Dependence of the interfacial atomic structure of SiO2/GaN upon SiO2 deposition methods and post-deposition annealing, as revealed by X-ray absorption spectroscopy

Abstract

Abstract The interface between a gate insulator (SiO2) and a semiconductor (GaN), which can affect the performance of a power device, was investigated via X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. Experiments were performed to sensitively detect the interface with analytical depth. In atomic layer deposition of SiO2, Ga oxide was formed at the interface during the formation of SiO2 film. However, in plasma-enhanced chemical vapor deposition, this formation was not observed, and the crystallinity of the GaN-side interface was improved via post-deposition annealing.