Selective Wet Etching of Lithium Gallate

Abstract

Lithium gallate (LGO) is an attractive, near lattice matched substrate for the growth of GaN. In addition, LGO substrates provide a convenient route to forming thin films of GaN as used in substrate removal or lift-off processes. We report the wet etching of LGO substrates for the production of GaN thin films. Two face-selective LGO etches have been used for the processing of substrates. The etch rate of the cation face is reported here for the first time and is 0.25 p.m min1 at 50CC. The etching solution is safe and benign to most materials including metallic bonding.