Fabrication of GaN micro-lens

GaN convex micro-lenses showing good convex lens shape with smooth surfaces were fabricated using non-selective inactively coupled plasma reactive ion etching process. The process consists of the thermal re-flowing of sacrificial photoresist and nonselective dry etching technique. The GaN lenses could be applied to the surface of GaN-based LEDs to give directionality and improve the external quantum efficiency by reducing the amounts of total reflection which could be absorbed by defects in the crystal. Such elements also could be fabricated on a variety microcavity structures such as, vertical cavity surface emitting laser diodes (VCSELs), asymmetric Fabry-Perot modulators, resonant cavity LEDs, and resonant cavity photodetectors.