Inductively-coupled-plasma reactive ion etching of single-crystal β-Ga ₂ O ₃

Dry etching behavior of unintentionally-doped β-Ga 2 O 3 has been studied in a BCl 3 /Ar chemistry using inductively-coupled-plasma reactive ion etching (ICP-RIE). The effects of various etch parameters like ICP and RIE powers, BCl 3 /Ar gas ratio and chamber pressure on etch rate are studied systematically. Higher ICP, RIE powers and lower pressure conditions are found to enhance the etch rate. A synergic etching mechanism between chemical and physical components is proposed and used to obtain fast Ga 2 O 3 etch rates more than 160 nm/min, nearly-vertical sidewalls and smooth etched surfaces. The findings of this work will enable Ga 2 O 3 vertical devices for power electronics.