Title :
New insight on VT stability of HK/MG stacks with scaling in 30nm FDSOI technology
Author :
Brunet, L. ; Garros, X. ; Casse, M. ; Weber, O. ; Andrieu, F. ; Fenouillet-Beranger, C. ; Perreau, P. ; Martin, F. ; Charbonnier, M. ; Lafond, D. ; Gaumer, C. ; Lhostis, S. ; Vidal, V. ; Brevard, L. ; Tosti, L. ; Denorme, S. ; Barnola, S. ; Damlencourt, J
Author_Institution :
STMicroelectronics, Crolles, France
Abstract :
In this paper it is shown that HfO2 and HfZrO oxides suffer from large VT instabilities, up to 230mV, when the device width (W) is scaled down to 80nm. It is explained by undesirable lateral oxygen diffusion through the spacers, which mainly modifies the metal workfunction in narrow transistors. HfSiO(N) oxides exhibit a much better immunity to this effect, attributed to a different crystallinity of the HK layer. Moreover, Al incorporation in the gate stack hardly changes the VT stability.
Keywords :
hafnium compounds; silicon compounds; silicon-on-insulator; HK-MG stacks; HfO2; HfSiO; HfZrO; VT stability; crystallinity; lateral oxygen diffusion; size 30 nm; size 80 nm; voltage 230 mV; Logic gates; MOS devices; Oxidation; Silicon; Tin; Transistors;
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.2010.5556131
