Title :
Comprehensive study and control of oxygen vacancy induced effective work function modulation in gate-first high-k/metal inserted poly-Si stacks
Author :
Hosoi, T. ; Saeki, M. ; Oku, Y. ; Arimura, H. ; Kitano, N. ; Shiraishi, K. ; Yamada, K. ; Shimura, T. ; Watanabe, H.
Author_Institution :
Grad. Sch. of Eng., Osaka Univ., Suita, Japan
Abstract :
We report the crucial impact of “Reductant Controlled MIPS (RC-MIPS) process” to obtain a sufficiently high effective work function (EWF) of poly-Si/TiN/HfSiON stacks in the gate-first process. It was found that carbon impurity, the strongest reductant element in the gate stack, dominates oxygen vacancy (Vo) formation kinetics and markedly enhances Fermi level pinning (FLP) phenomenon. We designed a high EWF gate-first RC-MIPS technology that uses both in situ metal/high-k fabrication and reduction suppressing processes, which leads to improved EOT-Jg characteristics and EWF stability.
Keywords :
Fermi level; hafnium compounds; high-k dielectric thin films; silicon compounds; vacancies (crystal); Fermi level pinning; RC-MIPS; carbon impurity; gate-first high-k/metal; oxygen vacancy formation kinetics; poly-Si/TiN/HfSiON stack; reductant controlled MIPS; work function modulation; High K dielectric materials; Impurities; Logic gates; Silicon; Sputtering; Tin;
Conference_Titel :
VLSI Technology (VLSIT), 2010 Symposium on
Conference_Location :
Honolulu
Print_ISBN :
978-1-4244-5451-8
Electronic_ISBN :
978-1-4244-5450-1
DOI :
10.1109/VLSIT.2010.5556218
