Image pickup device and method for manufacturing image pickup device

Abstract

An imaging element according to one embodiment of the present disclosure comprises: a semiconductor substrate having a valid pixel region in which a plurality of pixels are arranged and a peripheral region provided around the valid pixel region; a first electrode that is provided on the light-receiving surface side of the semiconductor substrate and that comprises a plurality of electrodes; a second electrode that is arranged opposite the first electrode; an organic photoelectric conversion unit that includes a charge storage layer and an organic photoelectric conversion layer that are provided stacked in order between the first electrode and the second electrode and that extend to the valid pixel region; and a sealing layer obtained by stacking, above the organic photoelectric conversion unit, a first layer and a second layer which have mutually different etching rates.

Description

[Technical field]

[0001] The present disclosure relates to an imaging element having a photoelectric conversion layer using an organic semiconductor material and a manufacturing method thereof. [Background technology]

[0002] For example, Patent Document 1 discloses an imaging device having a charge storage electrode disposed apart from the first electrode and facing the photoelectric conversion layer via an insulating layer in a photoelectric conversion section formed by stacking a first electrode, a photoelectric conversion layer, and a second electrode provided above a semiconductor substrate. In this imaging device, charges generated by photoelectric conversion are stored on the charge storage electrode, thereby reducing noise generation and improving image quality. In addition, Patent Document 2 discloses an imaging device in which layers consisting of a buffer layer, a sealing layer, a color filter, a planarizing layer, and a protective film are provided on the insulating layer or the upper electrode in the peripheral region, thereby reducing the occurrence of defects such as film peeling and improving the manufacturing yield. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-157816 A [Patent Document 2] JP 2019-140386 A Summary of the Invention

[0004] Thus, there is a demand for improving the manufacturing yield of image pickup devices.

[0005] It is desirable to provide an imaging device and a method for manufacturing an imaging device that can improve manufacturing yields.

[0006] An imaging element according to an embodiment of the present disclosure includes a semiconductor substrate having an effective pixel region in which a plurality of pixels are arranged and a peripheral region provided around the effective pixel region, an organic photoelectric conversion section provided on the light receiving surface side of the semiconductor substrate and including a first electrode composed of a plurality of electrodes, a second electrode arranged to face the first electrode, an organic photoelectric conversion layer and a charge storage layer provided in this order between the first electrode and the second electrode and extending into the effective pixel region, and a sealing layer formed by stacking a first layer and a second layer having different etching rates above the organic photoelectric conversion section. The first layer is selectively provided on a portion of the upper surface of the organic photoelectric conversion section. .

[0007] A method for manufacturing an imaging element according to an embodiment of the present disclosure includes stacking a first electrode, a charge storage layer, an organic photoelectric conversion layer, and a second electrode, each of which is made up of a plurality of electrodes, in this order as an organic photoelectric conversion section in an effective pixel region on a light-receiving surface side of a semiconductor substrate having an effective pixel region in which a plurality of pixels are arranged and a peripheral region provided around the effective pixel region, and then stacking a first layer and a second layer having different etching rates above the organic photoelectric conversion section. At the same time, the first layer is selectively provided on a part of the upper surface of the organic photoelectric conversion section. A sealing layer is formed.

[0008] In an imaging element according to one embodiment of the present disclosure and a manufacturing method for an imaging element according to one embodiment, a sealing layer formed by stacking a first layer and a second layer having different etching rates is provided above an organic photoelectric conversion unit, thereby facilitating the formation of a contact with the organic photoelectric conversion unit from above the organic photoelectric conversion unit. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view illustrating a configuration of an imaging element according to a first embodiment of the present disclosure. [Diagram 2] 2 is a schematic cross-sectional view for explaining the configuration of a main part of the image sensor shown in FIG. [Diagram 3] 2 is an equivalent circuit diagram of the image sensor shown in FIG. 1. [Figure 4] 2 is a schematic diagram showing an arrangement of transistors constituting a lower electrode and a control unit of the image sensor shown in FIG. 1. [Figure 5A]2 is a plan view showing an example of the layout of a lower electrode constituting the organic photoelectric conversion unit shown in FIG. 1. [Figure 5B] FIG. 5B is a perspective view of the layout of the bottom electrode shown in FIG. 5A. [Figure 6A] 1. FIG. 4 is a plan view schematic illustrating another example of the layout of the lower electrode constituting the organic photoelectric conversion unit shown in FIG. [Figure 6B] FIG. 6B is a perspective view of the layout of the bottom electrode shown in FIG. 6A. [Figure 7] 2 is a plan view showing an example of the layout of one inorganic photoelectric conversion unit and various transistors associated therewith shown in FIG. 1. FIG. [Figure 8] 2 is a plan view showing an example of the layout of another inorganic photoelectric conversion unit and various transistors associated therewith shown in FIG. 1. FIG. [Figure 9] FIG. 2 is a diagram showing an arrangement of signal lines for driving the storage electrodes shown in FIG. [Figure 10] FIG. 2 is a diagram showing a part of wiring connected to adjacent photoelectric conversion units and various transistors associated therewith. [Figure 11] FIG. 2 is a diagram showing a part of wiring connected to adjacent photoelectric conversion units and various transistors associated therewith. [Figure 12] FIG. 2 is a diagram showing a part of wiring connected to adjacent photoelectric conversion units and various transistors associated therewith. [Figure 13] 2A to 2C are cross-sectional views for explaining a method of manufacturing the image sensor shown in FIG. [Figure 14] FIG. 14 is a schematic cross-sectional view showing a step following FIG. 13. [Figure 15] FIG. 15 is a schematic cross-sectional view showing a step following FIG. 14. [Figure 16] FIG. 16 is a schematic cross-sectional view showing a step following FIG. [Figure 17] FIG. 17 is a schematic cross-sectional view showing a step following FIG. 16. [Figure 18] FIG. 18 is a schematic cross-sectional view showing a step following FIG. 17. [Figure 19] 2 is a timing chart illustrating an example of an operation of the image sensor illustrated in FIG. [Figure 20] 6 is a schematic cross-sectional view illustrating a configuration of an imaging element according to a second embodiment of the present disclosure. [Figure 21] 21A to 21C are cross-sectional views for explaining a method of manufacturing the image sensor shown in FIG. 20. [Figure 22] FIG. 22 is a schematic cross-sectional view showing a step following FIG. 21. [Diagram 23] FIG. 23 is a schematic cross-sectional view showing a step following FIG. 22. [Figure 24] FIG. 24 is a schematic cross-sectional view showing a step following FIG. 23. [Diagram 25] FIG. 25 is a schematic cross-sectional view showing a step following FIG. 24. [Figure 26] 13 is a schematic cross-sectional view illustrating an example of a configuration of a main part of an imaging element according to a third embodiment of the present disclosure. FIG. [Figure 27] 27 is a schematic diagram illustrating a planar configuration of the imaging element shown in FIG. 26. [Figure 28] 27A to 27C are cross-sectional views for explaining a method of manufacturing the image sensor shown in FIG. 26. [Figure 29] FIG. 29 is a schematic cross-sectional view showing a step following FIG. 28. [Diagram 30] FIG. 30 is a schematic cross-sectional view showing a step following FIG. 29. [Diagram 31] FIG. 31 is a schematic cross-sectional view showing a step following FIG. 30. [Diagram 32] FIG. 32 is a schematic cross-sectional view showing a step following FIG. 31. [Diagram 33] 13 is a schematic cross-sectional view illustrating another example of the configuration of the main part of the image sensor according to the third embodiment of the present disclosure. FIG. [Diagram 34] 13 is a schematic cross-sectional view illustrating another example of the configuration of the main part of the image sensor according to the third embodiment of the present disclosure. FIG. [Diagram 35] 13 is a schematic cross-sectional view illustrating another example of the configuration of the main part of the image sensor according to the third embodiment of the present disclosure. FIG. [Diagram 36] 13 is a schematic cross-sectional view illustrating another example of the configuration of the main part of the image sensor according to the third embodiment of the present disclosure. FIG. [Figure 37] 13 is a schematic cross-sectional view illustrating another example of the configuration of the main part of the image sensor according to the third embodiment of the present disclosure. FIG. [Figure 38] 13 is a schematic cross-sectional view illustrating an example of a configuration of a main part of an imaging element according to a fourth embodiment of the present disclosure. FIG. [Figure 39] 39 is a schematic diagram illustrating a planar configuration of the imaging element shown in FIG. 38. [Diagram 40] 40A to 40C are cross-sectional views for explaining a method of manufacturing the image sensor shown in FIG. 39. [Diagram 41] FIG. 41 is a schematic cross-sectional view showing a step following FIG. 40. [Diagram 42] FIG. 42 is a schematic cross-sectional view showing a step following FIG. 41. [Diagram 43] FIG. 43 is a schematic cross-sectional view showing a step following FIG. 42. [Diagram 44] FIG. 44 is a schematic cross-sectional view showing a step following FIG. 43. [Diagram 45] 13 is a schematic cross-sectional view illustrating another example of the configuration of the main part of the image sensor according to the fourth embodiment of the present disclosure. FIG. [Figure 46] 46 is a schematic diagram showing the planar configuration of the imaging element shown in FIG. 45. [Figure 47] 47A to 47C are cross-sectional views for explaining a method of manufacturing the image sensor shown in FIG. 46. [Figure 48] FIG. 48 is a schematic cross-sectional view showing a step following FIG. 47. [Figure 49] FIG. 49 is a schematic cross-sectional view showing a step following FIG. 48. [Figure 50] FIG. 50 is a schematic cross-sectional view showing a step following FIG. 49. [Figure 51] 11 is a schematic cross-sectional view illustrating an example of a configuration of a main part of an imaging element according to a modified example of the present disclosure. [Figure 52] 52 is a schematic diagram showing the planar configuration of the imaging element shown in FIG. 51. [Figure 53] 53 is a cross-sectional view for explaining a method of manufacturing the image sensor shown in FIG. 52. [Figure 54] FIG. 54 is a schematic cross-sectional view showing a step following FIG. 53. [Figure 55] FIG. 55 is a schematic cross-sectional view showing a step following FIG. 54. [Figure 56] FIG. 56 is a schematic cross-sectional view showing a step following FIG. 55. [Figure 57]2 is a block diagram showing a configuration of an imaging device using the imaging element shown in FIG. 1 etc. as a pixel. [Figure 58] FIG. 58 is a functional block diagram illustrating an example of an electronic device (camera) using the imaging device illustrated in FIG. 57. [Figure 59] 1 is a block diagram showing an example of a schematic configuration of an in-vivo information acquiring system. [Figure 60] 1 is a diagram illustrating an example of a schematic configuration of an endoscopic surgery system. [Figure 61] 2 is a block diagram showing an example of a functional configuration of a camera head and a CCU. FIG. [Figure 62] 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; [Figure 63] 4 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. The following description is a specific example of the present disclosure, and the present disclosure is not limited to the following aspect. Furthermore, the present disclosure is not limited to the arrangement, dimensions, dimensional ratios, etc. of each component shown in each drawing. The order of description is as follows. 1. First embodiment (an example of an imaging element having a sealing layer in which a first layer containing nitrogen and a second layer containing oxygen are laminated in this order above an organic photoelectric conversion section) 1-1.Image sensor configuration 1-2. Manufacturing method of image sensor 1-3. Actions and Effects 2. Second embodiment (an example of an imaging element having a sealing layer in which a second layer containing oxygen and a first layer containing nitrogen are laminated in this order above an organic photoelectric conversion section) 3. Third embodiment (example in which the first layer is selectively provided at the contact portion with the upper electrode) 4. Fourth embodiment (an example in which an inter-pixel light-shielding film is provided and used together with the first layer as an etching stopper layer) 5. Modification (An example in which a light-shielding film is provided between pixels and used as the first layer) 6. Application Examples 7. Application Examples

[0011] <1. First embodiment> (1-1. Configuration of the image sensor) FIG. 1 illustrates a cross-sectional configuration of an imaging element (imaging element 10A) according to a first embodiment of the present disclosure. FIG. 2 illustrates a schematic cross-sectional configuration of a main part of the imaging element 10A illustrated in FIG. 1. FIG. 3 illustrates an equivalent circuit diagram of the imaging element 10A illustrated in FIG. 1. FIG. 4 illustrates a schematic arrangement of a lower electrode 21 and transistors constituting a control unit of the imaging element 10A illustrated in FIG. 1. The imaging element 10A constitutes one pixel (unit pixel P) in an imaging device (imaging device 1; see FIG. 57) such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor used in electronic devices such as digital still cameras and video cameras. The imaging device 1 has an effective pixel area 110A in which a plurality of pixels are arranged, and a peripheral area 110B provided around the effective pixel area 110A and in which a peripheral circuit section 130 such as a row scanning section 131 is formed.

[0012] The imaging element 10A is a so-called vertical spectroscopic imaging element in which one organic photoelectric conversion section 20 and two inorganic photoelectric conversion sections 32B and 32R are stacked in the vertical direction, and has a pixel sharing structure in which four adjacent pixels share one corresponding floating diffusion FD1, FD2, and FD3. The organic photoelectric conversion section 20 is provided on the light receiving surface (first surface (rear surface) 30S1) of the semiconductor substrate 30. The organic photoelectric conversion section 20 has a configuration in which a lower electrode 21 (first electrode), an insulating layer 22, a charge storage layer 23, a photoelectric conversion layer 24 (organic photoelectric conversion layer), and an upper electrode 25 (second electrode) made of multiple electrodes are stacked in this order from the semiconductor substrate 30 side. In the imaging element 10A of this embodiment, a sealing layer 26 is provided above the organic photoelectric conversion section 20, specifically, on the upper electrode 25. The sealing layer 26 includes a first layer 26A, a second layer 26B, and a third layer 26C laminated in this order, the first layer 26A being made of an insulating material containing nitrogen, and the second layer 26B being made of an insulating material containing oxygen. The inorganic photoelectric conversion units 32B and 32R are embedded in the semiconductor substrate 30 and laminated in the thickness direction of the semiconductor substrate 30.

[0013] The organic photoelectric conversion unit 20 and the inorganic photoelectric conversion units 32B and 32R selectively detect light in different wavelength ranges and perform photoelectric conversion. Specifically, for example, the organic photoelectric conversion unit 20 acquires a green (G) color signal. The inorganic photoelectric conversion units 32B and 32R acquire blue (B) and red (R) color signals, respectively, due to differences in absorption coefficients. This makes it possible for the image sensor 10A to acquire multiple types of color signals in one pixel without using a color filter.

[0014] In this embodiment, a case where electrons among pairs of electrons and holes (excitons) generated by photoelectric conversion are read out as signal charges (when an n-type semiconductor region is used as a photoelectric conversion layer) will be described. In addition, in the figure, the "+ (plus)" attached to "p" and "n" indicates that the p-type or n-type impurity concentration is high.

[0015] The second surface (front surface) 30S2 of the semiconductor substrate 30 includes, for example, floating diffusions (floating diffusion layers) FD1 (region 35 in the semiconductor substrate 30), FD2, and FD3, transfer transistors TR2trs and TR3trs, amplifier transistors (modulation elements) TR1amp and TR2amp, reset transistors TR1rst and TR2rst, selection transistors TR1sel and TR2sel, and a multi-layer wiring layer 40. A reset gate Grst of the reset transistor TR1rst is disposed next to the floating diffusion FD1 (one of the source / drain regions of the reset transistor TR1rst). This allows the charge accumulated in the floating diffusion FD1 to be reset by the reset transistor TR1rst. The multi-layer wiring layer 40 has, for example, a configuration in which wiring layers 41, 42, and 43 are stacked in an insulating layer 44.

[0016] In the drawings, the first surface 30S1 side of the semiconductor substrate 30 is represented as a light incident side S1, and the second surface 30S2 side is represented as a wiring layer side S2.

[0017] In the imaging device 10A, light incident on the organic photoelectric conversion section 20 from the light incident side S1 is absorbed by the photoelectric conversion layer 24. The excitons generated by this move to the interface between the electron donor and electron acceptor constituting the photoelectric conversion layer 24, and are dissociated into excitons, that is, into electrons and holes. The charges (electrons and holes) generated here are carried to different electrodes by diffusion due to the difference in carrier concentration and by an internal electric field due to the difference in work function between the anode (here, the upper electrode 25) and the cathode (here, the lower electrode 21), and are detected as a photocurrent. In addition, the transport direction of the electrons and holes can be controlled by applying a potential between the lower electrode 21 and the upper electrode 25.

[0018] The structure and materials of each part will be described below.

[0019] The organic photoelectric conversion unit 20 is an organic photoelectric conversion element that absorbs green light corresponding to a part or all of a selective wavelength range (for example, 450 nm or more and 650 nm or less) and generates excitons. The organic photoelectric conversion unit 20 has a charge storage layer 23 and a photoelectric conversion layer 24 between a lower electrode 21 and an upper electrode 25 arranged opposite to each other, and an insulating layer 22 is provided between the lower electrode 21 and the charge storage layer 23. The lower electrode 21 is formed separately for each image sensor 10A, for example, and is composed of a readout electrode 21A and a storage electrode 21B separated from each other by the insulating layer 22, and a shield electrode 21C surrounding four adjacent pixels. Of the lower electrode 21, the readout electrode 21A is shared between two or four adjacent pixels, as shown in, for example, FIG. 5A and FIG. 6A, and is electrically connected to the charge storage layer 23 through an opening 22H provided in the insulating layer 22. The charge storage layer 23, the photoelectric conversion layer 24 and the upper electrode 25 are provided, for example, as a continuous layer common to the multiple image sensors 10A and extend into the effective pixel area 110A.

[0020] The lower electrode 21 is composed of the read electrode 21A, the storage electrode 21B, and the shield electrode 21C, which are formed separately as described above. The read electrode 21A is for transferring the charge (here, electrons) generated in the photoelectric conversion layer 24 to the floating diffusion FD1, and is connected to the floating diffusion FD1 via, for example, the via V1, the pad portion 36A, the via V2, the pad portion 35A, the through electrode 34, the connection portion 41A, and the lower first contact 45. The storage electrode 21B is for storing electrons as signal charges in the charge storage layer 23, among the charges generated in the photoelectric conversion layer 24. The storage electrode 21B is provided in a region that directly faces the light receiving surfaces of the inorganic photoelectric conversion units 32B and 32R formed in the semiconductor substrate 30 and covers these light receiving surfaces. The storage electrode 21B is preferably larger than the read electrode 21A, and thus can store a large amount of charge. The shield electrode 21C is for suppressing leakage of charges to adjacent pixels, as described above.

[0021] The lower electrode 21 is made of a conductive film having optical transparency, for example, ITO (indium tin oxide). However, the material of the lower electrode 21 may be other than ITO, such as tin oxide with a dopant added (SnO 2 Alternatively, a zinc oxide-based material obtained by adding a dopant to zinc oxide (ZnO) may be used. Examples of zinc oxide-based materials include aluminum zinc oxide (AZO) to which aluminum (Al) is added as a dopant, gallium zinc oxide (GZO) to which gallium (Ga) is added, and indium zinc oxide (IZO) to which indium (In) is added. In addition to these, CuI, InSbO 4 , ZnMgO, CuInO 2 , MgIN 2 O 4 , CdO, ZnSnO 3 The thickness of the lower electrode 21 is preferably, for example, 20 nm or more and 200 nm or less, and more preferably, 30 nm or more and 100 nm or less.

[0022] The insulating layer 22 is for electrically insulating the storage electrode 21B from the charge storage layer 23. The insulating layer 22 is provided, for example, on the interlayer insulating layer 29 and the lower electrode 21 so as to cover the lower electrode 21. The insulating layer 22 has an opening 22H provided on the read electrode 21A of the lower electrode 21, and the read electrode 21A and the charge storage layer 23 are electrically connected via this opening 22H. The insulating layer 22 is made of, for example, silicon oxide (SiO x ), silicon nitride (SiN x ) and silicon oxynitride (SiO x N y ) or a laminated film made of two or more of them. The thickness of the insulating layer 22 is, for example, 20 nm or more and 500 nm or less.

[0023] The charge storage layer 23 is provided below the photoelectric conversion layer 24, specifically between the insulating layer 22 and the photoelectric conversion layer 24, and is for storing signal charges (here, electrons) generated in the photoelectric conversion layer 24. The charge storage layer 23 is preferably formed using a material having a higher charge mobility and a larger band gap than the photoelectric conversion layer 24. For example, the band gap of the constituent material of the charge storage layer 23 is preferably 3.0 eV or more. Examples of such materials include oxide semiconductor materials such as IGZO and organic semiconductor materials. Examples of organic semiconductor materials include transition metal dichalcogenides, silicon carbide, diamond, graphene, carbon nanotubes, condensed polycyclic hydrocarbon compounds, and condensed heterocyclic compounds. The thickness of the charge storage layer 23 is, for example, 10 nm or more and 300 nm or less. By providing the charge storage layer 23 made of the above material below the photoelectric conversion layer 24, it is possible to prevent recombination of charges during charge storage and improve transfer efficiency.

[0024] The photoelectric conversion layer 24 converts light energy into electrical energy. The photoelectric conversion layer 24 is configured to include, for example, two or more organic materials (p-type semiconductor materials or n-type semiconductor materials) that function as p-type or n-type semiconductors, respectively. The photoelectric conversion layer 24 has a bulk heterojunction structure including a junction surface (p / n junction surface) between the p-type semiconductor material and the n-type semiconductor material within the layer. The p-type semiconductor functions relatively as an electron donor (donor), and the n-type semiconductor functions relatively as an electron acceptor (acceptor). The photoelectric conversion layer 24 provides a place where excitons generated when light is absorbed are separated into electrons and holes. Specifically, the excitons are separated into electrons and holes at the interface (p / n junction surface) between the electron donor and the electron acceptor.

[0025] The photoelectric conversion layer 24 may be configured to contain an organic material, so-called dye material, that converts light in a predetermined wavelength range into electric current while transmitting light in other wavelength ranges, in addition to the p-type semiconductor material and the n-type semiconductor material. When the photoelectric conversion layer 24 is formed using three types of organic materials, the p-type semiconductor material, the n-type semiconductor material, and the dye material, the p-type semiconductor material and the n-type semiconductor material are preferably materials that have optical transparency in the visible range (e.g., 450 nm or more and 800 nm or less). The thickness of the photoelectric conversion layer 24 is, for example, 50 nm or more and 500 nm or less.

[0026] Examples of organic materials constituting the photoelectric conversion layer 24 include quinacridone, chlorinated boron subphthalocyanine, pentacene, benzothienobenzothiophene, and fullerene, or derivatives thereof. The photoelectric conversion layer 24 is formed by combining two or more of the above organic materials. The above organic materials function as p-type or n-type semiconductors depending on the combination.

[0027] The organic material constituting the photoelectric conversion layer 24 is not particularly limited. In addition to the above organic materials, for example, any one of naphthalene, anthracene, phenanthrene, tetracene, pyrene, perylene, and fluoranthene or derivatives thereof is preferably used. Alternatively, polymers such as phenylenevinylene, fluorene, carbazole, indole, pyrene, pyrrole, picoline, thiophene, acetylene, and diacetylene, or derivatives thereof may be used. In addition, metal complex dyes, cyanine dyes, merocyanine dyes, phenylxanthene dyes, triphenylmethane dyes, rhodacyanine dyes, xanthene dyes, macrocyclic azaannulene dyes, azulene dyes, naphthoquinone, anthraquinone dyes, condensed polycyclic aromatics such as anthracene and pyrene, and chain compounds in which aromatic rings or heterocyclic compounds are condensed, or two nitrogen-containing heterocycles such as quinoline, benzothiazole, and benzoxazole having a squarylium group and a croconite methine group as a binding chain, or cyanine-like dyes bonded by a squarylium group and a croconite methine group, etc. can be preferably used. Note that, as the above-mentioned metal complex dyes, dithiol metal complex dyes, metal phthalocyanine dyes, metal porphyrin dyes, or ruthenium complex dyes are preferred, but are not limited thereto.

[0028] Other layers may be provided between the photoelectric conversion layer 24 and the lower electrode 21 (for example, between the charge storage layer 23 and the photoelectric conversion layer 24) and between the photoelectric conversion layer 24 and the upper electrode 25. Specifically, for example, the charge storage layer 23, the electron blocking layer, the photoelectric conversion layer 24, the hole blocking layer, and the work function adjustment layer may be laminated in this order from the lower electrode 21 side. Furthermore, an undercoat layer and a hole transport layer may be provided between the lower electrode 21 and the photoelectric conversion layer 24, and a buffer layer and an electron transport layer may be provided between the photoelectric conversion layer 24 and the upper electrode 25.

[0029] The upper electrode 25 is made of a conductive film having optical transparency, similar to the lower electrode 21. In the imaging device 1 using the imaging element 10A as one pixel, the upper electrode 25 may be separated for each pixel, or may be formed as a common electrode for each pixel. The thickness of the upper electrode 25 is, for example, 10 nm or more and 200 nm or less. As shown in FIG. 2, the upper electrode 25 is electrically connected to a wiring 52, for example, through an opening 51H2. As shown in FIG. 2, the wiring 52 is electrically connected to a pad portion 36D provided in the peripheral region 110B, through an opening 51H1 penetrating the flattening layer 51 and the sealing layer 26 described later. That is, the upper electrode 25 is electrically connected to the pad portion 36D, for example, through the wiring 52.

[0030] As described above, the sealing layer 26 including the first layer 26A, the second layer 26B, and the third layer 26C is provided on the upper electrode 25. The sealing layer 26 prevents hydrogen (H 2 ) is intended to suppress the intrusion of hydrogen, and it is preferable that the hydrogen content is low or that the film itself does not contain hydrogen. In the sealing layer 26, the first layer 26A and the second layer 26B are provided on the upper surface of the upper electrode 25, and the third layer 26C is formed on the insulating layer 22 from the upper surface of the upper electrode 25 through the side surfaces of the upper electrode 25, the photoelectric conversion layer 24, and the charge storage layer 23, and extends, for example, to the end of the peripheral region 110B.

[0031] Examples of materials constituting the sealing layer 26 include insulating materials that are optically transparent and have high sealing properties. Specifically, the first layer 26A is made of, for example, aluminum nitride (AlN x ) or silicon nitride (SiN x The second layer 26B and the third layer 26C can be formed using, for example, aluminum oxide (AlO x The first layer 26A and the second layer 26B can be formed, for example, by atomic layer deposition (ALD) to a film thickness of, for example, 1 nm to 100 nm. As a result, a high-density insulating film is formed on the upper surface of the upper electrode 25, and hydrogen (H 2The third layer 26C can be formed, for example, by sputtering to a thickness of, for example, 100 nm or more and 1000 nm or less.

[0032] Between the first surface 30S1 of the semiconductor substrate 30 and the lower electrode 21, for example, a fixed charge layer 27, an insulating layer 28, and an interlayer insulating layer 29 are provided in this order.

[0033] The fixed charge layer 27 may be a film having a positive fixed charge or a film having a negative fixed charge. Examples of materials for a film having a negative fixed charge include hafnium oxide (HfO x ), aluminum oxide (AlO x ), zirconium oxide (ZrO x ), tantalum oxide (TaO x ), titanium dioxide (TiO x ), lanthanum oxide (LaO x ), praseodymium oxide (PrO x ), cerium oxide (CeO x ), neodymium oxide (NdO x ), promethium oxide (PmO x ), samarium oxide (SmO x ), europium oxide (EuO x ), gadolinium oxide (GdO x ), terbium oxide (TbO x ), dysprosium oxide (DyO x ), Holmium oxide (HoO x ), thulium oxide (TmO x ), ytterbium oxide (YbO x ), lutetium oxide (LuO x ), yttrium oxide (YO x ), hafnium nitride (HfN x ), Aluminum Nitride (AlN x ), hafnium oxynitride (HfO x N y ) and aluminum oxynitride (AlO x N y ) etc.

[0034] The fixed charge layer 27 may have a structure in which two or more types of films are laminated together, which can further enhance the function as a hole accumulation layer, for example, in the case of a film having a negative fixed charge.

[0035] The insulating layer 28 is provided on the fixed charge layer 27 formed on the first surface 30S1 of the semiconductor substrate 30 and between the fixed charge layer 27 and the through electrodes 34A, 34B, 34C, and 34D in the through holes 30H1, 30H2, 30H3, and 30H4 in which the through electrodes 34A, 34B, 34C, and 34D are formed, as described below, to electrically insulate the through electrodes 34A, 34B, 34C, and 34D from the semiconductor substrate 30. The constituent material of the insulating layer 28 is not particularly limited, and may be, for example, silicon oxide (SiO x ), TEOS, silicon nitride (SiN x ) and silicon oxynitride (SiO x N y ) etc.

[0036] The interlayer insulating layer 29 is made of, for example, silicon oxide (SiO x ), TEOS, silicon nitride (SiN x ) and silicon oxynitride (SiO x N y ) or a laminated film made of two or more of them. In addition, in the interlayer insulating layer 29, wirings such as pads 35A, 36A electrically connecting the read electrode 21A and the through electrode 34A, pads 35B, 36B electrically connecting the storage electrode 21B and the through electrode 34B, pads 35C, 36C electrically connecting the shield electrode 21C and the through electrode 34C, pads 35D, 36D electrically connecting the wiring 52 and the through electrode 34D, and vias V1, V2 electrically connecting each electrode and the pads are provided.

[0037] The semiconductor substrate 30 is, for example, made of an n-type silicon (Si) substrate, and has a p-well 31 in a predetermined region (for example, the effective pixel region 110A). The above-mentioned transfer transistors TR1trs, TR2trs, TR3trs, amplifier transistors TR1amp, TR2amp, reset transistors TR1rst, TR2rst, selection transistors TR1sel, TR2sel, etc. are provided on a second surface 30S2 of the p-well 31. Furthermore, a peripheral circuit section 130 including a logic circuit, etc. is provided on the peripheral region 110B of the semiconductor substrate 30.

[0038] As described above, the image sensor 10A of the present embodiment is laid out so that one floating diffusion FD1, FD2, and FD3 is shared by four adjacent pixels. FIG. 5A shows an example of the layout of the lower electrode 21 constituting the organic photoelectric conversion section 20, and FIG. 5B shows the layout of the lower electrode 21 shown in FIG. 5A as a perspective view. FIG. 6A shows an example of the layout of the lower electrode 21 constituting the organic photoelectric conversion section 20, and FIG. 6B shows the layout of the lower electrode 21 shown in FIG. 6A as a perspective view. FIG. 7 shows an example of the layout of the inorganic photoelectric conversion section 32B and various transistors associated therewith. FIG. 8 shows an example of the layout of the inorganic photoelectric conversion section 32R and various transistors associated therewith. FIG. 9 shows an example of signal wiring for driving the storage electrode 21B in the organic photoelectric conversion section 20. 10 to 12 show an example of wiring connected to the photoelectric conversion units 20, 32B, and 32R and various transistors associated therewith.

[0039] In this embodiment, the four adjacent organic photoelectric conversion units 20 are connected to one floating diffusion FD1. The floating diffusion FD1 is connected in series with one reset transistor TR1rst and a power supply line Vdd. In addition, the floating diffusion FD1 is connected in series with one of the amplifier transistor TR1amp and the selection transistor TR1sel and a signal line (data output line) VSL1. The four adjacent storage electrodes 21B, the reset transistor TR1rst, the amplifier transistor TR1amp, and the selection transistor TR1sel provided for each pixel constitute a set of control units (first control units) that perform the read operation and reset operation of the four adjacent organic photoelectric conversion units 20. When reading out signal charges from the four adjacent organic photoelectric conversion units 20, the first control unit is used to perform a read process in sequence, for example, in a time-division manner.

[0040] In the inorganic photoelectric conversion unit 32B, four photodiodes PD2 adjacent to each other are connected to one floating diffusion FD2 via four transfer transistors TR2trs provided one for each pixel.

[0041] In the inorganic photoelectric conversion unit 32R, similarly to the inorganic photoelectric conversion unit 32B, four adjacent photodiodes PD3 are connected to one floating diffusion FD3 via four transfer transistors TR3trs provided one for each pixel.

[0042] A single floating diffusion FD2 is connected in series to a single reset transistor TR2rst and a power supply line Vdd. In addition to this, a signal line (data output line) VSL2 is connected in series to the floating diffusion FD2 to each of the amplifier transistor TR2amp and the selection transistor TR2sel. In the image sensor 10A having a pixel sharing structure as in the present embodiment, the inorganic photoelectric conversion unit 32B and the inorganic photoelectric conversion unit 32R are configured as a set of control units (second control units) that perform the read operation and reset operation of the four mutually adjacent inorganic photoelectric conversion units 32B and the inorganic photoelectric conversion units 32R, including the transfer transistor TR2trs and the transfer transistor TR3trs provided for each pixel, and the reset transistor TR2rst, the amplifier transistor TR2amp, and the selection transistor TR2sel provided for each pixel. That is, the four inorganic photoelectric conversion units 32B and the four inorganic photoelectric conversion units 32R included in the stacked-type imaging element 10A for four pixels are configured to share one control unit (second control unit) except for the transfer transistors TR2trs and TR3trs. When reading out signal charges from the floating diffusions FD2 corresponding to the four inorganic photoelectric conversion units 32B and the floating diffusions FD3 corresponding to the four inorganic photoelectric conversion units 32R adjacent to each other, the second control unit is used to perform a readout process in sequence, for example, in a time-division manner.

[0043] In this embodiment, the floating diffusions FD2 and FD3 shared by the four adjacent inorganic photoelectric conversion units 32B and 32R are disposed at positions spaced apart by one pixel each, thereby enabling high integration of the image sensor 10A to be achieved.

[0044] Between the first surface 30S1 and the second surface 30S2 of the semiconductor substrate 30, through electrodes 34A, 34B, 34C, and 34D are provided.

[0045] The through electrode 34A is electrically connected to the readout electrode 21A of the organic photoelectric conversion unit 20, and the organic photoelectric conversion unit 20 is connected, for example, to the gate Gamp of the amplifier transistor TR1amp and one of the source / drain regions of the reset transistor RST (reset transistor TR1rst) that also serves as the floating diffusion FD1 via the through electrode 34A. This makes it possible for the image sensor 10A to effectively transfer charges (here, electrons) generated in the organic photoelectric conversion unit 20 on the first surface 30S1 side of the semiconductor substrate 30 to the second surface 30S2 side of the semiconductor substrate 30, thereby improving the characteristics.

[0046] The through electrode 34B is electrically connected to the storage electrode 21B of the organic photoelectric conversion unit 20, which makes it possible to apply a voltage to the storage electrode 21B independent of the readout electrode 21A.

[0047] The through electrode 34C is electrically connected to the shield electrode 21C, thereby suppressing leakage of charges to adjacent pixels. The through electrode 34D is electrically connected to a pad portion 36D provided in the peripheral region 110B. As shown in FIG. 1, the wiring 52 is electrically connected to the pad portion 36D through the opening 51H1 to form a guard ring 55. This allows a voltage to be applied to the upper electrode 25. The guard ring 55 can also prevent water from entering from the periphery. The wiring 52 forming the guard ring 55 does not necessarily have to be electrically connected to the upper electrode 25. In addition, in FIG. 2, an example in which the protective layer 53 is embedded in the opening 51H1 forming the guard ring 55 is shown, but this is not limiting, and for example, the sealing layer 26 or the planarization layer 51 may be embedded therein.

[0048] The lower ends of the through electrodes 34A, 34B, 34C, and 34D are each connected to the wiring layer 41. In particular, the through electrode 34A is connected to a connection portion 41A in the wiring layer 41, and the connection portion 41A and the floating diffusion FD1 (region 35) are connected, for example, via a lower first contact 45. The upper end of the through electrode 34A is connected to the read electrode 21A, for example, via a pad portion 35A, a via V2, a pad portion 36A, and a via V1.

[0049] The through electrode 34A is provided, for example, for every four pixels adjacent to each other. The through electrode 34A functions as a connector between the organic photoelectric conversion unit 20 of each pixel and the gate Gamp of the amplifier transistor TR1amp and the floating diffusion FD1, and also serves as a transmission path for charges (here, electrons) generated in the organic photoelectric conversion unit 20.

[0050] On the sealing layer 26, a planarization layer 51, a protection layer 53, and an on-chip lens layer 56 are further provided in this order.

[0051] The planarization layer 51 and the protective layer 53 are provided, for example, on the entire surface of the semiconductor substrate 30 including the effective pixel region 110A and the peripheral region 110B. The planarization layer 51 and the protective layer 53 are preferably formed using a material that is optically transparent and has high sealing properties. Examples of such materials include aluminum oxide (AlO x ), silicon nitride (SiN x ) and carbon-containing silicon oxide (SiOC). Similarly to the sealing layer 26, the planarization layer 51 and the protective layer 53 preferably have a lower hydrogen content than the insulating layer 22, or the film itself does not contain hydrogen. Furthermore, the planarization layer 51 and the protective layer 53 preferably have, for example, a small stress and an ultraviolet absorbing ability. Furthermore, the planarization layer 51 and the protective layer 53 preferably have a small moisture content, and moisture (H 2For these reasons, it is preferable to suppress the intrusion of aluminum oxide (AlO) among the above-mentioned materials as the constituent material of the planarization layer 51 and the protective layer 53. x ) is preferably used.

[0052] The planarization layer 51 and the protective layer 53 may be formed using the same materials as the insulating layer 28 and the interlayer insulating layer 29. For example, the planarization layer 51 and the protective layer 53 may be formed using silicon oxide (SiO x ), silicon nitride (SiN x ) and silicon oxynitride (SiO x N y ), or aluminum oxide (AlO x ), silicon nitride (SiN x ), carbon-containing silicon oxide film (SiOC), silicon oxide (SiO x ) and silicon oxynitride (SiO x N y The planarization layer 51 may have a thickness of, for example, 100 nm or more and 1000 nm or less. The protective layer 53 may have a thickness of, for example, 10 nm or more and 1000 nm or less.

[0053] A wiring 52 is provided on the protective layer 53 in the peripheral region 110B. As described above, the wiring 52 is electrically connected to the upper electrode 25, for example, through an opening 51H2 penetrating the planarization layer 51 and the sealing layer 26. In addition, the wiring 52 is electrically connected to a pad portion 36D provided in the interlayer insulating layer 29 in the peripheral region 110B through an opening 51H1 penetrating the planarization layer 51, the sealing layer 26, and the insulating layer 22, forming a guard ring 55. A through electrode 34D is connected to the pad portion 36D, which penetrates the via V2, the pad portion 35D, and the semiconductor substrate 30 and is connected to the wiring layer 41 provided on the second surface 30S2 side of the semiconductor substrate 30, thereby functioning as a transmission path for charges (here, holes) generated in the organic photoelectric conversion unit 20.

[0054] A light-shielding film 54 is provided on the protective layer 53 in the peripheral region 110B. Examples of materials for the light-shielding film 54 include tungsten (W), titanium (Ti), titanium nitride (TiN), and aluminum (Al), and the light-shielding film 54 is configured as, for example, a laminated film of W / TiN / Ti or a single layer film of W. The thickness of the light-shielding film 54 is, for example, not less than 50 nm and not more than 400 nm.

[0055] Furthermore, an on-chip lens layer 56 is provided on the protective layer 53, in which an on-chip lens 56L (microlens) is formed for each unit pixel P in the effective pixel region 110A. The on-chip lens 56L focuses incident light onto the light receiving surfaces of the organic photoelectric conversion unit 20, the inorganic photoelectric conversion unit 32B, and the inorganic photoelectric conversion unit 32R. Note that an optical member such as a color filter for controlling light dispersion may be provided below the on-chip lens 56L.

[0056] (1-2. Manufacturing method of image sensor) The imaging element 10A of the present embodiment can be manufactured, for example, as follows.

[0057] First, for example, a p-well 31 is formed as a first conductivity type well in the semiconductor substrate 30, and inorganic photoelectric conversion units 32B, 32R of a second conductivity type (for example, n-type) are formed in this p-well 31. A p+ region is formed in the vicinity of the first surface 30S1 of the semiconductor substrate 30.

[0058] On the second surface 30S2 of the semiconductor substrate 30, n+ regions that become floating diffusions FD1 to FD3, for example, are formed, and then a gate insulating layer 33 and a gate wiring layer 47 including the gates of various transfer transistors TR1trs, TR2trs, TR3trs, selection transistors TR1sel, TR2sel, amplifier transistors TR1amp, TR2amp, and reset transistors TR1rst, TR2rst are formed. As a result, various transfer transistors TR1trs, TR2trs, TR3trs, selection transistors TR1sel, TR2sel, amplifier transistors TR1amp, TR2amp, and reset transistors TR1rst, TR2rst are formed. Furthermore, on the second surface 30S2 of the semiconductor substrate 30, a multilayer wiring layer 40 including wiring layers 41 to 43 including a lower first contact 45 and a connection portion 41A and an insulating layer 44 is formed.

[0059] The base of the semiconductor substrate 30 is, for example, an SOI (Silicon on Insulator) substrate in which the semiconductor substrate 30, a buried oxide film (not shown), and a holding substrate (not shown) are laminated. The buried oxide film and the holding substrate are bonded to the first surface 30S1 of the semiconductor substrate 30. After the ion implantation, an annealing process is performed.

[0060] Next, a support substrate (not shown) or another semiconductor base is bonded to the second surface 30S2 side (the multilayer wiring layer 40 side) of the semiconductor substrate 30, and the substrate is turned upside down. The semiconductor substrate 30 is then separated from the buried oxide film of the SOI substrate and the holding substrate, and the first surface 30S1 of the semiconductor substrate 30 is exposed. The above steps can be performed by techniques used in normal CMOS processes, such as ion implantation and chemical vapor deposition (CVD).

[0061] Next, the semiconductor substrate 30 is processed from the first surface 30S1 side by, for example, dry etching to form, for example, annular through holes 30H1, 30H2, 30H3, and 30H4. The through holes 30H1 to 30H4 have a depth that penetrates from the first surface 30S1 of the semiconductor substrate 30 to the second surface 30S2.

[0062] Next, the fixed charge layer 27 is formed on the first surface 30S1 of the semiconductor substrate 30 and the side surface of the through hole 30H by, for example, the ALD method. As a result, the fixed charge layer 27 is formed continuous with the first surface 30S1 of the semiconductor substrate 30 and the side and bottom surfaces of the through holes 30H1, 30H2, 30H3, and 30H4. Next, the insulating layer 28 is formed on the first surface 30S1 of the semiconductor substrate 30 of the fixed charge layer 27 and in the through holes 30H1, 30H2, 30H3, and 30H4, and then an insulating film constituting an interlayer insulating layer 29 is formed on the insulating layer 28.

[0063] Next, through holes are formed in the insulating layer 28 formed in the through holes 30H1, 30H2, 30H3, and 30H4 by, for example, dry etching, penetrating the insulating film constituting the interlayer insulating layer 29, the insulating layer 28, the fixed charge layer 27, and the insulating layer 44, and reaching the connection portion 41A. At this time, the insulating film constituting the interlayer insulating layer 29 on the first surface 30S1 is also thinned. Next, a conductive film is formed on the insulating film constituting the interlayer insulating layer 29 and in the through hole 27H, and then a photoresist is formed at a predetermined position on the conductive film. Then, the etching and the photoresist are removed, thereby forming the through electrodes 34A, 34B, 34C, and 34D having the pad portions 35A, 35B, 35C, and 35D, respectively, on the first surface 30S1 of the semiconductor substrate 30.

[0064] Next, the via V2, the pads 36, 36B, 36C, 36D, and the via V1 are formed on the insulating film and the through electrodes 34A, 34B, 34C, 34D constituting the interlayer insulating layer 29, respectively, and then the surface of the interlayer insulating layer 29 is planarized by chemical mechanical polishing (CMP). Next, a conductive film is formed on the interlayer insulating layer 29, and then a photoresist is formed at a predetermined position of the conductive film. Then, the read electrode 21A, the storage electrode 21B, and the shield electrode 21C are formed by etching and removing the photoresist. Next, the insulating layer 22 is formed on the interlayer insulating layer 29, the read electrode 21A, the storage electrode 21B, and the shield electrode 21C, and then an opening 22H is provided on the read electrode 21A. Next, the charge storage layer 23, the photoelectric conversion layer 24, and the upper electrode 25 are formed on the insulating layer 22.

[0065] When the charge storage layer 23 or other organic layers are formed using an organic material, it is desirable to form them continuously in a vacuum process (in a vacuum integrated process). The method for forming the photoelectric conversion layer 24 is not necessarily limited to a method using a vacuum deposition method, and other methods, such as a spin coating technique or a printing technique, may also be used.

[0066] 13, aluminum nitride (AlN x ) film and aluminum oxide (AlO x ) film is formed to a thickness of, for example, 30 nm by using the ALD method. Specifically, first, trimethylaluminum is used as an Al precursor, and nitrogen (N 2 ) plasma to form AlN x After forming the film (first layer 26A), nitrogen (N 2 ) plasma with oxygen (O 2 ) plasma to produce AlO x A film (second layer 26B) is formed.

[0067] The first layer 26A is made of silicon nitride (SiN x When forming a silicon (Si) film, for example, bis(tert-butylamino)silane is used as the silicon precursor, and nitrogen (N 2 ) / Ammonia (NH 3 ) Plasma is irradiated to produce SiN x Then, an Al precursor (e.g., trimethylaluminum) and oxygen (O 2 ) plasma and AlO x A film (second layer 26B) is formed.

[0068] 14, the charge storage layer 23, the photoelectric conversion layer 24, and the upper electrode 25 in the peripheral portion of the peripheral region 110B are removed by using lithography technology. The charge storage layer 23, the photoelectric conversion layer 24, and the upper electrode 25 can be removed, for example, by forming a photoresist at a predetermined position of the second layer 26B, patterning the second layer 26B, and then performing dry etching using the photoresist as a mask.

[0069] Next, as shown in FIG. 15, AlO 2 extending on the second layer 26B, the charge storage layer 23, the photoelectric conversion layer 24, the upper electrode 25, the side surfaces of the first layer 26A and the second layer 26B, and the insulating layer 22 is formed by, for example, an ALD method. x After forming a film (third layer 26C) with a thickness of, for example, 30 nm, AlO x A film (planarization layer 51) is formed to a thickness of, for example, 500 nm.

[0070] 17, openings 51H1 and 51H2 are formed which penetrate to the pad portion 36D and the upper electrode 25. Specifically, first, a photoresist is patterned on the planarization layer 51, and then wet etching is performed. As a result, an opening 51H1 which reaches the pad portion 36D is formed as shown in FIG. 16. In the portion which becomes the opening 51H2, the first layer 26A (AlN x The etching stopper film serves as an etching stopper film, and an opening 51H2a is formed to expose the first layer 26A. Thereafter, the first layer 26A at the exposed bottom surface of the opening 51H2a is etched by dry etching using, for example, hydrogen fluoride (HF), thereby forming an opening 51H2 reaching the upper electrode 25.

[0071] 16 may be formed by a two-stage process of dry etching and wet etching. Specifically, for example, AlO x The third layer 26C and the planarization layer 51 made of a film are etched to a thickness of, for example, 50 to 100 nm, and then the remaining AlO x The film may be removed, which allows the openings 51H1 and 51H2a to be processed into the desired shapes.

[0072] 18, continuous wiring 52 is formed on the planarization layer 51 and on the side and bottom surfaces of the openings 51H1 and 51H2, and then a protective layer 53 is formed on the planarization layer 51 and wiring 52, and filling the openings 51H1 and 51H2. This prevents hydrogen and moisture from entering the charge storage layer 23 through the openings 51H1 and 51H2. Finally, a light-shielding film 54 and an on-chip lens layer 56 are formed. With the above steps, the image sensor 10A shown in FIG. 1 is completed.

[0073] In the imaging element 10A, when light is incident on the organic photoelectric conversion unit 20 through the on-chip lens 56L, the light passes through the organic photoelectric conversion unit 20 and the inorganic photoelectric conversion units 32B and 32R in this order, and is photoelectrically converted into green, blue, and red light during the passing process. The operation of acquiring signals of each color will be described below.

[0074] (Acquisition of a green signal by the organic photoelectric conversion unit 20) Of the light incident on the imaging element 10A, green light is first selectively detected (absorbed) by the organic photoelectric conversion section 20 and photoelectrically converted.

[0075] The organic photoelectric conversion unit 20 is connected to the gate Gamp of the amplifier transistor AMP and the floating diffusion FD1 via the through electrode 34. Thus, electrons of the excitons generated in the organic photoelectric conversion unit 20 are extracted from the lower electrode 21 side, transferred to the second surface 30S2 side of the semiconductor substrate 30 via the through electrode 34, and accumulated in the floating diffusion FD1. At the same time, the amount of charge generated in the organic photoelectric conversion unit 20 is modulated into a voltage by the amplifier transistor AMP.

[0076] In addition, a reset gate Grst of the reset transistor TR1rst is disposed next to the floating diffusion FD1, so that the charge accumulated in the floating diffusion FD1 is reset by the reset transistor TR1rst.

[0077] Here, the organic photoelectric conversion unit 20 is connected not only to the amplifier transistor TR1amp but also to the floating diffusion FD1 via the through electrode 34A, so that the charge accumulated in the floating diffusion FD1 can be easily reset by the reset transistor TR1rst.

[0078] On the other hand, if the through electrode 34A and the floating diffusion FD1 are not connected, it becomes difficult to reset the charge accumulated in the floating diffusion FD1, and a large voltage is applied to pull it out to the upper electrode 25. This may damage the photoelectric conversion layer 24. In addition, a structure that enables resetting in a short time leads to an increase in dark noise, which is a trade-off, making this structure difficult to implement.

[0079] 19 shows an example of the operation of the image sensor 10A. (A) shows the potential at the storage electrode 21B, (B) shows the potential at the floating diffusion FD1 (readout electrode 21A), and (C) shows the potential at the gate (Gsel) of the reset transistor TR1rst. In the image sensor 10A, voltages are applied to the readout electrode 21A and the storage electrode 21B individually.

[0080] In the imaging element 10A, during the accumulation period, a potential V1 is applied from the drive circuit to the readout electrode 21A, and a potential V2 is applied to the storage electrode 21B. Here, the potentials V1 and V2 are set to V2>V1. As a result, the charge (here, electrons) generated by photoelectric conversion is attracted to the storage electrode 21B and accumulated in the region of the charge storage layer 23 facing the storage electrode 21B (accumulation period). Incidentally, the potential of the region of the charge storage layer 23 facing the storage electrode 21B becomes a more negative value as the time of photoelectric conversion elapses. Incidentally, the holes are sent from the upper electrode 25 to the drive circuit.

[0081] In the imaging device 10A, a reset operation is performed in the latter stage of the accumulation period. Specifically, at timing t1, the scanning unit changes the voltage of the reset signal RST from a low level to a high level. As a result, in the unit pixel P, the reset transistor TR1rst is turned on, and the voltage of the floating diffusion FD1 is set to the power supply voltage VDD, and the voltage of the floating diffusion FD1 is reset (reset period).

[0082] After the completion of the reset operation, the charge is read out. Specifically, at timing t2, the potential V3 is applied to the readout electrode 21A and the potential V4 is applied to the storage electrode 21B from the drive circuit. Here, the potentials V3 and V4 are set such that V3 < V4. As a result, the charge (here, electrons) accumulated in the region corresponding to the storage electrode 21B is read out from the readout electrode 21A to the floating diffusion FD1. That is, the charge accumulated in the charge storage layer 23 is read out to the control unit (transfer period).

[0083] After the completion of the readout operation, again, the potential V1 is applied to the readout electrode 21A and the potential V2 is applied to the storage electrode 21B from the drive circuit. As a result, the charge (here, electrons) generated by the photoelectric conversion is attracted to the storage electrode 21B and accumulated in the region of the photoelectric conversion layer 24 facing the storage electrode 21B (accumulation period).

[0084] (Acquisition of blue and red signals by the inorganic photoelectric conversion units 32B and 32R) Next, of the light transmitted through the organic photoelectric conversion section 20, the blue light is absorbed in the inorganic photoelectric conversion section 32B, and the red light is absorbed in the inorganic photoelectric conversion section 32R, in that order, and photoelectrically converted. In the inorganic photoelectric conversion section 32B, electrons corresponding to the incident blue light are accumulated in the n-region of the inorganic photoelectric conversion section 32B, and the accumulated electrons are transferred to the floating diffusion FD2 by the transfer transistor TR2trs. Similarly, in the inorganic photoelectric conversion section 32R, electrons corresponding to the incident red light are accumulated in the n-region of the inorganic photoelectric conversion section 32R, and the accumulated electrons are transferred to the floating diffusion FD3 by the transfer transistor TR3trs.

[0085] (1-3. Actions and Effects) The imaging element 10A of the present embodiment includes a sealing layer 26 covering the upper surface of the organic photoelectric conversion unit 20, which contains nitrogen (N 2 ) containing insulating materials (e.g., AlN x or SiN x ) and oxygen (O 2 ) containing insulating materials (e.g., AlO x ) are laminated in this order. This makes it possible to easily form an opening 51H2 in the peripheral region 110B, for example, through which the wiring 52 for applying a voltage to the upper electrode 25 of the organic photoelectric conversion unit 20 is connected to the upper electrode 25. This will be described below.

[0086] In recent years, development of stacked imaging elements in which multiple photoelectric conversion units are stacked vertically has been progressing as imaging elements constituting CCD image sensors, CMOS image sensors, etc. The stacked imaging element has, for example, a configuration in which two inorganic photoelectric conversion units, each made of a photodiode (PD), are stacked in a silicon (Si) substrate, and an organic photoelectric conversion unit having a photoelectric conversion layer containing an organic material is provided above the Si substrate.

[0087] In such a stacked-type image sensor, a contact with the upper electrode is formed at the edge of the effective pixel area. A sealing layer is generally formed on the upper electrode, and the contact with the upper electrode is formed by, for example, etching the sealing layer by dry etching, and then depositing a metal film to serve as wiring.

[0088] In this case, if the sealing layer is made of only aluminum oxide, two-stage dry etching is performed. Specifically, for example, the sealing layer is etched halfway using a chlorine-based gas, and then the remaining sealing layer is etched using a fluorine-based gas, stopping at the surface of the upper electrode. In such two-stage dry etching, there are problems in that in-plane variations occur in the first stage and aluminum fluoride (AlF) particles are generated in the second stage, resulting in a decrease in manufacturing yield.

[0089] In contrast, in the present embodiment, nitrogen (N 2 ) containing insulating materials (e.g., AlN x or SiN x ) and oxygen (O 2 ) containing insulating materials (e.g., AlO x ) is formed, and the first layer 26A and the second layer 26B are laminated in this order on the upper surface of the organic photoelectric conversion unit 20. As a result, in the wet etching process for forming the opening 51H2 for connecting the upper electrode 25 of the organic photoelectric conversion unit 20 to the wiring 52 for applying a voltage, the first layer 26A is used as an etching stopper film to prevent the AlO x This makes it possible to prevent the occurrence of in-plane variations as described above. Furthermore, in the subsequent dry etching process, since only the first layer 26A is etched, it is possible to reduce the generation of aluminum fluoride (AlF) particles. Also, the first layer 26A can be etched by removing SiN x When the insulating film is formed using the above, it is possible to prevent the generation of particles.

[0090] As described above, in the imaging element 10A of the present embodiment, the upper surface of the organic photoelectric conversion unit 20 is covered with nitrogen (N 2 ) containing insulating materials (e.g., AlN x or SiN x ) and oxygen (O 2 ) containing insulating materials (e.g., AlO x ) is covered with sealing layer 26 laminated in this order, it becomes easy to form opening 51H2 through which upper electrode 25 and wiring 52 are connected. This makes it possible to improve the manufacturing yield.

[0091] Next, a second embodiment will be described below. Note that components similar to those of the image sensor 10A of the first embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0092] <2. Second embodiment> 20 illustrates a cross-sectional configuration of an image sensor (image sensor 10B) according to a second embodiment of the present disclosure. Similar to image sensor 10A in the first embodiment, image sensor 10B constitutes one pixel (unit pixel P) in an image sensor (image sensor 1) such as a CMOS image sensor used in electronic devices such as digital still cameras and video cameras.

[0093] The imaging element 10B of the present embodiment is made of oxygen (O 2 ) containing insulating materials (e.g., AlO x ) and the second layer 26B made of nitrogen (N 2 ) containing insulating materials (e.g., AlN x or SiN x) are laminated in this order from the organic photoelectric conversion section 20 side. Specifically, in the imaging element 10B, the sealing layer 26 is composed of the first layer 26A, the second layer 26B, and the third layer 26C, as in the first embodiment, and the second layer 26B, the first layer 26A, and the third layer 26C are laminated in this order from the organic photoelectric conversion section 20 side. In this embodiment, the second layer 26B is provided on the upper surface of the organic photoelectric conversion section 20, and the first layer 26A and the third layer 26C are formed on the insulating layer 22 from the upper surface of the upper electrode 25 via the side surfaces of the upper electrode 25, the photoelectric conversion layer 24, and the charge storage layer 23, respectively, and extend to, for example, the end of the peripheral region 110B.

[0094] The imaging element 10B can be manufactured, for example, as follows.

[0095] First, in the same manner as in the first embodiment, a charge storage layer 23, a photoelectric conversion layer 24, and an upper electrode 25 are formed on an insulating layer 22. Then, as shown in FIG. 21, aluminum oxide (AlO x ) film is formed to a thickness of, for example, 30 nm by the ALD method, and then a photoresist is formed at a predetermined position of the second layer 26B, and the second layer 26B is patterned.

[0096] Next, as shown in FIG. 22, the charge storage layer 23, the photoelectric conversion layer 24, and the upper electrode 25 in the peripheral portion of the peripheral region 110B are removed by dry etching using the second layer 26B as a mask.

[0097] 23, the first layer 26A and the third layer 26C extending on the second layer 26B, the charge storage layer 23, the photoelectric conversion layer 24, the upper electrode 25, the side surfaces of the first layer 26A and the second layer 26B, and the insulating layer 22 are deposited in this order to a thickness of, for example, 30 nm by, for example, ALD. x The film (flattening layer 51) is formed to a thickness of, for example, 500 nm. Specifically, the first layer 26A and the third layer 26C are first formed by using trimethylaluminum as an Al precursor and nitrogen (N2 ) plasma to form AlN x After forming the film (first layer 26A), nitrogen (N 2 ) plasma with oxygen (O 2 ) plasma to produce AlO x A film (third layer 26C) is formed.

[0098] The first layer 26A is made of silicon nitride (SiN x ) film, or silicon nitride (SiN x When forming a silicon (Si) film, for example, bis(tert-butylamino)silane is used as the silicon precursor, and nitrogen (N 2 ) / Ammonia (NH 3 ) Plasma is irradiated to produce SiN x Then, an Al precursor (e.g., trimethylaluminum) and oxygen (O 2 ) plasma and AlO x A film (third layer 26C) is formed.

[0099] Thereafter, as shown in FIG. 24, openings 51H1 and 51H2 are formed which penetrate to the pad portion 36D and the upper electrode 25. Specifically, first, a photoresist is patterned on the planarization layer 51, and then wet etching is performed. As a result, as shown in FIG. 24, an opening 51H1 which reaches the pad portion 36D is formed. In the portion which becomes the opening 51H2, the first layer 26A (AlN x The planarization layer 51 and the third layer 26C are removed using the etching stopper film. Thereafter, the first layer 26A and the second layer 26B are etched by dry etching using, for example, hydrogen fluoride (HF). As a result, an opening 51H2 reaching the upper electrode 25 is formed.

[0100] 25, continuous wiring 52 is formed on the planarization layer 51 and on the side and bottom surfaces of the openings 51H1 and 51H2, and then a protective layer 53 is formed on the planarization layer 51 and wiring 52, and filling the openings 51H1 and 51H2. This prevents hydrogen and moisture from entering the charge storage layer 23 through the openings 51H1 and 51H2. Finally, a light-shielding film 54 and an on-chip lens layer 56 are formed. With the above steps, the image sensor 10B shown in FIG. 20 is completed.

[0101] As described above, in the imaging element 10B of the present embodiment, the upper surface of the organic photoelectric conversion unit 20 is exposed to oxygen (O 2 ) containing insulating materials (e.g., AlO x ) and the second layer 26B made of nitrogen (N 2 ) containing insulating materials (e.g., AlN x or SiN x ) is covered with sealing layer 26 laminated in this order. As a result, compared to the first embodiment, more particles of aluminum fluoride (AlF) are generated for second layer 26B during dry etching to form opening 51H2, but compared to a general sealing layer etching process, it is easier to form opening 51H2 to connect upper electrode 25 and wiring 52. This makes it possible to improve the manufacturing yield.

[0102] <3. Third embodiment> Fig. 26 illustrates an example of a cross-sectional configuration of an imaging element (imaging element 10C) according to a third embodiment of the present disclosure. Fig. 27 illustrates a schematic planar configuration of the imaging element illustrated in Fig. 26. As with the imaging element 10A in the first embodiment, the imaging element 10C constitutes one pixel (unit pixel P) in an imaging device (imaging device 1) such as a CMOS image sensor used in electronic devices such as digital still cameras and video cameras.

[0103] The imaging element 10C of the present embodiment is a nitrogen (N 2 ) containing insulating materials (e.g., AlN xor SiN x ) is provided partially, specifically, in a contact portion where the upper electrode 25 and the wiring 52 are electrically connected. In the sealing layer 26, a second layer 26B, a third layer 26C, and the first layer 26A are laminated in this order from the organic photoelectric conversion unit 20 side in the contact portion.

[0104] The imaging element 10C can be manufactured, for example, as follows.

[0105] First, in the same manner as in the first embodiment, the charge storage layer 23, the photoelectric conversion layer 24, and the upper electrode 25 are formed on the insulating layer 22. Then, aluminum oxide (AlO x 28, the charge storage layer 23, the photoelectric conversion layer 24, the upper electrode 25, and the second layer 26B in the peripheral portion of the peripheral region 110B are removed.

[0106] Next, as shown in FIG. 29, a film is formed, for example, using an ALD method, on the second layer 26B and on the charge storage layer 23, the photoelectric conversion layer 24, the upper electrode 25, the side surfaces of the second layer 26B, and the third layer 26C extending onto the insulating layer 22, with a thickness of, for example, 30 nm.

[0107] Next, as shown in FIG. 30, the first layer 26A is formed on the third layer 26C using, for example, an ALD method to a thickness of, for example, 50 nm, and then a photoresist is formed at a predetermined position of the first layer 26A, i.e., the contact position between the upper electrode 25 and the wiring 52, and the first layer 23A is patterned.

[0108] Next, as shown in FIG. 31, an AlO x A film (planarization layer 51) is formed.

[0109] Next, after patterning a photoresist on the planarization layer 51, wet etching is performed as shown in FIG. 32 to form an opening 51H2. At this time, in the opening 51H2, the first layer 26A serves as an etching stopper film and the planarization layer 51 is removed. Next, the first layer 26A and the second layer 26B are etched by dry etching using, for example, hydrogen fluoride (HF). As a result, the opening 51H2 reaching the upper electrode 25 is formed. Thereafter, the wiring 52, the protective layer 53, the light-shielding film 54, and the on-chip lens layer 56 are formed in the same manner as in the first embodiment. With the above, the image sensor 10C shown in FIG. 26 is completed.

[0110] The formation range and the formation position in the stacking direction of the first layer 26A are not limited to this. For example, as shown in FIG. 33, the first layer 23A may extend to the side surface of the organic photoelectric conversion section 20. Also, as shown in FIG. 34, the first layer 23A may extend from the side surface of the organic photoelectric conversion section 20 to the peripheral region 110B. Furthermore, as shown in FIGS. 35 to 37, the sealing layer 26 may be formed in the order of the first layer 26A, the second layer 26B, and the third layer 26C, similar to the first embodiment.

[0111] As described above, in the imaging element 10C of the present embodiment, the nitrogen (N 2 ) containing insulating materials (e.g., AlN x or SiN x The first layer 26A made of hydrogen (H 2 O 3 ) is selectively provided at the contact portion where the upper electrode 25 and the wiring 52 are electrically connected. In addition to the effect of the first embodiment, this reduces the loss of light (incident light) entering the photoelectric conversion section 20 due to the first layer 26A, and makes it possible to improve the device characteristics. 2 ) is suppressed from penetrating into the organic photoelectric conversion section 20. This suppresses reduction of the upper electrode 25 constituting the organic photoelectric conversion section 20 and deterioration of the organic film, making it possible to further improve the device characteristics.

[0112] <4. Fourth embodiment> 38 illustrates an example of a cross-sectional configuration of an image sensor (image sensor 10D) according to the fourth embodiment of the present disclosure. As with the image sensor 10A in the first embodiment, the image sensor 10D constitutes one pixel (unit pixel P) in an image sensor (image sensor 1) such as a CMOS image sensor used in electronic devices such as digital still cameras and video cameras.

[0113] In the imaging element 10D of the present embodiment, an inter-pixel light-shielding film (light-shielding film 57) is provided on the upper electrode 25 of the organic photoelectric conversion section 20, and this light-shielding film 57 is used as an etching stopper layer together with the first layer 26A. Also, in the present embodiment, similarly to the third embodiment, the first layer 26A constituting the sealing layer 26 is selectively provided in a contact portion where the upper electrode 25 and the wiring 52 are electrically connected.

[0114] The light-shielding film 57 may be made of a metal material having light-shielding properties, such as tungsten (W), titanium (Ti), titanium nitride (TiN) or aluminum (Al), and the light-shielding film 54 is formed, for example, as a laminated film of W / TiN / Ti or a single layer film of W.

[0115] The imaging element 10D can be manufactured, for example, as follows.

[0116] First, in the same manner as in the first embodiment, the charge storage layer 23, the photoelectric conversion layer 24, and the upper electrode 25 are formed on the insulating layer 22. Then, aluminum oxide (AlO x 28, the charge storage layer 23, the photoelectric conversion layer 24, the upper electrode 25, and the second layer 26B in the peripheral portion of the peripheral region 110B are removed.

[0117] 39, for example, ALD is used to deposit a W film as the third layer 26C and the light-shielding film 57 extending on the second layer 26B, the charge storage layer 23, the photoelectric conversion layer 24, the upper electrode 25, the side surfaces of the second layer 26B, and the insulating layer 22, in this order, each having a thickness of, for example, 30 nm. In this embodiment, the first layer 26A is made of aluminum nitride (AlN x ) and silicon nitride (SiN x ), silicon oxide (SiO x ) can be used to form the

[0118] Next, a photoresist is formed at predetermined positions of the W film (light-shielding film 57), i.e., between adjacent pixels and at contact positions between the upper electrode 25 and the wiring 52, to pattern the light-shielding film 57. Thereafter, the first layer 26A is formed on the third layer 26C and on the light-shielding film 57 to a thickness of, for example, 30 nm, using, for example, the ALD method, as shown in FIG.

[0119] Next, a photoresist is formed at the contact position of the upper electrode 25 of the first layer 26A and the wiring 52, and the first layer 26A is patterned. As a result, the first layer 26A is selectively formed on the light-shielding film 57 formed at the contact position of the upper electrode 25 and the wiring 52, as shown in FIG.

[0120] Next, as shown in FIG. 42, AlO x A film (planarization layer 51) is formed to a thickness of, for example, 500 nm.

[0121] 43, a photoresist (mask 61) is patterned on the planarization layer 51, and then dry etching is performed using, for example, a chlorine-based gas to form an opening 51H2. x A film (flattening layer 51) and, for example, SiO x Selective processing ratio (AlO x / SiO x ) is about 10. Therefore, even if about 30% overetching is performed to absorb the variation in etching, the SiO xThe film is removed by only about 20 nm, and the first layer 26A becomes an etching stopper film, and the planarizing layer 51 is removed.

[0122] Next, the first layer 26A, the light-shielding film 57, and the second layer 26B are etched. For example, the first layer 26A is etched using a CF-based gas, and the light-shielding film 57 is etched using SF 6 The second layer 26B can be removed by dry etching using a CF gas. The second layer 26B is removed using, for example, a CF-based gas. As a result, an opening 51H2 reaching the upper electrode 25 is formed as shown in FIG. 44. Thereafter, the wiring 52, the protective layer 53, the light-shielding film 54, and the on-chip lens layer 56 are formed in the same manner as in the first embodiment. With the above steps, the image sensor 10D shown in FIG. 38 is completed.

[0123] 38 shows an example in which the first layer 26A is provided only on the light-shielding film 57 provided in the contact portion where the upper electrode 25 and the wiring 52 are electrically connected, but the present invention is not limited to this. For example, the first layer 26A may also be provided on the light-shielding film 57 provided between adjacent pixels as shown in Fig. 45. The image sensor 10D shown in Fig. 45 can be manufactured, for example, as follows.

[0124] First, in the same manner as described above, the charge storage layer 23, the photoelectric conversion layer 24, the upper electrode 25, and the second layer 26B are removed from the peripheral portion of the peripheral region 110B as shown in Fig. 28. Next, as shown in Fig. 46, the third layer 26C, the light-shielding film 57, and the first layer 26A extending on the second layer 26B and on the side surfaces of the charge storage layer 23, the photoelectric conversion layer 24, the upper electrode 25, and the second layer 26B, and on the insulating layer 22 are formed in this order, for example, by the ALD method, each having a thickness of, for example, 30 nm.

[0125] 47, photoresist is formed at predetermined positions of the first layer 26A, i.e., between adjacent pixels and at contact positions between the upper electrode 25 and the wiring 52, and the light-shielding film 57 is patterned. As a result, a laminated film of the light-shielding film 57 and the first layer 26A is selectively formed between adjacent pixels and at contact positions between the upper electrode 25 and the wiring 52.

[0126] Next, as shown in FIG. 48, AlO x A film (planarization layer 51) is formed to a thickness of, for example, 500 nm.

[0127] 49, a photoresist (mask 61) is patterned on the planarization layer 51, and then dry etching is performed using, for example, a chlorine-based gas to form an opening 51H2. x Selective processing ratio (AlO x / SiO x ) is about 10. Therefore, even if about 30% overetching is performed to absorb the variation in etching, the SiO x The film is removed by only about 20 nm, and the first layer 26A becomes an etching stopper film, and the planarizing layer 51 is removed.

[0128] Next, the first layer 26A, the light-shielding film 57, and the second layer 26B are etched in the same manner as described above. For example, the first layer 26A is etched using a CF-based gas, and the light-shielding film 57 is etched using SF 6 The second layer 26B can be removed by dry etching using a CF gas. The second layer 26B is removed using, for example, a CF-based gas. As a result, an opening 51H2 reaching the upper electrode 25 is formed as shown in FIG. 50. Thereafter, the wiring 52, the protective layer 53, the light-shielding film 54, and the on-chip lens layer 56 are formed in the same manner as in the first embodiment. With the above steps, the image sensor 10D shown in FIG. 45 is completed.

[0129] As described above, in the imaging element 10D of the present embodiment, the light-shielding film 57 is provided between adjacent pixels on the upper electrode 25 of the organic photoelectric conversion section 20 and on the periphery of the effective pixel region 110A, and this light-shielding film 57 is used as an etching stopper layer together with the first layer 26A. This makes it possible to stably form the opening 51H2 without exposing the organic film of the organic photoelectric conversion section 20, as compared to the third embodiment. This makes it possible to improve the manufacturing yield.

[0130] Furthermore, in the imaging element 10D of the present embodiment, a light-shielding film 57 is provided between adjacent pixels, so that, compared to the first embodiment described above, color mixing between pixels of obliquely incident light on the photoelectric conversion section 20 can be reduced, thereby enabling device characteristics to be improved.

[0131] <5. Modifications> FIG. 51 shows another example of the cross-sectional configuration of the imaging element 10D as a modified example of the fourth embodiment. In the fourth embodiment, the first layer 26A is provided on the light-shielding film 57 and used as an etching stopper film. However, since the light-shielding film 57 has a different etching rate from the second layer 26B and the third layer 26C, the first layer 26A may be omitted. In other words, the light-shielding film 57 may be used as the first layer 26A. In addition, in the fourth embodiment, the light-shielding film 57 is provided on the third layer 26C. However, the light-shielding film 57 may be provided directly on the upper electrode 25 of the organic photoelectric conversion unit 20.

[0132] The imaging element 10D shown in FIG. 51 can be manufactured, for example, as follows.

[0133] First, in the same manner as in the first embodiment, the charge storage layer 23, the photoelectric conversion layer 24, and the upper electrode 25 are formed on the insulating layer 22. Then, as shown in Fig. 52, the light-shielding film 57 extending between adjacent pixels and from the contact position between the upper electrode 25 and the wiring 52 to the peripheral region 110B and the second layer 26B covering the upper electrode 25 and the light-shielding film 57 are formed on the upper electrode 25 by the ALD method to a thickness of, for example, 30 nm.

[0134] Next, as shown in FIG. 53, the charge storage layer 23, the photoelectric conversion layer 24, the upper electrode 25, the light-shielding film 57 and the second layer 26B in the peripheral portion of the peripheral region 110B are removed.

[0135] Next, as shown in FIG. 54, a third layer 26C is formed, for example, using an ALD method, on the second layer 26B and extending onto the light-shielding film 57, the charge storage layer 23, the photoelectric conversion layer 24, the upper electrode 25 and the side surfaces of the second layer 26B, and the insulating layer 22, to a thickness of, for example, 30 nm.

[0136] Next, as shown in FIG. 55, AlO x A film (planarization layer 51) is formed to a thickness of, for example, 500 nm.

[0137] 56, a photoresist is patterned on the planarization layer 51 to form an opening 51H2. Here, reactive ion etching (dry etching) using, for example, a chlorine-based gas is performed. x The selective processing ratio between the film (flattening layer 51) and the W film (light-shielding film 57) (AlO x / W) is about 10. Therefore, even if overetching of about 30% is performed to absorb etching variations, the W film (light-shielding film 57) remains. In this modification, since the light-shielding film 57 is formed using a metal material as described above, it is possible to ensure electrical continuity between the upper electrode 25 and the wiring 52 even if the upper electrode 25 is not exposed in the opening 51H2.

[0138] Thereafter, the photoresist is removed, and then the wiring 52, the protective layer 53, the light-shielding film 54, and the on-chip lens layer 56 are formed in the same manner as in the first embodiment. Through the above steps, the image sensor 10D shown in FIG.

[0139] As described above, in the image sensor 10D of this modification, the light-shielding film 57 is used as an etching stopper film when processing the second layer 26B and the third layer 26C, and is provided directly on the upper electrode 25. This makes it possible to stably form the opening 51H2 without etching the upper electrode 25, as compared to the fourth embodiment. This makes it possible to further improve the manufacturing yield.

[0140] <6. Application Examples> (Application example 1) 57 shows the overall configuration of an imaging device (imaging device 1) in which the imaging element 10A (or imaging element 10B) described in the first and second embodiments is used for each pixel. The imaging device 1 is a CMOS image sensor, and has a pixel section 1a as an imaging area on a semiconductor substrate 30, and also has a peripheral circuit section 130 in the peripheral region of the pixel section 1a, which includes, for example, a row scanning section 131, a horizontal selection section 133, a column scanning section 134, and a system control section 132.

[0141] The pixel section 1a has a plurality of unit pixels P arranged two-dimensionally in a matrix, for example. In the unit pixels P, for example, a pixel drive line Lread (specifically, a row selection line and a reset control line) is wired for each pixel row, and a vertical signal line Lsig is wired for each pixel column. The pixel drive line Lread transmits a drive signal for reading out a signal from the pixel. One end of the pixel drive line Lread is connected to an output terminal of the row scanning section 131 corresponding to each row.

[0142] The row scanning unit 131 is a pixel driving unit that is configured with a shift register, an address decoder, etc., and drives each unit pixel P of the pixel unit 1a, for example, row by row. A signal output from each unit pixel P of a pixel row selected and scanned by the row scanning unit 131 is supplied to the horizontal selection unit 133 through each vertical signal line Lsig. The horizontal selection unit 133 is configured with an amplifier, a horizontal selection switch, etc., provided for each vertical signal line Lsig.

[0143] The column scanning unit 134 is composed of a shift register, an address decoder, etc., and sequentially drives while scanning each horizontal selection switch of the horizontal selection unit 133. By the selective scanning by this column scanning unit 134, the signals of each pixel transmitted through each vertical signal line Lsig are output in sequence to the horizontal signal line 135, and transmitted to the outside of the semiconductor substrate 30 through the horizontal signal line 135.

[0144] A circuit portion consisting of row scanning section 131, horizontal selection section 133, column scanning section 134, and horizontal signal line 135 may be formed directly on semiconductor substrate 30, or may be disposed in an external control IC. Moreover, these circuit portions may be formed on another substrate connected by a cable or the like.

[0145] The system control unit 132 receives a clock and data instructing an operation mode provided from outside the semiconductor substrate 30, and also outputs data such as internal information of the imaging device 1. The system control unit 132 further has a timing generator that generates various timing signals, and performs drive control of peripheral circuits such as the row scanning unit 131, horizontal selection unit 133, and column scanning unit 134 based on the various timing signals generated by the timing generator.

[0146] (Application example 2) The imaging device 1 can be applied to any type of electronic device with an imaging function, such as a camera system such as a digital still camera or a video camera, or a mobile phone with an imaging function. Fig. 58 shows a schematic configuration of an electronic device 2 (camera) as an example. The electronic device 2 is, for example, a video camera capable of taking still or moving images, and includes the imaging device 1, an optical system (optical lens) 310, a shutter device 311, a drive unit 313 that drives the imaging device 1 and the shutter device 311, and a signal processing unit 312.

[0147] The optical system 310 guides image light (incident light) from a subject to the pixel section 1a of the imaging device 1. The optical system 310 may be composed of a plurality of optical lenses. The shutter device 311 controls the light irradiation period and light blocking period of the imaging device 1. The drive section 313 controls the transfer operation of the imaging device 1 and the shutter operation of the shutter device 311. The signal processing section 312 performs various signal processing on the signal output from the imaging device 1. The video signal Dout after signal processing is stored in a storage medium such as a memory, or Alternatively, it is output to a monitor or the like.

[0148] <7. Application Examples> Furthermore, the imaging device 1 can be applied to the following electronic devices (a capsule endoscope 10100 and a moving object such as a vehicle).

[0149] <Application example to in-body information acquisition system> Furthermore, the technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

[0150] FIG. 59 is a block diagram showing an example of a schematic configuration of a patient's in-vivo information acquisition system using a capsule endoscope to which the technology according to the present disclosure (the present technology) can be applied.

[0151] The in-vivo information acquisition system 10001 includes a capsule endoscope 10100 and an external control device 10200 .

[0152] The capsule endoscope 10100 is swallowed by a patient during an examination. The capsule endoscope 10100 has an imaging function and a wireless communication function, and while moving inside an organ such as the stomach or intestines by peristalsis or the like until it is naturally discharged from the patient, sequentially captures images of the inside of the organ (hereinafter also referred to as in-vivo images) at predetermined intervals, and sequentially wirelessly transmits information about the in-vivo images to an external control device 10200 outside the body.

[0153] The external control device 10200 comprehensively controls the operation of the in-vivo information acquisition system 10001. In addition, the external control device 10200 receives information about the in-vivo image transmitted from the capsule endoscope 10100, and generates image data for displaying the in-vivo image on a display device (not shown) based on the received information about the in-vivo image.

[0154] In this manner, the in-vivo information acquiring system 10001 can obtain in-vivo images capturing images of the state inside the patient's body at any time from when the capsule endoscope 10100 is swallowed to when it is expelled.

[0155] The configurations and functions of the capsule endoscope 10100 and the external control device 10200 will be described in more detail.

[0156] The capsule endoscope 10100 has a capsule-shaped housing 10101, which houses a light source unit 10111, an imaging 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.

[0157] The light source unit 10111 is composed of a light source such as an LED (light emitting diode), and irradiates the imaging field of the imaging unit 10112 with light.

[0158] The imaging unit 10112 is composed of an imaging element and an optical system consisting of multiple lenses provided in front of the imaging element. Reflected light (hereinafter referred to as observation light) of light irradiated onto the body tissue to be observed is collected by the optical system and enters the imaging element. In the imaging unit 10112, the imaging element photoelectrically converts the observation light incident thereon, and generates an image signal corresponding to the observation light. The image signal generated by the imaging unit 10112 is provided to an image processing unit 10113.

[0159] The image processing unit 10113 is configured with a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), and performs various signal processing on the image signal generated by the imaging unit 10112. The image processing unit 10113 provides the image signal after the signal processing to the wireless communication unit 10114 as RAW data.

[0160] The wireless communication unit 10114 performs predetermined processing such as modulation processing on the image signal that has been subjected to signal processing by the image processing unit 10113, and transmits the image signal to the external control device 10200 via the antenna 10114A. The wireless communication unit 10114 also receives a control signal related to drive control of the capsule endoscope 10100 from the external control device 10200 via the antenna 10114A. The wireless communication unit 10114 provides the control signal received from the external control device 10200 to the control unit 10117.

[0161] The power supply unit 10115 is composed of an antenna coil for receiving power, a power regeneration circuit for regenerating power from a current generated in the antenna coil, a boost circuit, etc. In the power supply unit 10115, power is generated using the principle of so-called non-contact charging.

[0162] The power supply unit 10116 is composed of a secondary battery, and stores the power generated by the power supply unit 10115. In Fig. 59, to avoid cluttering the drawing, arrows and the like indicating the destination of the power supply from the power supply unit 10116 are omitted, but the power stored in the power supply unit 10116 is supplied to the light source unit 10111, the imaging unit 10112, the image processing unit 10113, the wireless communication unit 10114, and the control unit 10117 and can be used to drive these units.

[0163] The control unit 10117 is composed of a processor such as a CPU, and appropriately controls the driving of the light source unit 10111, the imaging unit 10112, the image processing unit 10113, the wireless communication unit 10114, and the power supply unit 10115 in accordance with control signals transmitted from the external control device 10200.

[0164] The external control device 10200 is composed of a processor such as a CPU or a GPU, or a microcomputer or a control board in which a processor and a storage element such as a memory are mixed. The external control device 10200 controls the operation of the capsule endoscope 10100 by transmitting a control signal to the control unit 10117 of the capsule endoscope 10100 via the antenna 10200A. In the capsule endoscope 10100, for example, the light irradiation conditions for the observation target in the light source unit 10111 can be changed by the control signal from the external control device 10200. Furthermore, the imaging conditions (for example, the frame rate and exposure value in the imaging unit 10112) can be changed by the control signal from the external control device 10200. Furthermore, the content of the processing in the image processing unit 10113 and the conditions for the wireless communication unit 10114 to transmit an image signal (for example, the transmission interval, the number of transmitted images, etc.) may be changed by the control signal from the external control device 10200.

[0165] The external control device 10200 also performs various image processing on the image signal transmitted from the capsule endoscope 10100 to generate image data for displaying the captured in-vivo image on a display device. The image processing includes, for example, development processing (demosaic processing), high image quality processing (band enhancement processing, super-resolution processing, NR (Noise reduction) processing, and / or camera shake correction processing). The external control device 10200 can perform various signal processing such as image processing (electronic zoom processing), image correction processing, and / or enlargement processing (electronic zoom processing). The external control device 10200 controls the driving of a display device to display an in-vivo image captured based on the generated image data. Alternatively, the external control device 10200 may record the generated image data in a recording device (not shown) or print out the image data on a printing device (not shown).

[0166] An example of an in-vivo information acquisition system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to, for example, the imaging unit 10112 of the above-described configuration. This improves detection accuracy.

[0167] <Application example to endoscopic surgery system> The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

[0168] FIG. 60 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to the present disclosure (the present technology) can be applied.

[0169] 60 shows a state in which an operator (doctor) 11131 is performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, other surgical tools 11110 such as an insufflation tube 11111 and an energy treatment tool 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0170] The endoscope 11100 is composed of a lens barrel 11101, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 11132, and a camera head 11102 connected to the base end of the lens barrel 11101. In the illustrated example, the endoscope 11100 is configured as a so-called rigid scope having a rigid lens barrel 11101, but the endoscope 11100 may be configured as a so-called flexible scope having a flexible lens barrel.

[0171] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 11101. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 11101, and is irradiated via the objective lens toward an observation target in the body cavity of the patient 11132. The endoscope 11100 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0172] An optical system and an image sensor are provided inside the camera head 11102, and reflected light (observation light) from an observation target is collected on the image sensor by the optical system. The observation light is photoelectrically converted by the image sensor to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to an observation image. The image signal is transmitted to a camera control unit (CCU) 11201 as RAW data.

[0173] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and controls the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102, and performs various types of image processing on the image signal, such as development processing (demosaic processing), for displaying an image based on the image signal.

[0174] Under the control of the CCU 11201, the display device 11202 displays an image based on an image signal that has been subjected to image processing by the CCU 11201.

[0175] The light source device 11203 is composed of a light source such as an LED (light emitting diode), and supplies the endoscope 11100 with irradiation light when photographing an operation site or the like.

[0176] The input device 11204 is an input interface for the endoscopic surgery system 11000. A user can input various information and instructions to the endoscopic surgery system 11000 via the input device 11204. For example, the user inputs an instruction to change the imaging conditions (type of irradiated light, magnification, focal length, etc.) of the endoscope 11100.

[0177] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterizing tissue, incising, sealing blood vessels, etc. The insufflation device 11206 sends gas into the body cavity of the patient 11132 via the insufflation tube 11111 to inflate the body cavity for the purpose of securing the field of view of the endoscope 11100 and securing the working space of the surgeon. The recorder 11207 is a device capable of recording various information related to the surgery. The printer 11208 is a device capable of printing various information related to the surgery in various formats such as text, image, or graph.

[0178] The light source device 11203 that supplies irradiation light to the endoscope 11100 when photographing the surgical site can be composed of a white light source composed of, for example, an LED, a laser light source, or a combination of these. When the white light source is composed of a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, so that the white balance of the captured image can be adjusted in the light source device 11203. In this case, it is also possible to capture images corresponding to each of the RGB colors in a time-division manner by irradiating the observation object with laser light from each of the RGB laser light sources in a time-division manner and controlling the driving of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter to the image sensor.

[0179] The light source device 11203 may be controlled to change the intensity of the light it outputs at predetermined time intervals. The driving of the image sensor of the camera head 11102 may be controlled in synchronization with the timing of the change in the light intensity to obtain images in a time-division manner, and the images may be synthesized to generate an image with a high dynamic range that is free of so-called blackout and whiteout.

[0180] The light source device 11203 may be configured to supply light of a predetermined wavelength band corresponding to the special light observation. In the special light observation, for example, by utilizing the wavelength dependency of light absorption in body tissue, a narrow band light is irradiated compared to the irradiated light (i.e., white light) during normal observation, and a predetermined tissue such as blood vessels on the mucous membrane surface is photographed with high contrast, so-called narrow band imaging is performed. Alternatively, in the special light observation, a fluorescent observation may be performed in which an image is obtained by fluorescence generated by irradiating an excitation light. In the fluorescent observation, it is possible to irradiate an excitation light to a body tissue and observe the fluorescence from the body tissue (autofluorescence observation), or to locally inject a reagent such as indocyanine green (ICG) into the body tissue and irradiate the body tissue with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow band light and / or excitation light corresponding to such special light observation.

[0181] FIG. 61 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0182] The camera head 11102 has a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 has 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 so as to be able to communicate with each other.

[0183] The lens unit 11401 is an optical system provided at the connection portion with the lens barrel 11101. Observation light taken in from the tip of the lens barrel 11101 is guided to the camera head 11102 and enters the lens unit 11401. The lens unit 11401 is configured by combining a plurality of lenses including a zoom lens and a focus lens.

[0184] The imaging unit 11402 may include one imaging element (so-called single-plate type) or multiple imaging elements (so-called multiple-plate type). When the imaging unit 11402 is configured as a multiple-plate type, for example, each imaging element may generate an image signal corresponding to each of RGB, and a color image may be obtained by combining the image signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to a 3D (dimensional) display. By performing a 3D display, the surgeon 11131 can more accurately grasp the depth of the biological tissue in the surgical site. Note that when the imaging unit 11402 is configured as a multiple-plate type, the lens unit 11401 may also be provided in multiple systems corresponding to each imaging element.

[0185] Furthermore, the imaging unit 11402 does not necessarily have to be provided in the camera head 11102. For example, the imaging unit 11402 may be provided inside the lens barrel 11101, immediately behind the objective lens.

[0186] The driving unit 11403 is configured by an actuator, and moves the zoom lens and focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera head control unit 11405. This allows the magnification and focus of the image captured by the imaging unit 11402 to be appropriately adjusted.

[0187] The communication unit 11404 is configured by a communication device for transmitting and receiving various information to and from the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 to the CCU 11201 via the transmission cable 11400 as RAW data.

[0188] Furthermore, the communication unit 11404 receives a control signal for controlling the driving of the camera head 11102 from the CCU 11201, and supplies the control signal to the camera head control unit 11405. The control signal includes information on the imaging conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value at the time of capturing the image, and / or information specifying the magnification and focus of the captured image.

[0189] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by the user, or may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function are implemented in the endoscope 11. This means that it will be installed in the 100.

[0190] The camera head control unit 11405 controls the driving of the camera head 11102 based on a control signal received from the CCU 11201 via the communication unit 11404.

[0191] The communication unit 11411 is configured with a communication device for transmitting and receiving various information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted from the camera head 11102 via the transmission cable 11400.

[0192] Furthermore, the communication unit 11411 transmits, to the camera head 11102, a control signal for controlling the driving of the camera head 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication, or the like.

[0193] The image processing unit 11412 performs various types of image processing on the image signal, which is RAW data sent from the camera head 11102 .

[0194] The control unit 11413 performs various controls related to imaging of the surgical site etc. by the endoscope 11100 and display of the captured image obtained by imaging the surgical site etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

[0195] Further, the control unit 11413 causes the display device 11202 to display the captured image showing the surgical site, etc., based on the image signal that has been image-processed by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition techniques. For example, the control unit 11413 can recognize surgical tools such as forceps, specific living body parts, bleeding, mist when the energy treatment tool 11112 is used, etc., by detecting the shape and color of the edge of an object included in the captured image. When the control unit 11413 causes the display device 11202 to display the captured image, it may use the recognition result to superimpose various types of surgery support information on the image of the surgical site. By superimposing and presenting the surgery support information to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0196] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for communication of electrical signals, an optical fiber for optical communication, or a composite cable of these.

[0197] Here, in the illustrated example, communication is performed wired using a transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may also be performed wirelessly.

[0198] An example of an endoscopic surgery system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the imaging unit 11402 among the configurations described above. By applying the technology according to the present disclosure to the imaging unit 11402, detection accuracy is improved.

[0199] Although an endoscopic surgery system has been described here as an example, the technology disclosed herein may also be applied to other systems, such as a microsurgery system.

[0200] <Applications to moving objects> The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, a drone, a ship, a robot, a construction machine, an agricultural machine (tractor), etc.

[0201] FIG. 62 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a moving object control system to which the technology of the present disclosure can be applied.

[0202] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 62, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. The integrated control unit 12050 includes a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (interface) 120. 53 is shown.

[0203] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0204] The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as head lamps, back lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves or signals of various switches transmitted from a portable device that replaces a key may be input to the body system control unit 12020. The body system control unit 12020 receives the input of these radio waves or signals and controls the door lock device, power window device, lamps, and the like of the vehicle.

[0205] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture an image outside the vehicle and receives the captured image. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for a person, a car, an obstacle, a sign, or characters on a road surface, based on the received image.

[0206] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according to the amount of light received. The imaging unit 12031 can output the electrical signal as an image, or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0207] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing.

[0208] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, the steering mechanism, or the braking device based on the information inside and outside the vehicle acquired by the outside-of-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output a control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0209] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on the driver's operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle acquired by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0210] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside-vehicle information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside-vehicle information detection unit 12030, and perform cooperative control for the purpose of preventing glare, such as switching from high beams to low beams.

[0211] The audio / video output unit 12052 transmits at least one output signal of audio and video to an output device capable of visually or audibly notifying information to passengers in the vehicle or the outside of the vehicle. In the example of Fig. 62, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are exemplified as the output device. The display unit 12062 may include at least one of an on-board display and a head-up display, for example.

[0212] FIG. 63 is a diagram showing an example of the installation position of the imaging unit 12031.

[0213] In FIG. 63, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0214] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided at positions such as the front nose, side mirrors, rear bumper, back door, and the upper part of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided at the front nose and the imaging unit 12105 provided at the upper part of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided at the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided at the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided at the upper part of the windshield inside the vehicle cabin is mainly used to detect a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.

[0215] 63 shows an example of the imaging ranges of the imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, an overhead image of the vehicle 12100 viewed from above is obtained by superimposing the image data captured by the imaging units 12101 to 12104.

[0216] At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera made up of a plurality of imaging elements, or may be an imaging element having pixels for detecting a phase difference.

[0217] For example, the microcomputer 12051 can extract, as a preceding vehicle, a three-dimensional object that is the closest three-dimensional object on the travel path of the vehicle 12100 and travels at a predetermined speed (for example, 0 km / h or more) in approximately the same direction as the vehicle 12100, by calculating the distance to each three-dimensional object in the imaging ranges 12111 to 12114 and the change over time of this distance (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104. Furthermore, the microcomputer 12051 can set a vehicle distance to be secured in advance in front of the preceding vehicle, and perform automatic brake control (including follow-up stop control) and automatic acceleration control (including follow-up start control). In this way, cooperative control can be performed for the purpose of automatic driving that travels autonomously without relying on the driver's operation.

[0218] For example, the microcomputer 12051 classifies and extracts three-dimensional object data on three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. Then, the microcomputer 12051 determines a collision risk indicating the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0219] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not a pedestrian is present in the captured images of the imaging units 12101 to 12104. The recognition of such a pedestrian is performed, for example, by a procedure of extracting feature points in the captured images of the imaging units 12101 to 12104 as infrared cameras, and a procedure of performing pattern matching processing on a series of feature points that indicate the contour of an object to determine whether or not the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the captured images of the imaging units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular contour line for emphasis on the recognized pedestrian. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating a pedestrian at a desired position.

[0220] Although the first and second embodiments and application examples have been described above, the present disclosure is not limited to the above embodiments and can be modified in various ways. For example, in the above embodiment, the imaging element is configured by stacking the organic photoelectric conversion unit 20 that detects green light and the inorganic photoelectric conversion units 32B and 32R that detect blue light and red light, respectively, but the present disclosure is not limited to such a structure. That is, the organic photoelectric conversion unit may detect red light or blue light, and the inorganic photoelectric conversion unit may detect green light.

[0221] Furthermore, the numbers of organic photoelectric conversion units and inorganic photoelectric conversion units and their ratios are not limited, and color signals of multiple colors may be obtained only from the organic photoelectric conversion units.

[0222] Furthermore, in the above-mentioned embodiments, an example has been shown in which the multiple electrodes constituting the lower electrode 21 are composed of two electrodes, the read electrode 21A and the storage electrode 21B, but in addition to this, three or four or more electrodes such as a transfer electrode or an exhaust electrode may be provided.

[0223] Furthermore, in the first embodiment, the charge storage layer 23, the photoelectric conversion layer 24, and the upper electrode 25 are formed as a continuous layer common to the plurality of image pickup elements 10A, but they may be formed separately for each pixel P. In that case, however, there is a risk that the dark current characteristics may deteriorate due to the influence of processing damage to the charge storage layer 23 and the photoelectric conversion layer 24. In addition, when the charge storage layer 23, the photoelectric conversion layer 24, and the upper electrode 25 are formed as a continuous layer common to the plurality of image pickup elements 10A and extend within the effective pixel area 110A as in the first embodiment, the pixels are connected by the photoelectric conversion layer, so there is a risk that color mixing due to charge mixing between the pixels may occur. This can be suppressed by providing the shield electrode 21C as described above.

[0224] Also, for example, the first surface 30S1 of the semiconductor substrate 30 may have an uneven structure. This reduces the reflection of light incident from the light incident side S1 on the first surface 30S1 of the semiconductor substrate 30, making it possible to suppress the occurrence of noise, etc. Also, it becomes possible to improve the detection sensitivity of the inorganic photoelectric conversion units 32B, 32R.

[0225] Furthermore, the present technology can also be applied to an imaging element having a stacked structure of one organic photoelectric conversion unit and one inorganic photoelectric conversion unit, for example, a color filter that selectively transmits red light (R), green light (G), and blue light (B) provided below the on-chip lens layer 56, and capable of detecting each of the colors R, G, and B in the organic photoelectric conversion unit and infrared light (IR) in the inorganic photoelectric conversion unit.

[0226] It should be noted that the effects described in this specification are merely examples and are not limiting, and other effects may also be obtained.

[0227] The present disclosure may be configured as follows. According to the present technology having the following configuration, a sealing layer formed by laminating a first layer containing nitrogen and a second layer containing oxygen is provided above the organic photoelectric conversion unit, so that it is easy to form a contact with the organic photoelectric conversion unit from above the organic photoelectric conversion unit. This makes it possible to improve the manufacturing yield. (1) a semiconductor substrate having an effective pixel area in which a plurality of pixels are arranged and a peripheral area provided around the effective pixel area; an organic photoelectric conversion unit provided on the light receiving surface side of the semiconductor substrate and including a first electrode composed of a plurality of electrodes, a second electrode arranged to face the first electrode, and a charge storage layer and an organic photoelectric conversion layer sequentially stacked between the first electrode and the second electrode and extending into the effective pixel region; a sealing layer including a first layer and a second layer having different etching rates stacked above the organic photoelectric conversion unit; Equipped with The first layer is selectively provided on a portion of the upper surface of the organic photoelectric conversion unit. Photography Image element. (2) The imaging element according to (1), wherein the first layer and the second layer are stacked in this order above the organic photoelectric conversion section. (3) The imaging element according to (1), wherein the second layer and the first layer are stacked in this order above the organic photoelectric conversion section. (4 ) before the first layer is a nitrogen-containing insulating film or a light-shielding metal film, The above The second layer is an insulating film containing oxygen. Any one of (1) to (3) above The imaging element according to claim 1. (5) The first layer is an aluminum nitride film, a silicon nitride film, a silicon oxide film, or a tungsten film. Any one of (1) to (4) above The imaging element according to claim 1. (6) The second layer is an aluminum oxide film. Any one of (1) to (3) and (5) above The imaging element according to claim 1. (7) the organic photoelectric conversion unit further includes an insulating layer between the first electrode and the charge storage layer, the insulating layer has an opening on one of the plurality of electrodes constituting the first electrode, and the one electrode and the charge storage layer are electrically connected through the opening. Any one of (1) to (6) above The imaging element according to claim 1. (8) The semiconductor substrate has an inorganic photoelectric conversion unit embedded therein. Any one of (1) to (7) above The imaging element according to claim 1. (9) A semiconductor substrate has an effective pixel region in which a plurality of pixels are arranged and a peripheral region provided around the effective pixel region. The effective pixel region is provided on a light receiving surface side of the semiconductor substrate. The effective pixel region is provided with a plurality of electrodes, and a first electrode, a charge storage layer, an organic photoelectric conversion layer, and a second electrode are laminated in this order as an organic photoelectric conversion unit. A first layer and a second layer having different etching rates are laminated above the organic photoelectric conversion part. At the same time, the first layer is selectively provided on a part of the upper surface of the organic photoelectric conversion unit. Forming a sealing layer A method for manufacturing an imaging element. (10) The first layer is deposited using atomic layer deposition using trimethylaluminum and nitrogen plasma; (9) A method for manufacturing the imaging element according to claim 1. (11) The second layer is deposited using atomic layer deposition using trimethylaluminum and oxygen plasma; (9) or (10) above A method for manufacturing the imaging element according to claim 1. (12) forming the first layer above the organic photoelectric conversion unit, and then forming the second layer; Any one of (9) to (11) above A method for manufacturing the imaging element according to claim 1. (13) forming an opening in the second layer using wet etching, and then removing the first layer in the opening using dry etching; (12) A method for manufacturing the imaging element according to claim 1. (14) forming the second layer above the organic photoelectric conversion unit, and then forming the first layer; Any one of (9) to (11) aboveA method for manufacturing the imaging element according to claim 1. (15) forming an opening through the first layer and the second layer at the same time using dry etching; (14) A method for manufacturing the imaging element according to claim 1.

[0228] This application claims priority based on Japanese Patent Application No. 2020-011603, filed on January 28, 2020 in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0229] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur to those skilled in the art depending on design requirements and other factors, and that such modifications are within the scope of the appended claims and their equivalents.

Claims

1. a semiconductor substrate having an effective pixel area in which a plurality of pixels are arranged and a peripheral area provided around the effective pixel area; an organic photoelectric conversion unit provided on the light receiving surface side of the semiconductor substrate and including a first electrode composed of a plurality of electrodes, a second electrode disposed opposite to the first electrode, and a charge storage layer and an organic photoelectric conversion layer sequentially stacked between the first electrode and the second electrode and extending into the effective pixel region; a sealing layer including a first layer and a second layer having different etching rates stacked above the organic photoelectric conversion unit; The first layer is selectively provided on a portion of the upper surface of the organic photoelectric conversion unit. Image sensor.

2. The imaging element according to claim 1 , wherein the first layer and the second layer are stacked in this order above the organic photoelectric conversion unit.

3. The imaging element according to claim 1 , wherein the second layer and the first layer are stacked in this order above the organic photoelectric conversion unit.

4. 2 . The image sensor according to claim 1 , wherein the first layer is an insulating film containing nitrogen or a metal film having a light-shielding property, and the second layer is an insulating film containing oxygen.

5. The image sensor according to claim 1 , wherein the first layer is an aluminum nitride film, a silicon nitride film, a silicon oxide film, or a tungsten film.

6. The imaging device according to claim 1 , wherein the second layer is an aluminum oxide film.

7. the organic photoelectric conversion unit further includes an insulating layer between the first electrode and the charge storage layer, 2. The image sensor according to claim 1, wherein the insulating layer has an opening on one of the plurality of electrodes constituting the first electrode, and the one electrode and the charge storage layer are electrically connected via the opening.

8. The imaging element according to claim 1 , wherein the semiconductor substrate has an inorganic photoelectric conversion section embedded therein.

9. A semiconductor substrate has an effective pixel region in which a plurality of pixels are arranged and a peripheral region provided around the effective pixel region. The effective pixel region is provided on a light-receiving surface side of the semiconductor substrate. The effective pixel region is provided with a plurality of electrodes, and a first electrode, a charge storage layer, an organic photoelectric conversion layer, and a second electrode are laminated in this order as an organic photoelectric conversion unit. A sealing layer is formed by laminating a first layer and a second layer having different etching rates above the organic photoelectric conversion section, and the first layer is selectively provided on a part of the upper surface of the organic photoelectric conversion section. A method for manufacturing an imaging element.

10. The method for manufacturing an image sensor according to claim 9 , wherein the first layer is formed by atomic layer deposition using trimethylaluminum and nitrogen plasma.

11. The method for manufacturing an image sensor according to claim 9 , wherein the second layer is formed by atomic layer deposition using trimethylaluminum and oxygen plasma.

12. The method for manufacturing an image sensor according to claim 9 , further comprising forming the second layer above the organic photoelectric conversion section after forming the first layer.

13. The method for manufacturing an image sensor according to claim 12 , further comprising the steps of: forming an opening in the second layer by wet etching; and then removing the first layer in the opening by dry etching.

14. The method for manufacturing an image sensor according to claim 9 , further comprising forming the first layer above the organic photoelectric conversion section after forming the second layer.

15. The method for manufacturing an image sensor according to claim 14 , wherein the openings penetrating the first layer and the second layer are formed at the same time by dry etching.

Images