Control of p-Type conductivity at AlN surfaces by carbon doping

Abstract

Carbon doping can form surface p-Type conductive layers on AlN with high sheet carrier densities (∼1013 cm-2). Current-voltage measurements indicate carrier injection occurs through the surface conductive layer into AlN, suggesting that the surface conductive layer may act as a p-contact layer for AlN-based materials. Mass spectroscopy reveals that the surface layers with p-Type conductivity involve molecular species, including aluminum carbides and carbons, while those without p-Type conductivity do not. Carbon-containing layers at AlN surfaces are responsible for surface p-Type conduction.