Surface roughness scattering effects on the ballisticity of Schottky barrier nanowire field effect transistors

Abstract

The surface roughness scattering effects on Schottky barrier (SB) silicon nanowire metal-oxide-semiconductor field effect transistors (MOSFETs) are investigated and compared to those of silicon nanowire MOSFETs with doped source and drain. In particular, the ballisticity of both types of devices is examined extensively as the root-mean-square (RMS) value of surface roughness, channel length, channel width (W), Schottky barrier height, and drain voltage are varied. It is found that the surface roughness scattering effectively raises the Schottky barrier height by delta(Phi) over tilde (B) and the overall characteristics of the ballisticity of SB-MOSFETs are determined by delta(Phi) over tilde (B). Contrary to the case of MOSFETs with doped source and drain, the ballisticity shows little dependence on channel length and a linear decrease with RMS/W in SB-MOSFETs.