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.