Inductively coupled plasma reactive ion etching of sapphire using C 2F 6- and NF 3-based gas mixtures

Abstract

Inductively coupled plasma reactive ion etching (ICP-RIE) of sapphire wafers using C 2F 6- and NF 3-based plasma was investigated as a function of ICP power, bias power, pressure, and plasma chemistry. Etch rate of about 150 nm/min in the case of C 2F 6 plasma and about 260 nm/min in the case of NF 3 plasma was obtained at the optimum condition, with anisotropic profiles and smooth surfaces. No chamber corrosion was observed after the etching, indicating that ICP-RIE using the fluorine-related gases is a promising technique for sapphire patterning.