Reduction of threading edge dislocation density in n-type GaN by Si delta-doping

In this study, the defect structure of periodic Si delta-doping (δ-doping) GaN films grown by low-pressure metalorganic chemical vapor deposition has been investigated by high-resolution X-ray diffraction. Rocking curves of five planes were investigated: (0 0 0 2), (101¯3), (101¯2), (101¯1) and (202¯1), respectively. Pseudo-Voigt function was used to simulate the rocking-curve of every plane. The effects of Si δ-doping on the different types of dislocations were discussed. It was demonstrated that Si δ-doping significantly reduces the threading dislocations with a pure edge character, and induces no changes in the threading dislocations with a screw component. The results are consistent with AFM results.