Function of quantum-confinement effect in the AlGaN∕AlN∕GaN heterostructure with an AlN interfacial layer

Abstract

This is a theoretical study of the distribution of two-dimensional electron gas (2DEG) in an AlGaN∕AlN∕GaN heterostructure. It is shown that the addition of an AlN interfacial layer leads to a slight increase of 2DEG density. The role of quantum-confinement effect in the change of 2DEG distribution with an inserted AlN interfacial layer is revealed by comparing calculated 2DEG distributions in an AlGaN∕(AlN)∕GaN heterostructure with and without considering the quantum-confinement effect. In the classic model, insertion of an AlN interfacial layer has a negligible effect on the 2DEG distribution. While taking the quantum effect into account, we can clearly see that incorporation of an AlN interfacial layer results in a substantial influence of 2DEG distribution, with the electron spillover into barrier layer reduced from 1.35×1012to0.23×1012cm−2, which are 9.8% and 1.5%, respectively, of the total 2DEG sheet density.