Vertical high quality mirrorlike facet of GaN-based device by reactive ionetching

Reactive ion etching (RIE) of GaN has been performed using BCl3 and additiv es Ar, CH4, and N-2 to BCl3 plasma. The etching rate, surface roughness and the etch profile have been investigated. When BCl3/Ar was used as the RIE plasma source with 200 W RF power and 60 mTorr pre-sure, the highest etchin g rates of 505 Angstrom /min and 448 Angstrom /min were obtained for n- and p-GaN, respectively. It was found that the addition of CH4 and N-2 to the BCl3 plasma would result in significant changes of the etching results, suc h as the etching rate and surface morphology. It was also found that with t he proper etching parameter, the mirrorlike facet of GaN can be obtained us ing BCl3/Ar/CH4/N-2 by RIE.