Wet chemical etching behavior of β-Ga2O3 single crystal

Wet chemical etching behavior of beta-Ga2O single crystal was investigated to evaluated its chemical stability and to explore etchants for beta-Ga2O3 single crystal. Undoped and Sn doped beta-Ga2O3 single crystals were grown by the flowating zone method, and (110) and (001) oriented samples were chemicall mechanical polished to wafers. The samples were wet chemically etched in solutions such as HCl, H2SO4, HNO3, HF, H2O2 H2SO4, H2O2 1 4 1, KOH and NaOH. The samples were chemically stable against both acids and alkalis except HF and NaOH. Aqueous HF solution was found to etch beta-Ga2O3 uniformly at room temperature. The etch rate in creased with increasing immersion time and HF content. Anisotropy of etch rate was observed between the (100) and (001) planes. The etch rate of Sn-doped beta-Ga2O3 was lower than that of undoped beta-Ga2O3, and the etch rate decreased with increasing Sn doping content. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.