BCl3-Based Dry Etching of Exfoliated (100) ß-Ga2O3 Flakes

We report on BCl 3 -based dry etching characteristics of (100) β- Ga 2 O 3 flakes using inductively coupled plasma etching technique, which were prepared by mechanical exfoliation from ( 2 ¯ 01 ) Ga 2 O 3 single crystal. The etch rate of (100) Ga 2 O 3 flake increased with increasing bias rf powers up to 52 nm min −1 using 25 sccm BCl 3 /15 sccm N 2 gas chemistry. We also examined the etch rate dependence of Ga 2 O 3 on crystal orientation. The (100) Ga 2 O 3 flake has the lowest etch rate when compared with (010) and ( 2 ¯ 01 ) Ga 2 O 3 surfaces. The lowest etch rate of (100) Ga 2 O 3 surface results from less Ga-O bond breaking efficiency and low dangling bond density on the surface. It is notable that ( 2 ¯ 01 ) Ga 2 O 3 surface is etched at higher rate than (010) and (100) Ga 2 O 3 surfaces. The surface morphologies of etched (100) Ga 2 O 3 surface exhibited little change, and rms roughness values remained less than 1.5 nm over a broad range of etch conditions.