Defect-free interface between amorphous (Al2O3)1-x(SiO2)x and GaN(0001) revealed by first-principles simulated annealing technique

We report first-principles molecular dynamics (MD) simulations that unveil the interface structures of amorphous mixed oxide (Al2O3)(1-x)(SiO2)(x) and GaN polar surfaces. The MD allows us to perform the melt and quench (simulated annealing) simulations to forge distinct amorphous samples. We find that the dangling bonds are completely absent at all the obtained interfaces. This annihilation is due to the diffusion of appropriate species, O for (Al2O3)(1-x)(SiO2)(x)/GaN(0001) and Al and Si for (Al2O3)(1-x)(SiO2)(x)/GaN(000 (1) over bar), from the amorphous to the interface and the subsequent formation of strong bonds with both ionicity and covalency at the interface. This absence of the dangling bond indicates the superiority of (Al2O3)(1-x)(SiO2)(x) films to Al2O3 or SiO2 as a gate oxide for the GaN-metal-oxide-semiconductor field effect transistor. Published under an exclusive license by AIP Publishing.

Automated summary

First-principles molecular dynamics simulations revealed that dangling bonds are completely absent at the interfaces of amorphous mixed oxide and GaN polar surfaces. This indicates the superiority of the mixed oxide films for use as gate oxides in GaN-metal-oxide-semiconductor field effect transistors.