Investigation of amorphous (Ir,Ru)-Si and (Ir,Ru)-Si-O Schottky contacts to (001) β-Ga2O

In this work we propose a new scheme for Schottky contacts to β-Ga2O3, namely — Ru-Si-O and Ir-Si-O conductive layers, fabricated by means of reactive magnetron sputtering of ruthenium or iridium silicide (Ru-Si, Ir-Si) targets in oxygen containing atmosphere. The influence of oxygen partial pressure during deposition on the microstructure and electrical parameters of layers was investigated. The properties of Ir-Si-O and Ru-Si-O as well as Ir-Si and Ru-Si Schottky contacts to β-Ga2O3 were compared. Work function of Ir-Si-O layers was in range of 4.97–5.08 eV as compared to 5.6–5.65 eV for Ru-Si-O layers. The investigated Schottky contacts show strong positive correlation between homogeneous barrier height and contact work function, roughly following Schottky–Mott relation. Our findings opens new possibilities to produce Schottky contacts to β-Ga2O3 with tailored properties using the M-Si-O (where M is transition metal) material system.