High-Speed Plasma Etching of Gallium Oxide Substrates Using Atmospheric-Pressure Plasma with Hydrogen-Helium Mixed Gas

In addition to silicon carbide (SiC) and gallium nitride (GaN), gallium oxide (Ga2O3) is attracting attention as a widegap semiconductor material. Ga2O3, unlike SiC and GaN, is not as hard, but has strong cleavage properties, making highly effective mechanical machining difficult. Thus, the processing of Ga2O3 by high-speed etching employing atmospheric-pressure plasma was studied. An extremely high removal rate of 60 μm/min was obtained due to basic processing experiments using hydrogen gas instead of toxic and corrosive chlorine gas as the reaction gas.