Title :
Dipole Moment Model Explaining nFET Vt Tuning Utilizing La, Sc, Er, and Sr Doped HfSiON Dielectrics
Author :
Sivasubramani, P. ; Böscke, T.S. ; Huang, J. ; Young, C.D. ; Kirsch, P.D. ; Krishnan, S.A. ; Quevedo-Lopez, M.A. ; Govindarajan, S. ; Ju, B.S. ; Harris, H.R. ; Lichtenwalner, D.J. ; Jur, J.S. ; Kingon, A.I. ; Kim, J. ; Gnade, B.E ; Wallace, R.M. ; Bersuke
Author_Institution :
SEMATECH, Austin
Abstract :
A dipole moment model explaining Vt tuning in HfSiON gated nFETs is proposed and its impact on performance and reliability is presented. La, Sc, Er, and Sr dopants are utilized due to their differing electronegativities and ionic radii. These dopants tune Vt in the range of 250-600 mV. Vt tuning is found to be proportional to the net dipole moment associated with the Hf-O and rare earth (RE)-O bonds at the high-k/SiO2 interface. The magnitude of this interfacial dipole moment is determined by the electronegativities and ionic radii of the RE cations. LaOx is the most effective dopant based on Vt, mobility, and reliability,
Keywords :
dielectric materials; electric moments; erbium; field effect transistors; hafnium compounds; lanthanum; rare earth compounds; scandium; strontium; HfSiON; HfSiON:Er; HfSiON:Sc; HfSiON:Sr; SiO2; dielectrics; dipole moment model; gated nFET; interfacial dipole moment; Atherosclerosis; Capacitance; Channel bank filters; Doping; Erbium; High K dielectric materials; High-K gate dielectrics; MOS devices; Semiconductor process modeling; Strontium;
Conference_Titel :
VLSI Technology, 2007 IEEE Symposium on
Conference_Location :
Kyoto
Print_ISBN :
978-4-900784-03-1
DOI :
10.1109/VLSIT.2007.4339730
