Title :
Effects of boron diffusion in pMOSFETs with TiN-HfSiO gate stack
Author :
Song, Seung-Chul ; Zhang, Zhibo ; Lee, Byoung Hun
Author_Institution :
Sematech, Austin, TX, USA
fDate :
6/1/2005 12:00:00 AM
Abstract :
Boron diffusion in TiN-HfSiO gate stack capped with polysilicon layer has been studied. SIMS analysis indicates that a significant amount of B diffused from B-doped polysilicon through TiN layer into nitrided HfSiO gate dielectrics. Grain boundaries in TiN thin film are considered a conduit of B into HfSiO. Even though most of B was stopped within HfSiO film owing to N incorporation, significant Vt shift and interface properties degradation were observed. It was found that B in HfSiO serves as positive charge and shifts pMOSFET Vt to negative side.
Keywords :
MOSFET; boron; dielectric materials; diffusion; grain boundaries; hafnium compounds; interface phenomena; silicon compounds; titanium compounds; B; B-doped polysilicon; TiN-HfSiO; Vt shift; boron diffusion; grain boundaries; interface properties degradation; nitrided gate dielectrics; pMOSFET; polysilicon layer; positive charge; Boron; CMOS process; Degradation; Dielectric materials; Dielectric thin films; Hafnium; Leakage current; MOSFET circuits; Thermal stability; Tin; Boron; SIMS; TiN; hafnium; high-; metal gate; pMOSFET; silicate;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2005.848071
