This paper applies remote plasma processing techniques, remote plasma assisted oxidation (nitridation) RPAO(N) and RP, enhanced chemical vapor deposition (RPECVD), developed originally for fabrication of Si MOS devices with deposited SiO2, Si3N4 and Si oxynitride alloys to the formation of device-quality GaN MOS devices. Significant improvements in device performance for GaN-SiO2 interfaces are demonstrated by following an RPAO process step that forms the device interface with an interface nitridation RPAN step prior to the deposition of an SiO2 dielectric film by RPECVD. On-line Auger electron spectroscopy (AES) is used to monitor interface bonding for different ordering of RPAO and RPAN process steps. (C) 2004 Published by Elsevier B.V.