# US 2020/0400587 A1 · Method for inspecting surface of wafer, device for inspecting surface of wafer, and manufacturing method of electronic component > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0400587 A1 - Document ID: US20200400587A1 - Status: Published application - Kind: A1 - Application number: 16/900,492 - Filed: 2020-06-12 - Published: 2020-12-24 - Earliest claimed: 2019-06-18 - Assignees: Sumitomo Electric Device Innovations, Inc. - Applicants: Sumitomo Electric Device Innovations, Inc. - Inventors: Hiroyuki OGURI - Web page: https://patentgrep.com/patent/US20200400587A1 ## CPC - G01N 21/9501: {Semiconductor wafers (manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20)} - H10P 74/203: {Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects} - G01N 21/55: Specular reflectivity - G01N 21/94: Investigating contamination, e.g. dust (G01N21/85 takes precedence) - G01N 21/956: Inspecting patterns on the surface of objects {(contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20)} - H10D 1/692: {Electrodes} - H10P 14/46: using a liquid - H10P 72/0616: {Monitoring of warpages, curvatures, damages, defects or the like} - H10P 74/23: {characterised by multiple measurements, corrections, marking or sorting processes} - G01N 21/8806: {Specially adapted optical and illumination features} - G01N 2021/8845: {Multiple wavelengths of illumination or detection} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES ## Abstract A method for inspecting a surface of a wafer, includes steps of: irradiating a surface of the wafer with a laser beam having three or more distinct wavelengths; detecting a reflected light from the surface of the wafer when the surface of the wafer is irradiated with the laser beam; and determining whether a foreign matter exists on the surface of the wafer based on reflectances of the surface of the wafer with respect to the laser beam having the three or more distinct wavelengths, wherein the step of determining whether the foreign matter exists includes a step of determining whether the foreign matter is a metal or a non-metal. ## Claims ### Claim 1 A method for inspecting a surface of a wafer, the method comprising steps of: irradiating a surface of the wafer with a laser beam having three or more distinct wavelengths; detecting a reflected light from the surface of the wafer when the surface of the wafer is irradiated with the laser beam; and determining whether a foreign matter exists on the surface of the wafer based on reflectances of the surface of the wafer with respect to the laser beam having the three or more distinct wavelengths, wherein the step of determining whether the foreign matter exists includes a step of determining whether the foreign matter is a metal or a non-metal. ### Claim 2 (depends on 1) The method according to claim 1, wherein the step of determining whether the foreign matter is a metal or a non-metal includes steps of: obtaining respective reflectances at the distinct wavelengths, and determining whether the foreign matter is a metal or a non-metal based on a difference between two reflectances of the respective reflectances at the distinct wavelengths. ### Claim 3 (depends on 1) The method according to claim 1, wherein the step of determining whether the foreign matter is a metal or a non-metal includes steps of: obtaining a largest reflectance and a smallest reflectance among the respective reflectances at the distinct wavelengths, obtaining a difference between the largest reflectance and the smallest reflectance and a sum of the largest reflectance and the smallest reflectance, and determining that the foreign matter is a metal when a ratio of the difference to the sum is less than 0.15, and that the foreign matter is a non-metal when the ratio is 0.15 or greater. ### Claim 4 (depends on 1) The method according to claim 1, wherein each of the three or more distinct wavelengths of the laser beam is 600 nm or greater. ### Claim 5 (depends on 1) The method according to claim 1, further comprising a step of: irradiating the surface of the wafer with a laser beam having five or more distinct wavelengths. ### Claim 6 A device for inspecting a surface of a wafer, the device comprising: a laser source irradiating a surface of the wafer with a laser beam having three or more distinct wavelengths; a detector detecting a reflected light from the wafer when the surface of the wafer is irradiated with the laser beam; and a controller determining whether a foreign matter exists and whether the foreign matter is a metal or a non-metal based on reflectances with respect to the laser beam having the three or more distinct wavelengths. ### Claim 7 A manufacturing method of an electronic component, the manufacturing method comprising steps of: forming a metal layer on a surface of a wafer; forming a resist pattern on a surface of the metal layer; irradiating the surface of the wafer with a laser beam having three or more distinct wavelengths after the step of forming the resist pattern to determine whether a foreign matter exists on the surface of the wafer based on reflectances with respect to the laser beam having the three or more distinct wavelengths; when the foreign matter exists, determining whether the foreign matter is a metal or a non-metal; and when no foreign matter exists or when the foreign matter is a metal, forming a plated layer on the metal layer. ### Claim 8 (depends on 7) The manufacturing method according to claim 7, wherein the electronic component is a capacitor, the plated layer is included in a lower electrode of the capacitor, and the manufacturing method further comprises steps of: forming a dielectric film on the plated layer; and forming an upper electrode on the dielectric film.