# US 12,179,308 B2 · Method of transferring semiconductor wafer to polishing apparatus and method of producing semiconductor wafer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,179,308 B2 - Document ID: US12179308B2 - Status: Granted - Kind: B2 - Application number: 17/788,834 - Filed: 2020-10-13 - Published: 2023-02-02 - Granted: 2024-12-31 - Earliest claimed: 2019-12-25 - Assignees: Sumco Corporation - Applicants: Sumco Corporation - Inventors: Ryoya Terakawa - Web page: https://patentgrep.com/patent/US12179308B2 ## CPC - B24B 37/345: {Feeding, loading or unloading work specially adapted to lapping} - B24B 37/04: designed for working plane surfaces - B24B 37/30: for single side lapping of plane surfaces - B24B 37/34: Accessories - B24B 41/061: {axially supporting turning workpieces, e.g. magnetically, pneumatically} - H10P 52/00: Grinding, lapping or polishing of wafers, substrates or parts of devices - H10P 52/402: {of semiconductor materials} - H10P 72/0428: {Apparatus for mechanical treatment or grinding or cutting} - H10P 90/129: {by polishing} - B24B 41/06: Work supports, e.g. adjustable steadies (B24B37/27 takes precedence) - B24B: MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING (grinding of gear teeth B23F, of screw-threads B23G1/36; by electro-erosion B23H; abrasive or related blasting B24C; tools for grinding, buffing or sharpening B24D; polishing compositions C09G1/00; abrasives C09K3/14; electrolytic etching or polishing C25F3/00; grinding arrangements for use on assembled railway tracks E01B31/17); DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract Provided is a method of transferring a semiconductor wafer to a single-side polishing apparatus without forming scratches on the surface of the semiconductor wafer. The method includes: starting to splay the liquid from each spray hole; placing the semiconductor wafer on the retainer portion to hold a surface of the semiconductor wafer by suction without contact, and raising the tray to attach the semiconductor wafer to the polishing head, wherein a period of time from a point at which the semiconductor wafer is held by the retainer portion to a point at which the attaching of the semiconductor wafer W to the polishing head is completed is 5 s or more, or wherein a ratio of a total area of the protrusions to an area of the semiconductor wafer is 15% or more. ## Claims ### Claim 1 A method of transferring a semiconductor wafer to be polished to a single-side polishing apparatus by placing the semiconductor wafer on a temporary cradle, and then, transferring the semiconductor wafer to a polishing head of the single-side polishing apparatus, the temporary cradle comprising: a retainer portion that holds a peripheral portion of the semiconductor wafer; a tray that is configured to be liftable and has a plurality of ring-shaped protrusions on a surface of the tray, with each protrusion having an inner wall provided with a spray hole through which a liquid is sprayed along the inner wall, such that the semiconductor wafer is held by suction without contact by spraying the liquid from each spray hole; and a guide portion that is placed around the semiconductor wafer and aligns the semiconductor wafer when the semiconductor wafer is raised by raising the tray, the method comprising: starting to splay the liquid from each spray hole at a first flow rate; placing the semiconductor wafer on the retainer portion to hold a surface to be polished of the semiconductor wafer by suction without contact with the tray, and raising the tray to attach the semiconductor wafer to the polishing head after that, wherein a period of time from a point at which the semiconductor wafer is held by the retainer portion to a point at which the attaching of the semiconductor wafer to the polishing head is completed is 5 s or more. ### Claim 2 (depends on 1) The method of transferring a semiconductor wafer to a polishing apparatus, according to claim 1, wherein a flow rate of the liquid during a period from the raising of the tray to the attaching of the semiconductor wafer to the polishing head is a second flow rate higher than the first flow rate. ### Claim 3 (depends on 1) The method of transferring a semiconductor wafer to a polishing apparatus, according to claim 1, wherein after the semiconductor wafer is transferred to the polishing head, the surface of the semiconductor wafer to be polished is polished using the single-side polishing apparatus; the semiconductor wafer is then removed from the polishing head, followed by starting spraying of the liquid from each spray hole at the first flow rate again; the semiconductor wafer having been polished is then placed on the retainer portion to hold the polished surface of the semiconductor wafer by suction without contact with the tray; and the tray is raised to attach the semiconductor wafer to the polishing head after that. ### Claim 4 (depends on 1) A method of producing a semiconductor wafer, comprising: slicing a single crystal ingot grown by a given method to obtain semiconductor wafers; subjecting the semiconductor wafer obtained to lapping, etching, and double-side polishing; and then transferring the semiconductor wafer to a single-side polishing apparatus by the method of transferring a semiconductor wafer to a polishing apparatus, according to claim 1; and polishing a surface of the semiconductor wafer by the single-side polishing. ### Claim 5 (depends on 4) The method of producing a semiconductor wafer, according to claim 4, wherein the semiconductor wafer is a silicon wafer. ### Claim 6 (depends on 2) A method of producing a semiconductor wafer, comprising: slicing a single crystal ingot grown by a given method to obtain semiconductor wafers; subjecting the semiconductor wafer obtained to lapping, etching, and double-side polishing; and then transferring the semiconductor wafer to a single-side polishing apparatus by the method of transferring a semiconductor wafer to a polishing apparatus, according to claim 2; and polishing a surface of the semiconductor wafer by the single-side polishing. ### Claim 7 (depends on 6) The method of producing a semiconductor wafer, according to claim 6, wherein the semiconductor wafer is a silicon wafer. ### Claim 8 (depends on 3) A method of producing a semiconductor wafer, comprising: slicing a single crystal ingot grown by a given method to obtain semiconductor wafers; subjecting the semiconductor wafer obtained to lapping, etching, and double-side polishing; and then transferring the semiconductor wafer to a single-side polishing apparatus by the method of transferring a semiconductor wafer to a polishing apparatus, according to claim 3; and polishing a surface of the semiconductor wafer by the single-side polishing. ### Claim 9 (depends on 8) The method of producing a semiconductor wafer, according to claim 8, wherein the semiconductor wafer is a silicon wafer. ### Claim 10 A method of transferring a semiconductor wafer to be polished to a single-side polishing apparatus by placing the semiconductor wafer on a temporary cradle, and then, transferring the semiconductor wafer to a polishing head of the single-side polishing apparatus, the temporary cradle comprising: a retainer portion that holds a peripheral portion of the semiconductor wafer; a tray that is configured to be liftable and has a plurality of ring-shaped protrusions on a surface of the tray, with each protrusion having an inner wall provided with a spray hole through which a liquid is sprayed along the inner wall, such that the semiconductor wafer is held by suction without contact by spraying the liquid from each spray hole; and a guide portion that is placed around the semiconductor wafer and aligns the semiconductor wafer when the semiconductor wafer is raised by raising the tray, the method comprising: starting to splay the liquid from each spray hole at a first flow rate; placing the semiconductor wafer on the retainer portion to hold a surface to be polished of the semiconductor wafer by suction without contact with the tray, and raising the tray to attach the semiconductor wafer to the polishing head after that, wherein a ratio of a total area of the plurality of ring-shaped protrusions to an area of the semiconductor wafer is 15% or more. ### Claim 11 (depends on 10) The method of transferring a semiconductor wafer to a polishing apparatus, according to claim 10, wherein a flow rate of the liquid during a period from the raising of the tray to the attaching of the semiconductor wafer to the polishing head is a second flow rate higher than the first flow rate. ### Claim 12 (depends on 10) The method of transferring a semiconductor wafer to a polishing apparatus, according to claim 10, wherein after the semiconductor wafer is transferred to the polishing head, the surface of the semiconductor wafer to be polished is polished using the single-side polishing apparatus; the semiconductor wafer is then removed from the polishing head, followed by starting spraying of the liquid from each spray hole at the first flow rate again; the semiconductor wafer having been polished is then placed on the retainer portion to hold the polished surface of the semiconductor wafer by suction without contact with the tray; and the tray is raised to attach the semiconductor wafer to the polishing head after that. ### Claim 13 (depends on 10) A method of producing a semiconductor wafer, comprising: slicing a single crystal ingot grown by a given method to obtain semiconductor wafers; subjecting the semiconductor wafer obtained to lapping, etching, and double-side polishing; and then transferring the semiconductor wafer to a single-side polishing apparatus by the method of transferring a semiconductor wafer to a polishing apparatus, according to claim 10; and polishing a surface of the semiconductor wafer by the single-side polishing. ### Claim 14 (depends on 13) The method of producing a semiconductor wafer, according to claim 13, wherein the semiconductor wafer is a silicon wafer. ### Claim 15 (depends on 11) A method of producing a semiconductor wafer, comprising: slicing a single crystal ingot grown by a given method to obtain semiconductor wafers; subjecting the semiconductor wafer obtained to lapping, etching, and double-side polishing; and then transferring the semiconductor wafer to a single-side polishing apparatus by the method of transferring a semiconductor wafer to a polishing apparatus, according to claim 11; and polishing a surface of the semiconductor wafer by the single-side polishing. ### Claim 16 (depends on 15) The method of producing a semiconductor wafer, according to claim 15, wherein the semiconductor wafer is a silicon wafer. ### Claim 17 (depends on 12) A method of producing a semiconductor wafer, comprising: slicing a single crystal ingot grown by a given method to obtain semiconductor wafers; subjecting the semiconductor wafer obtained to lapping, etching, and double-side polishing; and then transferring the semiconductor wafer to a single-side polishing apparatus by the method of transferring a semiconductor wafer to a polishing apparatus, according to claim 12; and polishing a surface of the semiconductor wafer by the single-side polishing. ### Claim 18 (depends on 17) The method of producing a semiconductor wafer, according to claim 17, wherein the semiconductor wafer is a silicon wafer.