In situ plasma enhanced atomic layer deposition half cycle study of Al2O3 on AlGaN/GaN high electron mobility transistors

Abstract

A half cycle study of plasma enhanced atomic layer deposited (PEALD) Al2O3 on AlGaN is investigated using in situ X-ray photoelectron spectroscopy, low energy ion scattering, and ex situ electrical characterizations. A faster nucleation or growth is detected from PEALD relative to purely thermal ALD using an H2O precursor. The remote O2 plasma oxidizes the AlGaN surface slightly at the initial stage, which passivates the surface and reduces the OFF-state leakage. This work demonstrates that PEALD is a useful strategy for Al2O3 growth on AlGaN/GaN devices.