High conductivity of Mg-doped Al0.3Ga0.7N with Al0.4Ga0.6N/AlN superlattice structure

Abstract

The highly conductance of Mg-doped Al0.3Ga0.7N layer using low-pressure metal organic chemical vapour deposition (MOCVD) on Al 0.4Ga0.6N/AlN superlattice structure was reported. The rapid thermal annealing (RTA) has been employed for the effective activation and generation of holes, and a minimum p-type resistivity of 3 Ω·cm for p-type Al0.3Ga0.7N was achieved. The RTA annealing impacted on electrical, doping profile and morphological properties of Mg-doped Al0.3Ga0.7N with Al0.4Ga0.6N/AlN superlattice structure have been also discussed. The quality of Mg-doped Al 0.3Ga0.7N with Al0.4Ga0.6N/AlN superlattice structure degraded after annealing from HRXRD. At appropriate annealing temperature and time, surface morphology of Mg-doped Al 0.3Ga0.7N can be improved. A step-like distribution of [Mg] and [H] in p-type Al0.3Ga0.7N was observed, and thermal diffusion direction of [Mg] and [H] was also discussed. © 2014 Zhiming Li et al.