US 12,446,254 B2
Semiconductor device and methods of forming same
Chih-Yu Ma, Hsinchu (TW); Shahaji B. More, Hsinchu (TW); Yi-Min Huang, Tainan (TW); and Shih-Chieh Chang, Taipei (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Co., Ltd., Hsinchu (TW)
Filed on Feb. 13, 2024, as Appl. No. 18/440,071.
Application 18/440,071 is a continuation of application No. 18/061,031, filed on Dec. 2, 2022, granted, now 11,935,955.
Application 18/061,031 is a continuation of application No. 17/240,432, filed on Apr. 26, 2021, granted, now 11,522,086, issued on Dec. 6, 2022.
Application 17/240,432 is a continuation of application No. 16/933,325, filed on Jul. 20, 2020, granted, now 10,991,826, issued on Apr. 27, 2021.
Application 16/933,325 is a continuation of application No. 16/196,832, filed on Nov. 20, 2018, granted, now 10,720,530, issued on Jul. 21, 2020.
Claims priority of provisional application 62/737,770, filed on Sep. 27, 2018.
Prior Publication US 2024/0186415 A1, Jun. 6, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H10D 30/62 (2025.01); H10D 30/01 (2025.01); H10D 62/13 (2025.01); H10D 64/00 (2025.01); H10D 64/01 (2025.01); H10D 84/01 (2025.01); H10D 84/03 (2025.01); H10D 84/85 (2025.01)
CPC H10D 30/6211 (2025.01) [H10D 30/0243 (2025.01); H10D 62/151 (2025.01); H10D 64/017 (2025.01); H10D 84/0184 (2025.01); H10D 84/0193 (2025.01); H10D 84/038 (2025.01); H10D 84/853 (2025.01)] 20 Claims
OG exemplary drawing
 
1. A device comprising:
a fin extending from a substrate;
a gate stack over and along sidewalls of the fin;
a gate spacer along a sidewall of the gate stack; and
an epitaxial source/drain region in the fin and adjacent the gate spacer, the epitaxial source/drain region comprising:
a first epitaxial layer on the fin, the first epitaxial layer comprising silicon, germanium, and a first n-type dopant;
a second epitaxial layer on the first epitaxial layer, the second epitaxial layer comprising silicon and a second n-type dopant different than the first n-type dopant, the first epitaxial layer separating the second epitaxial layer from the fin; and
a third epitaxial layer on the second epitaxial layer, the third epitaxial layer comprising silicon, germanium, and the second n-type dopant.