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, typically two orders of magnitude lower than those,usually obtained at [III-V]-dielectric interfaces, have been demonstr ated for GaN capacitors and field effect transistors (FETs). Separate and i ndependently controlled interface formation and film deposition by remote p lasma-assisted processing steps performed at 300 degrees C were employed. T he interfacial oxide is Ga2O3, and the deposited gate dielectric is SiO2. M odels for the chemical bonding at the GaN-Ga2O3 interface and at the intern al dielectric Ga2O3-SiO2 are presented. The most important aspect of the in terface formation involves a redistribution of electrons in the surface ato m dangling bonds of the GaN polar face that promotes formation of two-elect ion bonds with the interfacial dielectric.