Efficient Outdiffusion of Hydrogen from Mg-Doped Nitrides by NF3 Annealing

Abstract

High concentration (more than 1 × 1018 cm−3) of hydrogen atoms remaining in Mg-doped GaN epitaxial layers grown by metalorganic chemical vapor deposition even after conventional annealing in N2 ambient could induce degradation in GaN-based devices containing Mg-doped layers. In this study, by annealing Mg-doped nitrides in NF3 ambient, we successfully reduced residual hydrogen below mid-1017 cm−3, which is much smaller than by N2 annealing. NF3 annealing enhances outdiffusion of hydrogen from the bulk, which is possibly because the nitrogen and fluorine radicals decomposed from NF3 accelerate desorption of hydrogen adatoms from the surface. The proposed method for Mg activation would improve the reliability of GaN-based light-emitting diodes and laser diodes.