The properties of n-type Si-doped GaN films grown by metalorganic chemical vapour deposition were studied systemically. It was suggested that the main stress relaxation was induced by bending dislocations in low-doping samples. For higher-doping samples, as the Si doping concentration increased, in-plane stresses in the grown films were quickly relaxed due to a rapid increase in edge-dislocation densities. Hall effect measurements revealed that the carrier mobility first increased rapidly, and then decreased, with increasing Si doping concentration. This was attributed to the interaction between various scattering processes. It was suggested that the predominant scattering process was defect scattering for low-doping samples and ionized impurity scattering for high-doping samples.

Stress, Structural and Electrical Properties of Si-Doped GaN Film Grown by MOCVD. Z.Xu, J.Zhang, H.Duan, Z.Zhang, Q.Zhu, H.Xu, Y.Hao: Journal of Semiconductors, 2009, 30[12], 123003