THERMODYNAMIC MODEL FOR THE ANNEALING PROCESS OF SI-IMPLANTED GAAS

We theoretically investigate the annealing process of Si-implanted GaA s. Four different annealing methods are considered, and the calculatio n of Point defect concentrations is carried out, assuming that the con ditions of the phase equilibrium for GaAs are different depending on t he annealing method. In an anneal with As overpressure, GaAs is in equ ilibrium with a gas phase. When an SiO2 cap is used, GaAs will be in e quilibrium 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 anneal ing methods are discussed, and a new annealing method is proposed.