Anisotropic transport properties in InAs/AlSb heterostructures

We have investigated the anisotropic transport behavior of InAs/AlSb heterostructures grown on a (001) InP substrate. An electrical analysis showed anisotropic sheet resistance Rsh and electron mobility μn in the two dimensional electron gas (2DEG). Hall measurements demonstrated an enhanced anisotropy in μn when cooled from room temperature to 2 K. High electron mobility transistors exhibited 27% higher maximum drain current IDS and 23% higher peak transconductance gm when oriented along the [1-10] direction. The anisotropic transport behavior in the 2DEG was correlated with an asymmetric dislocation pattern observed in the surface morphology and by cross-sectional microscopy analysis of the InAs/AlSb heterostructure.