Effect of thermal annealing in NH3 ambient on nanoporous n-GaN and subsequent epilayer

Thermal annealing effects on the recovery of surface-etched nanoporous n-type gallium nitride (GaN) templates for growth optimization have been investigated. The electrical and optical performances of nanoporous GaN templates can be improved by annealed at 950°C within the NH3 ambient, leading to the quality increase for subsequent growth. Mechanisms responsible for reducing defects and recovering nonstoichiometric layer are then discussed.