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Enhanced etching of sapphire damaged by ion implantation

Enhanced ion beam etching and chemical etching of sapphire damaged by ion implantation have been investigated. In our experiments an amorphous layer or a damaged layer were produced respectively by high-dose yttrium ion or platinum ion implantation. Rutherford backscattering spectrometry and channelling (RBS-C) was used to analyse the material removed by ion beam etching or chemical etching. For 500 eV Ar ion beam etching, the etching rate for amorphous sapphire was 1.5 times faster than for single-crystalline sapphire. For chemical etching the etchant was acid solution of HCI-HF-. Etching for 10 min removed a 150 nm thick amorphous layer, while only about 62 nm of the damaged layer (non-amorphous) was removed, and no visible change was observed for single-crystalline sapphire.