IMAGE ELEMENT AND IMAGE DEVICE

Abstract

Imaging element, comprising: a semiconductor substrate (30) having one surface (30S1) and another surface (30S2) facing opposite each other, wherein the semiconductor substrate (30) has a through hole (30H) passing between one surface (30S1) and the other surface (30S2); a first photoelectric converter (20) which is provided above one surface (30S1) of the semiconductor substrate (30); a through-electrode (34) which is electrically coupled to the first photoelectric transducer (20), wherein the through-electrode (34) penetrates the semiconductor substrate (30) inside the through-hole (30H); a first dielectric film (26a) provided on one surface (30S1) of the semiconductor substrate (30), wherein the first dielectric film (26a) has a first film thickness (W1); and a second dielectric film (26b) provided on a lateral surface of the through-hole (30H), wherein the second dielectric film (26b) has a second film thickness (W2) wherein the second film thickness (W2) is less than the first film thickness (W1), wherein the first dielectric film (26a) and the second dielectric film (26b) each contain at least one of a material with a negatively fixed charge or of a semiconductor material or of an electrically conductive material with a wider band gap than a band gap of the semiconductor substrate (30), and the through-electrode (34) inside the through-hole (30H) includes an insulating film (27) around the through-electrode (34), which further extends on one surface (30S1) of the semiconductor substrate (30), wherein the first dielectric film (26a) is provided between one surface (30S1) of the semiconductor substrate (30) and the insulating film (27).

Description

Technical field

[0001] The present disclosure relates to an imaging element, which, for example, contains an organic material, and an imaging device containing this. Background technology

[0002] Solid-state imaging devices are widely used in CCD (charge-coupled device) image sensors, CMOS (complementary metal-oxide-semiconductor) image sensors, and similar devices. These devices each have a pixel array in which primary color filters for red, green, and blue are arranged two-dimensionally. However, a solid-state imaging device with such a pixel array performs an interpolation process between pixels when the respective color signals are generated. This produces so-called false colors.

[0003] A solid-state imaging element in which photoelectric conversion regions are stacked was developed for this purpose. The photoelectric conversion regions are used to photoelectrically convert the respective components of light in the red, green, and blue wavelength bands. Furthermore, a structure was proposed to install the photoelectric conversion regions outside the semiconductor substrate. For example, a solid-state imaging element is developed that positions a photoelectric converter above the semiconductor substrate and accumulates signal charges generated by the photoelectric converter within the semiconductor substrate.As a back-illuminated solid-state imaging device using the structure described above, PTL 1, for example, discloses a solid-state imaging device equipped with a through-electrode on the semiconductor substrate and transmitting signal charges generated by an organic photoelectric transducer via this through-electrode to the front surface side of the semiconductor substrate. The organic photoelectric transducer is located on the back surface side of the semiconductor substrate. Exemplary imaging devices and materials contained therein are disclosed in US 2016 / 0204156A1, WO 2017 / 061082A1, WO 2018 / 066256A1, WO 2018 / 047517A1, US 2019 / 0081106A1, and SRIVASTAVA, J.K.; PRASAD, M.; WAGNER, JB, Jr.: Electrical conductivity of silicon dioxide thermally grown on silicon. In: Journal of the Electrochemical Society, Vol. 132, 1985, No. 4, pp. 955-963.ISSN 1945-7111 is known. List of citations from patent literature

[0004] PTL 1: Unexamined Japanese patent application Publication No. JP 2011 - 29 337 A Summary of the invention

[0005] Furthermore, it is required that an imaging device increase sensitivity characteristics.

[0006] It is desirable to provide an imaging element and an imaging device that make it possible to increase sensitivity characteristics.

[0007] The invention is defined in the independent patent claims. Further developments are the subject of the dependent patent claims.

[0008] An imaging element according to one embodiment of the present disclosure comprises: a semiconductor substrate; a first photoelectric transducer; a through-electrode; a first dielectric film; and a second dielectric film. The semiconductor substrate has one surface and another surface facing opposite each other. The semiconductor substrate has a through-hole extending between the one surface and the other surface. The first photoelectric transducer is positioned above one surface of the semiconductor substrate. The through-electrode is electrically coupled to the first photoelectric transducer. The through-electrode penetrates the semiconductor substrate within the through-hole. The first dielectric film is provided on one surface of the semiconductor substrate. The first dielectric film has a first film thickness.The second dielectric film is located on a lateral surface of the through-hole. This second dielectric film has a different thickness, which is less than the thickness of the first film.

[0009] An imaging device according to an embodiment of the present disclosure includes, for each of a plurality of pixels, one or more imaging elements according to the embodiment of the present disclosure described above.

[0010] In the imaging element according to the embodiment of the present disclosure and the imaging device according to the embodiment, the first dielectric film with the first film thickness is provided on one surface of the semiconductor substrate, above which the first photoelectric transducer is arranged. The second dielectric film with the second film thickness is provided on the lateral surface of the through-hole that passes between the one surface and the other surface of the semiconductor substrate. The film thickness (second film thickness) of the second dielectric film is less than the film thickness (first film thickness) of the first dielectric film. The through-hole electrode is provided within the through-hole. The through-hole electrode is electrically coupled to the first photoelectric transducer and penetrates the semiconductor substrate.This reduces the reflection of incident light on one surface of the semiconductor substrate, while suppressing an increase in the capacitance of the through-electrode.

[0011] The imaging element according to the embodiment of the present disclosure and the imaging device according to the embodiment are each provided with the first insulating film of the first film thickness on one surface of the semiconductor substrate and the second insulating film of a film thickness (second film thickness) that is less than the film thickness of the first insulating film on the lateral surface of the through-hole. This reduces the reflection of incident light on one surface of the semiconductor substrate while suppressing an increase in the capacitance of the through-hole electrode. The through-hole extends between one surface and the other surface of the semiconductor substrate and has the through-hole formed therein. Consequently, it is possible to provide the imaging element with high sensitivity characteristics and the imaging device containing it.

[0012] It is particularly important to mention that the effects described here are not necessarily limited, but may include any of the effects described in the present disclosure. Brief description of the drawings [ Fig. 1] Fig. Figure 1 is a schematic cross-sectional diagram illustrating an example of a configuration of an imaging element according to a first embodiment of the present disclosure. [ Fig. 2] Fig. 2 is a diagram showing an overall configuration of the in Fig. 1 illustrated imaging element. [ Fig. 3] Fig. 3 is an equivalent circuit diagram of the one in Fig. 1 illustrated imaging element. [ Fig. 4] Fig. Figure 4 is a schematic diagram illustrating an arrangement of a lower electrode and a transistor in a control section of the device in Fig. 1 illustrated imaging element are included. [ Fig. 5A] Fig. 5A is a schematic cross-sectional diagram showing an example of a configuration of a dielectric film around a through-electrode in the Fig. 1 illustrated imaging element illustrated. [ Fig. 5B] Fig. 5B is a schematic cross-sectional diagram showing another example of the configuration of the dielectric film around the through-electrode in the Fig. 1 illustrated imaging element illustrated. [ Fig. 5C] Fig. 5C is a schematic cross-sectional diagram showing another example of the configuration of the dielectric film around the through-electrode in the Fig. 1 illustrated imaging element illustrated. [ Fig. 5D] Fig. 5D is a schematic cross-sectional diagram that shows another example of the configuration of the dielectric film around the through-electrode in the Fig. 1 illustrated imaging element illustrated. [ Fig. 6] Fig. 6 is a cross-sectional view to illustrate a method for producing the in Fig. To describe the illustrated imaging element. [ Fig. 7] Fig. 7 is a cross-sectional view, taken one step after Fig. 6 illustrates. [ Fig. 8] Fig. 8 is a cross-sectional view, which follows one step after Fig. 7 illustrates. [ Fig. 9] Fig. 9 is a cross-sectional view, which follows one step after Fig. 8 illustrates. [ Fig. 10] Fig. 10 is a cross-sectional view, taken one step after Fig. 9 illustrates. [ Fig. 11] Fig. 11 is a cross-sectional view, which follows a step after Fig. 10 illustrated. [ Fig. 12] Fig. 12 is a timing diagram that illustrates an operational example of the in Fig. 1 illustrated imaging element. [ Fig. 13] Fig. Figure 13 is a schematic diagram to describe the capacitance of the through-electrode. [ Fig. 14] Fig. Figure 14 is a schematic cross-sectional diagram illustrating an example of a configuration of an imaging element according to a second embodiment of the present disclosure. [ Fig. 15] Fig. Figure 15 is a schematic cross-sectional diagram illustrating an example of a configuration of an imaging element according to a third embodiment of the present disclosure. [ Fig. 16] Fig. Figure 16 is a schematic cross-sectional diagram illustrating an example of a configuration of an imaging element according to Modification Example 1 of the present disclosure. [ Fig. 17] Fig. Figure 17 is a schematic cross-sectional diagram illustrating an example of a schematic configuration of a main section of an imaging element according to Modification Example 2 of the present disclosure. [ Fig. 18] Fig. 18 is a block diagram illustrating a configuration of an imaging device that performs the function described in Fig. 1 illustrated imaging element or the like contains as pixels. [ Fig. 19] Fig. Figure 19 is a functional block diagram illustrating an example of an electronic device (camera) that performs the function described in Figure 19. Fig. Contains 18 illustrated imaging devices. [ Fig. 20] Fig. Figure 20 is a block diagram that shows an example of a schematic configuration of an in-vivo information acquisition system. [ Fig. 21] Fig. Figure 21 is a view that shows an example of a schematic configuration of a system for endoscopic surgery. [ Fig. 22] Fig. Figure 22 is a block diagram that shows an example of a functional configuration of a camera head and a camera control unit (CCU). [ Fig. 23] Fig. Figure 23 is a block diagram that shows an example of a schematic configuration of a vehicle control system. [ Fig. 24] Fig. Figure 24 is a diagram to assist in explaining an example of installation positions of a section for detecting information from outside the vehicle and an imaging section. Modes for carrying out the invention

[0013] The following describes, with reference to the drawings, an embodiment of the present disclosure in detail. The following description is a specific example of the present disclosure; however, the present disclosure is not limited to the following mode. Furthermore, the present disclosure does not limit the arrangement, dimensions, dimensional ratios, and the like of the respective components illustrated in the corresponding diagrams. It is particularly noteworthy that the description is given in the following order. 1. First embodiment (an example in which a lateral surface of a through-hole with a through-electrode formed on and in a light-receiving surface is provided with a dielectric film having a greater film thickness on the light-receiving surface than on the lateral surface of the through-hole) 1-1. Configuration of an imaging element 1-2. Method for manufacturing an imaging element 1-3. Working method and effects 2. Second embodiment (an example in which two organic photoelectric transducers are stacked on a semiconductor substrate) 3. Third embodiment (an example in which a lower electrode contains an organic photoelectric transducer formed using a continuous film) 4. Modification Examples 4-1. Modification example 1 (an example in which the thickness of a dielectric film in a predetermined area on a light-receiving surface is increased by forming a dielectric film separately on a region of the light-receiving surface) 4-2. Modification example 2 (an example in which a through-electrode is provided in a peripheral area) 5. Application examples <1. First embodiment>

[0014] Fig. Figure 1 illustrates a cross-sectional configuration of an imaging element (imaging element 10A) according to a first embodiment of the present disclosure. Fig. Figure 2 illustrates a planar configuration of the in Fig. 1 illustrated imaging element 10A. Fig. 3 is an equivalent circuit diagram of the one in Fig. 1 illustrated imaging element 10A. This corresponds to one in Fig. 2 illustrated area 100. Fig. Figure 4 schematically illustrates the arrangement of a lower electrode 21 and a transistor, which are located in a control section of the device. Fig. The imaging element 10A is contained, for example, in a pixel (unit pixel P) in an imaging device such as a CMOS (complementary metal oxide semiconductor) image sensor (imaging device 1; see Figure 1). Fig. 18) contained in an electronic device such as a digital camera or a video camera.

[0015] The imaging element 10A according to the present embodiment comprises a dielectric film 26 formed on a light-receiving surface (a surface; first surface (surface 30S1)) of a semiconductor substrate 30 and on the lateral surface of a through-hole 30H. The through-hole 30H extends between the first surface (surface 30S1) and a second surface (surface 30S2) of the semiconductor substrate. A through-hole electrode 34 is formed inside the through-hole 30H. The film thickness of the dielectric film 26 varies between the first surface (surface 30S1) of the semiconductor substrate 30 and the lateral surface of the through-hole 30H. This dielectric film 26 is provided on the first surface (surface 30S1) of the semiconductor substrate 30.The dielectric film 26 comprises a first dielectric film 26a with a first film thickness and a second dielectric film 26b, which is provided on the lateral surface of the through-hole 30H. The first film thickness is greater than the second film thickness. That is, the imaging element 10A has the dielectric film 26 configured such that the dielectric film 26 is thicker on the side of the first surface (surface 30S1) of the semiconductor substrate 30 than on the side of the lateral surface of the through-hole 30H. The dielectric film 26 is provided above the lateral surface of the through-hole 30H with the through-electrode 34 located therein, extending from the first surface (surface 30S1), which serves as the light-receiving surface. (1-1. Configuration of an imaging element)

[0016] Imaging element 10A, for example, is a so-called vertical spectroscopic imaging element in which an organic photoelectric converter 20 and two inorganic photoelectric converters 32B and 32R are stacked vertically. The organic photoelectric converter 20 is located on the side of the first surface (back surface; surface 30S1) of the semiconductor substrate 30. The inorganic photoelectric converters 32B and 32R are configured to be embedded in the semiconductor substrate 30 and stacked in the direction of the thickness of the semiconductor substrate 30. The organic photoelectric converter 20 includes a photoelectric conversion layer 24 between the lower electrode 21 (first electrode) and an upper electrode 25 (second electrode). The lower electrode 21 (first electrode) and the upper electrode 25 (second electrode) are arranged so that they face each other.The photoelectric conversion layer 24 is formed using an organic material. This photoelectric conversion layer 24 contains a p-type semiconductor and an n-type semiconductor and exhibits a bulk heterojunction structure within the layer. The bulk heterojunction structure is a p / n junction surface formed by mixing the p-type and n-type semiconductors.

[0017] The lower electrode 21 of the organic photoelectric converter 20 according to the present embodiment comprises a plurality of electrodes (readout electrode 21A and accumulation electrode 21B). The organic photoelectric converter 20 according to the present embodiment includes, in sequence, an insulating layer 22 and a semiconductor layer 23 between this lower electrode 21 and this photoelectric conversion layer 24. The insulating layer 22 is provided with an opening 22H above the readout electrode 21A, and the readout electrode 21A is electrically coupled to the semiconductor layer 23 via this opening 22H.

[0018] The organic photoelectric converter 20 and the inorganic photoelectric converters 32B and 32R perform a photoelectric conversion by selectively detecting the respective proportions of light in different wavelength ranges. Specifically, the organic photoelectric converter 20 detects a color signal for green (G). The inorganic photoelectric converters 32B and 32R detect a color signal for blue (B) and a color signal for red (R), respectively, by utilizing different absorption coefficients. This enables the imaging element 10A to detect a variety of color signals in a single pixel without the use of color filters.

[0019] It is particularly noteworthy that the present embodiment describes a case in which the electron of an electron-hole pair generated by a photoelectric conversion is read as a signal charge (a case in which the n-type semiconductor region is used as the photoelectric conversion layer). Furthermore, in the diagram, the "+" appended to "p" and "n" indicates a high concentration of p-type or n-type impurities.

[0020] The second surface (front surface; 30S2) of the semiconductor substrate 30 is provided, for example, with floating diffusion regions (floating diffusion layers) FD1 (region 36B in the semiconductor substrate 30), FD2 (region 37C in the semiconductor substrate 30), and FD3 (region 38C in the semiconductor substrate 30), transmission transistors Tr2 and Tr3, an amplifier transistor (modulation element) AMP, a reset transistor RST, a selection transistor SEL, and a multilayer wiring conductor 40. The multilayer wiring conductor 40 has a configuration in which wiring layers 41, 42, and 43 are stacked, for example, within an insulating layer 44.

[0021] It is particularly worth mentioning that in the diagrams, the side of the first surface (surface 30S1) of the semiconductor substrate 30 is referred to as the light incidence side S1 and the side of the second surface (surface 30S2) is referred to as the wiring layer side S2.

[0022] The organic photoelectric converter 20 has a configuration in which, starting from the side of the first surface (surface 30S1) of the semiconductor substrate 30, for example, the lower electrode 21, the semiconductor layer 23, the photoelectric conversion layer 24, and the upper electrode 25 are stacked in that order. Furthermore, the insulating layer 22 is provided between the lower electrode 21 and the semiconductor layer 23. For example, the lower electrodes 21 are configured separately for the respective imaging elements 10A. The lower electrodes 21 each comprise the readout electrode 21A and the accumulation electrode 21B, which are separated from each other by the insulating layer 22, although this is described in detail below. The readout electrode 21A and the lower electrode 21 are electrically coupled to the semiconductor layer 23 via the opening 22H provided in the insulating layer 22. Fig. Figure 1 illustrates an example in which the semiconductor layer 23, the photoelectric conversion layer 24, and the upper electrode 25 are provided as continuous layers common to the plurality of imaging elements 10A; however, the semiconductor layers 23, the photoelectric conversion layers 24, and the upper electrodes 25 can be configured separately for the respective imaging elements 10A. For example, the dielectric film 26, an insulating film 27, and an intermediate insulating layer 28 are provided between the first surface (surface 30S1) of the semiconductor substrate 30 and the lower electrode 21. A protective layer 51 is provided on the upper electrode 25. Above the readout electrode 21A, for example, a light-shielding film 52 is provided within the protective layer 51.It is sufficient if this light-shielding film 52A is designed such that it covers the area of ​​the readout electrode 21A in direct contact with at least the semiconductor layer 23 without overlapping with at least the accumulation electrode 21B. Optical components such as a (not illustrated) planarization layer and an on-chip lens 53 are provided above the protective layer 51.

[0023] The through-electrode 34 is located between the first surface (surface 30S1) and the second surface (surface 30S2) of the semiconductor substrate 30. This through-electrode 34 is electrically coupled to the readout electrode 21A of the organic photoelectric converter 30. The organic photoelectric converter 20 is coupled via the through-electrode 34 to a gate Gamp of the amplifier transistor AMP and to one source / drain region 36B of the reset transistor RST (reset transistor Tr1rst), which also serves as the floating diffusion region FD1. This enables the imaging element 10A to advantageously transfer charges (here electrons) generated in the organic photoelectric converter 20 on the side of the first surface (surface 30S1) of the semiconductor substrate 30 to the side of the second surface (surface 30S2) of the semiconductor substrate 30, thereby increasing characteristics.

[0024] The lower end of the through-wire electrode 34 is coupled to a coupling section 41A in the wiring layer 41. The coupling section 41A and the gate Gamp are coupled via a lower first contact 45. The coupling section 41A and the floating diffusion area FD1 (area 36B) are coupled, for example, via a lower second contact 46. The upper end of the through-wire electrode 34 is coupled, for example, via an upper first contact 29A, a pad section 39A, and an upper second contact 29B to the readout electrode 21A.

[0025] The through-electrode 34 is provided for each of the organic photoelectric converters 20 in the respective imaging elements 10A. The through-electrode 34 functions as a connector for the organic photoelectric converter 20 and the gate Gamp of the amplifier transistor AMP and the floating diffusion region FD1. The through-electrode 34 serves as a transfer path for charges (here electrons) generated in the organic photoelectric converter 20.

[0026] A reset gate Grst of the reset transistor RST is located next to the floating diffusion region FD1 (a source / drain region 36B of the reset transistor RST). This allows the reset transistor RST to reset the charges accumulated in the floating diffusion region FD1.

[0027] In the imaging element 10A according to the present embodiment, light entering the organic photoelectric converter 20 from the side of the upper electrode 25 is absorbed by the photoelectric conversion layer 24. The excitons generated thereby migrate to the interface between an electron donor and an electron acceptor contained in the photoelectric conversion layer 24 and undergo exciton decomposition. In other words, the exciton is separated into an electron and a hole. Due to a difference in concentration in the carriers and an internal electric field caused by the different work functions at the anode (here the upper electrode 25) and the cathode (here the lower electrode 21), the charges generated here (electrons and holes) are transported to different electrodes by diffusion.Furthermore, applying a potential between the lower electrode 21 and the upper electrode 25 makes it possible to control the transport direction of electrons and holes.

[0028] The following describes the configurations, materials, and similar aspects of the respective sections.

[0029] The organic photoelectric converter 20 is an organic photoelectric conversion element that absorbs green light corresponding to a portion of a selective wavelength range (e.g. 450 nm or greater and 650 nm or less) or the entire range and generates electron-hole pairs.

[0030] As described above, the lower electrode 21 comprises the readout electrode 21A and the accumulation electrode 21B, which are configured separately. The readout electrode 21A transfers charges (here, electrons) generated in the photoelectric conversion layer 24 to the floating diffusion layer FD1. For example, the readout electrode 21A is coupled to the floating diffusion region FD1 via the upper first contact 29A, the upper second contact 29B, the pad section 39A, the through-electrode 34, the coupling section 41A, and a lower second contact 46. The accumulation electrode 21B serves to accumulate the electrons of the charges generated in the photoelectric conversion layer 24 in the semiconductor layer 23 as signal charges.The accumulation electrode 21B is located in an area opposite and covering the light-receiving surfaces of the inorganic photoelectric transducers 32B and 32R formed in the semiconductor substrate 30. It is desirable that the accumulation electrode 21B be larger than the readout electrode 21A. This allows the accumulation electrode 21B to accumulate a large number of charges. As shown in... Fig. As illustrated in Figure 4, a circuit 60 is coupled to the accumulating electrode 21B via a wiring line for applying a voltage.

[0031] The lower electrode 21 contains an electrically conductive, translucent film. For example, the lower electrode 21 contains ITO (indium tin oxide). However, in addition to ITO, a tin oxide (SnO2)-based material with a dopant added, or a zinc oxide-based material prepared by adding a dopant to zinc oxide (ZnO), can be used as a material contained in the lower electrode 21. Examples of zinc oxide-based materials include aluminum zinc oxide (AZO) with aluminum (Al) added as a dopant, gallium zinc oxide (GZO) with added gallium (Ga), and indium zinc oxide (IZO) with added indium (In). Other materials that can be used include CuI, InSbO4, ZnMgO, CuInO2, MglN2O4, CdO, ZnSnO3, and the like.

[0032] The semiconductor layer 23 is located in a lower layer of the photoelectric conversion layer 24, specifically between the insulating layer 22 and the photoelectric conversion layer 24. The semiconductor layer 23 serves to accumulate signal charges (here, electrons) generated in the photoelectric conversion layer 24. It is preferable that the semiconductor layer 23 be formed using a material with a higher charge mobility and a larger band gap than those of the photoelectric conversion layer 24. For example, it is preferable that the band gap of a material contained in the semiconductor layer 23 be 3.0 eV or greater. Examples of such a material include an oxide semiconductor material such as IGZO, an organic semiconductor material, and the like.Examples of organic semiconductor materials include a transition metal dichalcogenide, silicon carbide, diamond, graphene, a carbon nanotube, a condensed polycyclic aromatic hydrocarbon, a condensed heterocyclic compound, and the like. The semiconductor layer 23, for example, has a thickness of 10 nm or more and 300 nm or less. The semiconductor layer 23, containing the materials described above, is arranged in a lower layer of the photoelectric conversion layer 24. This prevents charge recombination during the charge accumulation period and increases the transfer efficiency.

[0033] The photoelectric conversion layer 24 converts light energy into electrical energy. The photoelectric conversion layer 24 contains, for example, two or more types of organic semiconductor materials (a p-type semiconductor material or an n-type semiconductor material), each acting as a p-type or n-type semiconductor, respectively. Within the layer, the photoelectric conversion layer 24 contains the junction (p / n junction) between this p-type and n-type semiconductor material. The p-type semiconductor acts as a relative electron donor, and the n-type semiconductor acts as a relative electron acceptor. The photoelectric conversion layer 24 provides an electric field in which excitons, generated when light is absorbed, are separated into electrons and holes.Specifically, excitons are separated into electrons and holes at the interface (p / n junction) between the electron donor and the electron acceptor.

[0034] The photoelectric conversion layer 24 can contain, in addition to the p-type and n-type semiconductor materials, an organic material or a so-called dye material. The organic or dye material photoelectrically converts light in a predetermined wavelength range and transmits light in another wavelength range. If the photoelectric conversion layer 24 is formed using the three types of organic materials—a p-type semiconductor, an n-type semiconductor, and a dye material—it is preferable that the p-type and n-type semiconductor materials each have a light transmittance in the visible range (e.g., 450 nm to 800 nm). The photoelectric conversion layer 24, for example, has a thickness of 50 nm to 500 nm.

[0035] Examples of organic materials contained in the photoelectric conversion layer 24 include quinacridone, borochloride subphthalocyanine, pentacene, benzothienobenzothiophene, fullerene, and their derivatives. The photoelectric conversion layer 24 contains a combination of the two or more types of organic materials described above. Depending on the combination, the organic materials described above function as p-type and n-type semiconductors.

[0036] It is particularly noteworthy that the organic materials contained in the photoelectric conversion layer 24 are not particularly limited. For example, in addition to the organic materials listed above, preferably any of naphthalene, anthracene, phenanthere, tetracene, pyrene, perylene, and fluoranthene, or their derivatives, is used. Alternatively, a polymer such as phenylenevinylene, fluorene, carbazole, indole, pyrene, pyrrole, picoline, thiophene, acetylene, and diacetylene, or their derivatives, can be used.Furthermore, it is advantageously possible to use a metal complex dye, a cyan-based dye, a merocyanine-based dye, a phenylxanthene-based dye, a triphenylmethane-based dye, a rhodacyanine-based dye, a xanthene-based dye, a macrocyclic azaannule-based dye, an azulene-based dye, naphthaquinone, an anthraquinone-based dye, a chain compound in which a condensed polycyclic aromatic group such as anthracene and pyrene and an aromatic ring or a heterocyclic compound are condensed, a cyano-like dye bound by two nitrogenous heterorings such as quinoline, benzothiazole and benzoxazole, which have a squarylium group and a crocone-methine group as a bound chain, or by a squarylium group or a crocone-methine group, etc.It is particularly worth mentioning that the metal complex dye described above is preferably, but not limited to, a dye based on a dithiol metal complex, a metallophthalocyanine dye, a metalloporphyrin dye, or a ruthenium complex dye.

[0037] Other layers can be provided between the photoelectric conversion layer 24 and the lower electrode 21 (e.g., between the semiconductor layer 23 and the photoelectric conversion layer 24) and between the photoelectric conversion layer 24 and the upper electrode 25. Specifically, starting from the lower electrode 21, the semiconductor layer 23, an electron-blocking film, the photoelectric conversion layer 24, a hole-blocking film, a work-function adjustment film, and the like can be stacked sequentially. Furthermore, an underlying layer and a hole-transfer layer can be provided between the lower electrode 21 and the photoelectric conversion layer 24, and a buffer layer and an electron-transfer layer can be provided between the photoelectric conversion layer 24 and the upper electrode 25.

[0038] The upper electrode 25 contains an electrically conductive film with the same light transmittance as the lower electrode 21. In the imaging device 1, which contains the imaging element 10A as a pixel, the upper electrodes 25 can be separate for the respective pixels or configured as a single electrode common to all pixels. The upper electrode 25 has, for example, a thickness of 10 nm to 200 nm.

[0039] The dielectric film 26 serves to prevent light reflection caused by a refractive index difference between the semiconductor substrate 30 and the insulating film 27. It is preferable that the dielectric film 26 material have a refractive index between that of the semiconductor substrate 30 and that of the insulating film 27. Furthermore, it is preferable that the dielectric film 26 material be made of a material that allows the formation of a film with, for example, a negatively fixed charge. Alternatively, it is preferable that the dielectric film 26 material be made of a semiconductor material or an electrically conductive material with a wider band gap than that of the semiconductor substrate 30. This makes it possible to suppress the generation of dark currents at the interface of the semiconductor substrate 30. Examples of such materials include hafnium oxide (HfO₂).x ), aluminum oxide (AlO x ), Zirconium oxide (ZrO₂) x ), tantalum oxide (TaO x ), Titanium oxide (TiO₂) x ), lanthanum oxide (LaO x ), praseodymium oxide (PrO₂) x ), Cerium oxide (CeO x ), Neodymium dioxide (NdO x ), Promethium oxide (PmO₂) x ), Samarium oxide (SmO₂) x ), Europium oxide (EuO x ), Gadolinium oxide (GdO x ), Terbium oxide (TbO x ), Dysprosium oxide (DyO x ), Holmium oxide (HoO₂) x ), Thulium oxide (TmO x ), Ytterbium oxide (YbO x ), lutetium oxide (LuO x ), Yttrium oxide (YO x ) , Hafnium nitride (HfN x ), Aluminum nitride (AlN x ), Hafnium oxynitride (HfO₂) x N y ), Aluminum oxynitride (AlO x N y ) and the like.

[0040] As described above, the dielectric film 26 comprises the first dielectric film 26a and the second dielectric film 26b. The first dielectric film 26a is located on the first surface (surface 30S1) of the semiconductor substrate 30 and has a first film thickness W1. The second dielectric film 26b is located on the side surface of the through-hole 30H and has a second film thickness W2. The first dielectric film 26a on the first surface (surface 30S1) of the semiconductor substrate 30 has a film thickness (first film thickness: W1) that is greater than the film thickness (second film thickness: W2) of the second dielectric film 26b, which is located on the side surface of the through-hole 30H. Specifically, it is preferable, for example, that the first dielectric film 26a has a film thickness of 10 nm or more and 500 nm or less if, for example, the imaging element 10A is an imaging element for visible light.It is preferred that the second dielectric film 26b, for example, has a film thickness of 1 nm or more and 200 nm or less. It is preferable that the first dielectric film 26a has a film thickness of 10 nm or more and 1000 nm or less, for example, in a case where the imaging element 10A is an infrared imaging element. It is preferable that the second dielectric film 26b, for example, has a film thickness of 1 nm or more and 200 nm or less. This makes it possible to suppress the reflection of incident light on the light-receiving surface (first surface (surface 30S1)) of the semiconductor substrate 30, while suppressing an increase in the capacitance of the through-hole electrode 34 provided within the through-hole 30H.

[0041] As in Fig. As illustrated in Figure 5A, for example, the first dielectric film 26a of the dielectric film 26 on the semiconductor substrate 30 and the second dielectric film 26b of the dielectric film 26, which is formed on the lateral surface of the through-hole 30H, can be formed as single-layer films; however, this is not a limiting factor.

[0042] As in Fig. As illustrated in Figure 5B, for example, the first dielectric film 26a with a greater film thickness than that of the second dielectric film 26b can be formed on the lateral surface of the through-hole 30H by forming the dielectric film 26 as a partially stacked film of a dielectric film 26A and a dielectric film 26B. The dielectric film 26A is formed as a continuous film with a uniform film thickness from the first surface (surface 30S1) of the semiconductor substrate 30 to the lateral surface of the through-hole 30H. The dielectric film 26B is formed only on the dielectric film 26A on the first surface (surface 30S1) of the semiconductor substrate 30.

[0043] As in Fig. As illustrated in Figure 5C, the dielectric film 26 can, for example, be designed such that it has a greater film thickness on the first surface (surface 30S1) of the semiconductor substrate 30 than on the lateral surface of the through-hole 30H, by forming the entire dielectric film 26 as a stacked film (dielectric films 26A and 26B) and by forming first dielectric films 26a1 and 26a2 on the semiconductor substrate 30 such that their film thickness is greater than that of the second dielectric films 26b1 and 26b2, which are formed on the lateral surface of the through-hole 30H.

[0044] It is particularly worth mentioning that Fig. 5B and Fig. Section 5C illustrates an example in which the two dielectric films 26 are stacked as a stacked film, but three or more films can also be stacked. For example, the first three dielectric films 26a and the second dielectric film 26b can be stacked, or the first three dielectric films 26a and the two second dielectric films 26b can be stacked. As described above, in a case where the dielectric films 26 are formed as a stacked film, the same materials can be used to form the dielectric films 26, or different materials can be used to form the dielectric films 26. The first dielectric film 26a with two or more types of stacked films is thus provided on the first surface (surface 30S1) of the semiconductor substrate 30. This makes it possible to add the performance of a hole accumulation layer.As described above, it is further preferable that the dielectric film 26 has a refractive index that gradually approaches the refractive index of the semiconductor substrate 30 from the side of the insulating film 27 to the side of the semiconductor substrate 30, if the dielectric film 26 is formed as a stacked film. This makes it possible to suppress the reflection of incident light at the interface of the semiconductor substrate 30, to facilitate the entry of incident light into the semiconductor substrate 30, and to increase the photoelectric conversion efficiency of the embedded inorganic photoelectric transducers 32B and 32R.

[0045] Although described in detail below, dry etching is also used, for example, as a method for forming the through-hole 30H in the semiconductor substrate 30. In this case, the upper region of the through-hole 30H or the region near the first surface (surface 30S1) of the semiconductor substrate 30 exhibits significant damage. It is therefore preferable that the dielectric film 26A at the upper region of the through-hole 30H be as described in Fig. As illustrated in Figure 5D, the dielectric film 26B is formed, extending from above the first surface (surface 30S1) of the semiconductor substrate 30 to the upper region of the lateral surface of the through-hole 30H, and the second dielectric film 26B is formed such that it has an increased film thickness at the upper region of the lateral surface of the through-hole 30H. The dielectric film 26A is a continuous film with a uniform film thickness from the first surface (surface 30S1) of the semiconductor substrate 30 to the lateral surface of the through-hole 30H.

[0046] It is particularly worth mentioning that an insulating film, such as an oxide film, can be formed between the semiconductor substrate 30 and the dielectric film 26.

[0047] The insulating film 27 is provided on the first dielectric film 26a, which is formed on the first surface (surface 30S1) of the semiconductor substrate 30, and between the second dielectric film 26b, which is formed on the lateral surface of the through-hole 30H, and the through-electrode 34. The insulating film 27 serves to electrically insulate the through-electrode 34 and the semiconductor substrate 30. The material of the insulating film is not particularly restricted; however, the insulating film 27 is formed, for example, by silicon dioxide (SiO₂). x ), TEOS, silicon nitride (SiN x ), silicon oxynitride (SiON) and the like are used.

[0048] The intermediate insulating layer 28, for example, comprises a single-layer film consisting of silicon oxide (Si-O₂). x ), TEOS, silicon nitride (SiN x ), silicon oxynitride (SiON) and the like, or a stacked film comprising two or more of them.

[0049] The insulating layer 22 serves to electrically isolate the accumulating electrode 21B and the semiconductor layer 23. The insulating layer 22 is provided, for example, on the intermediate insulating layer 28 to cover the lower electrode 21. Furthermore, the insulating layer 22 is provided with an opening 22H on the readout electrode 21A of the lower electrode 21. The readout electrode 21A and the semiconductor layer 23 are electrically coupled via this opening 22H. It is possible to form the insulating layer 22 by using, for example, a material similar to that of the intermediate insulating layer 28. The insulating layer 22 comprises, for example, a single-layer film made of silicon dioxide (SiO₂). x ), silicon nitride (SiN x ), silicon oxynitride (SiON) and the like, or a stacked film comprising two or more of them. The insulating layer 22 has a thickness of, for example, 20 nm to 500 nm.

[0050] The protective layer 51 contains a light-transmitting material. The protective layer 51 comprises, for example, a single-layer film containing silicon oxide, silicon nitride, silicon oxynitride, and the like, or a stacked film containing two or more of them. This protective layer 51 has, for example, a thickness of 100 nm to 30,000 nm.

[0051] The semiconductor substrate 30, for example, contains an n-type silicon (Si) substrate and has a p-well 31 in a predetermined region (e.g., pixel section 1a). The second surface (surface 30S2) of the p-well 31 is equipped with the transmission transistors Tr2 and Tr3, the amplifier transistor AMP, the reset transistor RST, the selection transistor SEL, and the like, as described above. Furthermore, a peripheral section (peripheral section 1b) of the semiconductor substrate 30 is provided as shown in Fig. Figure 2 illustrates, for example, a pixel readout circuit 110 and a pixel control circuit 120, each containing a logic circuit or the like.

[0052] The reset transistor RST (reset transistor Tr1rst) resets charges transferred from the organic photoelectric converter 20 to the floating diffusion region FD1 and contains, for example, a MOS transistor. Specifically, the reset transistor Tr1rst includes the reset gate Grst, a channel formation region 36A, and the source / drain regions 36B and 36C. The reset gate Grst is coupled to a reset line RST1. One source / drain region 36B of the reset transistor Tr1rst also serves as the floating diffusion region FD1. The other source / drain region 36C contained in the reset transistor Tr1rst is coupled to a power supply VDD.

[0053] The amplifier transistor AMP is a modulation element that modulates the amount of charge generated in the organic photoelectric converter 20 into a voltage. The amplifier transistor AMP contains, for example, a MOS transistor. Specifically, the amplifier transistor AMP includes the reset gate Gamp, a channel formation region 35A, and source / drain regions 35B and 35C. The gate Gamp is coupled to the readout electrode 21A and one source / drain region 36B (floating diffusion layer FD1) of the reset transistor Tr1rst via the lower first contact 45, the coupling section 41A, the lower second contact 46, the through-electrode 34, and the like. Furthermore, one source / drain region 35B shares a region with the other source / drain region 36C, which is contained in the reset transistor Tr1rst, and is coupled to the power supply VDD.

[0054] The selection transistor SEL (selection transistor TR1sel) contains a gate Gsel, a channel training region 34A, and source / drain regions 34B and 34C. The gate Gsel is coupled to a selection line SEL1. Furthermore, one source / drain region 34B shares a region with the other source / drain region 34C, which is contained in the amplifier transistor AMP, and the other source / drain region 34C is coupled to a signal line (data output line) VSL1.

[0055] The inorganic photoelectric converters 32B and 32R each feature a pn junction in a predetermined region of the semiconductor substrate 30. Both the inorganic photoelectric converters 32B and 32R enable light to be dispersed or split in the vertical direction, as components of light with different wavelengths are absorbed in a silicon substrate according to the depth of incidence. The inorganic photoelectric converter 32B selectively detects blue light to accumulate signal charges corresponding to a blue color. The inorganic photoelectric converter 32B is installed at a depth that allows for efficient photoelectric conversion of blue light. The inorganic photoelectric converter 32R selectively detects red light to accumulate signal charges corresponding to a red color.The inorganic photoelectric converter 32R is installed at a depth that allows for efficient photoelectric conversion of red light. It is particularly important to note that blue (B) is a color corresponding to a wavelength range of, for example, 450 nm to 495 nm. Red (R) is a color corresponding to a wavelength range of, for example, 620 nm to 750 nm. It is sufficient if the inorganic photoelectric converters 32B and 32R are configured to detect light in a portion or the entirety of their respective wavelength ranges.

[0056] The inorganic photoelectric converter 32B, for example, contains a (p+) region that serves as a hole accumulation layer and an n region that serves as an electron accumulation layer. The inorganic photoelectric converter 32R, for example, contains a (p+) region that serves as a hole accumulation layer and an n region that serves as an electron accumulation layer (with a pnp stacked structure). The n region of the inorganic photoelectric converter 32B is coupled to the vertical transfer transistor Tr2. The (p+) region of the inorganic photoelectric converter 32B is bent along the transfer transistor Tr2 and leads to the (p+) region of the inorganic photoelectric converter 32R.

[0057] The transfer transistor Tr2 (transfer transistor TR2trs) serves to transfer signal charges (here electrons) corresponding to the blue color, which were generated and accumulated in the inorganic photoelectric converter 32B, to the floating diffusion region FD2. The inorganic photoelectric converter 32B is formed at a low position from the second surface (surface 30S2) of the semiconductor substrate 30, and it is therefore preferable for the transfer transistor TR2trs of the inorganic photoelectric converter 32B to be a vertical transistor. Furthermore, the transfer transistor TR2trs is coupled to a transfer gate line TG2. In addition, the floating diffusion region FD2 is located in region 37C near a gate Gtrs2 of the transfer transistor TR2trs.The charges accumulated in the inorganic photoelectric converter 32B are read out via a transmission channel formed along the gate Gtrs2 through the floating diffusion region FD2.

[0058] The transmission transistor Tr3 (transmission transistor TR3trs) transfers signal charges (here electrons) corresponding to the red color, which were generated and accumulated in the inorganic photoelectric converter 32R, to the floating diffusion region. The transmission transistor Tr3 (transmission transistor TR3trs) contains, for example, a MOS transistor. Furthermore, the transmission transistor TR3trs is coupled to a transmission gate line TG3. In addition, the floating diffusion region FD3 is located in region 38C near a gate Gtrs3 of the transmission transistor TR3trs. The charges accumulated in the inorganic photoelectric converter 32R are read out via a transmission channel formed along the gate Gtrs3 through the floating diffusion region FD3.

[0059] Furthermore, a reset transistor TR2rst, an amplifier transistor TR2amp, and a select transistor TR2sel are provided on the second surface (surface 30S2) of the semiconductor substrate 30. The reset transistor TR2rst, the amplifier transistor TR2amp, and the select transistor TR2sel are included in the control section of the inorganic photoelectric converter 32B. Additionally, a reset transistor TR3rst, an amplifier transistor TR3amp, and a select transistor TR3sel are provided, which are included in the control section of the inorganic photoelectric converter 32R.

[0060] The reset transistor TR2rst comprises a gate, a channel formation region, and a source / drain region. The gate of the reset transistor TR2rst is coupled to a reset line RST2, and one source / drain region of the reset transistor TR2rst is coupled to the power supply VDD. The other source / drain region of the reset transistor TR2rst also serves as the floating diffusion region FD2.

[0061] The amplifier transistor TR2amp contains a gate, a channel formation region, and a source / drain region. The gate is coupled to the other source / drain region (floating diffusion region FD2) of the reset transistor TR2rst. Furthermore, the source / drain region in the amplifier transistor TR2amp shares a region with the source / drain region in the reset transistor Tr2rst and is coupled to the power supply VDD.

[0062] The selection transistor TR2sel contains a gate, a channel formation region, and a source / drain region. The gate is coupled to a selection line SEL2. Furthermore, one source / drain region within the selection transistor TR2sel shares a region with the other source / drain region within the amplifier transistor Tr2amp. The other source / drain region within the selection transistor TR2sel is coupled to a signal line (data output line) VSL2.

[0063] The reset transistor TR3rst contains a gate, a channel formation region, and a source / drain region. The gate of the reset transistor TR3rst is coupled to a reset line RST3, and one source / drain region within the reset transistor TR3rst is coupled to the power supply VDD. The other source / drain region within the reset transistor TR3rst also serves as the floating diffusion region FD3.

[0064] The amplifier transistor TR3amp contains a gate, a channel formation region, and a source / drain region. The gate is coupled to the other source / drain region (floating diffusion region FD3) contained in the reset transistor TR3rst. Furthermore, the source / drain region in the amplifier transistor TR3amp shares a region with the source / drain region in the reset transistor Tr3rst and is coupled to the power supply VDD.

[0065] The selection transistor TR3sel contains a gate, a channel formation region, and a source / drain region. The gate is coupled to a selection line SEL3. Furthermore, one source / drain region within the selection transistor TR3sel shares a region with the other source / drain region within the amplifier transistor Tr3amp. The other source / drain region within the selection transistor TR3sel is coupled to a signal line (data output line) VSL3.

[0066] The reset lines RST1, RST2 and RST3, the selection lines SEL1, SEL2 and SEL3, and the transmission gate lines TG2 and TG3 are each coupled to a vertical control circuit 112 contained in a control circuit. The signal lines (data output lines) VSL1, VSL2 and VSL3 are coupled to a column signal processing circuit 113 contained in the control circuit.

[0067] The lower first contact 45, the lower second contact 46, the upper first contact 29A, the upper second contact 29B and an upper third contact 29C each contain, for example, a doped silicon material such as PDAS (phosphorus-doped amorphous silicon) or a metal material such as aluminum (Al), tungsten (W), titanium (Ti), cobalt (Co), hafnium (Hf) and tantalum (Ta). (1-2. Method for producing an imaging element)

[0068] It is possible to manufacture the imaging element 10A according to the present embodiment, for example, as follows.

[0069] Fig. Figures 6 to 11 illustrate the procedure for manufacturing the imaging element 10A in the sequence of steps. First, as shown in Fig. Figure 6 illustrates, for example, that the p-well 31 is configured as a well for a first electrical conductor type in the semiconductor substrate 30. The inorganic photoelectric transducers 32B and 32R of a second electrical conductor type (e.g., n-type) are configured in this p-well 31. A (p+) region is configured in a region near the first surface (surface 30S1) of the semiconductor substrate 30.

[0070] As also in Fig. As illustrated in Figure 6, (n+) regions, serving as the floating diffusion regions FD1 to FD3, are formed on the second surface (surface 30S2) of the semiconductor substrate 30, and a gate insulating layer 33 and a gate wiring layer 47 are then formed. The gate wiring layer 47 contains the respective gates of the transmission transistor Tr2, the transmission transistor Tr3, the selection transistor SEL, the amplifier transistor AMP, and the reset transistor RST. This forms the transmission transistor Tr2, the transmission transistor Tr3, the selection transistor SEL, the amplifier transistor AMP, and the reset transistor RST. Furthermore, the multilayer wiring line 40 is formed on the second surface (surface 30S2) of the semiconductor substrate 30. The multilayer wiring cable 40 contains the wiring layers 41 to 43 and the insulating layer 44.Wiring layers 41 to 43 contain the lower first contact 45, the lower second contact 46 and the coupling section 41A.

[0071] For example, the base of the semiconductor substrate 30 is an SOI (silicon-on-insulator) substrate in which the semiconductor substrate 30, an embedded oxide film (not illustrated), and a semiconductor substrate (not illustrated) are stacked. Although in Fig. Figure 6 does not illustrate the embedded oxide film and the semiconductor substrate connected to the first surface (surface 30S1) of the semiconductor substrate 30. Following ion implantation, a curing treatment is performed.

[0072] Next, a (not illustrated) support substrate, another semiconductor base, or the like is bonded to the side of the second surface (surface 30S2) (side of the multilayer wiring lead 40) of the semiconductor substrate 30 and rotated vertically. The semiconductor substrate 30 is then separated from the embedded oxide film and the semiconductor substrate of the SOI substrate to expose the first surface (surface 30S1) of the semiconductor substrate 30. It is possible to perform the steps described above using a technology employed in a standard CMOS process, such as ion implantation and CVD (chemical vapor deposition).

[0073] Next, as in Fig. Figure 7 illustrates that the semiconductor substrate 30 is processed from the side of the first surface (surface 30S1), for example by dry etching, to form, for example, the annular through-hole 30H. The depth of the through-hole 30H extends as shown in Fig. Figure 7 illustrates from the first surface (surface 30S1) to the second surface (surface 30S2) of the semiconductor substrate 30.

[0074] As in Fig. As illustrated in Figure 8, the dielectric film 26A is then formed on the first surface (surface 30S1) of the semiconductor substrate 30 and the side surface of the through-hole 30H, for example using atomic layer deposition (ALD). This forms the dielectric film 26A, which is continuous over the first surface (surface 30S1) of the semiconductor substrate 30 and the side and bottom surfaces of the through-hole 30H. Next, the dielectric film 26B is formed on the dielectric film 26A on the first surface (surface 30S1) of the semiconductor substrate 30, for example using sputtering. Finally, the insulating film 27 is formed over the first surface (surface 30S1) of the insulating film of the semiconductor substrate 30 and inside the through-hole 30H.

[0075] As in Fig. As illustrated in Figure 9, a through-hole 27H is subsequently formed in the insulating film 27, which is located within the through-hole 30H, for example by dry etching. The through-hole 27H reaches the coupling section 41A through the insulating film 27, the first dielectric film 26a, and the insulating layer 44. It is particularly noteworthy that the thickness of the insulating film 27 above the first surface (surface 30S1) is also reduced in this case.

[0076] As in Fig. As illustrated in Figure 10, an electrically conductive film 34x is formed on the insulating film 27 and inside the through-hole 27H, and then a photoresist or photoresist PR is formed at a predetermined position on the electrically conductive film 34x. After that, the Fig. 11 illustrated through-electrode 34, which contains a protruding section on the first surface (surface 30S1) of the semiconductor substrate 30 formed by etching and removal of the photoresist PR.

[0077] Subsequently, an insulating film contained in the interlayer insulating layer 28 is formed on an insulating film 37 and the through-electrode 34. The upper first contact 29A, the pad sections 39A and 39B, the upper second contact 29B, and the upper third contact 29C are formed on the through-electrode 34, and the surface of the interlayer insulating layer 28 is planarized using CMP (chemical-mechanical polishing). An electrically conductive film is then formed on the interlayer insulating layer 28, followed by the formation of a photoresist at a predetermined position on the electrically conductive film. The readout electrode 21A and the accumulation electrode 21B are then formed by etching and removing the photoresist.Next, the insulating layer 22 is formed on the intermediate insulating layer 28, the readout electrode 21A, and the accumulation electrode 21B, and the opening 22H is then provided on the readout electrode 21A. Subsequently, the semiconductor layer 23, the photoelectric conversion layer 24, the top electrode 25, the protective layer 51, and the light-blocking film 52 are formed on the insulating layer 22. It is particularly noteworthy that if the semiconductor layer 23 and the other inorganic layer are formed using organic materials, it is preferable that the semiconductor layer 23 and the other organic layer be formed continuously in a vacuum step (in an in-situ vacuum process). Furthermore, the method for forming the photoelectric conversion layer 24 is not necessarily limited to a process using vacuum evaporation.Another method, for example a spin coating technology, a printing technology, or the like, can be used. Finally, the protective layer 51, the light-blocking film 52, and the on-chip lens 53 are arranged. As described above, this is done in . Fig. 1 illustrated imaging element 10A completed.

[0078] When light enters the organic photoelectric converter 20 in the imaging element 10A via the on-chip lens 53, it passes sequentially through the organic photoelectric converter 20 and the inorganic photoelectric converters 32B and 32R. As the light passes through the organic photoelectric converter 20 and the inorganic photoelectric converters 32B and 32R, it is photoelectrically converted into green, blue, and red light, respectively. The following describes an operation for detecting signals of the respective colors. (Detection of a green color signal using the organic photoelectric converter 20)

[0079] First, the organic photoelectric converter 20 selectively detects (absorbs) the green light component of the light that has entered the imaging element 10A in order to be subjected to photoelectric conversion.

[0080] The organic photoelectric converter 20 is coupled via the through-electrode 34 to the gate Gamp of the amplifier transistor AMP and the floating diffusion region FD1. Thus, the electrons of the electron-hole pairs generated in the organic photoelectric converter 20 are extracted from the side of the lower electrode 21, transferred via the through-electrode 34 to the side of the second surface (surface 30S2) of the semiconductor substrate 30, and accumulated in the floating diffusion region FD1. Simultaneously, the amplifier transistor AMP modulates the amount of charge generated in the organic photoelectric converter into a voltage.

[0081] Furthermore, the reset gate Grst of the reset transistor RST is located next to the floating diffusion region FD1. This causes the reset transistor RST to reset the charges accumulated in the floating diffusion region FD1.

[0082] The organic photoelectric converter 20 is coupled here via the through-electrode 34 not only to the amplifier transistor AMP, but also to the floating diffusion region FD1, which allows the reset transistor RST to simply reset the charges accumulated in the floating diffusion region FD1.

[0083] In contrast, if the through-electrode 34 and the floating diffusion region FD1 are not coupled, it is difficult to reset the charges accumulated in the floating diffusion region FD1. This necessitates applying a large voltage to pull the charges towards the side of the upper electrode 25. The photoelectric conversion layer 24 can thus be damaged. Furthermore, a structure that allows for reset within a short time period leads to increased dark-time noise and represents a compromise. This structure is therefore problematic.

[0084] Fig. Figure 12 illustrates an operating example of the imaging element 10A. (A) illustrates a potential at the accumulation electrode 21B, (B) illustrates a potential at the floating diffusion region FD1 (readout electrode 21A), and (C) illustrates a potential at the gate (Grst) of the reset transistor TR1rst. In the imaging element 10A, voltages are individually applied to the readout electrode 21A and the accumulation electrode 21B.

[0085] The control circuit applies a potential V1 to the readout electrode 21A and a potential V2 to the accumulation electrode 21B in the imaging element 10A during one accumulation period. Here, it is assumed that the potentials V1 and V2 satisfy V2 > V1. This causes charges (electrons) generated by photoelectric conversion to be attracted to the accumulation electrode 21B and accumulated in the region of the semiconductor layer 23 opposite the accumulation electrode 21B (accumulation period). Furthermore, the potential of the region of the semiconductor layer 23 opposite the accumulation electrode 21B becomes more negative over the course of a photoelectric conversion. It is particularly noteworthy that holes are sent from the upper electrode 25 to the control circuit.

[0086] In imaging element 10A, a reset operation is performed in the second part of the accumulation period. Specifically, at time t1, a scan section changes the voltage of a reset signal RST from a low level to a high level. This switches on the reset transistor TR1rst in unit pixel P. As a result, the voltage of the floating diffusion region FD1 is set at a supply voltage VDD and is then reset (reset period).

[0087] After the reset operation is complete, the charges are read out. Specifically, at time t2, the control circuit applies a potential V3 to the readout electrode 21A and a potential V4 to the accumulation electrode 21B. It is assumed here that the potentials V3 and V4 satisfy V3 ​​< V4. This causes the charges (here electrons) accumulated in the region corresponding to the accumulation electrode 21B to be read out by the readout electrode 21A to the floating diffusion region FD1. That is, the charges accumulated in the semiconductor layer 23 are read out to the control section (transfer period).

[0088] After the read operation is complete, the control circuit again applies potential V1 to the readout electrode 21A and potential V2 to the accumulation electrode 21B. This causes charges (here electrons) generated by photoelectric conversion to be attracted to the accumulation electrode 21B and accumulated in the region of the photoelectric conversion layer 24 that is opposite the accumulation period 21B (accumulation period). (Detection of a blue color signal and a red color signal by the inorganic photoelectric converters 32B and 32R)

[0089] Next, the blue and red light components of the light that has passed through the organic photoelectric converter 20 are successively absorbed and photoelectrically converted by the inorganic photoelectric converter 32B and the inorganic photoelectric converter 32R, respectively. In the inorganic photoelectric converter 32B, electrons corresponding to the incident blue light are accumulated in an n-region of the converter and transferred to the floating diffusion region FD2 via the transfer transistor Tr2. Similarly, in the inorganic photoelectric converter 32R, electrons corresponding to the incident red light are accumulated in an n-region and read out to the floating diffusion region FD3 via the transfer transistor Tr3. (1-3. Working method and effects)

[0090] As described above, solid-state imaging devices are widely used in CCD image sensors, CMOS image sensors, and similar devices. These devices each have a pixel array in which primary color filters for red, green, and blue are arranged two-dimensionally, but this produces false colors. As a countermeasure, a structure is proposed in which photoelectric conversion regions are stacked. These regions photoelectrically convert the respective light components in the red, green, and blue wavelength bands. For example, one region of the photoelectric conversion regions is installed above the semiconductor substrate.

[0091] In a case where the structure described above is used for a back-illuminated imaging element, it is conceivable, for example, to form contact sections above the back surface of the semiconductor substrate to conduct signal charges generated by photoelectric transducers located above the semiconductor substrate to the semiconductor substrate. However, it is not possible to apply a high-temperature process to the back surface of the semiconductor substrate. Accordingly, it is not possible to place a pixel transistor on the back surface or to convert signal charges into a voltage.Therefore, an imaging element is proposed that is equipped with a through-electrode on the semiconductor substrate and transmits a signal charge, generated by an organic photoelectric transducer located on the back surface of the semiconductor substrate, via this through-electrode to a pixel transistor located on the front surface of the semiconductor substrate. It is possible to share the through-electrode among a multitude of pixels; however, the through-electrode is generally located within a single pixel area. This necessitates that the through-electrode be designed to be smaller than the size of a pixel cell.

[0092] Furthermore, the back-illuminated CIS has a charge-fixing film formed on the back surface of the semiconductor substrate to suppress the generation of dark currents on this surface. This charge-fixing film also has a refractive index closer to that of silicon than to that of an oxide film contained in the interlayer insulating layer formed above the back surface of the semiconductor substrate. This allows it to function as an antireflection film.

[0093] If the charge-fixing film (hereinafter referred to as the antireflection film), to which the antireflection function described above has been added, is used for an imaging element containing a through-electrode, the antireflection film is formed on the side facing the light-incident surface of the semiconductor substrate and on the side wall of the through-electrode. The antireflection film applied to the side facing the light-incident surface of the semiconductor substrate serves to prevent reflection at the interface of the semiconductor substrate and to fix charges. From the perspective of preventing reflection, the antireflection film must have a thickness of several tens of nm. The antireflection film applied to the side surface of the through-electrode serves to fix charges. The antireflection film must have a thickness of several nm to fix charges.

[0094] Furthermore, the antireflection film around the passing electrode can increase the capacitance of the passing electrode. The capacitance of the passing electrode is simply expressed as in the following expressions (1) and (2). It is assumed here that, as in Fig. Figure 13 illustrates two types of insulating films 1121 and 1122 embedded between a through-electrode 1110 and a semiconductor substrate (not illustrated). In the case of a constant outer diameter (r3) and a constant inner diameter (e1), the capacitance of the through-electrode 1110 increases when the embedded insulating films 1121 and 1122 each have a larger dielectric constant. The through-electrode is a component of a floating diffusion region FD. This reduces the conversion efficiency with increasing capacitance of the through-electrode. [Expression 1] V=∫r1r2Q2π ε11r=Q2π{1ε1logr2r1+1ε2logr3r2} C=2π(1ε1logr2r1+1ε2logr3r2)L

[0095] In contrast, in the present embodiment, the first dielectric film 26a, with the first film thickness, is formed on the first surface (surface 30S1) of the semiconductor substrate 30, which serves as the light-receiving surface, and the second dielectric film 26b, with the second film thickness, which is less than the first film thickness, is formed on the lateral surface of the through-hole 30H. The through-hole 30H extends from the first surface (surface 30S1) to the second surface (surface 30S2) of the semiconductor substrate 30. The through-hole 30H has the through-electrode 34 formed therein. This makes it possible to reduce the reflection of incident light on the first surface (surface 30S1) of the semiconductor substrate 30 by suppressing an increase in capacitance on the lateral surface of the through-electrode 30H, without increasing the outer diameter of the through-electrode 34.

[0096] As described above, in the imaging element 10A according to the present embodiment, the first dielectric film 26a with the first film thickness is formed on the first surface (surface 30S1) of the semiconductor substrate 30, and the second dielectric film 26b with the second film thickness, which is less than the first film thickness, is formed on the lateral surface of the through-hole electrode 30H with the through-hole electrode 34 formed therein. This makes it possible to reduce the reflection of incident light on the first surface (surface 30S1) of the semiconductor substrate 30, while suppressing an increase in capacitance on the lateral surface of the through-hole 30H. This makes it possible to provide the imaging element 10A with characteristics of high sensitivity.

[0097] Next, second and third embodiments and modification examples of the present disclosure are described. The following assigns the same reference numerals to components similar to those in the first embodiment described above, omitting their descriptions where appropriate. <2. Second embodiment>

[0098] Fig. Figure 14 illustrates a cross-sectional configuration of an imaging element (imaging element 10B) according to a second embodiment of the present disclosure. The imaging element 10B is contained within a pixel (unit pixel P) in an imaging device (imaging device 1), such as a CMOS image sensor, which is used for an electronic device such as a digital camera or a video camera. In the imaging element 10B according to the present embodiment, the two organic photoelectric transducers 20 and 70 and an inorganic photoelectric transducer 32 are stacked in the vertical direction.

[0099] The organic photoelectric converters 20 and 70 and the inorganic photoelectric converter 32 each perform a photoelectric conversion by selectively detecting light within a specific wavelength range. Specifically, for example, the organic photoelectric converter 20 detects a color signal for green (G) as described in the first embodiment above. The organic photoelectric converter 70 detects, for example, a color signal for red (R). The inorganic photoelectric converter 32 detects, for example, a color signal for blue (B). This enables the imaging element 10A to detect a variety of color signals in a single pixel without the use of color filters.

[0100] The organic photoelectric converter 70 is stacked, for example, above the organic photoelectric converter 20. Similar to the organic photoelectric converter 20, the organic photoelectric converter 70 has a configuration in which, starting from the side of the first surface (surface 30S1) of the semiconductor substrate 30, a lower electrode 71, a semiconductor layer 73, a photoelectric conversion layer 74, and an upper electrode 75 are stacked in that order. There is also an insulating layer 72 between the lower electrode 71 and the semiconductor layer 73. The lower electrodes 71 are configured separately for the respective imaging elements 10B. Each lower electrode 71 comprises a readout electrode 71A and an accumulation electrode 71B, separated from each other by the insulating layer 72, although this is described in detail below.The readout electrode 71A of the lower electrode 71 is electrically coupled to the photoelectric conversion layer 74 via an opening 72H provided in the insulating layer 72. Fig. Figure 14 illustrates an example in which the semiconductor layers 73, the photoelectric conversion layers 74 and the upper electrodes 75 are formed separately for the respective imaging elements 10B; however, the semiconductor layers 73, the photoelectric conversion layers 74 and the upper electrodes 75 can, for example, be formed as continuous layers common to the plurality of imaging elements 10B.

[0101] The photoelectric conversion layer 74 converts light energy into electrical energy. Similar to the photoelectric conversion layer 24, the photoelectric conversion layer 74 contains two or more types of organic materials (a p-type semiconductor material or an n-type semiconductor material), each acting as a p-type or n-type semiconductor, respectively. In addition to the p-type and n-type semiconductor materials, the photoelectric conversion layer 74 may also contain an organic material or a so-called dye material. The organic material or dye material photoelectrically converts light in a predetermined wavelength range and allows light in a different wavelength range to pass through.If the photoelectric conversion layer 74 is formed using three types of organic materials—a p-type semiconductor, an n-type semiconductor, and a dye material—it is preferable that the p-type and n-type semiconductor materials each have a light transmittance in the visible range (e.g., 400 nm to 700 nm). The photoelectric conversion layer 74, for example, has a thickness of 50 nm to 500 nm. Examples of dye materials used for the photoelectric conversion layer 74 include a rhodamine-based dye, a merocyanine-based dye, and the like.

[0102] Two through-electrodes 34X and 34Y are provided between the first surface (surface 30S1) and the second surface (surface 30S2) of the semiconductor substrate 30.

[0103] As in the first embodiment described above, the through-electrode 34X is electrically coupled to the readout electrode 21A of the organic photoelectric converter 20. The organic photoelectric converter 20 is coupled via the through-electrode 34 to the gate Gamp of the amplifier transistor AMP and to a source / drain region 36B1 of the reset transistor RST (reset transistor Tr1rst), which also serves as the floating diffusion region FD1. The upper end of the through-electrode 34X is coupled, for example, via the upper first contact 29A, the pad section 39A, and the upper second contact 29B to the readout electrode 21A.

[0104] The through-electrode 34Y is electrically coupled to the readout electrode 71A of the organic photoelectric converter 70. The organic photoelectric converter 70 is coupled via the through-electrode 34Y to the gate Gamp of the amplifier transistor AMP and to a source / drain region 36B2 of the reset transistor RST (reset transistor Tr2rst), which also serves as the floating diffusion region FD2. The upper end of the through-electrode 34Y is coupled, for example, via an upper fourth contact 79A, a pad section 69A, an upper fifth contact 79B, a pad section 69B, and an upper sixth contact 79C to the readout electrode 71A. Additionally, a pad 69C is coupled via an upper seventh contact 79D to the accumulation electrode 71B. The lower electrode 71 is contained in the organic photoelectric converter 70.

[0105] The second dielectric film 26b, with a smaller film thickness than the first dielectric film 26b, is formed on the lateral surfaces of the through holes 30H1 and 30H2, as in the first embodiment described above. The through holes 30H1 and 30H2 have the through electrode 34X and the through electrode 34Y formed therein. The first dielectric film 26a is formed on the first surface (surface 30S1) of the semiconductor substrate 30.

[0106] As described above, the imaging element 10B, according to the present embodiment, has a configuration in which the two organic photoelectric transducers 20 and 70 and the one inorganic photoelectric transducer 32 are stacked. The dielectric film 26, which is formed on the first surface (surface 30S1) of the semiconductor substrate 30 and the lateral surfaces of the through-holes 30H1 and 30H2, is a second dielectric film 26b, which is formed on the lateral surfaces of the through-holes 30H1 and 30H2, and is designed to have a thinner film thickness than the first dielectric film 26a on the first surface (surface 30S1) of the semiconductor substrate 30. The through-electrodes 34X and 34Y are electrically coupled to the organic photoelectric transducers 20 and 70, respectively. The through-hole electrodes 34X and 34Y pass through the through-holes 30H1 and 30H2.This makes it possible to obtain effects similar to those of the first embodiment described above. <3. Third embodiment>

[0107] Fig. Figure 15 schematically illustrates a cross-sectional configuration of a photoelectric conversion element (imaging element 10C) according to a third embodiment of the present disclosure. The imaging element 10C is contained within a pixel (unit pixel P) in an imaging device (imaging device 1), such as a CMOS image sensor, which is used, for example, in an electronic device such as a digital camera or a video camera. An organic photoelectric converter 80 according to the present embodiment differs from those of the first and second embodiments described above in that the organic photoelectric converter 80 according to the present embodiment has a configuration in which a lower electrode 81, the photoelectric conversion layer 24, and the upper electrode 25 are stacked in that order, and the lower electrode 81 is formed as a continuous film within a pixel.

[0108] In the imaging element 10C, one organic photoelectric converter 80 and two inorganic photoelectric converters 32B and 32R are stacked vertically for each unit pixel P. The organic photoelectric converter 80 and the inorganic photoelectric converters 32B and 32R perform a photoelectric conversion by selectively detecting the respective light components in different wavelength bands. For example, the organic photoelectric converter 80 specifically detects a color signal for green (G) as in the first embodiment described above. A multilayer wiring layer 90 is provided on the second surface (surface 30S2) of the semiconductor substrate 30. The multilayer wiring layer 90 has a configuration in which wiring layers 91, 92, and 93 are stacked, for example, within an insulating layer 94.

[0109] The organic photoelectric converter 80 is an organic photoelectric conversion element that absorbs light corresponding to a region of a selective wavelength band (e.g., 45 nm or greater and 650 nm or less) or to the whole and generates electron-hole pairs. As described above, the organic photoelectric converter 80 includes, for example, the lower electrode 81 and the upper electrode 25, which are arranged so that they face each other, and the photoelectric conversion layer 24, which is provided between the lower electrode 81 and the upper electrode 25.The lower electrode 81, the photoelectric conversion layer 24 and the upper electrode 25 of the organic photoelectric converter 80 according to the present embodiment each have a configuration similar to that of the organic photoelectric converter 20 according to the first embodiment described above, except that the lower electrode 81 in each pixel uses a continuous film as in . Fig. 15 illustrates how trained.

[0110] For example, on the second surface (surface 30S2) of the semiconductor substrate 30, the floating diffusion regions (floating diffusion layers) FD1, FD2 and FD3, a vertical transistor (transmission transistor) Tr1, a transmission transistor Tr2, the amplifier transistor (modulation element) AMP and the reset transistor RST are provided.

[0111] The vertical transistor T1 is a transfer transistor that transmits the signal charges (here electrons) generated and accumulated in the inorganic photoelectric converter 32B to the floating diffusion region FD1. The signal charges correspond to blue. The inorganic photoelectric converter 32B is formed at a deep position from the second surface (surface 30S2) of the semiconductor substrate 30, and it is therefore preferable for the vertical transistor Tr1 to be a transfer transistor of the inorganic photoelectric converter 32B. The transfer transistor Tr2 transmits signal charges corresponding to red, which are generated and accumulated in the inorganic photoelectric converter 32R, to the floating diffusion region FD2. The transfer transistor Tr2 contains, for example, a MOS transistor.The amplifier transistor AMP is a modulation element that modulates the amount of charge generated in the organic photoelectric converter 80 into a voltage. The amplifier transistor AMP contains, for example, a MOS transistor. The reset transistor RST resets charges transferred from the organic photoelectric converter 80 to the floating diffusion region FD3 and contains, for example, a MOS transistor.

[0112] A lower first contact 95 and a lower second contact 96 each contain, for example, a doped silicon material such as PDAS (phosphorus-doped amorphous silicon) or a metal material such as aluminum (Al), tungsten (W), titanium (Ti), cobalt (Co), hafnium (Hf) and tantalum (Ta).

[0113] The imaging element 10C detects signals of the respective colors as follows. (Detection of a green color signal by the organic photoelectric converter 80)

[0114] First, green light from the portion of light that has entered the imaging element 10C is selectively detected (absorbed) by the organic photoelectric converter 80 to be subjected to photoelectric conversion.

[0115] The organic photoelectric converter 80 is coupled via the through-electrode 34 to the gate Gamp of the amplifier transistor AMP and the floating diffusion region FD3. Consequently, the electrons of the electron-hole pairs generated in the organic photoelectric converter 80 are extracted from the side of the lower electrode 81, transferred via the through-electrode 34 to the side of the second surface (surface 30S2) of the semiconductor substrate 30, and accumulated in the floating diffusion region FD3. At the same time, the amplifier transistor AMP modulates the amount of charge generated in the organic photoelectric converter 80 into a voltage.

[0116] Furthermore, the reset gate Grst of the reset transistor RST is located next to the floating diffusion region FD3. This causes the reset transistor RST to reset the charges accumulated in the floating diffusion region FD3.

[0117] The organic photoelectric converter 80 is coupled here not only to the amplifier transistor AMP, but also to the floating diffusion region FD3 via the through electrode 34, which allows the reset transistor RST to easily reset the charges accumulated in the floating diffusion region FD3.

[0118] If, in contrast, the through-electrode 34 and the floating diffusion region FD3 are not coupled, it is difficult to reset the charges accumulated in the floating diffusion region FD3. This necessitates applying a large voltage to the side of the upper electrode 25 to remove the charges. The photoelectric conversion layer 24 can thus be damaged. Furthermore, a structure that allows for a reset within a short time period leads to increased dark noise and represents a compromise. This structure is therefore problematic. (Detection of a blue color signal and a red color signal by the inorganic photoelectric converters 32B and 32R)

[0119] Next, the blue and red light components of the light that passed through the organic photoelectric converter 80 are successively absorbed and photoelectrically converted by the inorganic photoelectric converter 32B and the inorganic photoelectric converter 32R, respectively. In the inorganic photoelectric converter 32B, electrons corresponding to the incident blue light are accumulated in an n-region of the converter, and these accumulated electrons are transferred to the floating diffusion region FD1 via the vertical transistor Tr1. Similarly, in the inorganic photoelectric converter 32R, electrons corresponding to the incident red light are accumulated in an n-region of the converter, and these accumulated electrons are transferred to the floating diffusion region FD2 via the transfer transistor Tr2.

[0120] As described above, the imaging element 10C, according to the present embodiment, comprises the organic photoelectric transducer 80, which is configured as a continuous film. The dielectric film 26, which is formed on the first surface (surface 30S1) of the semiconductor substrate 30 and the lateral surface of the through-hole 30H, is a second dielectric film 26b formed on the lateral surface of the through-hole 30H. The second dielectric film 26b is configured to have a thinner film thickness than the first dielectric film 26a on the first surface (surface 30S1) of the semiconductor substrate 30. The through-electrode 34 is electrically coupled to the organic photoelectric transducer 80. The through-electrode 34 extends through the through-hole 30H. This makes it possible to obtain effects similar to those of the first embodiment described above. <4. Modification Examples>(4-1. Modification Example 1)

[0121] Fig. Figure 16 illustrates a cross-sectional configuration of an imaging element (imaging element 10D) according to a modification example 1 of the present disclosure. The imaging element 10D is contained in a pixel (unit pixel P) in an imaging device (imaging device 1), such as a CMOS image sensor, which is used, for example, in an electronic device such as a digital camera or a video camera. The imaging element 10D according to the present modification example is configured to have a first dielectric film 66a, which is provided to be partially thick on the first surface (surface 30S1) of the semiconductor substrate 30, which serves as the light-receiving surface. Specifically, the first dielectric film 66a is configured to be thick, for example, in the regions corresponding to the inorganic photoelectric transducers 32B and 32R embedded in the semiconductor substrate 30.

[0122] The first dielectric film 66a according to the present modification example can be configured as a single-layer film and can be configured such that it is thicker in the regions corresponding to the inorganic photoelectric converters 32B and 32R than in the other regions, but can also be configured as in Fig. Figure 16 illustrates that the dielectric film 66A is formed as a stacked film consisting of a dielectric film 66A and a dielectric film 66B. It is particularly noteworthy that the dielectric film 66A and the dielectric film 66B can be formed using the same materials or using different materials.

[0123] As described above, in the imaging element 10D according to the present modification example, the first dielectric film 66a, which is formed on the first surface (surface 30S1) of the semiconductor substrate 30, is designed to be thick only in the regions corresponding to the inorganic photoelectric converters 32B and 32R. Even if the first dielectric film 66a on the first surface (surface 30S1) of the semiconductor substrate 30 is made partially thick in this way, it is possible to obtain effects similar to those of the first embodiment described above. (4-2. Modification example 2)

[0124] Fig. Figure 17 schematically illustrates a configuration of a main section of an imaging element (imaging element 10E) according to Modification Example 2 of the present disclosure. In the first to third embodiments described above and in Modification Example 1, examples were shown in which the through-electrode 34 is provided for each pixel; however, the position at which the through-electrode 34 is formed is not limited thereto. For example, two or more pixels can be provided with each through-electrode 34, or the through-electrode 34 can be formed, for example, in the peripheral section 1b (peripheral region) that is provided around the pixel section 1a (pixel region), as shown in Fig. 17 is illustrated. <5. Application Examples>(Application Example 1)

[0125] Fig. Figure 18 illustrates an overall configuration of an imaging device (imaging device 1) that includes, for each of the pixels, the imaging element 10A (or imaging elements 10B to 10E) described in the first to third embodiments (or modification examples) described above. The imaging device 1 is a CMOS image sensor and includes a pixel section 1a as the imaging area and a peripheral circuit section 130 in a peripheral region of this pixel section 1a on the semiconductor substrate 30. The peripheral circuit section 130 includes, for example, a row scanner 131, a horizontal selector 133, a column scanner 134, and a system controller 132.

[0126] Pixel section 1a, for example, contains the multitude of unit pixels P (each corresponding to the imaging element 10) arranged two-dimensionally in a matrix. Within these unit pixels P, pixel control lines Lread (specifically, row select lines and reset control lines) are arranged, for example, in each row of pixels, and vertical signal lines Lsig are arranged in each column of pixels. The pixel control lines Lread each serve to transmit control signals to read signals from pixels. One end of each pixel control line Lread is coupled to the output end of the row scanner 131 for each row.

[0127] The row scanner 131 is a pixel driver containing a shift register, an address decoder, and the like, and controls the respective unit pixels P of pixel section 1a, for example, row by row. Signals output by the respective unit pixels P in the pixel rows selectively scanned by the row scanner 131 are provided to the horizontal selector 133 via the respective vertical signal lines Lsig. The horizontal selector 133 contains an amplifier, a horizontal selector switch, and the like, provided for each of the vertical signal lines Lsig.

[0128] The column scanner 134 contains a shift register, an address decoder, and the like, and controls each of the horizontal selector switches of the horizontal selector 133 sequentially while the horizontal selector switches are being scanned. The selective scanning by this column scanner 134 causes the signals of the respective pixels, which are transmitted via the respective vertical signal lines Lsig, to be output sequentially to a horizontal signal line 135 and transmitted via the horizontal signal line 135 outside the semiconductor substrate 30.

[0129] Circuit sections containing the row scanner 131, the horizontal selector 133, the column scanner 134, and the horizontal signal line 135 can be formed directly on the semiconductor substrate 30 or arranged in an external control IC. Alternatively, these circuit sections can be formed on another substrate coupled by means of a cable or the like.

[0130] The system controller 132 receives a clock signal provided from outside the semiconductor substrate 30, data for an instruction regarding an operating mode, and the like, and outputs data such as internal information from the imaging device 1. The system controller 132 also includes a timing generator that produces various timing signals and controls the operation of peripheral circuits such as the row scanner 131, the horizontal selector 133, the column scanner 134, and the like, based on the various timing signals generated by the timing generator. (Application example 2)

[0131] The imaging device 1 described above can be used, for example, for any type of electronic device with an imaging function, including a camera system such as a digital camera or video camera, a mobile phone with an imaging function, and the like. Fig. Figure 19 illustrates a schematic configuration of an electronic device 2 (camera) as an example. This electronic device 2 is, for example, a video camera that can capture a still image or a moving image. The electronic device 2 includes the imaging device 1, an optical system (optical lens) 310, an aperture device 311, a driver 313 that controls the imaging device 1 and the aperture device 311, and a signal processor 312.

[0132] The optical system 310 directs imaging light (incident light) from an object to the pixel section 1a of the imaging device 1. This optical system 310 can contain a plurality of optical lenses. The aperture device 311 controls a period during which the imaging device 1 is illuminated with light and a period during which light is blocked. The driver 313 controls a transmission operation of the imaging device 1 and an aperture operation of the aperture device 311. The signal processor 312 performs various types of signal processing on a signal output by the imaging device 1. An image signal Dout that has undergone signal processing is stored in a storage medium such as a memory or output to a monitoring device or the like.

[0133] Furthermore, the imaging device 1 described above can also be used for the following electronic devices (a capsule-type endoscope 10100 and a mobile body such as a vehicle). (Application example 3)<Beispiel einer Anwendung für ein In-Vivo-Informationserfassungssystem>

[0134] The technology (the present technology) according to the present disclosure is furthermore applicable to a variety of products. For example, the technology according to the present disclosure can be used for a system for endoscopic surgery.

[0135] Fig. Figure 20 is a block diagram that provides an example of a schematic configuration of an in vivo information acquisition system for a patient using a capsule-type endoscope, for which the technology according to an embodiment of the present disclosure (present technology) can be used.

[0136] The in vivo information acquisition system 10001 comprises a capsule-type endoscope 10100 and an external control unit 10200.

[0137] The capsule-type endoscope 10100 is swallowed by the patient during the examination. Equipped with an image acquisition and wireless communication function, the capsule-type endoscope 10100 sequentially captures images from inside an organ, such as the stomach or intestine (referred to below as the in-vivo image), at predetermined intervals as it moves within the organ via peristaltic movement until it is naturally expelled by the patient. The capsule-type endoscope 10100 then wirelessly transmits the in-vivo image information to the external control unit 10200 located outside the body.

[0138] The external control unit 10200 integrally controls the operation of the in-vivo information acquisition system 10001. In addition, the external control unit 10200 receives information about an in-vivo image transmitted to it by the capsule-type endoscope 10100 and generates image data for displaying the in-vivo image on a (not shown) display device based on the received information of the in-vivo image.

[0139] In the In-Vivo Information Acquisition System 10001, an in-vivo image that has captured a condition of the inside of a patient's body can be captured in this way at any time during a period until the capsule-type endoscope 10100 is excreted after being swallowed.

[0140] The configuration and functions of the capsule-type endoscope 10100 and the external control unit 10200 are described in more detail below.

[0141] The capsule-type endoscope 10100 has a capsule-type housing 10101 containing a light source unit 10111, an image acquisition unit 10112, an image processing unit 10113, a wireless communication unit 10114, a power supply unit 10115, a power supply unit 10116 and a control unit 10117.

[0142] The light source unit 10111 contains a light source such as a light-emitting diode (LED) and shines light onto an image capture field of view of the image capture unit 10112.

[0143] The image acquisition unit 10112 contains an image acquisition element and an optical system comprising a plurality of lenses located in a stage preceding the image acquisition element. Reflected light (hereinafter referred to as observation light) from light directed onto body tissue that is the observation target is collected by the optical system and introduced into the image acquisition element. In the image acquisition unit 10112, the incident observation light is photoelectrically converted by the image acquisition element, thereby generating an image signal corresponding to the observation light. The image signal generated by the image acquisition unit 10112 is provided to the image processing unit 10113.

[0144] The image processing unit 10113 contains a processor, such as a central processing unit (CPU) or a graphics processing unit (GPU), and performs various signal processing operations on an image signal generated by the image acquisition unit 10112. The image processing unit 10113 then provides the image signal, for which the signal processing operations have been performed, to the unit 10114 as raw data for wireless communication.

[0145] The wireless communication unit 10114 performs a predetermined process, such as a modulation process, on the image signal for which the signal processing was carried out by the image processing unit 10113, and transmits the resulting image signal via an antenna 10114A to the external control unit 10200. Furthermore, the wireless communication unit 10114 receives a control signal related to the drive control of the capsule-type endoscope 10100 from the external control unit 10200 via the antenna 10114A. The wireless communication unit 10114 then forwards the control signal received from the external control unit 10200 to the control unit 10117.

[0146] The 10115 power supply unit contains an antenna coil for power input, a power recovery circuit for recovering electrical power from the current generated in the antenna coil, a voltage amplifier circuit, and the like. The 10115 power supply unit generates electrical power using a principle of so-called contactless charging.

[0147] The power supply unit 10116 contains a secondary battery and stores the electrical power generated by the power supply unit 10115. Fig. Figure 34, to avoid a complicated illustration, omits an arrow indicating the destination of the electrical power supply from the power supply unit 10116, etc. However, the electrical power stored in the power supply unit 10116 is provided to, and can be used to drive, the light source unit 10111, the image acquisition unit 10112, the image processing unit 10113, the wireless communication unit 10114, and the control unit 10117.

[0148] The control unit 10117 contains a processor such as a CPU and appropriately controls the operation of the light source unit 10111, the image acquisition unit 10112, the image processing unit 10113, the wireless communication unit 10114 and the power supply unit 10115 according to a control signal transmitted there from the external control device 10200.

[0149] The external control device 10200 contains a processor, such as a CPU or GPU, a microcomputer, a control board, or the like, in which a processor and a memory element, such as a memory, are integrated. The external control device 10200 transmits a control signal via an antenna 10200A to the control unit 10117 of the capsule-type endoscope 10100 to control the operation of the capsule-type endoscope 10100. For example, in the capsule-type endoscope 10100, an illumination condition of light on an observation target of the light source unit 10111 can be changed according to a control signal from the external control device 10200. Furthermore, an image acquisition condition (for example, a frame rate, an exposure value, or the like in the image acquisition unit 10112) can be changed according to a control signal from the external control device 10200.Furthermore, the content of a processing operation by the image processing unit 10113 or a condition for transmitting an image signal from the unit 10114 for wireless communication (for example, a transmission interval, the number of transmitted images, and the like) can be changed according to a control signal from the external control device 10200.

[0150] Furthermore, the external control unit 10200 performs various image processing operations on an image signal transmitted from the capsule-type endoscope 10100 to generate image data for displaying a captured in-vivo image on the display unit. These image processing operations can include various signal processing operations, such as a development process (demosaicing), an image quality enhancement process (bandwidth expansion, super-resolution, noise reduction (NR), and / or image stabilization), and / or a magnification process (electronic zoom). The external control unit 10200 controls the display unit to cause it to display captured in-vivo images based on the generated image data.Alternatively, the external control device 10200 can also control a (not illustrated) recording device to record generated image data, or a (not illustrated) printing device to print generated image data.

[0151] The example of an in-vivo information acquisition system for which the technology according to the present disclosure can be used was described above. The technology according to the present disclosure can be used, for example, for the image acquisition unit 10112 among the components described above. This increases the detection accuracy. (Application example 4)<Beispiel einer Anwendung für ein System für endoskopische Chirurgie>

[0152] The technology (the present technology) according to the present disclosure can be used for a variety of products. For example, the technology according to the present disclosure can be used for a system for endoscopic surgery.

[0153] Fig. Figure 21 is a view that provides an example of a schematic configuration of a system for endoscopic surgery for which the technology according to an embodiment of the present disclosure (present technology) can be used.

[0154] In Fig. Figure 21 illustrates a situation in which a surgeon (physician) 11131 is using an endoscopic surgery system 11000 to perform a surgical procedure on a patient 11132 on a patient bed 11133. As shown, the endoscopic surgery system 11000 comprises an endoscope 11100, other surgical instruments 11110 such as a pneumoperitoneum tube 11111 and an energy treatment device 11112, a support arm device 11120 that carries the endoscope 11100, and a trolley 11200 on which various endoscopic surgery devices are mounted.

[0155] The endoscope 11100 comprises a lens tube 11101, with a predetermined length extending from its distal end for insertion into a body cavity of the patient 11132, and a camera head 11102 connected to a proximal end of the lens tube 11101. In the example shown, the endoscope 11100 is depicted as a rigid endoscope with the rigid lens tube 11101. However, the endoscope 11100 can also be a flexible endoscope with the flexible lens tube 11101.

[0156] At its distal end, the lens tube 11101 has an opening into which an object lens is fitted. A light source 11203 is connected to the endoscope 11100 such that light generated by the light source 11203 is introduced into a distal end of the lens tube 11101 through a light guide extending inside the lens tube 11101 and is directed through the object lens toward an observation target in a body cavity of the patient 11132. It is particularly noteworthy that the endoscope 11100 can be a straight-viewing endoscope, an oblique-viewing endoscope, or a lateral-viewing endoscope.

[0157] An optical system and an image capture element are arranged within the camera head 11102 such that reflected light (observation light) from the observation target is focused and collected by the optical system on the image capture element. The observation light is photoelectrically converted by the image capture element to generate an electrical signal corresponding to the observation light, namely an image signal corresponding to an observation image. The image signal is transmitted as raw data to a CCU 11201.

[0158] The CCU 11201 contains a central processing unit (CPU), a graphics processing unit (GPU), or the like, and controls the operation of the endoscope 11100 and a display unit 11202 in a comprehensive or integrated manner. Furthermore, the CCU 11201 receives an image signal from the camera head 11102 and performs various image processing operations on the image signal to display an image based on the image signal, such as a development process (demosaicing process).

[0159] The display unit 11202 displays an image based on an image signal for which the image processes were carried out by the CCU 11201, under the control of the CCU 11201.

[0160] The light source device 11203 contains a light source, such as a light-emitting diode (LED), and directs irradiation light to the endoscope 11100 when imaging an area of ​​a surgical procedure.

[0161] An input device 11204 is an input interface for the 11000 system for endoscopic surgery. A user can use the 11204 input device to enter various types of information or instructions into the 11000 system for endoscopic surgery. For example, the user can enter an instruction to change an image acquisition condition (such as the type of illumination, magnification, focal length, etc.) through the 11100 endoscope.

[0162] A device 11205 for controlling a treatment instrument controls the energy treatment device 11112 for cauterization or cutting of tissue, closure of a blood vessel, or the like. To ensure the field of view of the endoscope 11100 and to ensure the working space for the surgeon, a pneumoperitoneum device 11206 introduces gas through the pneumoperitoneum tube 11111 into a body cavity of the patient 11132 to expand the body cavity. A recording device 11207 is a device that can record various types of information relating to a surgical procedure. A printer 11208 is a device that can print various types of information relating to a surgical procedure in various forms, such as text, images, or graphic representations.

[0163] It is particularly noteworthy that the light source unit 11203, which supplies irradiation light to the endoscope 11100 when imaging an area of ​​a surgical procedure, can contain a white light source, such as an LED, a laser light source, or a combination thereof. If a white light source contains a combination of red, green, and blue (RGB) laser light sources, the output intensity and timing for each color (each wavelength) can be controlled with a high degree of accuracy, allowing the white balance of a captured image to be adjusted by the light source unit 11203. Furthermore, in this case, if laser beams from the respective RGB laser light sources are projected onto a target in a time-division multiplexing manner, the image acquisition elements of the camera head 11102 are controlled synchronously with the irradiation times.Then, images corresponding to the R, G, and B colors can also be individually captured using time-division multiplexing. According to this method, it is possible to obtain a color image even if no color filters are provided for the image capture element.

[0164] Furthermore, the light source device 11203 can be controlled to change the intensity of the emitted light for each predetermined time. By controlling the image acquisition element of the camera head 11102 synchronously with the time of the change in light intensity to capture images in a time-division multiplexing manner, and combining or synthesizing the images, an image with a high dynamic range can be produced without underdeveloped blocked shadows and overexposed highlights.

[0165] Furthermore, the light source device 11203 can be configured to provide light of a predetermined wavelength band suitable for special-light observation. In special-light observation, for example, by exploiting the wavelength dependence of light absorption in body tissue to emit a narrow band of light, a narrowband observation (narrowband imaging) is performed to image a predetermined tissue, such as a blood vessel or a surface region of the mucosal membrane, in high contrast compared to the irradiation light used in ordinary observation (namely, white light). Alternatively, special-light observation can be used to perform fluorescence observation, obtaining an image from fluorescence light generated by irradiation with excitation light.Fluorescence observation can be performed by observing fluorescence light from body tissue by shining excitation light onto the tissue (autofluorescence observation), or by obtaining a fluorescence image by locally injecting a reagent such as indocyanine green (ICG) into body tissue and shining excitation light corresponding to a fluorescence wavelength of the reagent onto the tissue. The light source device 11203 can be configured to provide such narrowband light and / or excitation light suitable for special light observation as described above.

[0166] Fig. Figure 22 is a block diagram showing an example of a functional configuration of the camera head 11102 and the CCU 11201, which is shown in Fig. 35 are shown.

[0167] The camera head 11102 contains a lens unit 11401, an image acquisition unit 11402, a control unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 contains a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other by a transmission cable 11400 for communication purposes.

[0168] The lens unit 11401 is an optical system located at a connection point with the lens tube 11101. Observation light received from a distal end of the lens tube 11101 is guided to the camera head 11102 and introduced into the lens unit 11401. The lens unit 11401 contains a combination of multiple lenses, including a zoom lens and a focusing lens.

[0169] The number of image acquisition units contained in the image acquisition unit 11402 can be one (single-plate type) or multiple (multi-plate type). For example, if the image acquisition unit 11402 is configured like the multi-plate type, the image acquisition elements generate corresponding R, G, and B image signals, and these signals can be synthesized to produce a color image. The image acquisition unit 11402 can also be configured to contain a pair of image acquisition elements to obtain separate image signals for the right and left eye, suitable for three-dimensional (3D) display. When a 3D display is performed, the depth of tissue in a living body within a surgical area can then be more accurately perceived by the surgeon 11131.It is particularly worth mentioning that when the image acquisition unit 11402 is configured as that of a stereoscopic type, a variety of systems of lens units 11401 are provided corresponding to the individual image acquisition elements.

[0170] Furthermore, the image acquisition unit 11402 does not necessarily have to be located on the camera head 11102. For example, the image acquisition unit 11402 can be located directly behind the lens inside the lens tube 11101.

[0171] The control unit 11403 contains an actuator and, under the control of the camera head control unit 11405, moves the zoom lens and the focus lens of the lens unit 11401 by a predetermined distance along an optical axis. Consequently, the magnification and focus of a captured image can be appropriately adjusted by the image acquisition unit 11402.

[0172] The communication unit 11404 contains a communication device for transmitting and receiving various types of information to and from the CCU 11201. The communication unit 11404 transmits an image signal obtained from the image acquisition unit 11402 as raw data to the CCU 11201 via the transmission cable 11400.

[0173] Furthermore, the communication unit 11404 receives a control signal from the CCU 11201 to control the camera head 11102 and provides the control signal to the camera head control unit 11405. The control signal contains information regarding image capture conditions, such as information that a frame rate for a captured image has been determined, information that an exposure value has been determined for an image capture, and / or information that a magnification and focus of a captured image have been determined.

[0174] It is particularly worth mentioning that the image capture conditions, such as frame rate, exposure value, magnification, or focus, can be determined by the user or automatically set by the control unit 11413 of the CCU 11201 based on the captured image signal. In the latter case, the endoscope 11100 incorporates an automatic exposure (AE) function, an autofocus (AF) function, and an automatic white balance (AWB) function.

[0175] The camera head control unit 11405 controls the camera head 11102 based on a control signal received from the CCU 11201 via the communication unit 11404.

[0176] The communication unit 11411 contains a communication device for transmitting and receiving various types of information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted to it from the camera head 11102 via the transmission cable 11400.

[0177] Furthermore, the communication unit 11411 transmits a control signal to the camera head 11102 for controlling the camera head 11102. The image signal and the control signal can be transmitted by means of electrical communication, optical communication or the like.

[0178] The image processing unit 11412 performs various image processes for an image signal in the form of raw data transmitted from the camera head 11102.

[0179] The control unit 11413 performs various types of control regarding the image acquisition of a surgical procedure area or the like by the endoscope 11100 and the display of a captured image obtained by means of image acquisition of the surgical procedure area or the like. For example, the control unit 11413 generates a control signal to control the camera head 11102.

[0180] Furthermore, the control unit 11413, based on an image signal generated by the image processing unit 11412, controls the display unit 11202 to display a captured image depicting the area of ​​a surgical procedure or the like. The control unit 11413 can then recognize various objects in the captured image using different image recognition technologies. For example, the control unit 11413 can recognize a surgical instrument such as forceps, a specific area of ​​a living body, bleeding, haze (when the energy treatment device 11112 is used), and so on, by detecting the shape, color, and other characteristics of the edges of objects contained in a captured image.When controlling the display unit 11202 to show a captured image, the control unit 11413 can cause various types of surgical-supportive information to be displayed overlapping with an image of the surgical area using a recognition result. When the surgical-supportive information is displayed in an overlapping manner and presented to the surgeon 11131, the workload for the surgeon 11131 can be reduced, and the surgeon 11131 can safely continue the surgical procedure.

[0181] The transmission cable 11400, which connects the camera head 11102 and the CCU 11201, is an electrical signal cable suitable for communication of electrical signals, an optical fiber suitable for optical communication, or a composite cable suitable for both electrical and optical communication.

[0182] While in the example shown communication is carried out using the transmission cable 11400 via a wired communication, here the communication between the camera head 11102 and the CCU 11201 can be carried out via a wireless communication.

[0183] The above has described the example of the endoscopic surgery system for which the technology according to the present disclosure can be used. The technology according to the present disclosure can be used for the image acquisition unit 11402 among the components described above. Applying the technology according to the present disclosure to the image acquisition unit 11402 increases the detection accuracy.

[0184] It is particularly worth mentioning that the system for endoscopic surgery has been described here as an example, but the technology according to the present disclosure can also be used for, for example, a system for microscopic surgery or the like. (Application example 5)<Beispiel einer Anwendung für einen beweglichen Körper>

[0185] The technology according to the present disclosure can be used for a variety of products. For example, the technology according to the present disclosure can be implemented as a device to be mounted on any type of movable body, such as a vehicle, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an aircraft, a drone, a ship, a robot, a construction machine, or an agricultural machine (tractor).

[0186] Fig. Figure 23 is a block diagram illustrating an example of a schematic configuration of a vehicle control system as an example of a system for controlling moving bodies for which the technology according to an embodiment of the present disclosure can be used.

[0187] The vehicle control system 12000 comprises a multitude of electronic control units interconnected via a communication network 12001. In the Fig. In the example shown in Figure 23, the vehicle control system 12000 comprises a powertrain control unit 12010, a body control unit 12020, a unit 12030 for detecting information from outside the vehicle, a unit 12040 for detecting information inside the vehicle, and an integrated control unit 12050. Furthermore, a microcomputer 12051, an audio / video output section 12052, and an interface (I / F) 12053 of the vehicle-mounted network are illustrated as a functional configuration of the integrated control unit 12050.

[0188] The 12010 drive system control unit controls the operation of devices related to the vehicle's drive system according to various types of programs. For example, the 12010 drive system control unit serves as a control device for a drive force generation device to generate the vehicle's drive force, such as an internal combustion engine, a drive motor, or the like; a drive force transmission mechanism to transfer the drive force to the wheels; a steering mechanism to adjust the vehicle's steering angle; a braking device to generate the vehicle's braking force; and the like.

[0189] The 12020 body control unit controls the operation of various types of devices integrated into a vehicle body, according to different programs. For example, the 12020 body control unit serves as a control device for a keyless entry system, a smart key system, automatic windows, or various types of lights such as headlights, taillights, brake lights, turn signals, fog lights, and the like. In this case, radio waves transmitted by a mobile device as an alternative to a key, or signals from various types of switches, can be fed into the 12020 body control unit.The body control unit 12020 receives these injected radio waves or signals and controls a door locking device, the automatic window device, the lights or the like of the vehicle.

[0190] The external information detection unit 12030 detects information about the external environment of the vehicle containing the vehicle control system 12000. For example, the external information detection unit 12030 is connected to an imaging section 12031. The external information detection unit 12030 causes the imaging section 12031 to take an image of the vehicle's external environment and receives the captured image. Based on the received image, the external information detection unit 12030 can perform processing to detect an object such as a person, a vehicle, an obstacle, a traffic sign, a marking on a road surface, or the like, or processing to detect the distance to it.

[0191] The imaging section 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging section 12031 can also output the electrical signal as an image or as information about a measured distance. Furthermore, the light received by the imaging section 12031 can be visible light or invisible light such as infrared radiation.

[0192] The 12040 vehicle information detection unit detects information about or from the interior of the vehicle. For example, the 12040 vehicle information detection unit is connected to a 12041 driver state detection section, which detects the driver's condition. The 12041 driver state detection section includes, for example, a camera that records the driver. Based on detection information provided by the 12041 driver state detection section, the 12040 vehicle information detection unit can calculate the driver's fatigue level, driver concentration level, or determine whether the driver is dozing off.

[0193] The microcomputer 12051 can calculate a control target value for the drive force generation device, the steering mechanism or the braking device based on information about the interior or external environment of the vehicle, which information is obtained by the unit 12030 for detecting information from outside the vehicle or the unit 12040 for detecting information inside the vehicle, and can issue a control command to the drive system control unit 12010.For example, the 12051 microcomputer can perform cooperative control intended to implement functions of an Advanced Driver Assistance System (ADAS), the functions of which include collision avoidance or impact mitigation for the vehicle, following based on a following distance, driving at a constant speed, warning of vehicle collision, warning of vehicle lane deviation, or the like.

[0194] Furthermore, the microcomputer 12051 can perform cooperative control intended for automated driving, which allows the vehicle to drive autonomously without dependence on driver intervention or the like, by controlling the drive force generation device, the steering mechanism, the braking device or the like based on information about the external environment or the interior of the vehicle, which information is obtained by the unit 12030 for detecting information from outside the vehicle or the unit 12040 for detecting information inside the vehicle.

[0195] The microcomputer 12051 can also issue a control command to the body control unit 12020 based on information about the vehicle's external environment, which is obtained by the external information detection unit 12030. For example, the microcomputer 12051 can perform cooperative control intended to prevent glare by controlling the headlights according to the position of a vehicle ahead or an oncoming vehicle, detected by the external information detection unit 12030, to switch from high beam to low beam.

[0196] The audio / video output section 12052 transmits an output signal of sound and / or image to an output device that can convey information visually or audibly to an occupant of the vehicle or the vehicle's external environment. For example, Fig. Item 13 specifies a loudspeaker 12061, a display section 12062, and a dashboard 12063 as the output device. The display section 12062 can, for example, include an on-board display and / or a head-up display.

[0197] Fig. Figure 24 is a diagram illustrating an example of an installation position of the imaging section 12031.

[0198] In Fig. 24 includes the imaging section 12031 imaging sections 12101, 12102, 12103, 12104 and 12105.

[0199] Imaging sections 12101, 12102, 12103, 12104, and 12105 are, for example, located at positions on the front of the vehicle 12100, on the side mirrors, on the rear bumper, and on the tailgate, as well as on the upper part of the windshield inside the vehicle. Imaging section 12101 at the front and imaging section 12105 at the upper part of the windshield inside the vehicle primarily receive an image of the area in front of the vehicle 12100. Imaging sections 12102 and 12103 at the side mirrors primarily receive an image of the sides of the vehicle 12100. Imaging section 12104 at the rear bumper or tailgate primarily receives an image of the area behind the vehicle 12100.The imaging section 12105, located on the upper part of the windshield inside, is primarily used to detect a vehicle ahead, a pedestrian, an obstacle, a traffic light, a traffic sign, a lane or the like.

[0200] Furthermore, Fig.Figure 24 shows an example of photographic areas of imaging sections 12101 to 12104. An imaging area 12111 represents the imaging area of ​​imaging section 12101 located at the front of the vehicle. Imaging areas 12112 and 12113 represent the imaging areas of imaging sections 12102 and 12103, respectively, located at the side mirrors. An imaging area 12114 represents the imaging area of ​​imaging section 12104 located at the rear bumper or tailgate. For example, a bird's-eye view image of the vehicle 12100, as seen from above, is obtained by superimposing image data captured by imaging sections 12101 to 12104.

[0201] At least one of the imaging sections 12101 to 12104 can have a function for obtaining distance information. For example, at least one of the imaging sections 12101 to 12104 can be a stereo camera composed of a multitude of imaging elements, or it can be an imaging element containing pixels for phase difference detection.

[0202] The microcomputer 12051 can, for example, determine a distance to any three-dimensional object within the imaging areas 12111 to 12114 and a change in distance over time (relative speed in relation to the vehicle 12100) based on the distance information obtained from the imaging sections 12101 to 12104, and thereby, in particular, extract the nearest three-dimensional object, such as a vehicle traveling ahead, which is on a path of the vehicle 12100 and which is traveling at a predetermined speed (for example, 0 km / h or higher) in essentially the same direction as the vehicle 12100.Furthermore, the 12051 microcomputer can predefine a following distance to be maintained from a vehicle ahead and perform automatic braking control (including follow-stop control), automatic acceleration control (including follow-start control), or similar functions. Consequently, it is possible to execute cooperative control intended for automated driving, allowing the vehicle to drive autonomously without driver intervention.

[0203] The microcomputer 12051 can, for example, classify three-dimensional object data about three-dimensional objects into three-dimensional object data of a two-wheeled vehicle, a vehicle of average size, a large vehicle, a pedestrian, a telephone pole, and other three-dimensional objects based on the distance information obtained from the imaging sections 12101 to 12104, extract the classified three-dimensional object data, and use the extracted three-dimensional objects for automatic obstacle avoidance. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 as obstacles that the driver of the vehicle 12100 can visually detect and obstacles that are difficult for the driver of the vehicle 12100 to visually detect. The microcomputer 12051 then determines a collision risk, which indicates the likelihood of a collision with each obstacle.In a situation where the risk of collision is equal to or higher than a set value, and thus a collision is possible, the microcomputer 12051 issues a warning to the driver via the speaker 12061 or the display section 12062 and initiates a forced braking or evasive steering maneuver via the drive system control unit 12010. The microcomputer 12051 can thus assist the driver in avoiding a collision.

[0204] At least one of the imaging sections 12101 to 12104 can be an infrared camera that detects infrared radiation. For example, the microcomputer 12051 can detect a pedestrian by determining whether or not a pedestrian is present in the images captured by the imaging sections 12101 to 12104. Such pedestrian detection is achieved, for example, by a procedure to extract characteristic points from the images captured by the imaging sections 12101 to 12104 as infrared cameras and a procedure to determine whether it is the pedestrian or not by performing pattern matching processing on a series of characteristic points that define the object's outline.When the microcomputer 12051 determines that a pedestrian is present in the images captured by imaging sections 12101 to 12104, and thus detects the pedestrian, the audio / video output section 12052 controls the display section 12062 so that a rectangular outline is displayed for highlighting purposes, superimposed on the detected pedestrian. The audio / video output section 12052 can also control the display section 12062 to display a symbol or similar element representing the pedestrian at a desired position.

[0205] Although the description was given with reference to the first to third embodiments, modification examples 1 and 2, and application examples, the contents of this disclosure are not limited to the embodiments described above and the like. This disclosure can be modified in a variety of ways. For example, in the embodiments described above, an imaging element has a configuration in which the organic photoelectric transducer 20, which detects green light, and the inorganic photoelectric transducers 32B and 32R, which detect blue light and red light, respectively, are stacked. However, the contents of this disclosure are not limited to such a structure. That is to say, the organic photoelectric transducer can detect either red light or blue light, or the inorganic photoelectric transducers can each detect green light.

[0206] Furthermore, the number of these organic and inorganic photoelectric converters, or the ratio between them, is not limited. Color signals of a wide variety of colors can be obtained using only the organic photoelectric converter.

[0207] Furthermore, in the embodiments described above and the like, examples have been shown in which a plurality of electrodes contained in the lower electrode 21 comprise the two electrodes of the readout electrode 21A and the accumulation electrode 21B. However, three or four or more additional electrodes, including a transfer electrode, a discharge electrode, or the like, may also be provided.

[0208] It is particularly important to note that the effects described herein are only examples and not limiting. Furthermore, other effects may occur.

[0209] It is particularly worth mentioning that the present disclosure may have the following configurations. (1) An imaging element comprising: a semiconductor substrate having one surface and another surface that are opposite to each other, wherein the semiconductor substrate has a through-hole passing between the one surface and the other surface; a first photoelectric converter provided above one surface of the semiconductor substrate; a through-electrode that is electrically coupled to the first photoelectric transducer, wherein the through-electrode penetrates the semiconductor substrate inside the through-hole; a first dielectric film provided on one surface of the semiconductor substrate, wherein the first dielectric film has a first film thickness; and a second dielectric film provided on a lateral surface of the through-hole, wherein the second dielectric film has a second film thickness, the second film thickness being less than the first film thickness. (2) The imaging element according to (1), wherein the semiconductor substrate further contains an amplifier transistor and a floating diffusion layer on the side of the other surface and the through-electrode is electrically coupled to at least one of the amplifier transistor or the floating diffusion layer. (3) The imaging element according to (1) or (2), wherein at least one of the first dielectric film or of the second dielectric film contains a stacked film. (4) The imaging element according to one of (1) to (3), wherein the first film thickness of the first dielectric film is 10 nm or more and 1000 nm or less and The second film thickness of the second dielectric film is 1 nm or more and 200 nm or less. (5) The imaging element according to one of (1) to (4), wherein the first dielectric film has a film thickness that varies between regions on the semiconductor substrate. (6) The imaging element according to paragraphs (1) to (5), wherein a second photoelectric converter is designed to be embedded in the semiconductor substrate, and The film thickness of the first dielectric film above the second photoelectric transducer is greater than the film thickness in an area around the through-electrode. (7) The imaging element according to one of (1) to (6), wherein the first dielectric film is formed using materials that are different between regions on the semiconductor substrate. (8) The imaging element according to any of (1) to (7), wherein the first dielectric film and the second dielectric film each contain at least one of a material having a negative fixed charge or of a semiconductor material or of an electrically conductive material having a band gap wider than a band gap of the semiconductor substrate. (9) The imaging element according to one of (1) to (8), wherein the second dielectric film has a film thickness that varies between an area near one surface and an area near the other surface, and The film thickness in the area near one surface is greater than the film thickness in the area near the other surface. (10) The imaging element according to one of (1) to (9), wherein the through-hole electrode inside the through-hole contains an insulating film around the through-hole electrode. (11) The imaging element according to one of (1) to (10), wherein the semiconductor substrate contains a large number of pixels in a planar direction and the through-electrode is provided for each of the pixels. (12) The imaging element according to one of (1) to (11), wherein the semiconductor substrate contains a large number of pixels in a planar direction and two or more of the pixels are each equipped with a through-electrode. (13) The imaging element according to any of (1) to (12), comprising a pixel region and a peripheral region in a planar direction of the semiconductor substrate, wherein the peripheral region surrounds the pixel region, wherein The through-electrode is located in the peripheral area. (14) The imaging element according to one of (1) to (13), wherein the first photoelectric converter comprises a first electrode and a second electrode and an organic photoelectric conversion layer, and the first electrode comprises a plurality of electrodes, wherein the first electrode and the second electrode are arranged so that they are opposite each other, and wherein the organic photoelectric conversion layer is provided between the first electrode and the second electrode. (15) The imaging element according to any of (6) to (14), further comprising a third photoelectric transducer inside the semiconductor substrate, wherein the third photoelectric transducer is stacked on top of the second photoelectric transducer. (16) The imaging element according to one of (6) to (14), further comprising a third photoelectric transducer above one surface of the semiconductor substrate, wherein the third photoelectric transducer is stacked on top of the first photoelectric transducer. (17) The imaging element according to one of (1) to (16), wherein a multilayer wiring layer is formed on the other surface of the semiconductor substrate. (18) An imaging device comprising: a multitude of pixels, each equipped with one or more imaging elements, where the imaging elements each comprise a semiconductor substrate having one surface and another surface that are opposite to each other, wherein the semiconductor substrate has a through-hole passing between the one surface and the other surface, a first photoelectric converter that is provided above one surface of the semiconductor substrate, a through-electrode that is electrically coupled to the first photoelectric transducer, wherein the through-electrode penetrates the semiconductor substrate inside the through-hole, a first dielectric film provided on one surface of the semiconductor substrate, wherein the first dielectric film has a first film thickness, and a second dielectric film provided on a lateral surface of the through-hole, wherein the second dielectric film has a second film thickness, the second film thickness being less than the first film thickness.

Claims

[1] Imaging element, comprising: a semiconductor substrate (30) having one surface (30S1) and another surface (30S2) facing opposite each other, wherein the semiconductor substrate (30) has a through hole (30H) passing between one surface (30S1) and the other surface (30S2); a first photoelectric converter (20) which is provided above one surface (30S1) of the semiconductor substrate (30); a through-electrode (34) which is electrically coupled to the first photoelectric transducer (20), wherein the through-electrode (34) penetrates the semiconductor substrate (30) inside the through-hole (30H); a first dielectric film (26a) provided on one surface (30S1) of the semiconductor substrate (30), wherein the first dielectric film (26a) has a first film thickness (W1); and a second dielectric film (26b) provided on a lateral surface of the through-hole (30H), wherein the second dielectric film (26b) has a second film thickness (W2) wherein the second film thickness (W2) is less than the first film thickness (W1), wherein the first dielectric film (26a) and the second dielectric film (26b) each contain at least one of a material with a negatively fixed charge or of a semiconductor material or of an electrically conductive material with a wider band gap than a band gap of the semiconductor substrate (30), and the through-electrode (34) inside the through-hole (30H) includes an insulating film (27) around the through-electrode (34), which further extends on one surface (30S1) of the semiconductor substrate (30), wherein the first dielectric film (26a) is provided between one surface (30S1) of the semiconductor substrate (30) and the insulating film (27). [2] Imaging element according to claim 1, wherein the semiconductor substrate (30) further includes an amplifier transistor (AMP) and a floating diffusion layer (FD1, FD2, FD3) on the side of the other surface (30S2), and the through-electrode (34) is electrically coupled to at least one of the amplifier transistor (AMP) or the floating diffusion layer (FD1, FD2, FD3). [3] Imaging element according to claim 1 or 2, wherein at least one of the first dielectric film (26a) or of the second dielectric film (26b) contains a stacked film. [4] Imaging element according to any one of claims 1 to 3, wherein the first film thickness (W1) of the first dielectric film (26a) is 10 nm or more and 1000 nm or less and the second film thickness (W2) of the second dielectric film (26b) is 1 nm or more and 200 nm or less. [5] Imaging element according to any one of claims 1 to 4, wherein the first dielectric film (26a) has a first film thickness (W1) which varies between regions on the semiconductor substrate (30). [6] Imaging element according to any one of claims 1 to 5, wherein a second photoelectric converter is designed to be embedded in the semiconductor substrate (30), and a first film thickness (W1) of the first dielectric film (26a) above the second photoelectric transducer is greater than a first film thickness (W1) in a region around the through-electrode (34). [7] Imaging element according to any one of claims 1 to 6, wherein the first dielectric film (26a) is formed using materials that are different between regions on the semiconductor substrate (30). [8] Imaging element according to any one of claims 1 to 7, wherein the second dielectric film (26b) has a second film thickness (W2) that varies between a region near one surface (30S1) and a region near the other surface (30S2), and a second film thickness (W2) in the region near one surface (30S1) is greater than a second film thickness (W2) in the region near the other surface (30S2). [9] Imaging element according to any one of claims 1 to 8, wherein the semiconductor substrate (30) contains a plurality of pixels in a planar direction and the through-electrode (34) is provided for each of the pixels. [10] Imaging element according to any one of claims 1 to 9, wherein the semiconductor substrate (30) contains a plurality of pixels in a planar direction and two or more of the pixels are provided with each passing electrode (34). [11] Imaging element according to any one of claims 1 to 10, comprising a pixel region (1a) and a peripheral region (1b) in a planar direction of the semiconductor substrate (30), wherein the peripheral region (1b) surrounds the pixel region (1a), wherein the through-electrode (34) is provided in the peripheral region (1b). [12] Imaging element according to any one of claims 1 to 11, wherein the first photoelectric converter (20) comprises a first electrode (21) and a second electrode (25) and an organic photoelectric conversion layer (24) and the first electrode (21) comprises a plurality of electrodes, wherein the first electrode (21) and the second electrode (25) are arranged such that they are opposite each other, wherein the organic photoelectric conversion layer (24) is provided between the first electrode (21) and the second electrode (25). [13] Imaging element according to one of claims 1 to 12, further comprising a third photoelectric transducer inside the semiconductor substrate (30), wherein the third photoelectric transducer is stacked on top of the second photoelectric transducer. [14] Imaging element according to one of claims 1 to 12, further comprising a third photoelectric transducer above one surface (30S1) of the semiconductor substrate (30), wherein the third photoelectric transducer is stacked on top of the first photoelectric transducer. [15] Imaging element according to one of claims 1 to 14, wherein a multilayer wiring layer (40) is formed on the other surface (30S2) of the semiconductor substrate (30). [16] Imaging device comprising: a multitude of pixels, each equipped with one or more imaging elements, where the imaging elements each comprise a semiconductor substrate (30) having one surface (30S1) and another surface (30S2) facing opposite each other, wherein the semiconductor substrate (30) has a through hole (30H) passing between one surface (30S1) and the other surface (30S2), a first photoelectric converter (20) provided above one surface (30S1) of the semiconductor substrate (30), a through-electrode (34) which is electrically coupled to the first photoelectric transducer (20), wherein the through-electrode (34) penetrates the semiconductor substrate (30) inside the through-hole (30H), a first dielectric film (26a) provided on one surface (30S1) of the semiconductor substrate (30), wherein the first dielectric film (26a) has a first film thickness (W1), and a second dielectric film (26b) provided on a lateral surface of the through-hole (30H), wherein the second dielectric film (26b) has a second film thickness (W2), the second film thickness (W2) being less than the first film thickness (W1), wherein the first dielectric film (26a) and the second dielectric film (26b) each contain at least one of a material with a negatively fixed charge or of a semiconductor material or of an electrically conductive material with a wider band gap than a band gap of the semiconductor substrate (30), and the through-electrode (34) inside the through-hole (30H) contains an insulating film (27) around the through-electrode (34) which further extends on one surface (30S1) of the semiconductor substrate (30), wherein the first dielectric film (26a) is provided between one surface (30S1) of the semiconductor substrate (30) and the insulating film (27).

Images