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

Reactive ion etching (RIE) of GaN has been performed using BCl₃ and additives Ar, CH₄, and N₂ 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 m Torr pressure, the highest etching rates of 505 Å/min and 448 Å/min were obtained for n- and p-GaN, respectively. It was found that the addition of CH₄ and N₂ to the BCl₃ plasma would result in significant changes of the etching results, such as the etching rate and surface morphology. It was also found that with the proper etching parameter, the mirrorlike facet of GaN can be obtained using BCl₃/Ar/CH₄/N₂ by RIE.