Intrinsic reduction of ballistic hole current due to quantum mechanical coupling of heavy and light holes in p-type Si nanowire field effect transistors

Abstract

Rigorous quantum mechanical transport calculations based on the multi-band k · p Hamiltonian are performed in this work to show that the coupling of heavy and light holes (LHs) greatly reduces on-state hole current in ultra-scaled p-type Si nanowire FETs. If the coupling between the heavy and light holes is artificially suppressed, on-current of the p-type devices almost doubles and becomes comparable to that of n-type counterparts. It is found that the effect of the coupling on the hole transport is maximized at the channel width of around 5 nm.