THERMODYNAMIC MODEL FOR THE ANNEALING PROCESS OF SI-IMPLANTED GAAS

We theoretically investigate the annealing process of Si-implanted GaAs. Four different annealing methods are considered, and the calculation of Point defect concentrations is carried out, assuming that the conditions of the phase equilibrium for GaAs are different depending on the annealing method. In an anneal with As overpressure, GaAs is in equilibrium with a gas phase. When an SiO2 cap is used, GaAs will be in equilibrium with an As-rich liquid phase. In the case of an anneal with an Si3N4 cap, equilibrium with the outside phases is not established. Without any surface protection, GaAs is in equilibrium with a Ga-rich liquid. On the basis of the results, influences of the various annealing methods are discussed, and a new annealing method is proposed.