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

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 T_B<;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.