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 [III-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 fiel d effect transistors (FETs). This paper i) discusses the low temperature pl asma process for GaN device fabrication, ii) briefly reviews GaN device per formance, and then iii) presents a chemical bonding model that provides a b asis for the improved interface electrical properties.