Fabrication of β-Ga2O3/Si heterointerface and characterization of interfacial structures for high-power device applications

In this work, we fabricated Ga2O3(001)/Si(100) and Ga2O3(010)/Si(100) heterointerfaces by surface activated bonding at room temperature and investigated the effect of Si thickness on the thermal stability of the heterointerfaces by heating the bonding samples at different temperatures. The heterointerface with a thin Si exhibited a good thermal stability at 1000 °C. A 4 nm thick intermediate layer with a uniform thickness was formed at the as-bonded Ga2O3(001)/Si(100) heterointerface, but for the as-bonded Ga2O3(010)/Si(100) heterointerface, an intermediate layer with a non-uniform thickness was formed. The thickness of both intermediate layers ranged from 3.6 to 5.4 nm and decreased after annealing at 500 °C, followed by an increase after annealing at 1000 °C. The component of the intermediate layer includes Ga, O, and Si atoms.