US 11,949,013 B2
Semiconductor device and method
Martin Christopher Holland, San Jose, CA (US); Blandine Duriez, Brussels (BE); Marcus Johannes Henricus van Dal, Linden (BE); and Yasutoshi Okuno, Hsinchu (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on Jan. 31, 2022, as Appl. No. 17/649,425.
Application 17/649,425 is a division of application No. 16/805,958, filed on Mar. 2, 2020, granted, now 11,239,368.
Claims priority of provisional application 62/893,947, filed on Aug. 30, 2019.
Prior Publication US 2022/0157991 A1, May 19, 2022
Int. Cl. H01L 29/201 (2006.01); H01L 21/8234 (2006.01); H01L 29/267 (2006.01); H01L 29/417 (2006.01); H01L 29/66 (2006.01); H01L 29/78 (2006.01)
CPC H01L 29/7851 (2013.01) [H01L 21/823418 (2013.01); H01L 21/823431 (2013.01); H01L 29/267 (2013.01); H01L 29/41791 (2013.01); H01L 29/66795 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A structure comprising:
a semiconductor substrate having a channel region;
a gate stack over the channel region; and
an epitaxial source/drain region adjacent the gate stack, the epitaxial source/drain region comprising:
a main portion in the semiconductor substrate, the main portion comprising a semiconductor material doped with gallium, a first concentration of gallium in the main portion being less than the solid solubility of gallium in the semiconductor material; and
a finishing portion over the main portion, the finishing portion doped with gallium, a second concentration of gallium in the finishing portion being greater than the solid solubility of gallium in the semiconductor material, the second concentration being greater than the first concentration.