Inductively coupled plasma reactive ion etching of sapphire using C2F6- and NF3-based gas mixtures

Inductively coupled plasma reactive ion etching (ICP-RIE) of sapphire wafers using C2F6- and NF3-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 C2F6 plasma and about 260 nm/min in the case of NF3 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.