Boron diffusion in silicon by a vacancy mechanism

Abstract

The commonly used expressions for the boron diffusivity are unsatisfactory in the case of heavily n doped silicon. An expression of diffusivity based on thermodynamic considerations is set up, taking into account not only the various charges of vacancies but also of the crystal structure. In this expression the theoretical and experimental values of various energies are substituted. A very good agreement with the entire set of existing experimental results is obtained. It appears that diffusion is mainly controlled by the positively ionized vacancies and simultaneously is confirmed that EV is 0.37 eV above the valence band.

Kinetic Monte Carlo for Process Simulation: First Principles Calibrated Parameters for BO2

“…This structure is likely to have a high migration barrier because of the stability of the boron atom in a substitutional position. Boron diffusion is only shown when associated with the presence of a vacancy [20]. Then, comparing the total energy between the B s O 2i in configuration A and isolated O 2i -st and B − s configuration indicates that the formation of B s O 2i is a favorable process (-1.09 eV).…”