US 11,705,507 B2
Semiconductor device and forming method thereof
Yao-Sheng Huang, Kaohsiung (TW); Hung-Chang Sun, Kaohsiung (TW); I-Ming Chang, Hsinchu (TW); and Zi-Wei Fang, Hsinchu County (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsinchu (TW)
Filed by TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsinchu (TW)
Filed on May 28, 2021, as Appl. No. 17/333,908.
Application 17/333,908 is a continuation of application No. 16/920,197, filed on Jul. 2, 2020, granted, now 11,024,723.
Application 16/920,197 is a continuation of application No. 16/191,244, filed on Nov. 14, 2018, granted, now 10,707,333, issued on Jul. 7, 2020.
Claims priority of provisional application 62/711,636, filed on Jul. 30, 2018.
Prior Publication US 2021/0288166 A1, Sep. 16, 2021
Int. Cl. H01L 29/66 (2006.01); H01L 21/02 (2006.01); H01L 29/78 (2006.01); H01L 29/08 (2006.01); H01L 21/311 (2006.01); H01L 21/306 (2006.01)
CPC H01L 29/66795 (2013.01) [H01L 21/0262 (2013.01); H01L 21/02488 (2013.01); H01L 21/02513 (2013.01); H01L 21/02532 (2013.01); H01L 21/02592 (2013.01); H01L 21/02598 (2013.01); H01L 21/02639 (2013.01); H01L 21/02661 (2013.01); H01L 21/02675 (2013.01); H01L 21/31116 (2013.01); H01L 29/0847 (2013.01); H01L 29/66545 (2013.01); H01L 29/785 (2013.01); H01L 21/02576 (2013.01); H01L 21/02579 (2013.01); H01L 21/30604 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
forming a semiconductor fin extending from a substrate;
forming a shallow trench isolation (STI) region around a lower portion of the semiconductor fin;
performing a deposition process to form a silicon layer having a crystalline silicon portion over the semiconductor fin and an amorphous silicon portion over the STI region;
performing an anneal process to crystallize the amorphous silicon portion into a polysilicon portion; and
selectively etching the polysilicon portion, while leaving the crystalline silicon portion over the semiconductor fin.