US 12,176,212 B2
Mandrel structures and methods of fabricating the same in semiconductor devices
Jen-Hong Chang, Hsinchu (TW); Yuan-Ching Peng, Hsinchu (TW); Jiun-Ming Kuo, Hsinchu (TW); Kuo-Yi Chao, Hsinchu (TW); Chih-Chung Chang, Nantou County (TW); You-Ting Lin, Hsinchu (TW); Yen-Po Lin, Taipei (TW); and Chen-Hsuan Liao, Hsinchu (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsin-Chu (TW)
Filed on Aug. 30, 2021, as Appl. No. 17/460,488.
Prior Publication US 2023/0062305 A1, Mar. 2, 2023
Int. Cl. H01L 21/033 (2006.01); H01L 21/8234 (2006.01); H01L 29/423 (2006.01); H01L 29/66 (2006.01)
CPC H01L 21/0337 (2013.01) [H01L 21/823431 (2013.01); H01L 29/42392 (2013.01); H01L 29/66795 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
forming a semiconductor substrate;
forming hard mask layers (HMs) over the semiconductor substrate;
forming first mandrels over the HMs;
forming second mandrels along sidewalls of the first mandrels, wherein the second mandrels differ from the first mandrels in composition;
forming a protective layer over the first mandrels and the second mandrels;
removing a portion of the protective layer to expose portions of the first and the second mandrels;
removing the exposed portions of the second mandrels with respect to the exposed portions of the first mandrels;
removing remaining portions of the protective layer to expose remaining portions of the first and second mandrels, wherein the exposed portions of the first mandrels and the remaining portions of the first and second mandrels form a mandrel structure;
patterning the HMs using the mandrel structure as an etching mask; and
patterning the semiconductor substrate to form a fin structure using the patterned HMs as an etching mask.