MODELING ACTIVATION OF IMPLANTED SI IN GAAS

We propose a model for electrical activation of implanted Si in GaAs that describes how various processing parameters affect the active concentrations. This model is based on the results of a series of experiments involving capacitance-voltage measurements of GaAs Schottky diodes. We describe two simultaneous processes, one that governs the rate of activation, and one that governs its extent. We propose that the rate of activation is controlled by the rate at which implanted Si atoms react with V(Ga) to form Si(Ga). The extent of activation is controlled by the temperature of the activation anneal which determines the equilibrium between the donor, Si(Ga)+, and acceptor species, Si(As)-. The activation behavior is initially dominated by the kinetics of activation. For long-duration anneals, the thermodynamics of activation dominate.