Etching of GaN by microwave plasma of hydrogen

An etching process for GaN on a sapphire substrate using a microwave plasma of hydrogen has been studied. Scanning electron microscopy observations of the surface morphology show that the etching of GaN with H-2 plasma can lead to the formation of etch pits in hexagonal shape. The average size of hexagonal pits is greater than 200 nm. The effects of processing pressure and etching time are demonstrated.