US 11,929,409 B2
Semiconductor device with improved source and drain contact area and methods of fabrication thereof
Wei Ju Lee, Hsinchu (TW); Chun-Fu Cheng, Hsinchu (TW); Chung-Wei Wu, Hsinchu (TW); and Zhiqiang Wu, Hsinchu (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD., Hsinchu (TW)
Filed by TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD., Hsinchu (TW)
Filed on Oct. 14, 2022, as Appl. No. 17/966,086.
Application 17/966,086 is a continuation of application No. 17/308,617, filed on May 5, 2021, granted, now 11,476,342.
Prior Publication US 2023/0042480 A1, Feb. 9, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 29/417 (2006.01); H01L 21/285 (2006.01); H01L 21/8238 (2006.01); H01L 27/092 (2006.01); H01L 29/08 (2006.01); H01L 29/45 (2006.01)
CPC H01L 29/41791 (2013.01) [H01L 21/28518 (2013.01); H01L 21/823814 (2013.01); H01L 21/823821 (2013.01); H01L 21/823871 (2013.01); H01L 27/0924 (2013.01); H01L 29/0847 (2013.01); H01L 29/45 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A semiconductor device structure, comprising:
a substrate having a plurality of fins formed from the substrate;
a first source/drain feature comprising:
a first epitaxial layer in contact with a first fin of the plurality of fins;
a second epitaxial layer formed on the first epitaxial layer; and
a third epitaxial layer formed on the second epitaxial layer, the third epitaxial layer comprising a center portion and an edge portion that is at a different height than the center portion; and
a fourth epitaxial layer formed on the third epitaxial layer; and
a second source/drain feature disposed adjacent to the first source/drain feature, the second source/drain feature comprising:
a first epitaxial layer in contact with a second fin of the plurality of fins;
a second epitaxial layer formed on the first epitaxial layer of the second source/drain feature;
a third epitaxial layer formed on the second epitaxial layer of the second source/drain feature, the third epitaxial layer comprising a center portion and an edge portion that is at a different height than the center portion of the third epitaxial layer of the second source/drain feature; and
a fourth epitaxial layer formed on the third epitaxial layer of the second source/drain feature,
wherein the center portion and the edge portion of the third epitaxial layer of the second source/drain feature are in contact with the center portion and edge portion of the third epitaxial layer of the first source/drain feature, respectively.