US 12,283,610 B2
Structure and formation method of semiconductor device with epitaxial structures
Chien-Tai Chan, Hsinchu (TW); Yu-Ching Huang, Taipei (TW); Chien-Chih Lin, Taichung (TW); and Hsueh-Jen Yang, Taipei (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on May 17, 2022, as Appl. No. 17/746,337.
Prior Publication US 2023/0378268 A1, Nov. 23, 2023
Int. Cl. H01L 29/423 (2006.01); H01L 29/08 (2006.01); H01L 29/66 (2006.01); H01L 29/786 (2006.01); H01L 29/06 (2006.01)
CPC H01L 29/0847 (2013.01) [H01L 29/66545 (2013.01); H01L 29/66553 (2013.01); H01L 29/66742 (2013.01); H01L 29/78621 (2013.01); H01L 29/78696 (2013.01); H01L 29/0665 (2013.01); H01L 29/42392 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for forming a semiconductor device structure, comprising:
forming a fin structure over a substrate, wherein the fin structure has a plurality of sacrificial layers and a plurality of semiconductor layers, and the sacrificial layers and the semiconductor layers have an alternating configuration;
forming a gate stack to wrap a portion of the fin structure;
partially removing the fin structure to form a recess exposing edges of the semiconductor layers; and
forming an epitaxial structure in the recess, wherein the formation of the epitaxial structure includes:
forming a bottom semiconductor portion on a bottom of the recess,
forming a lower semiconductor portion on the bottom semiconductor portion, and
forming a main semiconductor portion over the lower semiconductor portion, wherein the main semiconductor portion and the bottom semiconductor portion are oppositely doped.