Low-temperature activation of boron in silicon by soft X-ray irradiation

Novel activation method of B dopant using soft X-ray undulator was examined. As the photon energy of irradiated soft X-ray closed to the energy of core level of Si 2p, the activation ratio was increased. The effect of soft X-ray irradiation on B activation was remarkable at temperature lower than 400°C. The activation energy of B activation by soft X-ray irradiation (0.06 eV) was lower than that of B activation by thermal annealing (0.18 eV). The activation of B dopant occurs at low temperature, although the activation ratio shows small values of 6.2×10^-3 at 110°C.