Study of GaN/SiC contact using slow positron beam

Using a slow positron beam and the program VEPFIT, we found there exists a barrier in the interface between GaN and SiC, which is caused by lots of band-like defects existing in it. The existence of the barrier induced two backing electric fields in diverse directions close to the interface. These fields can produce a longer diffusion length in the SiC region where no field exists compared with that of SiC region, which has an electric field at a set value. The fitted value of the electric field offers a good reference for studying the situation in a real the interface.