Impact of etching process on Al2O3/GaN interface for MOSc-HEMT devices combining ToF-SIMS, HAXPES and AFM

Abstract

In this work we present the effect of inductively coupled plasma reactive ion etching (ICP-RIE) combined with atomic layer etching (ALE) on the Al2O3/GaN interface for MOSc-HEMT devices. Time of flight secondary ion mass spectrometry (ToF-SIMS) and hard x-ray photoelectron spectroscopy (HAXPES) highlight an increase of the N/Ga ratio near the interface after etching. ToF-SIMS profiles also show the presence of impurities (H, C, B) at this interface. Atomic force microscopy (AFM) also illustrates a change of the GaN surface morphology for the etched sample.