Mechanisms for low on-state current of Ge (SiGe) nMOSFETs: A comparative study on gate stack, resistance, and orientation-dependent effective masses

Author

Oh, J. ; Ok, I. ; Kang, C.-Y. ; Jamil, M. ; Lee, S.-H. ; Loh, W.-Y. ; Huang, J. ; Sassman, B. ; Smith, L. ; Parthasarathy, S. ; Coss, B.E. ; Choi, W.-H. ; Lee, H.-D. ; Cho, M. ; Banerjee, S.K. ; Majhi, P. ; Kirsch, P.D. ; Tseng, H.-H. ; Jammy, R.

Author_Institution

SEMATECH, Austin, TX, USA

fYear

2009

fDate

16-18 June 2009

Firstpage

238

Lastpage

239

Abstract

We report the results of a systematic study to understand low drive current of Ge-based nMOSFET. The poor electron transport property is primarily attributed to the intrinsically low density of state and high conductivity effective masses. Results are supported by interface trap density (D_it) and specific contact resistivity (rho_c), which are comparable (or symmetric) for both n- and p-MOSFETs. Effective masses of electrons, which populate L valleys are large for conductivity and small for the density of states in conventional (100) [110] channel directions, resulting in low electron mobility and carrier concentration in Ge-based nMOSFETs.

Keywords

Ge-Si alloys; MOSFET; contact resistance; effective mass; electron mobility; Ge(SiGe) nMOSFET; SiGe; carrier concentration; conductivity; density of states; effective mass; electron mobility; electron transport; interface trap density; on-state current; specific contact resistivity; Conductivity; Contact resistance; Degradation; Dielectric substrates; Effective mass; Electron mobility; Fabrication; Germanium silicon alloys; MOSFET circuits; Silicon germanium;

fLanguage

English

Publisher

ieee

Conference_Titel

VLSI Technology, 2009 Symposium on

Conference_Location

Honolulu, HI

Print_ISBN

978-1-4244-3308-7

Type

conf

Filename

5200612