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 amorpho us layer or a damaged layer were produced respectively by high-dose yt trium ion or platinum ion implantation. Rutherford backscattering spec trometry and channelling (RBS-C) was used to analyse the material remo ved by ion beam etching or chemical etching. For 500 eV Ar ion beam et ching, the etching rate for amorphous sapphire was 1.5 times faster th an for single-crystalline sapphire. For chemical etching the etchant w as acid solution of HCl-HF-H2O. Etching for 10 min removed a 150 nm th ick 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.