# US 12,009,380 B2 · Pixel of a semiconductor image sensor and method of manufacturing a pixel > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,009,380 B2 - Document ID: US12009380B2 - Status: Granted - Kind: B2 - Application number: 17/416,550 - Filed: 2019-11-13 - Published: 2022-03-17 - Granted: 2024-06-11 - Earliest claimed: 2018-12-21 - Assignees: ams Sensors Belgium BVBA - Applicants: ams Sensors Belgium BVBA - Inventors: Guy Meynants; Gerhard Eilmsteiner - Web page: https://patentgrep.com/patent/US12009380B2 ## CPC - H10F 39/806: {Optical elements or arrangements associated with the image sensors} - H10F 39/024: {of coatings or optical elements} - H10F 39/805: {Coatings} - H10F 39/8067: {Reflectors} - H10F 39/807: {Pixel isolation structures} - H10F 39/18: Complementary metal-oxide-semiconductor [CMOS] image sensors; Photodiode array image sensors - H10F 39/199: {Back-illuminated image sensors} - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION ## Abstract A pixel with enhanced quantum efficiency comprises a semiconductor body that has a first surface configured as an entrance surface and a light capturing region configured for capturing light that is incident on the first surface. The pixel further comprises a structured interface, isolation layers on at least two surfaces of the semiconductor body that are perpendicular to the first surface, and a filter element that is arranged at a distance from the first surface such that light that is incident on the first surface at an angle of incidence smaller than a critical angle impinges on the filter element. ## Claims ### Claim 1 A pixel comprising: a semiconductor body having a first surface configured as an entrance surface and a light-capturing region configured for capturing light incident on the first surface; a structured interface; isolation layers on at least two surfaces of the semiconductor body that are perpendicular to the first surface; and a filter element arranged at a distance from the first surface such that light incident on the first surface at an angle of incidence smaller than a critical angle impinges on the filter element, wherein the filter element is configured to reflect light if the angle of incidence is larger than the critical angle; and to transmit light if the angle of incidence is less than or equal to the critical angle. ### Claim 2 (depends on 1) The pixel according to claim 1, wherein the filter element is arranged such that the light incident at the angle of incidence smaller than the critical angle has to traverse the filter element before entering the semiconductor body. ### Claim 3 (depends on 1) The pixel according to claim 1, wherein a transmission value of the filter element depends on the angle of incidence and/or on a wavelength of the light. ### Claim 4 (depends on 1) The pixel according to claim 1, wherein the filter element comprises a dichroic filter. ### Claim 5 (depends on 4) The pixel according to claim 4, further comprising a waveguide structure arranged between the filter element and the first surface. ### Claim 6 (depends on 1) The pixel according to claim 1, wherein the filter element is configured to transmit light at optical wavelengths within a specific narrowband wavelength range. ### Claim 7 (depends on 1) The pixel according to claim 1, wherein the filter element is configured as a Fabry-Perot cavity. ### Claim 8 (depends on 1) The pixel according to claim 1, wherein the structured interface is arranged on a side of the pixel that comprises the first surface; or on a side of the pixel facing away from the first surface. ### Claim 9 (depends on 1) The pixel according to claim 1, wherein the isolation layers cover at least part of the at least two surfaces of the semiconductor body. ### Claim 10 (depends on 1) The pixel according to claim 1, further comprising isolation layers on all surfaces of the semiconductor body that are perpendicular, to the first surface. ### Claim 11 (depends on 1) An image sensor comprising a plurality of pixels according to claim 1, wherein the pixels are arranged such that an isolation layer of each of two adjacent pixels face each other. ### Claim 12 (depends on 11) The image sensor of claim 11, wherein the image sensor is a CMOS image sensor. ### Claim 13 (depends on 11) The image sensor according to claim 11, wherein the image sensor is operated in combination with active illumination. ### Claim 14 (depends on 11) An electronic device with a camera system comprising an image sensor according to claim 11. ### Claim 15 (depends on 1) The pixel according to claim 1, wherein the filter element is configured to transmit light at optical wavelengths within a wavelength range comprising 940 nm and/or 850 nm. ### Claim 16 (depends on 11) The image sensor according to claim 11, wherein the image sensor is operated in combination with active illumination in an infrared wavelength range. ### Claim 17 A method of manufacturing a pixel, the method comprising: providing a semiconductor body having a first surface that is configured as an entrance surface, and a light-capturing region that is configured for capturing light incident on the first surface; forming a structured interface; applying isolation layers on at least two surfaces of the semiconductor body that are perpendicular to the first surface; and arranging a filter element at a distance from the first surface such that light incident on the first surface at an angle of incidence smaller than a critical angle impinges on the filter element, wherein the filter element is configured to reflect light if the angle of incidence is larger than the critical angle; and to transmit light if the angle of incidence is less than or equal to the critical angle. ### Claim 18 (depends on 17) The method according to claim 17, wherein the filter element is arranged such that the light incident at the angle of incidence smaller than the critical angle has to traverse the filter element before entering the semiconductor body. ### Claim 19 A pixel comprising: a semiconductor body having a first surface configured as an entrance surface and a light-capturing region configured for capturing light incident on the first surface; a structured interface formed by a light scattering layer on a surface of the semiconductor body; isolation layers on at least two surfaces of the semiconductor body that are perpendicular to the first surface; and a filter element arranged at a distance from the first surface such that light incident on the first surface at an angle of incidence smaller than a critical angle impinges on the filter element.