STUDY OF GAN THIN-LAYERS SUBJECTED TO HIGH-TEMPERATURE RAPID THERMAL ANNEALING

A detailed study of the effect of rapid thermal annealing in a N-2 or Ar atmosphere on the properties of thin GaN layers grown by molecular- beam epitaxy on sapphire substrates was performed. After rapid thermal annealing, an enhancement of the crystal quality of such films was ob served. Low-temperature photoluminescence measurements revealed a subs tantial increase in impurity recombination near the fundamental absorp tion edge after a rapid high-temperature anneal in a nitrogen atmosphe re. A significant decrease in the impurity photoluminescence of the Ga N films with protective SiO2 coatings was observed following the annea ls. (C) 1998 American Institute of Physics. [S1063-7826(98)00610-3].