A two-step rapid thermal annealing (RTA) process is proposed in order to improve the electrical properties, the crystal quality, and the surface roughness of Mg-doped p-type GaN films. In the two-step RTA process, the first low temperature step (600 degreesC) with a long annealing time (5 min) was followed by the second high temperature (950 degreesC) step With a short annealing time. These results show that the two-step RTA process significantly improves electrical properties and reduces the surface roughness of p-GaN compared to the one-step RTA process.