# US 10,872,768 B2 · Method of manufacturing epitaxial silicon wafer, epitaxial silicon wafer, and method of manufacturing solid-state image sensing device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,872,768 B2 - Document ID: US10872768B2 - Status: Granted - Kind: B2 - Application number: 16/325,256 - Filed: 2017-04-25 - Published: 2019-06-20 - Granted: 2020-12-22 - Earliest claimed: 2016-08-22 - Assignees: Sumco Corporation - Applicants: Sumco Corporation - Inventors: Ayumi Masada - Web page: https://patentgrep.com/patent/US10872768B2 ## CPC - H10P 14/2905: {Silicon, silicon germanium or germanium} - H10D 62/83: being Group IV materials, e.g. B-doped Si or undoped Ge - H10F 39/014: {of CMOS image sensors} - H10F 39/026: {Wafer-level processing} - H10F 39/12: Image sensors - H10P 14/20: of semiconductor materials - H10P 14/24: using chemical vapour deposition [CVD] - H10P 14/3211: {Silicon, silicon germanium or germanium} - H10P 14/3411: {Silicon, silicon germanium or germanium} - H10P 14/36: {characterised by treatments done before the formation of the materials} - H10P 14/3822: {Controlling the interface between substrate and epitaxial layer, e.g. by ion implantation followed by annealing} - H10P 30/20: into semiconductor materials, e.g. for doping - H10P 30/204: {into Group IV semiconductors} - H10P 30/208: {of electrically inactive species} - H10P 30/224: {of a cluster, e.g. using a gas cluster ion beam} - H10P 36/00: Gettering within semiconductor bodies - H10P 36/03: {within silicon bodies} - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION ## Abstract Provided are an epitaxial silicon wafer which can reduce metal contamination by exerting higher gettering capability and a method of manufacturing the same. In a method of manufacturing an epitaxial silicon wafer which includes a silicon wafer, a first silicon epitaxial layer formed on the silicon wafer, a first modifying layer in which carbon is implanted in a surface layer portion of the first silicon epitaxial layer, and a second silicon epitaxial layer on the first modifying layer, the peak concentration of the oxygen concentration profile in the first modifying layer after formation of the second silicon epitaxial layer is set to 2×1017 atoms/cm3 or less and the oxygen concentration of the second silicon epitaxial layer is set to be equal to or less than the SIMS detection lower limit value. ## Claims ### Claim 1 A method of manufacturing an epitaxial silicon wafer, comprising: forming a first silicon epitaxial layer having a surface layer portion with an oxygen concentration of 2×1016 atoms/cm3 or less on a silicon wafer that has an oxygen concentration of 2×1017 atoms/cm3 or more: irradiating the surface layer portion of the first silicon epitaxial layer with first ions containing carbon to form in the surface layer portion of the first silicon epitaxial layer a first modifying layer in which the carbon is implanted; and forming a second silicon epitaxial layer on the first modifying layer, wherein after the forming the second silicon epitaxial layer, the epitaxial silicon wafer is obtained wherein a peak concentration of an oxygen concentration profile in the first modifying layer is 2×1017 atoms/cm3 or less, and an oxygen concentration of the second silicon epitaxial layer is 2×1016 atoms/cm3 or less, and wherein a thickness of the first silicon epitaxial layer is adjusted according to the oxygen concentration of the silicon wafer such that the surface layer portion of the first silicon epitaxial layer has an oxygen concentration of 2×1016 atoms/cm3 or less. ### Claim 2 (depends on 1) The method according to claim 1, wherein the first ions are cluster ions which contain carbon as a constituent element. ### Claim 3 (depends on 1) The method according to claim 1, further comprising, before the forming the first silicon epitaxial layer, irradiating the silicon wafer with second ions containing carbon to form in a surface layer portion of the silicon wafer a second modifying layer in which the carbon is implanted, such that the surface layer portion of the first silicon epitaxial layer before the irradiating the surface layer portion of the first silicon epitaxial layer has an oxygen concentration of 2×1016 atoms/cm3 or less. ### Claim 4 (depends on 3) The method according to claim 3, wherein the second ions are cluster ions which contain carbon as a constituent element. ### Claim 5 (depends on 1) The method according to claim 1, wherein the first silicon epitaxial layer has a dopant concentration that is equal to or less than a dopant concentration of the second silicon epitaxial layer. ### Claim 6 (depends on 5) The method according to claim 5, wherein the first silicon epitaxial layer is not doped with a dopant. ### Claim 7 An epitaxial silicon wafer comprising: a silicon wafer that has an oxygen concentration of 2×1017 atoms/cm3 or more; a first silicon epitaxial layer formed on the silicon wafer; a first modifying layer in which carbon is implanted, the first modifying layer being formed in a surface layer portion of the first silicon epitaxial layer; and a second silicon epitaxial layer formed on the first modifying layer, wherein a thickness of the first silicon epitaxial layer is configured such that a peak concentration of an oxygen concentration profile in the first modifying layer is 2×1017 atoms/cm3 or less and an oxygen concentration of the second silicon epitaxial layer is 2×1016 atoms/cm3 or less. ### Claim 8 (depends on 7) The epitaxial silicon wafer according to claim 7, wherein the first silicon epitaxial layer has a dopant concentration that is equal to or less than a dopant concentration of the second silicon epitaxial layer. ### Claim 9 (depends on 8) The epitaxial silicon wafer according to claim 8, wherein the first silicon epitaxial layer is not doped with a dopant. ### Claim 10 (depends on 1) A method of manufacturing a solid-state image sensing device, comprising: forming a solid-state image sensing device in the second silicon epitaxial layer of the epitaxial silicon wafer manufactured by the method according to claim 1. ### Claim 11 (depends on 7) A method of manufacturing a solid-state image sensing device, comprising: forming a solid-state image sensing device in the second silicon epitaxial layer of the epitaxial silicon wafer according to claim 7.