US 12,218,196 B2
Semiconductor device and method of manufacture
Yu-Chang Lin, Hsinchu (TW); Chun-Hung Wu, New Taipei (TW); Liang-Yin Chen, Hsinchu (TW); Huicheng Chang, Tainan (TW); and Yee-Chia Yeo, Hsinchu (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Co., Ltd., Hsinchu (TW)
Filed on Feb. 14, 2022, as Appl. No. 17/670,924.
Prior Publication US 2023/0261048 A1, Aug. 17, 2023
Int. Cl. H01L 29/06 (2006.01); H01L 21/8234 (2006.01); H01L 29/423 (2006.01); H01L 29/66 (2006.01); H01L 29/786 (2006.01)
CPC H01L 29/0665 (2013.01) [H01L 21/823412 (2013.01); H01L 21/823418 (2013.01); H01L 21/823468 (2013.01); H01L 29/42392 (2013.01); H01L 29/66545 (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:
depositing a multi-layer stack on a semiconductor substrate, the multi-layer stack comprising a plurality of sacrificial layers that alternate with a plurality of channel layers;
forming a dummy gate on the multi-layer stack;
forming a first spacer on a sidewall of the dummy gate;
performing a first implantation process to form a first doped region, the first implantation process having a first implant energy and a first implant dose;
performing a second implantation process to form a second doped region, wherein the first doped region and the second doped region are in a portion of the channel layers uncovered by the first spacer and the dummy gate, the second implantation process having a second implant energy and a second implant dose, wherein the second implant energy is greater than the first implant energy, and wherein the first implant dose is different from the second implant dose;
after performing the first implantation process and the second implantation process, forming a second spacer on a sidewall of the first spacer;
forming a first recess in the multi-layer stack adjacent the second spacer; and
forming an epitaxial source/drain region in the first recess.