Nonequilibrium diffusion of boron in SiC at low temperatures

Full text: The experimental data on low temperature diffusion of boron in a flow of carbon vacancies from the surface of SiC into a volume are presented and discussed. On the base of data on depth distribution of Boron impurity in SiC, mass-spectra and electro luminescence of Boron doped samples the possible mechanism of low temperature diffusion is proposed. In this mechanism is assumed that the large nonequilibrium concentration of carbon vacancies leads to increasing of number of silicon vacancies and mediates the diffusion coefficient of Boron. The evidence of this fact is an observation the electro luminescence peak of silicon - carbide divacancy in SiC. The diffusion equations describing the influence of carbon vacancy flow on diffusion of Boron are written and their solutions in a good qualitative agreement with experimental depth distributions of Boron. (authors)