US 12,354,881 B2
Methods of etching metals in semiconductor devices
Wei-Hao Liao, Taichung (TW); Hsi-Wen Tien, Hsinchu County (TW); Chih Wei Lu, Hsinchu (TW); Pin-Ren Dai, New Taipei (TW); and Chung-Ju Lee, Hsinchu County (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Co., Ltd., Hsin-Chu (TW)
Filed on Feb. 26, 2024, as Appl. No. 18/586,989.
Application 17/509,293 is a division of application No. 16/582,412, filed on Sep. 25, 2019, granted, now 11,158,518, issued on Oct. 26, 2021.
Application 18/586,989 is a continuation of application No. 17/509,293, filed on Oct. 25, 2021, granted, now 11,915,943.
Prior Publication US 2024/0258117 A1, Aug. 1, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 21/32 (2006.01); H01L 21/033 (2006.01); H01L 21/3213 (2006.01); H01L 21/768 (2006.01); H01L 23/522 (2006.01); H01L 23/532 (2006.01)
CPC H01L 21/32139 (2013.01) [H01L 21/0332 (2013.01); H01L 21/0337 (2013.01); H01L 21/32136 (2013.01); H01L 21/76816 (2013.01); H01L 21/76832 (2013.01); H01L 23/5226 (2013.01); H01L 23/53209 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
forming a first metal layer over a semiconductor substrate;
forming a second metal layer directly on the first metal layer, wherein a composition of the second metal layer is different from a composition of the first metal layer;
forming a metal-containing hard mask layer over the second metal layer;
patterning the metal-containing hard mask layer;
etching the second metal layer using the patterned metal-containing hard mask layer as an etch mask to form a conductive line, wherein the etched second metal layer exposes a portion of the first metal layer;
treating the exposed portion of the first metal layer with a plasma; and
removing both the patterned metal-containing hard mask layer and the treated exposed portion of the first metal layer in a wet etching process.