AlSb nucleation induced anisotropic electron mobility in AlSb/InAs heterostructures on GaAs

Abstract

The influence of the growth conditions at the AlSb/GaAs interface on the electron mobility in AlSb/InAs heterostructures is investigated. We show that an excessive antimony flux during the initial stage of the AlSb buffer growth leads to a strong anisotropy of electron mobility in InAs between [110] and [1-10] crystallographic orientations. This anisotropy is attributed to the formation of trenches oriented along the [1-10] direction in the InAs channel. Transmission electron microscopy reveals that these trenches are directly related to twinning defects originating from the AlSb/GaAs interface.