IMAGE ELEMENT, ELECTRONIC DEVICE AND METHOD FOR CONTROLLING AN IMAGE ELEMENT

Abstract

Imaging element, comprising: a first photoelectric conversion section; and a second photoelectric conversion section, wherein the first photoelectric conversion section and the second photoelectric conversion section are stacked in series from one side of the light incidence and selectively detect and photoelectrically convert light beams of different wavelength bands, wherein the second photoelectric conversion section is arranged in an interval that is narrower than a pixel spacing of the first photoelectric conversion section, wherein four pixels of the second photoelectric conversion section are arranged in relation to one pixel of the first photoelectric conversion section.

Description

Technical field

[0001] The present disclosure relates, for example, to an imaging element in which a plurality of photoelectric conversion sections are stacked in a vertical direction, an electronic device and a method for controlling the imaging element. Background technology

[0002] In recent years, there has been progress in reducing pixel size in solid-state imaging elements such as CCD (charge-coupled device) or CMOS (complementary metal oxide semiconductor) image sensors. This leads to a reduction in the number of photons entering a unit pixel, consequently resulting in decreased sensitivity and a lower signal-to-noise ratio. Furthermore, when using a color filter, where primary red, green, and blue filters are arranged two-dimensionally in an array for colorization, green and blue light rays are absorbed by the color filter in a red pixel, for example, resulting in reduced sensitivity. Additionally, interpolation processing between pixels is performed when generating each color signal, leading to the appearance of so-called false color.

[0003] For example, PTL 1 discloses a so-called vertical spectroscopic solid-state imaging device in which an organic photoelectric conversion section, containing an organic photoelectric conversion film, and two inorganic photoelectric conversion sections, each featuring a pn junction in a semiconductor substrate, are stacked. In such a solid-state imaging device, B / G / R signals are extracted separately from a pixel, thereby increasing sensitivity. List of citations from patent literature

[0004] Exemplary imaging elements are known from publication WO 2017 / 126 326 A1. Reference is also made to publications US 2017 / 0 257 587 A1, US 2016 / 0 351 630 A1 and JP 2011-29337 A. Summary of the invention

[0005] Furthermore, it is desirable that the vertical spectroscopic imaging device, as described above, achieves both an increase in resolution and an improvement in the grainy or granular appearance.

[0006] It is desirable to provide an imaging element that enables an increase in resolution and an improvement in granular impression, an electronic device containing the imaging element, and a method for controlling the imaging element.

[0007] An imaging element according to an embodiment of the present disclosure comprises a first photoelectric conversion section and a second photoelectric conversion section, which are stacked sequentially from one side of the light incidence and selectively detect and photoelectrically convert the light beams of different wavelength bands, wherein the second photoelectric conversion section is arranged in an interval that is narrower than a pixel pitch or pixel spacing of the first photoelectric conversion section.

[0008] An electronic device according to an embodiment of the present disclosure comprises a plurality of imaging elements for respective pixels and includes as each of the imaging elements the imaging element described above according to an embodiment of the present disclosure.

[0009] In an imaging element comprising a first photoelectric conversion section and a second photoelectric conversion section, which are stacked sequentially from a light-incident side and selectively detect and photoelectrically convert light beams of different wavelength bands, wherein the second photoelectric conversion section is arranged in an interval that is narrower than a pixel spacing of the first photoelectric conversion section, a method for controlling the imaging element according to an embodiment of the present disclosure comprises detecting a color signal of a first light using a pixel of the first photoelectric conversion section and detecting a color signal of a second light of a wavelength band different from the first light by addition in a plurality of the second photoelectric conversion sections.

[0010] In the imaging element, the electronic device, and the method for controlling the imaging element according to the respective embodiments of the present disclosure, the first photoelectric conversion section and the second photoelectric conversion section, which selectively detect and photoelectrically convert light beams of different wavelength bands, are stacked sequentially from one side of the light incidence, and the pixel spacing of the second photoelectric conversion section forms an interval that is narrower than the pixel spacing of the first photoelectric conversion section. This enables, for example, the detection of color signals from the respective photoelectric conversion sections without phase shift in high-sensitivity mode.

[0011] According to the imaging element, the electronic device, and the method for manufacturing the imaging element of the respective embodiments of the present disclosure, in the first photoelectric conversion section and the second photoelectric conversion section, which selectively detect and photoelectrically convert light beams of different wavelength bands, the pixel spacing of the second photoelectric conversion section is arranged at a closer interval than that of the first photoelectric conversion section located on the light-incidence side. This makes it possible, for example, to capture the color signals from the respective photoelectric conversion sections without phase shift in high-sensitivity mode. Thus, it is possible to achieve an increase in resolution and an improvement in the granular impression.

[0012] It is particularly important to mention that the effects described here are not necessarily limiting and may be any of the effects described in the present disclosure. Brief description of the drawings [ Fig. 1] Fig. Figure 1 is a perspective view illustrating a configuration of a main part of an imaging element according to an embodiment of the present disclosure. [ Fig. 2] Fig. Figure 2 is a schematic top view showing a configuration of an inorganic photoelectric conversion section relative to an organic photoelectric conversion section of the in Fig. 1 illustrated imaging element. [ Fig. 3] Fig. 3 is a schematic cross-sectional view of an example of a specific configuration of the in Fig. 1 illustrated imaging element. [ Fig. 4A] Fig. Figure 4A is a schematic top view of a relationship between an on-chip lens and the organic photoelectric conversion section of the [device]. Fig. 3 illustrated imaging elements. [ Fig. 4B] Fig. Figure 4B is a schematic top view of a relationship between the on-chip lens and the inorganic photoelectric conversion section of the in Fig. 3 illustrated imaging elements. [ Fig. 5A] Fig. 5A is a schematic cross-sectional view of light (incident light) entering the organic photoelectric conversion section via the on-chip lens. [ Fig. 5B] Fig. 5B is a schematic cross-sectional view of light (incident light) entering the inorganic photoelectric conversion section via the on-chip lens, which detects a blue signal. [ Fig. 5C] Fig. 5C is a schematic cross-sectional view of light (incident light) entering the inorganic photoelectric conversion section via the on-chip lens, which detects a red signal. [ Fig. 6] Fig. Figure 6 is a schematic top view of an example of a configuration of a unit pixel of the in Fig. 3 illustrated imaging elements. [ Fig. 7] Fig. 7 is a schematic cross-sectional view of an example of a manufacturing process of the in Fig. 3 illustrated imaging elements. [ Fig. 8] Fig. Figure 8 is a schematic cross-sectional view of a process following Fig. 7. [ Fig. 9A] Fig. Figure 9A is a schematic top view to describe a method for driving a green pixel in a high-resolution mode. [ Fig. 9B] Fig. Figure 9B is a schematic top view to describe a method for controlling a red pixel in high-resolution mode. [ Fig. 9C] Fig. Figure 9C is a schematic top view to describe a method for controlling a blue pixel in high-resolution mode. [ Fig. 10] Fig. Figure 10 is a schematic top view to describe development processing in high-resolution mode. [ Fig. 11A] Fig. Figure 11A is a schematic top view to describe a method for controlling the green pixel in a high-resolution mode. [ Fig. 11B] Fig. Figure 11B is a schematic top view to describe a method for controlling the red pixel in high-resolution mode. [ Fig. 11C] Fig. Figure 11C is a schematic top view to describe a method for controlling the blue pixel in high-resolution mode. [ Fig. 12] Fig. Figure 12 is a schematic top view to describe development processing in high-resolution mode. [ Fig. 13A] Fig. Figure 13A is a schematic top view to describe a method for driving the green pixel in a high-speed mode. [ Fig. 13B] Fig. Figure 13B is a schematic top view to describe a method for driving the red pixel in high-speed mode. [ Fig. 13C] Fig. Figure 13C is a schematic top view to describe a method for driving the blue pixel in high-speed mode. [ Fig. 14] Fig. Figure 14 is a schematic top view to describe a thinning process in high-speed mode. [ Fig. 15] Fig. Figure 15 is a schematic top view to describe development processing in high-speed mode. [ Fig. 16] Fig. 16 describes an FD addition. [ Fig. 17] Fig. 17 describes a digital addition. [ Fig. 18A] Fig. Figure 18A is a schematic top view to describe a high sensitivity mode in a typical imaging element. [ Fig. 18B] Fig. 18B is a schematic top view to illustrate a high-sensitivity mode in the typical imaging element following Fig. 18A to describe. [ Fig. 18C] Fig. 18C is a schematic top view to illustrate a high-sensitivity mode in the typical imaging element following Fig. 18B to describe. [ Fig. 18D] Fig. 18D is a schematic top view to illustrate a high-sensitivity mode in the typical imaging element following Fig. to describe 18C. [ Fig. 19] Fig. Figure 19 is a schematic cross-sectional view of an example of a specific configuration of an imaging element according to a modification example of the present disclosure. [ Fig. 20] Fig. 20 is a block diagram that shows an overall configuration of the Fig. 1 illustrated imaging element. [ Fig. 21] Fig. 21 is a functional block diagram illustrating an electronic device (camera) that performs the function described in Fig. Uses 20 illustrated imaging elements. [ Fig. 22] Fig. Figure 22 is a block diagram that shows an example of a schematic configuration of an in-vivo information acquisition system. [ Fig. 23] Fig. Figure 23 is a view that shows an example of a schematic configuration of a system for endoscopic surgery. [ Fig. 24] Fig. Figure 24 is a block diagram that shows an example of a functional configuration of a camera head and a camera control unit (CCU). [ Fig. 25] Fig. Figure 25 is a block diagram that shows an example of a schematic configuration of a vehicle control system. [ Fig. 26] Fig. Figure 26 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 embodiments of the present disclosure in detail with reference to the drawings. The following description is only a specific example of the present disclosure, and the present disclosure is not intended to be limited to the following aspects. Furthermore, the present disclosure is not limited to arrangements, dimensions, dimensional ratios, and the like of each component illustrated in the drawings. It is particularly noteworthy that the description is given in the following order. 1. Embodiment (An example of an imaging element in which four pixels of an inorganic photoelectric conversion section are arranged in relation to one pixel of an organic photoelectric conversion section) 1-1. Configuration of an imaging element 1-2. Method for manufacturing an imaging element 1-3. Method for controlling an imaging element 1-4. Working method and effects 2. Modification example 3. Application example <1. Design>

[0014] Fig. Figure 1 is a schematic perspective view of a configuration of a main part (an organic photoelectric conversion section 11G and inorganic photoelectric conversion sections 11B and 11R) of an imaging element (an imaging element 1) of an embodiment of the present disclosure. Fig. Figure 2 is a schematic top view of a configuration of the inorganic photoelectric conversion sections 11B and 11R with respect to the organic photoelectric conversion section 11G of the in Fig. 1 illustrated imaging element 1. Fig. Figure 3 schematically illustrates an example of a specific cross-sectional configuration of the in Fig. 1 illustrated imaging element 1. The imaging element 1 is, for example, a CCD (Charge-Coupled-Device) image sensor or a CMOS (Complementary-Metal-Oxide-Semiconductor) image sensor, etc., of a back-illuminated type (back-illuminated type) (see Fig. 20). The imaging element 1 is of a so-called vertical spectroscopic type, in which an organic photoelectric conversion section 11G and two inorganic photoelectric conversion sections 11B and 11R, which selectively detect light beams of different wavelength bands and perform a photoelectric conversion of these, are stacked in a vertical direction. (1-1. Configuration of an imaging element)

[0015] In the imaging element 1 of the present embodiment, the organic photoelectric conversion section 11G (first photoelectric conversion section), the inorganic photoelectric conversion section 11B (third photoelectric conversion section), and the inorganic photoelectric conversion section 11R (second photoelectric conversion section) are stacked in that order from one side facing the light incidence, and the inorganic photoelectric conversion sections 11B and 11R are each arranged at a pixel spacing (w) that is smaller than the pixel spacing (W) of the organic photoelectric conversion section 11G, relative to a pixel of the organic photoelectric conversion section 11G. Specifically, for example, four (2 × 2) pixels of the inorganic photoelectric conversion sections 11B and 11R are arranged in the imaging element 1 relative to a pixel of the organic photoelectric conversion section 11G.That is, the inorganic photoelectric conversion sections 11B and 11R each have a pixel spacing (w) which is, for example, 1 / 2 (w = 1 / 2 W) with respect to the pixel spacing (W) of the organic photoelectric conversion section 11G, and are each 1 / 4 with respect to the area.

[0016] The organic photoelectric conversion section 11G and the inorganic photoelectric conversion sections 11B and 11R selectively detect light rays of different wavelength bands and perform a photoelectric conversion on them. Specifically, the organic photoelectric conversion section 11G detects a green (G) color signal. Due to differences in their absorption coefficients, the inorganic photoelectric conversion sections 11B and 11R detect blue (B) and red (R) color signals, respectively. This enables the imaging element 1 to detect a variety of color signals in a single pixel without the use of a color filter.

[0017] It is particularly noteworthy that the present embodiment describes a case in which holes are read as signal charges from a pair of electrons and holes generated by photoelectric conversion (a case in which a p-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.

[0018] The organic photoelectric conversion section 11G is provided on one side of a back surface (a first surface 11S1) of a semiconductor substrate 11. The inorganic photoelectric conversion sections 11B and 11R are each configured to be embedded in the semiconductor substrate and are stacked in the direction of the thickness of the semiconductor substrate 11.

[0019] The semiconductor substrate 11 is formed, for example, from an n-type silicon (Si) substrate and contains a p-well 61 in a predetermined region. A second surface (front surface of the semiconductor substrate 11) 11S2 of the p-well is provided with, for example, floating diffusion regions (floating diffusion layers) FD2 and FD3. In addition to these, various transistors Tr (e.g., a TR group 1110, which will be described later) are provided (e.g., see [reference]). Fig. 4) Furthermore, the second surface 11S2 of the semiconductor substrate 11 is provided with a multilayer wiring layer 70. The multilayer wiring layer 70 has a configuration in which, for example, wiring layers 71, 72, and 73 are stacked in an insulating layer 74. In addition, a peripheral part of the semiconductor substrate 11 is provided with a peripheral circuit (not illustrated) containing a logic circuit or the like.

[0020] It is particularly worth mentioning that in Fig. 3 one side of the first surface 11S1 of the semiconductor substrate 11 is designated as a light incidence surface S1 and one side of the second surface 11S2 is designated as a wiring layer side S2.

[0021] The inorganic photoelectric conversion sections 11B and 11R are each formed by, for example, a PIN (positive, intrinsically negative) type photodiode, and each has a pn junction in a predetermined region of the semiconductor substrate 11. The inorganic photoelectric conversion sections 11B and 11R enable light to be distributed in the vertical direction by utilizing different wavelength bands that are to be absorbed depending on the penetration or incidence depth of light in the silicon substrate.

[0022] The inorganic photoelectric conversion section 11B selectively detects blue light and accumulates signal charges corresponding to a blue color; the inorganic photoelectric conversion section 11B is installed at a depth where the blue light can be efficiently converted to photoelectricity. The inorganic photoelectric conversion section 11R selectively detects red light and accumulates signal charges corresponding to a red light; the inorganic photoelectric conversion section 11R is installed at a depth where the red light can be efficiently converted to photoelectricity. It is particularly noteworthy that blue (B) is a color corresponding, for example, to a wavelength band of 450 nm to 495 nm, and red (R) is a color corresponding, for example, to a wavelength band of 620 nm to 750 nm.It is sufficient that each of the inorganic photoelectric conversion sections 11B and 11R can detect light of a portion of a respective wavelength band or of the entire band.

[0023] As in Fig. As illustrated in Figure 3, each of the inorganic photoelectric conversion section 11B and the inorganic photoelectric conversion section 11R, 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 (p+) region of the inorganic photoelectric conversion section 11B curves along a vertical transistor (a vertical transistor Tr1), for example, and is coupled to the (p+) region of the inorganic photoelectric conversion section 11R. Furthermore, as described above, in the inorganic photoelectric conversion sections 11B and 11R, four inorganic photoelectric conversion sections 11B and four inorganic photoelectric conversion sections 11R are each arranged in a (2 × 2) array with respect to an organic photoelectric conversion section 11G.In the inorganic photoelectric conversion sections 11B and 11R, for example, as described later. Fig. 9B and Fig. Figure 9C illustrates a floating diffusion region FD1 or FD2 arranged for each (2 × 2) array.

[0024] A region of the floating diffusion area FD1 is formed in the n-region of the inorganic photoelectric conversion section 11B, which is provided in the semiconductor substrate 11, in order to be electrically coupled to the inorganic photoelectric conversion section 11B. For example, a gate wiring layer 64, which forms the vertical transistor Tr1, is electrically coupled to the floating diffusion area FD1. The floating diffusion area FD2 is, for example, provided such that it faces the second surface 11S2 of the semiconductor substrate 11; a region of the floating diffusion area FD2 is formed in the n-region of the inorganic photoelectric conversion section 11B, which is provided in the semiconductor substrate 11, in such a way that it is electrically coupled to the inorganic photoelectric conversion section 11B.

[0025] In addition to these, as described above, the second surface 11S2 of the semiconductor substrate 11 is provided with, for example, the floating diffusion region FD3 and various transistors such as the vertical transistor Tr1 and the Tr group 1110, which will be described later.

[0026] A lower contact 75 is formed, for example, by 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).

[0027] The organic photoelectric conversion section 11G is located on the side of the first surface 11S1 of the semiconductor substrate 11. The organic photoelectric conversion section 11G has a configuration in which, for example, a lower electrode 15, an organic photoelectric conversion layer 16, and an upper electrode 17 are stacked in that order, starting from the side of the first surface S1 of the semiconductor substrate 11. The lower electrode 15 is, for example, configured separately for each unit pixel P. The organic photoelectric conversion section 16 and the upper electrode 17 are arranged as successive layers for a plurality of unit pixels P (e.g., a pixel section 1a of the imaging element 1, which is located in Fig. (20 illustrated) is provided. The organic photoelectric conversion section 11G is an organic photoelectric conversion element that absorbs green light corresponding to a portion of a selective wavelength band (e.g., ranging from 450 nm to 650 nm) or the entire band and generates electron-hole pairs.

[0028] Intermediate insulating layers 12 and 14 are stacked, for example, in this order, starting from the side of the semiconductor substrate 11, between the first surface 11S1 of the semiconductor substrate 11 and the lower electrode 15. Intermediate insulating layer 12 has a configuration in which, for example, a fixed charge layer 12A and an insulating dielectric layer 12B are stacked. A protective layer 18 is provided on the upper electrode 17. An on-chip lens layer 19, which forms an on-chip lens 19L and also serves as a planarization layer, is arranged above the protective layer 18.

[0029] A through-electrode 63 is provided between the first surface 11S1 and the second surface 11S2 of the semiconductor substrate 11. The organic photoelectric conversion section 11G is coupled via the through-electrode 63 to both the floating diffusion region FD3 and a gate of an amplifier transistor AMP (not shown). This enables the imaging element 1 to advantageously transfer charges generated in the organic photoelectric conversion section 11G on the side of the first surface 11S1 of the semiconductor substrate 11 via the through-electrode 63 to the side of the second surface 11S2 of the semiconductor substrate 11, thereby improving its properties.

[0030] The through-electrode 63 is provided, for example, for each organic photoelectric conversion section 11G of the imaging element 1. The through-electrode 63 serves as a connector between the organic photoelectric conversion section 11G and the floating diffusion region FD3 as well as the gate of the amplifier transistor AMP and serves as a transfer path for charges generated in the organic photoelectric conversion section 11G.

[0031] The lower end of the through-electrode 63 is coupled to, for example, a coupling section 71A in the wiring layer 71, and the coupling section 71A and the gate of the amplifier transistor AMP are coupled to each other via, for example, a contact (not illustrated) with a configuration similar to that of the lower contact 75. The coupling section 71A and the floating diffusion region FD3 are coupled to the lower electrode 15 via the lower contact 75. It is particularly noteworthy that in Fig. 1 The through-electrode 63 is illustrated as having a cylindrical shape; however, this is not restrictive; the through-electrode 63 can, for example, have a tapered or conical shape.

[0032] Although not illustrated, a reset gate of a reset transistor RST is preferably located near the floating diffusion region FD3. This makes it possible to reset charges accumulated in the floating diffusion region FD3 by the reset transistor RST.

[0033] In the imaging element 1, light incident on the photoelectric conversion section 11G from one side of the upper electrode 17 is absorbed by the organic photoelectric conversion layer 16. Excitons thus generated move to an interface between an electron donor and an electron acceptor, which form the organic photoelectric conversion layer 16, and undergo exciton separation, i.e., dissociate into electrons and holes. The charges generated here (electrons and holes) are transported to different electrodes by diffusion due to a difference in carrier concentrations or by an internal electric field due to a difference in work functions between an anode (here the lower electrode 15) and a cathode (here the upper electrode 17) and are detected as a photocurrent.Furthermore, applying an electrical potential between the lower electrode 15 and the upper electrode 17 makes it possible to control the directions in which electrons and holes are transported.

[0034] The following describes the configuration, materials, and other aspects of each section.

[0035] The organic photoelectric conversion section 11G contains the organic photoelectric conversion layer 16, which incorporates a p-type semiconductor and an n-type semiconductor and features a bulk heterojunction structure in a single layer. The bulk heterojunction structure is a p / n junction plane formed by mixing a p-type and an n-type semiconductor. The organic photoelectric conversion section 11G is an organic photoelectric conversion element that absorbs light corresponding to a portion of a selective wavelength band (e.g., from 450 nm to 750 nm) or the entire wavelength range and generates electron-hole pairs.As described above, the organic photoelectric conversion section 11G is formed by, for example, the lower electrode 15 and the upper electrode 17, which are arranged so that they are opposite each other, and the organic photoelectric conversion layer 16 provided between the lower electrode 15 and the upper electrode 17.

[0036] The lower electrode 15 is located in a region facing and covering the light-receiving surfaces of the four inorganic photoelectric conversion sections 11B and the four inorganic photoelectric conversion sections 11R, each arranged in a 2 × 2 configuration and formed in the semiconductor substrate 11. The lower electrode 15 is formed from a transparent metal oxide. Examples of metal atoms forming the metal oxide used as the material of the lower electrode 15 include tin (Sn), zinc (Zn), indium (In), silicon (Si), zirconium (Zr), aluminum (Al), gallium (Ga), tungsten (W), chromium (Cr), cobalt (Co), nickel (Ni), tantalum (Ta), niobium (Nb), and molybdenum (Mo). An example of a metal oxide containing one or more of the aforementioned metal atoms includes ITO (indium tin oxide).In addition to ITO, the material used for the lower electrode 15 can be a tin oxide (SnO2)-based doped material or a zinc oxide-based material doped with aluminum zinc oxide. Examples of zinc oxide-based materials include aluminum zinc oxide (AZO) doped with aluminum (Al), gallium zinc oxide (GZO) doped with gallium (Ga), and indium zinc oxide (IZO) doped with indium (In). Besides those described above, materials such as CuI, InSbO4, ZnMgO, CuInO2, MgIn2O4, CdO, ZnSnO3, or similar materials can also be used.

[0037] The organic photoelectric conversion layer 16 converts optical energy into electrical energy. The organic photoelectric conversion layer 16 contains, for example, two or more types of organic semiconductor materials (a p-type semiconductor material or an n-type semiconductor material), each functioning as a p-type or n-type semiconductor, respectively. The organic photoelectric conversion layer 16 contains a transition plane (p / n junction) between the p-type and n-type semiconductor materials. The p-type semiconductor acts as a relative electron donor, and the n-type semiconductor acts as a relative electron acceptor.The organic photoelectric conversion layer 16 provides a field in which excitons generated upon light absorption are separated into electrons and holes; specifically, excitons are separated into electrons and holes at an interface (p / n transition plane) between the electron donor and the electron acceptor.

[0038] The organic photoelectric conversion layer 16 can contain, in addition to the p-type and n-type semiconductor materials, an organic semiconductor material, i.e., a so-called dye material, which performs a photoelectric conversion of light from a predetermined wavelength band while transmitting light from another wavelength band. If the organic photoelectric conversion layer 16 is formed using three types of organic semiconductor materials—a p-type semiconductor material, an n-type semiconductor material, and a dye material—the p-type and n-type semiconductor materials are each preferably materials with a light transmittance in the visible region (e.g., 450 nm to 800 nm). The organic photoelectric conversion layer 16 has a thickness of, for example, 50 nm to 500 nm.

[0039] Examples of the organic semiconductor material that forms the organic photoelectric conversion layer 16 include quinacridone, chlorinated boron subphthalocyanine, pentacene, benzothione benzothiophene, fullerene, and a derivative thereof. The organic photoelectric conversion layer 16 is formed by combining two or more of the aforementioned organic semiconductor materials. Depending on their combination, the aforementioned organic semiconductor materials function as p-type or n-type semiconductors.

[0040] It should be particularly noted that there are no specific restrictions on the organic semiconductor material forming the organic photoelectric conversion layer 16. Besides the organic semiconductor material mentioned above, any of naphthalene, anthracene, phenanthrene, tetracene, pyrene, perylene, and fluoranthene, or a derivative thereof, can be suitably used. Alternatively, a polymer such as polyvinylphenol, fluorene, carbazole, pyrene, pyrrole, methylpyridine, thiophene, acetylene, and diacetylene, or a derivative thereof, can be used.Furthermore, a condensed polycyclic aromatic compound and a chain compound in which an aromatic cyclic or heterocyclic compound is condensed, such as a dye with a metal complex, a cyano-based dye, a merocyanine-based dye, a phenylxanthene-based dye, a triphenylmethane-based dye, a rhodacyanine-based dye, a xanthene-based dye, a macrocyclic aza-annulene-based dye, an azulene-based dye, naphthquinone, an anthraquinone-based dye, anthracene, and pyrene, may preferably be used. Alternatively, two nitrogen-containing heterorings, such as quinoline, benzothiazole, and benzoazole, each having a squaraine group and a croconmethine group linked together, or a cyano-like dye, etc., linked by the squaraine group and the croconmethine group, may be used.

[0041] It is particularly worth mentioning that, as the aforementioned dye with a metal complex, a dye based on a dithiol metal complex, a metallophthalocyanine dye, a metalloporphyrin dye or a dye with a ruthenium complex is preferred; however, this is not a limiting factor.

[0042] The upper electrode 17, similar to the lower electrode 15, is formed from an electrically conductive, transmissive film. In the imaging element 1, the upper electrode 17 can be separate for each unit pixel P or it can be configured as a common electrode for each unit pixel P. The upper electrode 17 has a thickness of, for example, 10 nm to 200 nm.

[0043] It is particularly noteworthy that further layers can be provided between the organic photoelectric conversion layer 16 and the lower electrode 15, and between the organic photoelectric layer 16 and the upper electrode 17. Specifically, a lower layer, a hole transport layer, an electron barrier layer, the organic photoelectric conversion layer 16, a hole barrier layer, a buffer layer, an electron transport layer, a work function adjustment layer, and the like can be stacked sequentially from the side of the lower electrode 15.

[0044] The fixed charge layer 12A can be a film with a positive fixed charge or a film with a negative fixed charge. Examples of materials for the film with a negative fixed charge include hafnium oxide (HfO₂), aluminum oxide (Al₂O₃), zirconium oxide (ZrO₂), tantalum oxide (Ta₂O₅), and titanium oxide (TiO₂). In addition to those mentioned above, materials such as lanthanum oxide, praseodymium oxide, cerium oxide, neodymium oxide, promethium oxide, samarium oxide, europium oxide, gadolinium oxide, terbium oxide, dysprosium oxide, holmium oxide, thulium oxide, ytterbium oxide, lutetium oxide, yttrium oxide, an aluminum nitride film, a hafnium oxynitride film, an aluminum oxynitride film, or similar materials can also be used.

[0045] The fixed charge layer 12A can have a configuration in which two or more types of films are stacked. This makes it possible to further enhance a function such as the hole accumulation layer, for example, in the case of a film with a negative fixed charge.

[0046] The material of the dielectric layer 12B is not particularly limited, and the dielectric layer 12B is formed, for example, by a silicon oxide film, a TEOS film, a silicon nitride film, a silicon oxynitride film, or the like.

[0047] Pad sections 13A and 13C and an upper contact 13B are formed similarly to the lower contact 75, for example by a doped silicon material such as PDAS (phosphorus-doped amorphous silicon) or a metallic material such as aluminum (Al), tungsten (W), titanium (Ti), cobalt (Co), hafnium (Hf) or tantalum (Ta).

[0048] The intermediate insulating layer 14 is formed, for example, by a single-layer film of silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON) and the like, or alternatively by a stacked film of two or more of these.

[0049] The protective layer 18 is formed by a light-transmitting material and is, for example, a single-layer film of silicon oxide, silicon nitride, silicon oxynitride, and the like, or alternatively, a stacked film of two or more of these. The protective layer 18 has a thickness of, for example, 100 nm to 30,000 nm.

[0050] The on-chip lens layer 19 is configured on the protective layer 18 such that it covers its entire surface. A plurality of on-chip lenses (microlenses) 19L are provided on the front surface of the on-chip lens layer 19. The on-chip lens 19L collects light incident from above onto the respective light-receiving surfaces of the organic photoelectric conversion section 11G and the inorganic photoelectric conversion sections 11B and 11R.

[0051] In the imaging element 1 as described above, the four inorganic photoelectric conversion sections 11B (blue pixels Pb), arranged in a 2 × 2 configuration, and the four inorganic photoelectric conversion sections 11R (red pixels Pr), also arranged in a 2 × 2 configuration, are arranged relative to an organic photoelectric conversion section 11G (a green pixel Pg). Therefore, in the present embodiment, as shown in Fig. 4A and Fig. Figure 4B illustrates an organic photoelectric conversion section 11G (one green pixel Pg), four inorganic photoelectric conversion sections 11B and four inorganic photoelectric conversion sections 11R (four blue pixels Pb and four red pixels Pr) arranged vertically for an on-chip lens 19L.

[0052] Fig. Figures 5A to 5C each schematically illustrate incident light (L) with respect to the organic photoelectric conversion section 11G and the inorganic photoelectric conversion sections 11B and 11R. In the present embodiment, as described above, one organic photoelectric conversion section 11G, four inorganic photoelectric conversion sections 11B, and four inorganic photoelectric conversion sections 11R are arranged for an on-chip lens 19L. This enables the inorganic photoelectric conversion sections 11B and 11R to acquire a signal for phase difference detection.

[0053] Furthermore, in the present embodiment, the multilayer wiring layer 70 is formed on the side of the second surface 11S2 of the semiconductor substrate 11. This allows the respective light-receiving surfaces of the organic photoelectric conversion section 11G and the inorganic photoelectric conversion sections 11B and 11R to be arranged close to each other, thus making it possible to reduce variations in the sensitivities between colors generated depending on the F-value of the on-chip lens 19L.

[0054] Fig. Figure 6 is a top view of a configuration example of the imaging element 1, wherein a plurality of photoelectric conversion sections for which the technology according to the present disclosure can be used (e.g. the inorganic photoelectric conversion sections 11B and 11R and the organic photoelectric conversion section 11G described above) are stacked. Fig. Figure 6 illustrates an example of a planar configuration of the unit pixel P, such as the one in Fig. 20 illustrated pixel section 1a forms and represents the configuration example of the imaging element 1, wherein the plurality of photoelectric conversion sections for which the technology can be used according to the present disclosure is stacked.

[0055] The unit pixel P contains a photoelectric conversion area 1100, in which a red photoelectric conversion section (the inorganic photoelectric conversion section 11R in Fig. 3), a blue photoelectric conversion section (the inorganic photoelectric conversion section 11B in Fig. 3) and a green photoelectric conversion section (the organic photoelectric conversion section 11G in Fig. 3) (none of which are in Fig. 6 is illustrated), which perform a photoelectric conversion of light rays of respective wavelengths of R (red), G (green) and B (blue), in three layers, for example in the order of the green photoelectric conversion section, the blue photoelectric conversion section and the red photoelectric conversion section from one side of the light-receiving surface (the light-incident surface S1 in Fig. 3) are stacked. Furthermore, the unit pixel P contains the Tr group 1110, a Tr group 1120, and a Tr group 1130 as charge readout sections, which read out charges corresponding to light beams of the respective wavelengths R, G, and B from the red photoelectric conversion section, the green photoelectric conversion section, and the blue photoelectric conversion section, respectively. The imaging element 1 performs spectroscopy in the vertical direction in a unit pixel P, i.e., spectroscopy of light beams R, G, and B, in respective layers such as the red photoelectric conversion section, the green photoelectric conversion section, and the blue photoelectric conversion section, which are stacked in the photoelectric conversion area 1100.

[0056] The Tr group 1110, Tr group 1120, and Tr group 1130 are located at the periphery of the photoelectric conversion area 1110. Tr group 1110 outputs a signal charge corresponding to a light R as a pixel signal, which was generated and accumulated in the red photoelectric conversion section. Tr group 1110 consists of a transfer Tr (MOSFET) 1111, a reset Tr 1112, a gain Tr 1113, and a select Tr 1114. Tr group 1120 outputs a signal charge corresponding to a light B as a pixel signal, which was generated and accumulated in the blue photoelectric conversion section. The Tr group 1120 consists of a transmit Tr 1121, a reset Tr 1122, an amplification Tr 1123, and a selection Tr 1124. The Tr group 1130 outputs a signal charge corresponding to a light G as a pixel signal, which was generated and accumulated in the green photoelectric conversion section.The Tr group 1130 includes a transmission Tr 1131, a reset Tr 1132, an amplification Tr 1133 and a selection Tr 1134.

[0057] The transmission line 1111 is formed by a gate G (forming a source / drain region), a source / drain region S / D, and a floating diffusion region FD 1115. The transmission line 1121 is formed by a gate G, a source / drain region S / D, and an FD 1125. The transmission line 1131 is formed by a gate G, a source / drain region S / D coupled to the green photoelectric conversion section of the photoelectric conversion region 1110, and an FD 1135. It is particularly worth mentioning that the source / drain area of ​​transmission line 1111 is coupled with the red photoelectric conversion section of photoelectric conversion area 1100, and that the source / drain area S / D of transmission line 1121 is coupled with the blue photoelectric conversion section of photoelectric conversion area 1100.

[0058] Each of the reset Trs 1112, 1132 and 1122, the amplification Trs 1113, 1133 and 1123 and the selection Trs 1114, 1134 and 1124 is formed by a gate G and a pair of source / drain regions S / D, arranged such that the gate G is located between them.

[0059] FDs 1115, 1135, and 1125 are coupled to the source / drain regions S / D, which serve as sources of the reset transceivers 1112, 1132, and 1122, respectively, and are coupled to gates of the amplification transceivers 1113, 1133, and 1123, respectively. A power supply Vdd is coupled to the common source / drain region S / D in each of the reset transceivers 1112 and 1113, 1132 and 1133, and 1122 and 1123. A VSL (vertical signal line) is coupled to each of the source / drain areas S / D, which serve as the sources of the selection Trs 1114, 1134 and 1124.

[0060] The technology according to the present disclosure is applicable to the photoelectric conversion element described above. (1-2. Method for producing an imaging element)

[0061] The imaging element 1 of the present embodiment can be manufactured, for example, as follows.

[0062] Fig. 7 and Fig. Figure 8 illustrates the procedure for manufacturing imaging element 1 in the order of the steps. First, as shown in Fig. As illustrated in Figure 7, for example, the p-well 61 is formed as a well of a first type of electrical conductivity in the semiconductor substrate 11, and the inorganic photoelectric conversion sections 11B and 11R of a second type of electrical conductivity (e.g., n-type) are formed in the p-well. The (p+) region is formed near the first surface 11S1 of the semiconductor substrate 11. An (n+) region, serving as the floating diffusion region FD1, is formed in the semiconductor substrate 11 such that a portion of it can be buried.

[0063] As in Fig. As illustrated in Figure 7, (n+) regions, serving as the floating diffusion regions FD2 and FD3, are also formed on the second surface 11S2 of the semiconductor substrate 11. Subsequently, a gate insulating layer 62 and a gate wiring layer 64, containing respective gates of the Tr group 1110 described above, are formed. As a result, the vertical transistor Tr1 and various Tr groups 1110, and the like, are formed. Furthermore, the multilayer wiring layer 70, containing the bottom contact, the wiring layers 71 to 73 including the coupling section 71A, and the insulating layer 74, is formed on the second surface 11S2 of the semiconductor substrate 11.

[0064] For example, a silicon-on-insulator (SOI) substrate is used as the basis of the semiconductor substrate 11, in which the semiconductor substrate 11, an embedded oxide film (not illustrated), and a holding substrate (not illustrated) are stacked. Although in Fig. Figure 7 does not illustrate the embedded oxide film and the holding substrate connected to the first surface 11S1 of the semiconductor substrate 11. After ion implantation, a curing process is performed.

[0065] Next, a (not illustrated) support substrate or another semiconductor substrate, etc., is connected to the second surface 11S2 (the side of the multilayer wiring lead 70) of the semiconductor substrate 11, and the substrate is flipped over. Subsequently, the semiconductor substrate 11 is separated from the embedded oxide film and the holding substrate of the SOI substrate to expose the first surface 11S1 of the semiconductor substrate 11. The above steps can be carried out using techniques employed in common CMOS processes, such as ion implantation and CVD (chemical vapor deposition).

[0066] Next, as in Fig. As illustrated in Figure 8, the semiconductor substrate 11 is processed from the side of the first surface 11S1, for example by dry etching, to form an annular opening 63H. As shown in Fig. As illustrated in Figure 8, the opening 63H penetrates from the first surface 11S1 to the second surface 11S2 of the semiconductor substrate 11 in terms of depth and reaches, for example, the coupling section 71A.

[0067] Then, as in Fig. As illustrated in Figure 8, layer 12A with a negatively fixed charge is formed on the first surface 11S1 of the semiconductor substrate 11 and on a side surface of the aperture 63H. Two or more types of film can be stacked as layer 12A with a negatively fixed charge. This makes it possible to further improve its function as a hole accumulation layer. After layer 12A with a negatively fixed charge is formed, the dielectric layer 12B is formed.

[0068] Next, an electrical conductor is buried in the opening 63H to form the through-electrode 63. In addition to a doped silicon material such as PDAS (phosphorus-doped amorphous silicon), it is possible to use a metallic material such as aluminum (Al), tungsten (W), titanium (Ti), cobalt (Co), hafnium (Hf), and tantalum (Ta) as the electrical conductor.

[0069] Subsequently, after the formation of the pad section 13A on the through-electrode 63 on the dielectric layer 12B and the pad section 13A, the intermediate layer insulating layer 14 is formed, in which the upper contact 13B and the pad section 13C, which electrically couple the lower electrode 15 and the through-electrode 63 (specifically the pad section 13A on the through-electrode 63), are provided on the pad section 13A.

[0070] The lower electrode 15, the organic photoelectric conversion layer 16, the upper electrode 17, and the protective layer 18 are formed in this order on the intermediate insulating layer 14. Finally, the on-chip lens layer 19 is arranged, which contains the plurality of on-chip lenses 19L on its surface. Thus, the in Fig. 3 illustrated imaging element 1 completed.

[0071] It is particularly noteworthy that, in the case of the formation of a further organic layer (e.g., an electron-blocking layer, etc.) on or beneath the organic photoelectric conversion layer 16, it is desirable to form the further organic layer continuously in a vacuum process (using a vacuum-compatible process). Furthermore, the method for forming the organic photoelectric conversion layer 16 is not necessarily limited to a vacuum deposition process; another method, for example, centrifugal coating, printing, or the like, may be used. (1-3. Methods for controlling an imaging element)

[0072] In the imaging element 1, when light passes through the on-chip lens 19L into the organic photoelectric conversion section 11G, the light passes through the photoelectric conversion section 11G, the inorganic photoelectric conversion sections 11B and 11R in that order, and is photoelectrically converted for each color (green, blue, and red) in the transmission process. The following section describes a signal acquisition operation for each color. (Detection of a green signal by the organic photoelectric conversion section 11G)

[0073] Green light from the light entering the imaging element 1 is first selectively detected (absorbed) by the photoelectric conversion section 11G and subjected to photoelectric conversion.

[0074] The organic photoelectric conversion section 11G is coupled to the gate of the gainer 1113 and the floating diffusion region FD3 via the through-electrode 63. Accordingly, holes of the electron-hole pairs generated in the organic photoelectric conversion section 11G are extracted from the side of the lower electrode 15, transferred via the through-electrode 63 to the side of the second surface 11S2 of the semiconductor substrate 11, and accumulated in the floating diffusion region FD3. At the same time, a charge generated in the organic photoelectric conversion section 11G is modulated into a voltage by the gainer 1113.

[0075] Furthermore, a gate G of the reset Tr 1112 is arranged next to the floating diffusion region FD3. As a result, the charges accumulated in the floating diffusion region FD3 are reset by the reset Tr 1112.

[0076] The organic photoelectric conversion section 11G is coupled here not only to the amplification Tr 1113, but also to the floating diffusion region FD3 via the through electrode 63, which consequently makes it possible to easily reset the charges accumulated in the floating diffusion region FD3 by the reset Tr 1112.

[0077] If, on the other hand, the through-electrode 63 and the floating diffusion region FD3 are not coupled, it is difficult to reset the charges accumulated in the floating diffusion region FD3. Consequently, a large voltage must be applied to pull the charges towards the side of the upper electrode 17. This poses a risk of damaging the organic photoelectric conversion layer 16. Furthermore, the structure that allows for a rapid reset leads to an increase in dark noise, resulting in a trade-off that makes this structure challenging. (Detection of a blue signal and red signal by inorganic photoelectric conversion sections 11B and 11R)

[0078] Subsequently, blue light and red light from the light passing through the organic photoelectric conversion section 11G are successively absorbed by the inorganic photoelectric conversion section 11B and the inorganic photoelectric conversion section 11R, respectively, and subjected to photoelectric conversion. In the inorganic photoelectric conversion section 11B, electrons corresponding to the incident blue light are accumulated in an n-region of the inorganic photoelectric conversion section 11B, and these accumulated electrons are transferred to the floating diffusion region FD1. Similarly, in the inorganic photoelectric conversion section 11R, electrons corresponding to the incident red light are accumulated in an n-region of the inorganic photoelectric conversion section 11R, and these accumulated electrons are transferred via a transfer transistor Tr to the floating diffusion region FD2.

[0079] The imaging element 1 of the present embodiment has a plurality of operating modes, e.g., three types of operating modes: a high-resolution mode, a high-sensitivity mode, and a high-speed mode. In the organic photoelectric conversion section 11G and the inorganic photoelectric conversion sections 11B and 11R, R / G / B signals are acquired in each of the operating modes as follows.

[0080] The high-resolution mode is described. In the organic photoelectric conversion section 11G, which detects a green signal, the following occurs as described in... Fig. Figure 9A illustrates the signal charges read from each of the green pixels Pg. In the inorganic photoelectric conversion section 11B, which detects a blue signal, and the inorganic photoelectric conversion section 11R, which detects a red signal, as shown in Fig. 9B and Fig. Figure 9C illustrates an FD addition using four (2 × 2) pixels (blue pixel Pb and red pixel Pr) as a single unit U. Subsequently, development processing is performed. In high-resolution mode, it is possible to capture phase-matched signals among green pixels Pg, 2 × 2 blue pixels Pb, and 2 × 2 red pixels Pr. Therefore, without signal processing at the unit pixel level, PR / G / B signals without phase shift are obtained.

[0081] The high-sensitivity mode is described. In the organic photoelectric conversion section 11G, which detects a green signal, as described in Fig. Figure 11A illustrates how signal charges from each of the green pixels Pg are read. In the inorganic photoelectric conversion section 11B, which detects a blue signal, and the inorganic photoelectric conversion section 11R, which detects a red signal, as shown in Figure 11A, the signal charges from each of the green pixels Pg are read. Fig. 11B and Fig. Figure 11C illustrates a digital addition using 16 (4 × 4) pixels (blue pixels Pb and red pixels Pr) as a unit U. At this stage, each unit U of the inorganic photoelectric conversion section 11B and the inorganic photoelectric conversion section 11R, which detects a red signal, is formed by 4 × 4 pixels shifted relative to each other by 2 × 2 pixels. Subsequently, the development processing is performed. As described above, each unit U of the inorganic photoelectric conversion section 11B and the inorganic photoelectric conversion section 11R, which detects a red signal, is configured to be shifted relative to each other by 2 × 2 pixels. Therefore, in high sensitivity mode, there is a unit pixel P without information from the blue pixel Pb or the red pixel Pr, or without information from both the blue pixel Pb and the red pixel Pr, in each unit pixel P.In the development processing of the high sensitivity mode, therefore, it is supplemented as in . Fig. Figure 12 illustrates a unit pixel P with, for example, a green signal and a blue signal receiving a red signal from surrounding pixels P with a green signal and a red signal. This enables R / G / B signals without phase shift in high-sensitivity mode.

[0082] The high-speed mode is described. In the organic photoelectric conversion section 11G, which detects a green signal, as described in Fig. Figure 13A illustrates the signal charges read from each of the green pixels Pg. In the inorganic photoelectric conversion section 11B, which detects a blue signal, and the inorganic photoelectric conversion section 11R, which detects a red signal, as shown in Figure 13A, the signal charges are read from each of the green pixels Pg. Fig. 13B and Fig. Figure 13C illustrates a digital addition performed using four (2 × 2) pixels (blue pixel Pb and red pixel Pr) as one unit U. In high-speed mode, thinning processing is then performed, and the green, blue, and red signals are processed as shown in Figure 13C. Fig. Figure 14 illustrates this in a Bayer form. Finally, the development processing is performed for each unit pixel P. This enables phase-shift-free R / G / B signals in high-speed mode.

[0083] It is particularly noteworthy that switching between addition modes used in the respective operating modes described above can be performed as follows. In the imaging element 1A of the present embodiment, switches SW1, SW2, SW3, and SW4 are each coupled to the four blue pixels Pb and the four red pixels Pr (P1, P2, P3, and P4) provided in a unit pixel P. In an FD addition mode, which is used in the high-resolution mode and the high-speed mode, as described in Fig. As illustrated in Figure 16, switches SW1, SW2, SW3, and SW4, which are coupled to color pixels P1, P2, P3, and P4 respectively, are switched on to allow signals from the four color pixels P1, P2, P3, and P4 to be output as a single pixel. In a digital addition mode used in high-sensitivity mode, as shown in Figure 16, the switches SW1, SW2, SW3, and SW4, which are coupled to color pixels P1, P2, P3, and P4 respectively, are switched on to allow signals from the four color pixels P1, P2, P3, and P4 to be output as a single pixel. In a digital addition mode, which is used in high-sensitivity mode, as shown in Figure 16, the switches SW1, SW2, SW3, and SW4, which are coupled to color pixels P1, P2, P3, and P4 respectively, are switched on to allow signals from the four color pixels P1, P2, P3, and P4 to be output as a single pixel Fig. Figure 17 illustrates that one of the switches SW1, SW2, SW3, and SW4, which are coupled to the color pixels P1, P2, P3, and P4 respectively, is switched on, while the remaining three switches are switched off. This allows signals to be read for each of the color pixels P1, P2, P3, and P4 and then output as four pixels. The signals for the four pixels are then added together in an ISP in a subsequent stage. (1-4. Method and effects)

[0084] As described above, it is desirable for the solid-state imaging device, such as the CMOS or CCD image sensor, to exhibit increased sensitivity. For this purpose, a so-called vertical spectroscopic solid-state imaging device was developed, in which an organic photoelectric conversion section with an organic photoelectric conversion film and two inorganic photoelectric conversion sections, each featuring a pn junction in a semiconductor substrate, are stacked. In this vertical spectroscopic solid-state imaging device, R / G / B signals can be acquired from a single pixel, thus enabling higher resolution compared to an imaging device in which individual color pixels (red, green, and blue) are arranged two-dimensionally in an array using primary color filters for red, green, and blue.

[0085] In the vertical spectroscopic solid-state imaging device described above, color mixing is increased in RB spectroscopy within the semiconductor substrate. This leads to a problem where color noise is amplified, and this noise is further amplified in dark states, consequently significantly degrading the granular impression. One method for improving the granular impression involves utilizing a high-sensitivity mode.

[0086] In high-sensitivity mode at a typical imaging element of 1000, as in Fig. As illustrated in Figure 18A, signal charges are first read from each of the green pixels Pg in the organic photoelectric conversion section 1011G, which detects a green signal. In both the inorganic photoelectric conversion section 11B, which detects a blue signal, and the inorganic photoelectric conversion section 11R, which detects a red signal, digital addition is performed using four pixels (blue pixel Pb and red pixel Pr) in a (2 × 2) array as one unit U. At this time, each unit U of the inorganic photoelectric conversion section 11B and the inorganic photoelectric conversion section 11R is formed from 2 × 2 pixels that are shifted relative to each other by 1 × 1 pixel. Then, as shown in Figure 18A, Fig. Figure 18B illustrates that pinning processing is performed, followed by demosaicing processing between the blue pixel Pb and the red pixel Pr to generate RB signals as shown in Figure 18B. Fig. Figure 18C illustrates this. Therefore, a phase shift occurs in the imaging element 1000 during an operation of the green signal (G-signal) and the RB signals as shown in Figure 18C. Fig. 18D illustrated.

[0087] In contrast, in the imaging element 1 of the present disclosure, the inorganic photoelectric conversion sections 11B and 11R are configured such that they have a narrower pixel spacing (w) than the pixel spacing (W) of the organic photoelectric conversion section 11G with respect to a pixel of the organic photoelectric conversion section 11G. Specifically, for example, four pixels are arranged in a (2 × 2) array of the inorganic photoelectric conversion sections 11B and 11R with respect to a pixel of the organic photoelectric conversion section 11G.In imaging element 1, a green signal is acquired from a pixel of the organic photoelectric conversion section 11G (green pixel Pg) during the three operating modes described above (high-resolution mode, high-sensitivity mode, and high-speed mode), whereas the blue and red signals are acquired by summing signals from four pixels in a 2 × 2 or 16 pixels in a 4 × 4 configuration of the inorganic photoelectric conversion section 11B (blue pixels Pb) and the inorganic photoelectric conversion section 11R (red pixels Pr), respectively. Therefore, it is possible to acquire R / G / B signals without phase shift.

[0088] As described above, in the imaging element 1 of the present embodiment, four (2 × 2) pixels of the inorganic photoelectric conversion sections 11B and 11R are arranged relative to one pixel of the organic photoelectric conversion section 11G. In each of the operating modes, the blue and red signals are acquired by adding four pixels in a 2 × 2 or 16 pixels in a 4 × 4 configuration of the inorganic photoelectric conversion section 11B (blue pixels Pb) and the inorganic photoelectric conversion section 11R (red pixels Pr) to one pixel of the organic photoelectric conversion section 11G (green pixel Pg), which acquires a green signal. In particular, in high-speed mode, the blue and red signals are each acquired by adding signals from 16 pixels in a 4 × 4 configuration, which consequently makes it possible to reduce a granular impression in a dark state.This means it is possible to provide an imaging element that achieves an improvement in resolution and an improvement in granular detail.

[0089] Next, a modification example of the present disclosure is described. Components similar to those of the preceding embodiment are designated by the same reference numerals, and their descriptions are omitted where appropriate. <2nd Modification Example>

[0090] Fig. Figure 19 illustrates a cross-sectional configuration of an imaging element (an imaging element 1B) according to a modification example of the present disclosure. Similar to the photoelectric conversion element 10A, the imaging element 1B forms a CCD image sensor or a CMOS image sensor, etc., of a back-illuminated type (back-light receiving type) (see Figure 19). Fig. 3) Similar to the imaging element 1A described above, the imaging element 1B is a vertical spectroscopic imaging element in which an organic photoelectric conversion section 20, which selectively detects and photoelectrically converts light beams of different wavelength bands, and two inorganic photoelectric conversion sections 11B and 11R are stacked vertically. The imaging element 1B of the present modification differs from the previous embodiment in that a lower electrode 21 comprises a plurality of electrodes (a readout electrode 21A and an accumulation electrode 21B).

[0091] Similar to the imaging element 1A in the preceding embodiment, the organic photoelectric conversion section 20 is provided on the side of the back surface (first surface 11S1) of the semiconductor substrate 11. The inorganic photoelectric conversion sections 11B and 11R are each configured to be embedded in the semiconductor substrate 11 and are stacked in the direction of the thickness of the semiconductor substrate 11.

[0092] The organic photoelectric conversion section 20 has a configuration in which, for example, the lower electrode 21, the organic photoelectric conversion layer 16, and the upper electrode 17 are stacked in that order from the side of the first surface 11S1 of the semiconductor substrate 11. It is particularly noteworthy that an insulating layer 22 is provided between the lower electrode 21 and a charge accumulation layer 23. For example, the lower electrode 21 is formed separately for each imaging element 1B and is formed by the readout electrode 21A and the accumulation electrode 21B, which are separated from each other by the insulating layer 22 arranged between them, although detailed descriptions of this layer will be given later.The insulating layer 22 on the readout electrode 21A is provided with an opening 22H, and the readout electrode 21A and the charge accumulation layer 23 are electrically coupled to each other via the opening 22H.

[0093] It is particularly worth mentioning that in the Fig. Figure 19 illustrates that the charge accumulation layer 23, the organic photoelectric conversion section 16, and the upper electrode 17 are formed separately for each imaging element 1, but can be provided as successive layers together for a plurality of imaging elements 1B, for example, similar to the imaging element 1A described above. For example, similar to the first embodiment, the fixed charge layer 12A, the dielectric layer 12B, and the intermediate insulating layer 14 are provided between the first surface 11S1 of the semiconductor substrate 11 and the lower electrode 21. The protective layer 18, containing a light-shielding film 51, is provided on the upper electrode 17. An optical component, such as the on-chip lens layer 19, which contains the on-chip lens 19L, is arranged on the protective layer 18.

[0094] As described above, the lower electrode 21 is formed by the readout electrode 21A and the accumulation electrode 21B, which are configured separately, and voltages are applied to them independently. The readout electrode 21A is designed to transfer charges (here, electrons) generated in the organic photoelectric conversion layer 16 to the floating diffusion region FD3 and is coupled to the floating diffusion region FD3, for example, via an upper first contact 24A, a pad section 39A, the through-electrode 63, the coupling section 71A, and the lower contact 75. The accumulation electrode 21B is designed to accumulate electrons as signal charges in the charge accumulation layer 23 under the charges generated in the organic photoelectric conversion layer 16 and to transfer the accumulated electrons to the readout electrode 21A.The accumulation electrode 21B is located in an area opposite and covering the light-receiving surfaces of the inorganic photoelectric conversion sections 11B and 11R formed in the semiconductor substrate 11. The accumulation electrode 21B is preferably larger than the readout electrode 21A, which allows a number of charges to be accumulated in the charge accumulation layer 23.

[0095] As described above, in the present modification example, the lower electrode 21 is divided into the readout electrode 21A and the accumulation electrode 21B, which consequently allows voltages to be applied to them independently. This enables the imaging element 1B to accumulate the charges generated in the organic photoelectric conversion layer 16 in the charge accumulation layer 23, which is arranged between the lower electrode 21 and the organic photoelectric conversion layer 16. The accumulated charges can then be read out via the readout electrode 21A into the floating diffusion region FD3. Thus, it is possible to completely deplete a charge accumulation section at the beginning of an exposure, which, in addition to the effects of the previous embodiment, results in an improvement in the quality of the captured image. <3. Application Example>(Application Example 1)

[0096] Fig. Figure 20 illustrates, for example, an overall configuration of the imaging element 1, wherein the imaging element 1 described in the preceding embodiment is used for each pixel. The imaging element 1 is a CMOS imaging sensor. The imaging element 1 comprises a pixel section 1a as the imaging area on the semiconductor substrate 11 and includes, for example, a peripheral circuit section 130, which is formed by a row-scanning device 131, a horizontal selector 133, a column-scanning device 134, and a system controller 132 in a peripheral area of ​​the pixel section 1a.

[0097] Pixel section 1a, for example, contains a multitude of unit pixels P (corresponding, for instance, to the green pixel Pg of imaging element 1), which are arranged two-dimensionally in a matrix. Pixel control lines Lread (specifically, row selection lines and reset control lines) are wired to the unit pixels P based on pixel rows, and vertical signal lines Lsig are wired based on pixel columns. The pixel control line Lread transmits a control signal for reading a signal from the pixel. One end of the pixel control line Lread is coupled to an output terminal corresponding to each row in the row scan unit 131.

[0098] The row scan device 131 is formed by a shift register, an address decoder, etc. The row scan device 131 is, for example, a pixel driver that controls the respective unit pixels P in pixel section 1 in units of rows. Signals emitted by the respective unit pixels P in the pixel row that is selectively scanned by the row scan device 131 are provided to the horizontal selector 133 via the respective vertical signal lines Lsig. The horizontal selector 133 is formed by an amplifier, a horizontal selector switch, etc., provided for each vertical signal line Lsig.

[0099] The column scan unit 134 is formed by a shift register, an address decoder, etc. The column scan unit 134 sequentially controls the respective switches for a horizontal selection in the horizontal selector 133, while the respective switches for a horizontal selection in the horizontal selector 133 are scanned. As a result of the selective scanning by the column scan unit 134, signals from the respective pixels, which are to be transmitted via the respective vertical signal lines Lsig, are sequentially output to the horizontal signal lines 135 and are transmitted via the horizontal signal lines 135 to the outside of the semiconductor substrate 11.

[0100] A circuit section comprising the row scan device 131, the horizontal selector 133, the column scan device 134, and the horizontal signal lines 135 can be formed directly on the semiconductor substrate 11 or can be arranged in an external control IC. Alternatively, the circuit section can be formed on another substrate coupled using a cable, etc.

[0101] The system controller 132 receives a clock signal, data specifying an operating mode, etc., provided from outside the semiconductor substrate 11. The system controller 132 also outputs data, such as internal information from the imaging element 1. Furthermore, the system controller 132 includes a timing generator that produces various timing signals and controls the operation of peripheral circuits, such as the row-scan device 131, the horizontal selector 133, and the column-scan device 134, based on the various timing signals generated by the timing generator. (Application example 2)

[0102] The imaging element 1 described above can be used for any type of electronic device with an imaging function, for example a camera system such as a digital camera and a video camera, and a mobile phone with an imaging function. Fig. Figure 21 illustrates a schematic configuration of a camera 2 as an example. This camera 2 is, for example, a video camera that can photograph a still image or record a moving image. The camera 2 includes, for example, the imaging element 1, an optical system (optical lens) 310, an aperture device 311, a control section 313 that controls the imaging element 1 and the aperture device 311, and a signal processing section 312.

[0103] The optical system 310 guides light (incident light) from an object to the pixel section 1a in the imaging element 1. The optical system 310 can be formed by a plurality of optical lenses. The aperture device 311 controls periods of light illumination and light blockage with respect to the imaging element 1. The control section 313 controls a transfer operation of the imaging element 1 and an aperture operation of the aperture device 311. The signal processing section 312 performs various types of signal processing on a signal output by the imaging element 1. The resulting image signal (Dout) is stored in a storage medium such as memory or output to a monitor, etc. (Application example 3)<Beispiel einer praktischen Anwendung für ein In-vivo-Informationserfassungssystem>

[0104] The technology according to one embodiment of the present disclosure (present technology) is furthermore applicable to various products. For example, the technology according to one embodiment of the present disclosure can be used for an endoscopic surgery system.

[0105] Fig. Figure 22 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.

[0106] The in vivo information acquisition system 10001 comprises a capsule-type endoscope 10100 and an external control unit 10200.

[0107] 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 excreted 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.

[0108] 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 from 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 from the in-vivo image.

[0109] 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.

[0110] The configuration and functions of the capsule-type endoscope 10100 and the external control unit 10200 are described in more detail below.

[0111] 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.

[0112] 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.

[0113] 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, which 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] The power supply unit 10116 contains a secondary battery and stores the electrical power generated by the power supply unit 10115. Fig. To avoid a complicated illustration, the arrow marking indicating the destination of the electrical power supply from the power supply unit 10116, etc., has been omitted in Figure 22. However, the electrical power stored in the power supply unit 10116 is provided to, and can be used to control, 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] The above description is of an example of an in-vivo information acquisition system for which the technology according to one embodiment of the present disclosure can be used. The technology according to one embodiment of the present disclosure can be described for, for example, the image acquisition unit 10112. This makes it possible to improve the detection accuracy. (Application example 4)<Beispiel einer praktischen Anwendung für ein System für endoskopische Chirurgie>

[0122] The technology according to one embodiment of the present disclosure (present technology) can be used for various products. For example, the technology according to one embodiment of the present disclosure can be used for an endoscopic surgery system.

[0123] Fig. Figure 23 is a view that represents 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.

[0124] In Fig. Figure 23 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 11120 that carries the endoscope 11100, and a trolley 11200 on which various endoscopic surgery devices are mounted.

[0125] The endoscope 11100 comprises a lens tube 11101, with a predetermined length at 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.

[0126] 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.

[0127] 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.

[0128] 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).

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] Fig. Figure 24 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. 23 are shown.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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 operation of the camera head 11102.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] An example of an endoscopic surgery system for which the technology according to one embodiment of the present disclosure can be used has been described above. The technology according to one embodiment of the present disclosure can be used for the image acquisition unit 11402 of the configurations described above. Applying the technology according to one embodiment of the present disclosure to the image acquisition unit 11402 enables the detection accuracy to be improved.

[0154] It is particularly worth mentioning that, although the system for endoscopic surgery has been described here as an example, the technology according to one embodiment of the present disclosure can also be used for, for example, a system for microscopic surgery and the like. (Application example 5)<Beispiel einer praktischen Anwendung für einen beweglichen Körper>

[0155] The technology according to one embodiment of the present disclosure (present technology) can be used for various products. For example, the technology according to one embodiment of the present disclosure can be implemented in the form of a device to be mounted on a movable body of any kind, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, any personal mobility device, an aircraft, an unmanned aerial vehicle (drone), a ship, a robot, a construction machine, and an agricultural machine (tractor).

[0156] Fig. Figure 25 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.

[0157] 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 25, 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.

[0158] 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.

[0159] 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.

[0160] 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 such an object.

[0161] 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.

[0162] 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 input from the 12041 driver state detection section, the 12040 vehicle information detection unit can calculate the driver's fatigue level, the driver's concentration level, or determine whether the driver is dozing off.

[0163] 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 a vehicle collision, warning of a vehicle lane deviation, or the like.

[0164] 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.

[0165] 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.

[0166] 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 25 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.

[0167] Fig. Figure 26 is a diagram illustrating an example of an installation position of the imaging section 12031.

[0168] In Fig. 26 includes the imaging section 12031 imaging sections 12101, 12102, 12103, 12104 and 12105.

[0169] 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.

[0170] Furthermore, Fig.Figure 26 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.

[0171] 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.

[0172] 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.

[0173] 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 collision risk 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.

[0174] 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.

[0175] A description has been given above with reference to the embodiment, the modification example, and the application examples; however, the content of the present disclosure is not limited to the preceding embodiment and the like, and various modifications can be made. For example, in the preceding embodiment, the imaging element has a configuration in which four inorganic photoelectric conversion sections 11B and four inorganic photoelectric conversion sections 11R, which detect blue light and red light respectively, are stacked sequentially with respect to an organic photoelectric conversion section 11G, which detects green light. However, the content of the present disclosure is not limited to such a structure.

[0176] For example, a configuration can be adopted in which eight inorganic photoelectric conversion sections 11B (eight pixels thereof) and eight inorganic photoelectric conversion sections 11R (eight pixels thereof), detecting blue light and red light respectively, are stacked sequentially with respect to one organic photoelectric conversion section 11G, which detects green light. Alternatively, a configuration can be adopted in which two organic photoelectric conversion sections and one inorganic photoelectric conversion section are stacked. In this case, the two organic photoelectric conversion sections can be configured with the same pixel spacing; however, the organic photoelectric conversion section located on one side of the inorganic photoelectric conversion section can be narrower.narrower than a pixel spacing of the organic photoelectric conversion section located on the light-incidence side, as formed in the inorganic photoelectric conversion sections 11B and 11R described above.

[0177] Furthermore, the preceding embodiment etc. exemplifies the configuration of the imaging element of the type with back-side illumination; however, the content of the present disclosure is also applicable to an imaging element of the type with front-side illumination. The imaging element of the present disclosure need not include all the components described in the preceding embodiment and, conversely, may include any other layer.

[0178] It is particularly important to note that the effects described herein are only exemplary and not limiting, and may include other effects as well.

[0179] It is particularly worth mentioning that the present disclosure may have the following configurations. (1) An imaging element comprising: a first photoelectric conversion section; and a second photoelectric conversion section, wherein the first photoelectric conversion section and the second photoelectric conversion section are stacked in series from one side of the light incidence and selectively detect and photoelectrically convert light beams of different wavelength bands, wherein the second photoelectric conversion section is arranged in an interval that is narrower than a pixel spacing of the first photoelectric conversion section. (2) The imaging element according to (1) wherein four pixels of the second photoelectric conversion section are arranged in relation to one pixel of the first photoelectric conversion section. (3) The imaging element according to (1) wherein eight pixels of the second photoelectric conversion section are arranged in relation to one pixel of the first photoelectric conversion section. (4) The imaging element according to one of (1) to (3) wherein, the first photoelectric conversion section contains an organic photoelectric conversion section formed using an organic material, and The second photoelectric conversion section contains an inorganic photoelectric conversion section designed to be embedded in a semiconductor substrate. (5) The imaging element according to (4), further comprising a third photoelectric conversion section which selectively detects and photoelectrically converts light of a wavelength band different from that of the first photoelectric conversion section and the second photoelectric conversion section, wherein the third photoelectric conversion section is arranged between the first photoelectric conversion section and the second photoelectric conversion section, wherein The third photoelectric conversion section contains an inorganic photoelectric conversion section designed to be embedded in the semiconductor substrate. (6) The imaging element according to (5) wherein the third photoelectric conversion section is arranged in an interval that is narrower than the pixel spacing of the first photoelectric conversion section. (7) The imaging element according to (5) or (6) wherein four pixels of the third photoelectric conversion section are arranged in relation to one pixel of the first photoelectric conversion section. (8) The imaging element according to (5) or (6) wherein eight pixels of the third photoelectric conversion section are arranged in relation to one pixel of the first photoelectric conversion section. (9) The imaging element according to one of (5) to (8), wherein the first photoelectric conversion section performs a photoelectric conversion of green light and The second photoelectric conversion section and the third photoelectric conversion section each perform a photoelectric conversion of red light or blue light. (10) The imaging element according to (4), further comprising a third photoelectric conversion section which selectively detects and photoelectrically converts light of a wavelength band different from that of the first photoelectric conversion section and the second photoelectric conversion section, wherein the third photoelectric conversion section is arranged between the first photoelectric conversion section and the second photoelectric conversion section, wherein The third photoelectric conversion section contains an organic photoelectric conversion section formed on top of the semiconductor substrate. (11) The imaging element according to (10) wherein the third photoelectric conversion section is arranged at a pixel spacing similar to the first photoelectric conversion section. (12) An electronic device containing an imaging element, the imaging element includes: a first photoelectric conversion section and a second photoelectric conversion section, wherein the first photoelectric conversion section and the second photoelectric conversion section are stacked in series from one side of the light incidence and selectively detect and photoelectrically convert light beams of different wavelength bands, wherein the second photoelectric conversion section is arranged in an interval that is narrower than a pixel spacing of the first photoelectric conversion section. (13) A method for controlling an imaging element comprising a first photoelectric conversion section and a second photoelectric conversion section stacked sequentially from the light-incident side and selectively detecting and photoelectrically converting light beams of different wavelength bands, wherein the second photoelectric conversion section is arranged at an interval narrower than a pixel spacing of the first photoelectric conversion section, the method comprising: a detection of a color signal of a first light using a pixel of the first photoelectric conversion section and a detection of a color signal of a second light of a wavelength band that is different from the first light, by addition in a plurality of the second photoelectric conversion sections. (14) The method for controlling the imaging element according to (13), wherein The imaging element has a high-resolution mode, a high-sensitivity mode, and a high-speed mode as operating modes and The detection of the color signal of the second light is carried out by adding four (2 × 2) pixels of the second photoelectric conversion section to one pixel of the first photoelectric conversion section in the high-resolution mode and the high-speed mode. (15) The method for controlling the imaging element according to (13), wherein The imaging element has a high-resolution mode, a high-sensitivity mode, and a high-speed mode as operating modes and The detection of the color signal of the second light is carried out by adding 16 (4 × 4) pixels of the second photoelectric conversion section to one pixel of the first photoelectric conversion section in high sensitivity mode.

Claims

[1] Imaging element, comprising: a first photoelectric conversion section; and a second photoelectric conversion section, wherein the first photoelectric conversion section and the second photoelectric conversion section are stacked in series from one side of the light incidence and selectively detect and photoelectrically convert light beams of different wavelength bands, wherein the second photoelectric conversion section is arranged in an interval that is narrower than a pixel spacing of the first photoelectric conversion section, wherein four pixels of the second photoelectric conversion section are arranged in relation to one pixel of the first photoelectric conversion section. [2] Imaging element according to claim 1, wherein the first photoelectric conversion section has an organic photoelectric conversion section formed using an organic material, and the second photoelectric conversion section comprises an inorganic photoelectric conversion section designed to be embedded in a semiconductor substrate. [3] Imaging element according to claim 2, further comprising a third photoelectric conversion section which selectively detects and photoelectrically converts light of a wavelength band different from that of the first photoelectric conversion section and the second photoelectric conversion section, wherein the third photoelectric conversion section is arranged between the first photoelectric conversion section and the second photoelectric conversion section, wherein the third photoelectric conversion section comprises an inorganic photoelectric conversion section which is designed to be embedded in the semiconductor substrate. [4] Imaging element according to claim 3, wherein the third photoelectric conversion section is arranged in an interval that is narrower than the pixel spacing of the first photoelectric conversion section. [5] Imaging element according to claim 3 or 4, wherein four pixels of the third photoelectric conversion section are arranged in relation to one pixel of the first photoelectric conversion section. [6] Imaging element according to claim 3 or 4, wherein eight pixels of the third photoelectric conversion section are arranged in relation to one pixel of the first photoelectric conversion section. [7] Imaging element according to any one of claims 3 to 6, wherein the first photoelectric conversion section performs a photoelectric conversion of green light and The second photoelectric conversion section and the third photoelectric conversion section each perform a photoelectric conversion of red light or blue light. [8] Imaging element according to claim 2, further comprising a third photoelectric conversion section which selectively detects and photoelectrically converts light of a wavelength band different from that of the first photoelectric conversion section and the second photoelectric conversion section, wherein the third photoelectric conversion section is arranged between the first photoelectric conversion section and the second photoelectric conversion section, wherein the third photoelectric conversion section comprises an organic photoelectric conversion section formed over the semiconductor substrate. [9] Imaging element according to claim 8, wherein the third photoelectric conversion section is arranged at a pixel spacing similar to the first photoelectric conversion section. [10] Electronic device comprising an imaging element, wherein the imaging element comprises: a first photoelectric conversion section and a second photoelectric conversion section, wherein the first photoelectric conversion section and the second photoelectric conversion section are stacked in series from one side of the light incidence and selectively detect and photoelectrically convert light beams of different wavelength bands, wherein the second photoelectric conversion section is arranged in an interval that is narrower than a pixel spacing of the first photoelectric conversion section, wherein four pixels of the second photoelectric conversion section are arranged in relation to one pixel of the first photoelectric conversion section. [11] Method for controlling an imaging element comprising a first photoelectric conversion section and a second photoelectric conversion section stacked sequentially from one side of the light incidence and selectively detecting and photoelectrically converting light beams of different wavelength bands, wherein the second photoelectric conversion section is arranged in an interval that is narrower than a pixel spacing of the first photoelectric conversion section, wherein four pixels of the second photoelectric conversion section are arranged in relation to one pixel of the first photoelectric conversion section, the procedure exhibits: a detection of a color signal of a first light using a pixel of the first photoelectric conversion section and a detection of a color signal of a second light of a wavelength band that is different from the first light, by addition in a plurality of the second photoelectric conversion sections. [12] Method for controlling the imaging element according to claim 11, wherein The imaging element has a high-resolution mode, a high-sensitivity mode, and a high-speed mode as operating modes and The detection of the color signal of the second light is carried out by adding four (2 × 2) pixels of the second photoelectric conversion section to one pixel of the first photoelectric conversion section in the high-resolution mode and the high-speed mode. [13] Method for controlling the imaging element according to claim 11, wherein The imaging element has a high-resolution mode, a high-sensitivity mode, and a high-speed mode as operating modes and The detection of the color signal of the second light is carried out by adding 16 (4 × 4) pixels of the second photoelectric conversion section to one pixel of the first photoelectric conversion section in high sensitivity mode.

Images