US 12,362,238 B2
Metal gate process and related structure
Chih-Lun Lu, New Taipei (TW); Jih-Sheng Yang, Hsinchu (TW); Chen-Wei Pan, Hsinchu County (TW); and Chih-Teng Liao, Hsinchu (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on May 26, 2022, as Appl. No. 17/804,146.
Prior Publication US 2023/0386920 A1, Nov. 30, 2023
Int. Cl. H01L 21/768 (2006.01); H01L 23/535 (2006.01); H10D 30/62 (2025.01); H10D 64/01 (2025.01)
CPC H01L 21/76897 (2013.01) [H01L 21/76805 (2013.01); H01L 21/76826 (2013.01); H01L 21/76895 (2013.01); H01L 23/535 (2013.01); H10D 30/6219 (2025.01); H10D 64/01 (2025.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
providing a device including a gate stack having a metal gate layer and a spacer layer disposed on a sidewall of the gate stack;
performing an etch-back process to the metal gate layer to form an opening over the gate stack, wherein the etch-back process forms a curved surface along a first portion of the spacer layer;
performing a plasma treatment process to modify a profile of the opening by removing a second portion of the spacer layer; and
forming a hard mask (HM) layer over the metal gate layer and within the opening having the modified profile.