US 12,464,707 B2
Semiconductor device having metal nitride gate doped with a low work function
Dong Soo Kim, Gyeonggi-do (KR); and Se Han Kwon, Gyeonggi-do (KR)
Assigned to SK hynix Inc., Gyeonggi-do (KR)
Filed by SK hynix Inc., Gyeonggi-do (KR)
Filed on Sep. 7, 2022, as Appl. No. 17/939,414.
Claims priority of application No. 10-2022-0029939 (KR), filed on Mar. 10, 2022.
Prior Publication US 2023/0292494 A1, Sep. 14, 2023
Int. Cl. H10B 12/00 (2023.01)
CPC H10B 12/34 (2023.02) [H10B 12/053 (2023.02)] 11 Claims
OG exemplary drawing
 
1. A semiconductor device comprising:
a trench formed in a substrate;
a gate dielectric layer covering sidewalls and a bottom surface of the trench;
a first gate electrode gap-filling a bottom portion of the trench over the gate dielectric layer;
a second gate electrode including a metal nitride which is the same as the first gate electrode over the first gate electrode and doped with a low work function adjusting element;
a buffer layer covering a top surface of the second gate electrode and the gate dielectric layer exposed over the second gate electrode; and
a capping layer gap-filling the trench over the buffer layer.