Title :
On the origin of the mobility reduction in bulk-Si, UTBOX-FDSOI and SiGe devices with ultrathin-EOT dielectrics
Author :
Ragnarsson, L. -Å ; Mitard, J. ; Kauerauf, T. ; De Keersgieter, A. ; Schram, T. ; Röhr, E. ; Collaert, N. ; Jurczak, M. ; Hong, S.-H. ; Tseng, J. ; Wang, W.-E. ; Trojman, L. ; Bourdelle, K.K. ; Nguyen, B.-Y. ; Absil, P. ; Hoffmann, T.Y.
Author_Institution :
Imec, Leuven, Belgium
Abstract :
The effects of ultrathin EOT on the carrier mobility in bulk-Si, UTBOX-FDSOI and SiGe-QW pFET devices were compared. The mobility is found to decrease dramatically with the EOT (Tinv) as a result of stronger charge and surface roughness scattering at thinner SiOx interface layers irrespective of the device technology. UTBOX-FDSOI and bulk-Si nFETs have identical mobility values (190 cm2/Vs) at Tinv=12.5Å. In the UTBOX-FDSOI device architecture, a positive back gate bias provides a strong enhancement in electron mobility. In SiGe-QW pFET devices, a 150% improvement in hole-mobility is observed with low thermal budget laser-anneal (LA).
Keywords :
Ge-Si alloys; dielectric properties; field effect transistors; hole mobility; laser beam annealing; silicon-on-insulator; SiGe devices; UTBOX-FDSOI; carrier mobility; hole-mobility; laser-anneal; mobility reduction; pFET devices; ultrathin-EOT dielectrics; Electron mobility; Logic gates; Rough surfaces; Scattering; Silicon; Silicon germanium; Surface roughness;
Conference_Titel :
VLSI Technology, Systems and Applications (VLSI-TSA), 2011 International Symposium on
Conference_Location :
Hsinchu
Print_ISBN :
978-1-4244-8493-5
DOI :
10.1109/VTSA.2011.5872255
