Effects of thermal annealing treatment on the optical and the electrical properties of GaN films grown on Si substrates

The effects of rapid thermal annealing on the optical and the electrical properties in GaN epilayers grown on Si substrates were investigated by using cathodoluminescence (CL) and Hall effect measurements. From the two-dimensional CL image measurements, the distribution of defects embedded in the films was investigated before and after rapid thermal annealing. The penetration depth dependence of the CL spectrum demonstrated that the defect density become large in the deeper region away from the GaN surface.