Molecular beam epitaxy of InAlN∕GaN heterostructures for high electron mobility transistors

Abstract

We describe the growth of In Al N ∕ Ga N heterostructures by rf-plasma molecular beam epitaxy. Due to the weak In–N bond, the InAlN growth temperature must be below about 460 ° C for In to incorporate reliably into the film. Thus far, a thin AlN spacer layer has been required to form a low resistance two dimensional electron gas(2DEG) at the In Al N ∕ Ga N interface. The thin AlN barrier is believed to reduce alloy scattering of carriers in the 2DEG. The best HEMTmaterial with an InAlN barrier and a thin AlN spacer layer has a sheet resistance of 980 Ω ∕ ◻ with a sheet electron density of 1.96 × 10 13 cm − 2 .