Strain and charge distribution in GaN-AlN-GaN semiconductor-insulator-semiconductor structure for arbitrary growth orientation

Abstract

We demonstrate that, in a GaN‐AlN‐GaN semiconductor‐insulator‐semiconductor structure, the strain‐induced electric fields across the interface depend on the angle, θ, between the c axis and the growth direction. The magnitude of the strain induced polarization has a maximum in (0001) crystallographic direction (θ=0°) and a subsidiary maximum near θ=70°. This angular dependence is a unique feature of wurtzite‐type structures. Considering θ as an independent parameter for device design, one can obtain structures with flat band voltage shift from 0 to 1.5 V for 30 Å AlN film, with different positions of accumulation‐depletion regions, and with electron (hole) charge varying from 0 to more than 10¹² cm⁻².