Mechanism of B diffusion in crystalline Ge under proton irradiation

B diffusion in crystalline Ge is investigated by proton irradiation in thin layers with B delta doping under different fluences (1×1015–10×1015 H+/cm2), fluxes (6×1011–35×1011 H+/cm2 s), and temperatures of the implanted target (from −196 to 550 °C), both during and after irradiation. B migration is enhanced by several orders of magnitude with respect to equilibrium. Moreover, B diffusion is shown to occur through a point-defect-mediated mechanism, compatible with a kick-out process. The diffusion mechanism is discussed. These results are a key point for a full comprehension of the B diffusion in Ge.