NH3/N2复合热退火技术改善高浓度Mg掺杂GaN材料性能OA北大核心CSTPCD

The effect of a novel post-growth process,i.e.high-temperature thermal annealing process in NH3,on the crystal quality,luminescence property,and electrical conductivity of the heavily Mg-doped GaN was studied.The experimental results showed that,compared with the traditional high-temperature annealing process in N2,the high-temperature thermal annealing process in NH3 can improve crystal quality in the heavily Mg-doped GaN,while promote the further effective doping of Mg acceptors,resulting in an enhancement of the intensity of the blue luminescence band in its photoluminescence spectra.The heavily Mg-doped GaN with sig-nificantly lower background electron concentration was obtained by combining high-temperature thermal anneal-ing process in NH3 with low-temperature thermal annealing process in N2.This is because that the thermal de-composition products of NH3 in the post-growth process can effectively reduce the concentration of shallow do-nor-type defects such as N vacancies and interstitial Ga atoms in the material,ultimately improving electrical conductivity of the heavily Mg-doped GaN.