Ballistic Hole Injection Velocity Analysis in Ge UTB pMOSFETs: Dependence on Body Thickness, Orientation and Strain

Saumitra R. Mehrotra, Purdue University - Main Campus
Abhijeet Paul, Purdue University - Main Campus
Gerhard Klimeck, Purdue University - Main Campus

Date of this Version



ISDRS 2011, December 7-9, 2011, College Park, MD, USA Student Paper


ISDRS 2011, December 7-9, 2011, College Park, MD, USA

Student Paper


Introduction: Ge exhibits a high bulk hole mobilty making it an attractive channel material for pMOSFET devices [1,2]. For improving the device performance and suppressing short channel effects ultra-thin-body (UTB) Ge-on-insulator ( GeOI) structures have been researched thoroughly [2]. Recentlyoriented Ge-OI pMOSFETs grown on (110) surface were shown to exhibit enhanced hole mobility, which was 3 times compared to (100)/Si and 2.3 times (100)/Ge pMOSFETs [2]. Due to heavy warping within valence bands and finite atomic granularity in sub-10 nm thick devices, atomistic modelling becomes important. To analyse the recent experimental results a tight binding based 10 band sp3s*d5 (including SO coupling) bandstructure model for is used for UTB Ge [3]. It has been reported in literature that carrier mobility is closely correlated with carrier injection velocity near the top-of-the barrier or the virtual source region [4]. Hence in this paper ballistic injection velocity (vinj) is used as the metric for analysing UTB Ge device performance.


Nanoscience and Nanotechnology