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

Interfacial defect densities are typically two orders of magnitude higher a t ID[I-V]-dielectric interfaces than at Si-SiO2 interfaces. This paper demo nstrates GaN devices with significantly reduced interfacial defect densitie s using a two-step remote plasma process to form the GaN-dielectric interfa ce and then deposit the dielectric film. Separate plasma oxidation and depo sition steps have previously been used for fabrication of aggressively scal ed Si devices. Essentially, the same 300 degrees C remote plasma processing has been applied to GaN metal-oxide-semiconductor (MOS) capacitors and fie ld 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 Publish ed by Elsevier Science B.V.