in the y-axis direction among the plurality of pixel electrode groups 401.

[0135] 9, the inter-electrode distance a between adjacent pixel electrodes 101 in the y-axis direction is greater than the inter-electrode distance b between adjacent counter electrodes 113 in the y-axis direction. This makes it possible to suppress deterioration of the photoelectric conversion function, as described above.

[0136] In addition, in Fig. 9, the planar shape of the photoelectric conversion layer 302 or 322 is represented by a dashed line. As shown in Fig. 9, the photoelectric conversion layer 302 or 322 is provided so as to continuously cover the multiple pixel electrodes 101 arranged two-dimensionally. Specifically, the photoelectric conversion layer 302 or 322 continuously covers all the pixel electrodes 101. The multiple counter electrodes 113 are provided so as to protrude from the photoelectric conversion layer 302 or 322 on the negative side of the x-axis.

[0137] Each of the multiple counter electrodes 113 is connected to an electrode terminal 402 at a portion protruding from the photoelectric conversion layer 302 or 322. Specifically, an electrode terminal 402 for power supply is provided at an end of each of the multiple counter electrodes 113 on the negative side of the x-axis. That is, a power supply voltage is applied to each of the multiple counter electrodes 113 from the negative side of the x-axis. So-called one-sided power supply is performed for the multiple counter electrodes 113. Note that the multiple electrode terminals 402 are not covered by the photoelectric conversion layer 302 or 322.

[0138] At this time, due to the effect of a voltage drop caused by the resistance component of the counter electrode 113, the potential difference between a portion close to the electrode terminal 402 and a portion far from the electrode terminal 402 becomes large. In the fifth embodiment, the electrode terminals 402 are provided on the negative side of the x-axis for all the counter electrodes 113, and the counter electrodes 113 extend toward the positive side of the x-axis, so that the direction in which the potential difference becomes large coincides with the x-axis direction. Therefore, the same shading correction can be performed for all the counter electrodes 113, and the correction process can be easily performed.

[0139] [3-2. Example 6] Next, a sixth embodiment will be described with reference to Fig. 10. In the following, differences from the fifth embodiment will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0140] Fig. 10 is a top view showing a counter electrode, pixel electrodes, and electrode terminals of an imaging device according to Example 6. In the example shown in Fig. 10, pixel electrode group 401 includes a plurality of pixel electrodes 101 arranged along each of the x-axis direction and the y-axis direction. Specifically, pixel electrode group 401 includes a total of 16 pixel electrodes 101 in 2 rows and 8 columns. Note that pixel electrode group 401 may include pixel electrodes 101 in multiple rows and one column.

[0141] Similar to the fifth embodiment, the counter electrode 113 is provided for each pixel electrode group 401. Therefore, the counter electrode 113 covers a plurality of rows of pixel electrodes 101. For example, the first counter electrode 113a covers two rows of first pixel electrodes 101a. Similarly, the second counter electrode 113b covers two rows of second pixel electrodes 101b.

[0142] As described above, the number of pixel electrodes 101 covered by one counter electrode 113 may be two or more in the y-axis direction which is the arrangement direction of the counter electrodes 113. In the imaging device according to the sixth embodiment, shading correction can be easily performed as in the fifth embodiment.

[0143] In the imaging device according to Example 6, the cross section perpendicular to the x-axis does not match the cross sections of the imaging devices according to Examples 1 to 4 shown in Figures 5 to 8. Specifically, it corresponds to a cross section in which two pixel electrodes 101 and connecting wires 105 are provided instead of one pixel electrode 101 and connecting wire 105 located directly below one counter electrode 113 in the cross sections shown in Figures 5 to 8.

[0144] In the sixth embodiment, the two electrode terminals 402 are provided at an end of the counter electrode 113 on the negative side of the x-axis. The size of the electrode terminals 402 is the same as that of the pixel electrode 101, but may be different. For example, one large electrode terminal 402 may be provided at an end of the counter electrode 113.

[0145] 3-3. Example 7 Next, the seventh embodiment will be described with reference to Fig. 11. In the following, the differences from the fifth embodiment will be mainly described, and the description of the commonalities will be omitted or simplified.

[0146] FIG. 11 is a top view showing the counter electrode, pixel electrode, and electrode terminal of the imaging device according to the seventh embodiment. In the example shown in FIG. 11, the distance between adjacent pixel electrodes 101 is different in the x-axis direction and the y-axis direction. Specifically, the inter-electrode distance between adjacent pixel electrodes 101 in the x-axis direction is smaller than the inter-electrode distance between adjacent pixel electrodes 101 in the y-axis direction. For example, as shown in FIG. 11, when the inter-electrode distance between pixel electrodes 101 arranged along the y-axis direction is a and the inter-electrode distance between pixel electrodes 101 arranged along the x-axis direction is c, a>c. Note that, as in the fifth and sixth embodiments, when the inter-electrode distance between the counter electrodes 113 is b, a>b is satisfied in the seventh embodiment. The inter-electrode distance b between the counter electrodes 113 may be equal to the inter-electrode distance c between the pixel electrodes 101 in the x-axis direction, or may be greater than c, or may be smaller than c.

[0147] In the seventh embodiment, by increasing the inter-electrode distance a, the inter-electrode distance b of the counter electrode 113 can also be increased. By increasing the inter-electrode distance b, the inclination of the end face of the counter electrode 113 and the upper face of the photoelectric conversion layer 302 or 322 can be made gentler. This makes it possible to prevent film breakage at the step portions of the protective film 106 and the insulating film 107 formed along the end face of the counter electrode 113 and the upper face of the photoelectric conversion layer 302 or 322. This makes it possible to suppress deterioration of the protective performance of the photoelectric conversion layer 302 or 322.

[0148] In addition, as in Example 6, when one counter electrode 113 covers multiple rows of pixel electrodes 101, the multiple rows of pixel electrodes 101 covered by the counter electrode 113 may be equally spaced in the row and column directions. For example, the inter-electrode distance between adjacent first pixel electrodes 101a in the y-axis direction may be equal to the inter-electrode distance between adjacent first pixel electrodes 101a in the x-axis direction and smaller than the inter-electrode distance between the first pixel electrode 101a and the second pixel electrode 101b. Similarly, the inter-electrode distance between adjacent second pixel electrodes 101b in the y-axis direction may be equal to the inter-electrode distance between adjacent second pixel electrodes 101b in the x-axis direction and smaller than the inter-electrode distance between the first pixel electrode 101a and the second pixel electrode 101b.

[0149] 3-4. Example 8 Next, the eighth embodiment will be described with reference to Fig. 12. In the following, the differences from the fifth embodiment will be mainly described, and the description of the commonalities will be omitted or simplified.

[0150] Fig. 12 is a top view showing the counter electrodes, pixel electrodes, and electrode terminals of an imaging device according to Example 8. In the example shown in Fig. 12, each of the multiple counter electrodes 113 is provided so as to protrude from the photoelectric conversion layer 302 or 322 on the positive side and the negative side of the x-axis, respectively. The electrode terminals 402 are provided at both ends of the counter electrodes 113 in the longitudinal direction, one each. That is, a power supply voltage is applied to each of the multiple counter electrodes 113 from the positive side and the negative side of the x-axis, respectively. So-called two-sided power supply is performed on the multiple counter electrodes 113.

[0151] In this case, the potential difference between the portion close to the electrode terminal 402 and the portion far from the electrode terminal 402 increases due to the effect of a voltage drop caused by the resistance component of the counter electrode 113. In the eighth embodiment, the electrode terminals 402 are provided on both the positive and negative sides of the x-axis for all the counter electrodes 113, so that the potential difference between the center portion and both end portions of each counter electrode 113 becomes the largest. Although the portion where the potential difference becomes the largest differs from that of the fifth embodiment, the direction in which the potential difference changes is the same in the x-axis direction for all the counter electrodes 113, as in the fifth embodiment. Therefore, the same shading correction only needs to be performed for all the counter electrodes 113, and the correction process can be easily performed.

[0152] In addition, both sides of the power supply may be performed in the sixth or seventh embodiment.

[0153] [4. Imaging device] Next, the imaging device according to the present embodiment will be described with reference to FIGS.

[0154] Fig. 13 is a circuit diagram showing a circuit configuration of an image pickup device 500 according to the present embodiment. Fig. 14 is a cross-sectional view of a unit pixel 510 in the image pickup device 500 according to the present embodiment.

[0155] [4-1. Circuit configuration] First, a circuit configuration of an image pickup device 500 according to the present embodiment will be described below. As shown in Fig. 13, the image pickup device 500 includes a plurality of unit pixels 510 and a peripheral circuit. Each of the unit pixels 510 includes a charge detection circuit 25, a light detection section 300, and a charge accumulation node 24 electrically connected to the charge detection circuit 25 and the light detection section 300.

[0156] The imaging device 500 is, for example, an organic image sensor realized by a one-chip integrated circuit, and has a pixel array including a plurality of unit pixels 510 arranged two-dimensionally. The plurality of unit pixels 510 are arranged two-dimensionally, that is, in row and column directions, to form a photosensitive region that is a pixel region. FIG. 13 shows an example in which the unit pixels 510 are arranged in a matrix of two rows and two columns. The imaging device 500 may be a line sensor. In this case, the plurality of unit pixels 510 may be arranged one-dimensionally. In this specification, the row direction and the column direction refer to the directions in which the rows and columns extend, respectively. In other words, the vertical direction is the column direction, and the horizontal direction is the row direction.

[0157] Each unit pixel 510 includes a charge storage node 24 electrically connected to the photodetector 300 and a charge detection circuit 25. The charge detection circuit 25 includes an amplification transistor 11, a reset transistor 12, and an address transistor 13.

[0158] The light detection section 300 includes a pixel electrode 101, a photoelectric conversion layer 302, and a counter electrode 113. A predetermined voltage is applied to the counter electrode 113 from a voltage control circuit 30 via a counter electrode signal line 16.

[0159] The pixel electrode 101 is connected to the gate electrode 39B (see FIG. 14) of the amplifying transistor 11. The signal charge collected by the pixel electrode 101 is stored in a charge storage node 24 located between the pixel electrode 101 and the gate electrode 39B of the amplifying transistor 11. In this embodiment, the signal charge is a hole, but the signal charge may also be an electron.

[0160] The signal charge stored in the charge storage node 24 is applied to the gate electrode 39B of the amplifying transistor 11 as a voltage according to the amount of the signal charge. The amplifying transistor 11 amplifies this voltage. The amplified voltage is selectively read out by the address transistor 13 as a signal voltage. The reset transistor 12 has one of its source electrode and drain electrode connected to the pixel electrode 101, and resets the signal charge stored in the charge storage node 24. In other words, the reset transistor 12 resets the potentials of the gate electrode 39B of the amplifying transistor 11 and the pixel electrode 101.

[0161] In order to selectively perform the above-mentioned operations in the plurality of unit pixels 510, the imaging device 500 has a power supply wiring 21, a vertical signal line 17, an address signal line 26, and a reset signal line 27, as shown in FIG. 13. These lines are connected to each unit pixel 510. Specifically, the power supply wiring 21 is connected to one of the source electrode and the drain electrode of the amplification transistor 11. The vertical signal line 17 is connected to one of the source electrode and the drain electrode of the address transistor 13. The address signal line 26 is connected to a gate electrode 39C (see FIG. 14) of the address transistor 13. The reset signal line 27 is connected to a gate electrode 39A (see FIG. 14) of the reset transistor 12.

[0162] The peripheral circuits include a vertical scanning circuit 15, a horizontal signal readout circuit 20, a plurality of column signal processing circuits 19, a plurality of load circuits 18, a plurality of differential amplifiers 22, and a voltage control circuit 30. The vertical scanning circuit 15 is also called a row scanning circuit. The horizontal signal readout circuit 20 is also called a column scanning circuit. The column signal processing circuit 19 is also called a row signal storage circuit. The differential amplifier 22 is also called a feedback amplifier.

[0163] The vertical scanning circuit 15 is connected to an address signal line 26 and a reset signal line 27. The vertical scanning circuit 15 selects a plurality of unit pixels 510 arranged in each row on a row-by-row basis, reads out a signal voltage, and resets the potential of the pixel electrode 101. A power supply line 21, which is a source follower power supply, supplies a predetermined power supply voltage to each unit pixel 510. The horizontal signal readout circuit 20 is electrically connected to a plurality of column signal processing circuits 19. The column signal processing circuit 19 is electrically connected to the unit pixels 510 arranged in each column via a vertical signal line 17 corresponding to each column. The load circuit 18 is electrically connected to each vertical signal line 17. The load circuit 18 and the amplifying transistor 11 form a source follower circuit.

[0164] A plurality of differential amplifiers 22 are provided corresponding to each column. The negative input terminals of the differential amplifiers 22 are connected to the corresponding vertical signal lines 17. The output terminals of the differential amplifiers 22 are connected to the unit pixels 510 via the feedback lines 23 corresponding to each column.

[0165] The vertical scanning circuit 15 applies a row selection signal, which controls the on and off of the address transistor 13, to the gate electrode 39C of the address transistor 13 via the address signal line 26. This causes the row to be read out to be scanned and selected. A signal voltage is read out from the unit pixel 510 of the selected row to the vertical signal line 17. The vertical scanning circuit 15 applies a reset signal, which controls the on and off of the reset transistor 12, to the gate electrode 39A of the reset transistor 12 via the reset signal line 27. This causes the row of the unit pixel 510 to be subjected to the reset operation to be selected. The vertical signal line 17 transmits the signal voltage read out from the unit pixel 510 selected by the vertical scanning circuit 15 to the column signal processing circuit 19.

[0166] The column signal processing circuit 19 performs noise suppression signal processing, such as correlated double sampling, and analog-to-digital conversion (AD conversion).

[0167] The horizontal signal read circuit 20 sequentially reads out signals from the multiple column signal processing circuits 19 to a horizontal common signal line .

[0168] The differential amplifier 22 is connected to the other of the source and drain electrodes of the reset transistor 12, which is not connected to the pixel electrode 101, via a feedback line 23. Therefore, when the address transistor 13 and the reset transistor 12 are in a conductive state, the differential amplifier 22 receives the output value of the address transistor 13 at its negative input terminal. The differential amplifier 22 performs a feedback operation so that the gate potential of the amplifying transistor 11 becomes a predetermined feedback voltage. At this time, the output voltage value of the differential amplifier 22 is 0V or a positive voltage close to 0V. The feedback voltage means the output voltage of the differential amplifier 22.

[0169] The voltage control circuit 30 may generate a constant control voltage, or may generate a plurality of control voltages with different values. For example, the voltage control circuit 30 may generate a control voltage with two or more different values, or may generate a control voltage that changes continuously within a predetermined range. The voltage control circuit 30 determines the value of the control voltage to be generated based on a command from an operator who operates the imaging device 500, or a command from another control unit or the like provided in the imaging device 500, and generates a control voltage of the determined value. The voltage control circuit 30 is provided outside the photosensitive region as a part of the peripheral circuit. The photosensitive region is substantially the same as the pixel region.

[0170] For example, the voltage control circuit 30 generates two or more different control voltages and applies the control voltages to the counter electrode 113, thereby changing the spectral sensitivity characteristics of the photoelectric conversion layer 302. The range in which the spectral sensitivity characteristics change includes the spectral sensitivity characteristics in which the sensitivity of the photoelectric conversion layer 302 becomes zero to the light to be detected. As a result, for example, in the imaging device 500, while the unit pixels 510 read out the detection signals row by row, the voltage control circuit 30 applies to the counter electrode 113 a control voltage that makes the sensitivity of the photoelectric conversion layer 302 zero, thereby substantially eliminating the influence of light incident during the readout of the detection signals. Therefore, even if the detection signals are read out substantially row by row, a global shutter operation can be realized.

[0171] In this embodiment, as shown in Fig. 13, the voltage control circuit 30 applies a control voltage to the counter electrodes 113 of the unit pixels 510 arranged in the row direction via the counter electrode signal lines 16. This changes the voltage between the pixel electrodes 101 and the counter electrodes 113, thereby switching the spectral sensitivity characteristics in the light detection section 300. Alternatively, the voltage control circuit 30 realizes an electronic shutter operation by applying a control voltage so as to obtain a spectral sensitivity characteristic in which the sensitivity to light becomes zero at a predetermined timing during imaging. The voltage control circuit 30 may also apply a control voltage to the pixel electrodes 101.

[0172] In order to irradiate the light detection unit 300 with light and cause the pixel electrode 101 to collect electrons as signal charges, the pixel electrode 101 is set to a higher potential than the counter electrode 113. This causes the electrons to move toward the pixel electrode 101. At this time, the direction of movement of the electrons is opposite to the direction of current flow, so that a current flows from the pixel electrode 101 to the counter electrode 113. In addition, in order to irradiate the light detection unit 300 with light and cause the pixel electrode 101 to collect holes as signal charges, the pixel electrode 101 is set to a lower potential than the counter electrode 113. At this time, a current flows from the counter electrode 113 to the pixel electrode 101.

[0173] [4-2. Cross-sectional configuration] Next, an example of a specific cross-sectional configuration of a unit pixel 510 of the imaging device 500 will be described with reference to Fig. 14. As shown in Fig. 14, the unit pixel 510 includes a semiconductor substrate 31, a charge detection circuit 25, a photodetection section 300, and a charge accumulation node 24. A plurality of unit pixels 510 are formed on the semiconductor substrate 31. For example, the photodetection section 300 is provided above the semiconductor substrate 31. The charge detection circuit 25 is provided inside and above the semiconductor substrate 31.

[0174] The semiconductor substrate 31 is an insulating substrate having a semiconductor layer on the surface on which the photosensitive region is formed, for example, a p-type silicon substrate. The semiconductor substrate 31 has impurity regions 41A, 41B, 41C, 41D, and 41E, and an element isolation region 42 for electrical isolation between the unit pixels 510. Here, the element isolation region 42 is also provided between the impurity region 41B and the impurity region 41C. This suppresses leakage of the signal charge accumulated in the charge accumulation node 24. The element isolation region 42 is formed, for example, by ion implantation of an acceptor under a predetermined implantation condition.

[0175] The impurity regions 41A, 41B, 41C, 41D, and 41E are, for example, diffusion layers formed in the semiconductor substrate 31. Here, the impurity regions 41A, 41B, 41C, 41D, and 41E are n-type impurity regions. As shown in FIG. 14, the amplifier transistor 11 includes an impurity region 41C, an impurity region 41D, a gate insulating film 38B, and a gate electrode 39B. The impurity region 41C and the impurity region 41D function as a source region and a drain region of the amplifier transistor 11, respectively. A channel region of the amplifier transistor 11 is formed between the impurity region 41C and the impurity region 41D.

[0176] Similarly, the address transistor 13 includes an impurity region 41D, an impurity region 41E, a gate insulating film 38C, and a gate electrode 39C. In the example shown in FIG. 14, the amplification transistor 11 and the address transistor 13 are electrically connected to each other by sharing the impurity region 41D. The impurity region 41D and the impurity region 41E function as a source region and a drain region of the address transistor 13, respectively. The impurity region 41E is connected to the vertical signal line 17 shown in FIG.

[0177] The reset transistor 12 includes an impurity region 41A, an impurity region 41B, a gate insulating film 38A, and a gate electrode 39A. The impurity region 41A and the impurity region 41B function as a source region and a drain region, respectively, of the reset transistor 12. The impurity region 41A is connected to a reset signal line 27 shown in FIG.

[0178] The gate insulating film 38A, the gate insulating film 38B, and the gate insulating film 38C are each an insulating film formed using an insulating material. The insulating film has a single layer structure or a multilayer structure, such as a silicon oxide film or a silicon nitride film.

[0179] Each of the gate electrodes 39A, 39B, and 39C is formed using a conductive material, such as conductive polysilicon.

[0180] An interlayer insulating layer 43 is laminated on the semiconductor substrate 31 so as to cover the amplifying transistor 11, the address transistor 13, and the reset transistor 12. A wiring layer (not shown) may be disposed in the interlayer insulating layer 43. The wiring layer may be formed of a metal such as copper, and may include, for example, wiring such as the above-mentioned vertical signal line 17 as a part thereof. The number of insulating layers in the interlayer insulating layer 43 and the number of layers included in the wiring layer disposed in the interlayer insulating layer 43 may be set arbitrarily.

[0181] A contact plug 45A connected to the impurity region 41B of the reset transistor 12, a contact plug 45B connected to the gate electrode 39B of the amplification transistor 11, a contact plug 47 connected to the pixel electrode 101, and a wiring 46 connecting the contact plug 47, the contact plug 45A, and the contact plug 45B are arranged in the interlayer insulating layer 43. As a result, the impurity region 41B of the reset transistor 12 is electrically connected to the gate electrode 39B of the amplification transistor 11.

[0182] The photodetector 300 is disposed on the interlayer insulating layer 43. The specific configuration of the photodetector 300 is the same as that in Fig. 5. The interlayer insulating layer 43 and the contact plug 47 correspond to the insulating layer 104 and the connection wiring 105 shown in Fig. 5, respectively. The electrode terminal 402 shown in Figs. 9 to 12 is provided, for example, not in the unit pixel 510 but in the peripheral portion of the photosensitive region.

[0183] Note that the imaging device 500 may include a photodetection section 310 shown in Fig. 7 or a photodetection section 320 shown in Fig. 8, instead of the photodetection section 300. Alternatively, the imaging device 500 may include a shield electrode 139 and a connection wiring 135 as shown in Fig. 6.

[0184] Above the light detection unit 300, a protective film 106, an insulating film 107, an insulating film 108, and a color filter 60 are provided in this order. A microlens 61 is provided above the color filter 60. The color filter 60 is formed, for example, as an on-chip color filter by patterning, and uses a photosensitive resin in which a dye or pigment is dispersed. The microlens 61 is provided, for example, as an on-chip microlens, and uses an ultraviolet-sensitive material, etc.

[0185] The imaging device 500 can be manufactured using a general semiconductor manufacturing process. In particular, when a silicon substrate is used as the semiconductor substrate 31, the imaging device 500 can be manufactured by utilizing various silicon semiconductor processes.

[0186] As described above, the imaging device 500 includes the light detection unit 300 according to the embodiment 5. Therefore, as described above, the imaging device 500 can reduce the leakage current between the adjacent counter electrodes 113.

[0187] (Other embodiments) Although the imaging device according to one or more aspects has been described based on the embodiments, the present disclosure is not limited to these embodiments. As long as it does not deviate from the gist of the present disclosure, various modifications conceived by a person skilled in the art to the present embodiment and forms constructed by combining components of different embodiments are also included within the scope of the present disclosure.

[0188] For example, in the above embodiment, the inter-electrode distance between adjacent counter electrodes 113 may be equal to the inter-electrode distance between pixel electrodes 101. Alternatively, the inter-electrode distance between adjacent counter electrodes 113 may be longer than the inter-electrode distance between pixel electrodes 101. In addition, for example, the end face of the counter electrode 113 may be inversely tapered. These are effective, for example, in the case where the photoelectric conversion unit including the photoelectric conversion layer 302 is formed using a material that is resistant to etching damage.

[0189] Furthermore, each of the above embodiments can be modified, substituted, added, omitted, and the like in various ways within the scope of the claims or their equivalents. [Industrial Applicability]

[0190] The present disclosure can be used as an imaging device in which leakage current between adjacent opposing electrodes is reduced, and can be used in, for example, a camera or a distance measuring device. [Explanation of symbols]

[0191] 11 Amplifying transistor 12 Reset transistor 13 Address transistor 15 Vertical scanning circuit 16 Counter electrode signal line 17 Vertical signal line 18 Load circuit 19 Column signal processing circuit 20 Horizontal signal readout circuit 21 Power wiring 22 Differential Amplifier 23 Feedback Line 24 Charge Storage Node 25 Charge detection circuit 26 Address signal line 27 Reset signal line 28 Horizontal common signal line 30 Voltage control circuit 31 Semiconductor Substrate 38A, 38B, 38C Gate insulating film 39A, 39B, 39C Gate electrode 41A, 41B, 41C, 41D, 41E Impurity region 42 Element isolation region 43 Interlayer insulation layer 45A, 45B, 47 Contact plug 46 Wiring 60 Color Filters 61 Microlens 100, 110, 120, 300, 310, 320 Light detection unit 101 Pixel electrode 101a First pixel electrode 101b Second pixel electrode 102, 122, 302, 322 Photoelectric conversion layer 103, 113 Counter electrode 104, 324 Insulating layer 105, 135 Connection wiring 106 Protective film 107, 108 Insulating film 113a first opposing electrode 113b Second opposing electrode 122a First photoelectric conversion layer 122b Second photoelectric conversion layer 139 Shield Electrode 201 Overlapping area 202 Interelectrode area 302a, 322a Overlapping part 302c, 322c non-overlapping part 312 Auxiliary layer 312a, 312b part 324c Recess 401 Pixel electrode group 401a First pixel electrode group 401b Second pixel electrode group 402 Electrode terminal 500 Imaging device 510 unit pixels

Claims

1. A plurality of first pixel electrodes arranged in a first direction; a plurality of second pixel electrodes arranged in the first direction and spaced apart from the plurality of first pixel electrodes; a photoelectric conversion unit that continuously covers upper surfaces of the first pixel electrodes and upper surfaces of the second pixel electrodes and includes a photoelectric conversion layer; a first counter electrode located above the photoelectric conversion unit and facing the first pixel electrodes; a second counter electrode located above the photoelectric conversion unit, electrically separated from the first counter electrode, and facing the second pixel electrodes; a sealing layer continuously covering an upper surface of the first opposing electrode and an upper surface of the second opposing electrode, the sealing layer including a metal oxide or a metal nitride; The first opposing electrode is spaced apart from the second opposing electrode, a first portion of an upper surface of the photoelectric conversion unit in an inter-electrode region between the first opposing electrode and the second opposing electrode is recessed in a plan view relative to a second portion of an upper surface of the photoelectric conversion unit in an overlap region overlapping with the first opposing electrode or the second opposing electrode in a plan view; the sealing layer is in contact with the photoelectric conversion unit in the inter-electrode region, The first opposing electrode has an elongated shape extending along the first direction, The second opposing electrode has an elongated shape extending along the first direction. Imaging device.

2. a thickness of the photoelectric conversion portion in the inter-electrode region is smaller than a thickness of the photoelectric conversion portion in the overlap region; The imaging device according to claim 1 .

3. a thickness of the photoelectric conversion layer in the inter-electrode region is smaller than a thickness of the photoelectric conversion layer in the overlap region; 3. The imaging device according to claim 1.

4. a distance between the first opposing electrode and the second opposing electrode is smaller than a distance between the first pixel electrodes and the second pixel electrodes; The imaging device according to claim 1 .

5. an end surface of the first opposing electrode has a forward tapered shape or a shape perpendicular to an upper surface of the first opposing electrode; an end surface of the second opposing electrode has a forward tapered shape or a shape perpendicular to an upper surface of the second opposing electrode; The imaging device according to claim 1 .

6. the photoelectric conversion unit further includes an auxiliary layer located between the photoelectric conversion layer and the first opposing electrode and between the photoelectric conversion layer and the second opposing electrode, a portion of the auxiliary layer that overlaps with the first opposing electrode in a plan view is separated from a portion of the auxiliary layer that overlaps with the second opposing electrode in a plan view; The imaging device according to claim 1 .

7. the sealing layer is in contact with the upper surface and the end surface of the first opposing electrode and the upper surface and the end surface of the second opposing electrode; The imaging device according to claim 1 .

8. a first pixel electrode group including the plurality of first pixel electrodes; a second pixel electrode group including the plurality of second pixel electrodes, The first pixel electrode group and the second pixel electrode group are arranged along a second direction perpendicular to the first direction. The imaging device according to claim 1 .

9. a distance between two adjacent first pixel electrodes among the plurality of first pixel electrodes along the first direction is smaller than a distance between each of the plurality of first pixel electrodes and a corresponding second pixel electrode among the plurality of second pixel electrodes, the second pixel electrode being adjacent to each of the plurality of first pixel electrodes in the second direction; The imaging device according to claim 8.

10. In the first pixel electrode group, the first pixel electrodes are arranged along the first direction and the second direction, In the second pixel electrode group, the second pixel electrodes are arranged along the first direction and the second direction.

10. The imaging device according to claim 8.

11. a first electrode terminal provided at an end of the first opposing electrode and to which a first power supply voltage is applied; a second electrode terminal provided at an end of the second opposing electrode and to which a second power supply voltage is applied; Further equipped with The first electrode terminal and the second electrode terminal are located on the same side in the first direction. The imaging device according to claim 8 .

12. a first electrode terminal pair provided at both ends of the first opposing electrode and to which a first power supply voltage is applied; a second electrode terminal pair provided at both ends of the second opposing electrode and to which a second power supply voltage is applied; The imaging device according to claim 8 .

13. The photoelectric conversion layer contains an organic compound, The sealing layer does not contain the organic compound. The imaging device according to claim 1 .

14. a difference between a thickness of the photoelectric conversion layer in the inter-electrode region and a thickness of the photoelectric conversion layer in the overlap region is 5 nm or more; The imaging device according to claim 3 .

Images