The annealing mechanism of selenium implanted into GaAs

A simple thermodynamic model has been developed to explain the incorporation of implanted impurities in GaAs. The model involves the interpretation of the electrical activity with annealing time and temperature and has been used to explain results obtained from 1014 cm-2 of 300 keV selenium implanted into GaAs at room temperature. The electrical activity was found to increase with time at a given temperature below 950 degrees C, reaching a saturation value at long times. From the latter results of the time independent region an energy of 1.2 eV was deduced. This energy is suggested to be that required to split-up the selenium-gallium vacancy complexes that are responsible for the inactivity of selenium in GaAs, and to place the selenium atoms on nearby arsenic vacancies where they can act as donors. Analysis of the time dependent regime has produced an energy of about 4.5 eV which is thought to be the energy of diffusion of selenium in GaAs.