US 12,283,616 B2
FinFET having a work function material gradient
Peng-Soon Lim, Johor (MY); Zi-Wei Fang, Hsinchu County (TW); and Cheng-Ming Lin, Kaohsiung (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsinchu (TW)
Filed by TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsinchu (TW)
Filed on Mar. 21, 2022, as Appl. No. 17/700,424.
Application 17/700,424 is a division of application No. 16/031,859, filed on Jul. 10, 2018, granted, now 11,282,933.
Claims priority of provisional application 62/593,118, filed on Nov. 30, 2017.
Prior Publication US 2022/0216318 A1, Jul. 7, 2022
Int. Cl. H01L 29/423 (2006.01); H01L 21/28 (2006.01); H01L 29/06 (2006.01); H01L 29/10 (2006.01); H01L 29/49 (2006.01); H01L 29/66 (2006.01); H01L 29/78 (2006.01)
CPC H01L 29/42372 (2013.01) [H01L 21/28088 (2013.01); H01L 21/28097 (2013.01); H01L 29/0649 (2013.01); H01L 29/1033 (2013.01); H01L 29/4966 (2013.01); H01L 29/66545 (2013.01); H01L 29/66795 (2013.01); H01L 29/6681 (2013.01); H01L 29/785 (2013.01); H01L 29/7853 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
forming a semiconductor fin;
forming a gate dielectric layer over the semiconductor fin;
depositing a p-type work function metal layer over the gate dielectric layer;
depositing an n-type work function metal layer over the p-type work function metal layer; and
forming a gate electrode over the n-type work function metal layer, wherein a concentration of a work function material in the n-type work function metal layer increases from a first value to a peak value and then decreases from the peak value to a second value, and wherein the concentration of the work function material in the n-type work function metal layer at an interface of the gate electrode and the n-type work function metal layer has a first non-zero value lower than about 35%.