Halide Vapor Phase Epitaxy 1

Abstract

Homoepitaxial growth of β-Ga2O3 on β-Ga2O3 substrates by halide vapor-phase epitaxy (HVPE) using GaCl and O2 was investigated by both thermodynamic analysis and growth experiments. The thermodynamic analysis clarified that growth of Ga2O3 is expected at high temperatures around 1000 °C using an inert carrier gas. The experimental results revealed that homoepitaxial growth of unintentionally doped (UID) layers with a low effective donor concentration (Nd − Na) of less than 1013 cm−3 is possible at 1000 °C on β-Ga2O3 (001) substrates with a high growth rate of up to 28 μm/h. Furthermore, HVPE growth of intentionally Si-doped β-Ga2O3 layers was investigated by supplying SiCl4, which revealed that n-type carrier density almost equal to the Si-doping concentration can be controlled in the range of 1015–1018 cm−3. The carrier mobility decreased with increasing Si impurity concentration and was about 150 cm2/V·s at room temperature for a layer with a carrier density of 3.2 × 1015 cm−3. Thus, the intentionally Si-doped homoepitaxial layers grown on β-Ga2O3 substrates can be applicable for the production of β-Ga2O3-based power devices.