Impact of channel length and thickness on the short channel effects of GeOI MOSFETs

Germanium on insulator (GeOI) MOSFETs have shown great promise for future nanoelectronics due to outstanding carrier transport properties in Ge and better electrostatic control. In this paper, we develop an accurate 2D surface potential based model for GeOI device to calculate threshold voltage V_TH, drain induced barrier lowering DIBL and sub-threshold swing SS for channel thickness ranging 25-5 nm and channel length L in the range a few hundred down to 20 nm. Our formulation takes into account both the front and back interface-trapped charge density, oxide charge density, and the effect of back gate coupling. Our studies reveal that short channel effects as estimated in terms of V_TH roll-up, DIBL and SS become pronounced for sub-40 nm while improve as the channel thickness shrinks below 15 nm.