	US 12,074,204 B2
	Semiconductor structure and method for forming the same
Jung-Hung Chang, Changhua County (TW); Lo Heng Chang, Hsinchu (TW); Zhi-Chang Lin, Zhubei (TW); Shih-Cheng Chen, New Taipei (TW); Chien-Ning Yao, Hsinchu (TW); Kuo-Cheng Chiang, Zhubei (TW); and Chih-Hao Wang, Baoshan Township, Hsinchu County (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on Jul. 23, 2021, as Appl. No. 17/384,667.
Prior Publication US 2023/0026310 A1, Jan. 26, 2023
Int. Cl. H01L 29/417 (2006.01); H01L 21/8234 (2006.01); H01L 29/06 (2006.01); H01L 29/40 (2006.01); H01L 29/423 (2006.01); H01L 29/66 (2006.01); H01L 29/775 (2006.01); H01L 29/786 (2006.01)

CPC H01L 29/41733 (2013.01) [H01L 21/823475 (2013.01); H01L 29/401 (2013.01); H01L 29/42392 (2013.01); H01L 29/66439 (2013.01); H01L 29/66545 (2013.01); H01L 29/66742 (2013.01); H01L 29/775 (2013.01); H01L 29/78606 (2013.01); H01L 29/0653 (2013.01); H01L 29/0665 (2013.01); H01L 29/0673 (2013.01); H01L 29/78696 (2013.01)]

20 Claims

1. A method for forming a semiconductor structure, comprising:

sequentially stacking a first SiGe layer and a first Si layer over a substrate;

alternatingly stacked second SiGe layers and second Si layers over first Si layer, wherein a germanium concentration of the first SiGe layer is lower than a germanium concentration of the second SiGe layers;

patterning the second Si layers, the second SiGe layers, the first Si layer, the first SiGe layer and the substrate to form a fin structure;

forming a first source/drain recess in the fin structure;

forming a sacrificial contact in the first source/drain recess;

forming an etching stop layer on the sacrificial contact in the first source/drain recess;

forming a first source/drain feature on the etching stop layer in the first source/drain recess;

removing the second SiGe layers and the first Si layer to form gaps; and

forming a gate stack to fill the gaps.