Hole mobility in InSb-based devices: Dependency on surface orientation, body thickness and strain

Abstract

This work presents an investigation on hole mobility in InSb-based ultra-thin body (UTB) devices with arbitrary surface orientation, body thickness and biaxial strain. The anisotropic band structures with quantum confinement are computed using a fully self-consistent solver for six-band k·p Schrödinger and Poisson equations. Hole mobility is computed using the Kubo-Greenwood formalism accounting for nonpolar acoustic and optical phonons, polar optical phonons and surface roughness scattering. The models are calibrated by fitting the experimental data. Our results suggest that for TB<;10nm, mobility trend with surface orientation and channel directions for InSb devices is: (110)/[T10]>(111)>(110)/[001]>(001), where devices with (111) have more excellent behavior than for Si. In addition, biaxial compressive strain introduces maximum mobility gain in the (110)/[110] case. Nevertheless, (110)/[110] is the optimal surface and channel direction for InSb-based UTB devices, followed by (111) orientation.