US 12,237,232 B2
Methods for forming source/drain features
I-Hsieh Wong, Hsinchu (TW); Wei-Yang Lee, Taipei (TW); Chia-Pin Lin, Hsinchu County (TW); and Yuan-Ching Peng, Hsinchu (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsin-Chu (TW)
Filed on Feb. 8, 2022, as Appl. No. 17/667,115.
Prior Publication US 2023/0253260 A1, Aug. 10, 2023
Int. Cl. H01L 21/8238 (2006.01); H01L 21/02 (2006.01); H01L 27/092 (2006.01); H01L 29/06 (2006.01); H01L 29/423 (2006.01); H01L 29/66 (2006.01); H01L 29/786 (2006.01)
CPC H01L 21/823814 (2013.01) [H01L 21/0259 (2013.01); H01L 21/823807 (2013.01); H01L 21/823878 (2013.01); H01L 27/092 (2013.01); H01L 29/0665 (2013.01); H01L 29/42392 (2013.01); H01L 29/66545 (2013.01); H01L 29/66553 (2013.01); H01L 29/66742 (2013.01); H01L 29/78618 (2013.01); H01L 29/78696 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
receiving a workpiece comprising:
a substrate,
an active region protruding from the substrate and comprising a channel region and a source/drain region, and
a dummy gate structure disposed over the channel region;
forming a source/drain trench in the source/drain region of the active region;
forming a sacrificial structure in the source/drain trench;
after the forming of the sacrificial structure, conformally depositing a dielectric film over the workpiece;
performing a first etching process to etch back the dielectric film to form fin sidewall (FSW) spacers extending along sidewalls of the sacrificial structure;
removing the sacrificial structure to expose the source/drain trench;
forming an epitaxial source/drain feature in the source/drain trench, a portion of the epitaxial source/drain feature being sandwiched by the FSW spacers; and
replacing the dummy gate structure with a gate stack.