# US 2023/0056769 A1 · Multilayer film and imaging element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0056769 A1 - Document ID: US20230056769A1 - Status: Published application - Kind: A1 - Application number: 17/904,313 - Filed: 2021-02-17 - Published: 2023-02-23 - Earliest claimed: 2020-02-25 - Assignees: Sony Semiconductor Solutions Corporation - Applicants: Sony Semiconductor Solutions Corporation - Inventors: KOJI SEKIGUCHI; KENICHI MURATA; TOMIYUKI YUKAWA; MASAHIRO JOEI; HIDEAKI TOGASHI - Web page: https://patentgrep.com/patent/US20230056769A1 ## CPC - G02B 5/281: {designed for the infrared light} - G02B 1/113: using inorganic layer materials only - G02B 5/207: {comprising semiconducting materials} - G02B 5/22: Absorbing filters {(G02B5/201 - G02B5/208 take precedence)} - G02B 5/28: Interference filters - H04N 23/12: with one sensor only - H04N 23/20: for generating image signals from infrared radiation only - H04N 25/70: SSIS architectures; Circuits associated therewith - H10F 39/12: Image sensors - H10K 39/32: Organic image sensors - H10K 30/87: Light-trapping means - Y02E 10/549: Organic PV cells - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A multilayer film according to an embodiment of the present disclosure includes: semiconductor layers; and dielectric layers. In each of the semiconductor layers, a value of an optical constant k1 for light having a wavelength in a visible light region among optical constants k is larger than a value of an optical constant k2 for light having a wavelength in an infrared light region. The optical constants k each serves as an extinction coefficient that includes an imaginary part of a complex refractive index. The semiconductor layers and the dielectric layers are alternately stacked and the multilayer film has an optical distance of 0.3 μm or more and 10 μm or less in a stack direction and absorbs at least a portion of visible light and transmits infrared light. ## Claims ### Claim 1 A multilayer film comprising: semiconductor layers in each of which a value of an optical constant k1 for light having a wavelength in a visible light region among optical constants k is larger than a value of an optical constant k2 for light having a wavelength in an infrared light region, the optical constants k each serving as an extinction coefficient that includes an imaginary part of a complex refractive index; and dielectric layers, wherein the semiconductor layers and the dielectric layers are alternately stacked and the multilayer film has an optical distance of 0.3 μm or more and 10 μm or less in a stack direction and absorbs at least a portion of visible light and transmits infrared light. ### Claim 2 (depends on 1) The multilayer film according to claim 1, comprising: a first semiconductor layer, a second semiconductor layer, and a third semiconductor layer as the semiconductor layers; and a first dielectric layer and a second dielectric layer as the dielectric layers, wherein the first semiconductor layer, the first dielectric layer, the second semiconductor layer, the second dielectric layer, and the third semiconductor layer are stacked in this order from a light incidence surface side. ### Claim 3 (depends on 1) The multilayer film according to claim 1, wherein each of the semiconductor layers includes any of silicon, germanium, or silicon germanium or an amorphous material thereof. ### Claim 4 (depends on 1) The multilayer film according to claim 1, wherein each of the dielectric layers includes any of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, aluminum oxide, or magnesium fluoride. ### Claim 5 (depends on 2) The multilayer film according to claim 2, further comprising a first protective layer in an upper layer of the first semiconductor layer, the first protective layer including silicon oxide. ### Claim 6 (depends on 2) The multilayer film according to claim 2, further comprising a second protective layer in a lower layer of the third semiconductor layer, the second protective layer including silicon oxide. ### Claim 7 An imaging element comprising: a first photoelectric conversion section having sensitivity to light having a wavelength in an infrared light region; a second photoelectric conversion section that is stacked on a light incidence surface side of the first photoelectric conversion section, the second photoelectric conversion section having sensitivity to light having a wavelength in a visible light region; and a multilayer film that is provided between the first photoelectric conversion section and the second photoelectric conversion section, the multilayer film including semiconductor layers in each of which a value of an optical constant k1 for light having a wavelength in a visible light region among optical constants k is larger than a value of an optical constant k2 for light having a wavelength in an infrared light region, the optical constants k each serving as an extinction coefficient that includes an imaginary part of a complex refractive index, and dielectric layers, wherein the semiconductor layers and the dielectric layers are alternately stacked and the multilayer film has an optical distance of 0.3 μm or more and 10 μm or less in a stack direction and absorbs at least a portion of visible light and transmits infrared light. ### Claim 8 (depends on 7) The imaging element according to claim 7, comprising: a first semiconductor layer, a second semiconductor layer, and a third semiconductor layer as the semiconductor layers; and a first dielectric layer and a second dielectric layer as the dielectric layers, wherein the first semiconductor layer, the first dielectric layer, the second semiconductor layer, the second dielectric layer, and the third semiconductor layer are stacked in this order from a light incidence surface side. ### Claim 9 (depends on 7) The imaging element according to claim 7, wherein each of the semiconductor layers includes any of silicon, germanium, or silicon germanium or an amorphous material thereof. ### Claim 10 (depends on 7) The imaging element according to claim 7, wherein each of the dielectric layers includes any of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, aluminum oxide, or magnesium fluoride. ### Claim 11 (depends on 7) The imaging element according to claim 7, further comprising a fixed electric charge layer and an anti-reflection layer between the first photoelectric conversion section and the multilayer film, the fixed electric charge layer and the anti-reflection layer being stacked in order from the first photoelectric conversion section side. ### Claim 12 (depends on 7) The imaging element according to claim 7, further comprising a first optical film on the light incidence surface side of the second photoelectric conversion section, the first optical film transmitting light in a predetermined wavelength band corresponding to a color component. ### Claim 13 (depends on 12) The imaging element according to claim 12, further comprising a second optical film closer to the light incidence surface side than the first optical film, the second optical film selectively transmitting the light having the wavelength in the visible light region and the light having the wavelength in the infrared light region. ### Claim 14 (depends on 7) The imaging element according to claim 7, further comprising a semiconductor substrate having one surface and another opposed surface, wherein the first photoelectric conversion section is formed to be buried in the semiconductor substrate, and the second photoelectric conversion section is disposed on the one surface side of the semiconductor substrate. ### Claim 15 (depends on 14) The imaging element according to claim 14, wherein the semiconductor substrate further includes a through electrode that extends between the one surface and the other surface of the semiconductor substrate and a readout circuit that is provided on the other surface side, the readout circuit outputting a signal based on electric charge outputted from the second photoelectric conversion section through the through electrode.