Physical-chemical etching of GaN layers on sapphire

Summary form only given. In this work we report the reactive ion etching (RIE) of GaN using CF/sub 4//Ar and CHF/sub 3//Ar chemistries. The effects of RF plasma power, pressure and gas flow rates on the etch rate were investigated as well as the interaction of physical and chemical components of the etch process. We used 2.8 /spl mu/m, n-type GaN film, grown on Al/sub 2/O/sub 3/ substrate. It was patterned with evaporated aluminum, which was chemically removed after the etch process.