High concentration (more than 1 × 10 18 cm -3) of hydrogen atoms remaining in Mg-doped GaN epitaxial layers grown by metalorganic chemical vapor deposition even after conventional annealing in N 2 ambient could induce degradation in GaN-based devices containing Mg-doped layers. In this study, by annealing Mg-doped nitrides in NF 3 ambient, we successfully reduced residual hydrogen below mid-10 17 cm -3, which is much smaller than by N 2 annealing. NF 3 annealing enhances outdiffusion of hydrogen from the bulk, which is possibly because the nitrogen and fluorine radicals decomposed from NF 3 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.
- Acceptor activation
- Annealing ambient