Charge redistribution at GaN-Ga2O3 interfaces:: a microscopic mechanism for low defect density interfaces in remote-plasma-processed MOS devices prepared on polar GaN faces

Interfacial defect densities are typically two orders of magnitude higher at ID[I-V]-dielectric interfaces than at Si-SiO2 interfaces. This paper demonstrates GaN devices with significantly reduced interfacial defect densities using a two-step remote plasma process to form the GaN-dielectric interface and then deposit the dielectric film. Separate plasma oxidation and deposition steps have previously been used for fabrication of aggressively scaled Si devices. Essentially, the same 300 degrees C remote plasma processing has been applied to GaN metal-oxide-semiconductor (MOS) capacitors and field effect transistors (FETs). This paper (i) discusses the low-temperature plasma process for GaN device fabrication, (ii) briefly reviews GaN device performance, and then (iii) presents a chemical bonding model that provides a basis for the improved interface electrical properties. (C) 2000 Published by Elsevier Science B.V.