中性子照射されたP型シリコンにおける欠陥群の易動度への影響

Abstract

The carrier scattering due to the defect clusters in neutron-irradiated P-type silicon was studied. The spherical cluster model was found to be inadequate to explain the carrier scattering in neutron-irradiated p-type silicon. So, we presented the model about the cluster scattering on the basis of the empirical relation, which is called "empirical model". The scattering cross section per defect cluster A_e and per defect S_e in the empirical model were much larger than those in the spherical model, respectively. S_e was one to two orders of magnitude larger than the scattering cross section per singly charged center. A_e and S_e did not depend on the oxygen concentration and Cu-contamination but only on the acceptor concentration. The acceptor concentration dependence of A_e was not so simple as the spherical model expected. The temperature dependence of the mobility after neutron irradiation in the empirical model was in good agreement with the experimental results over the measurement temperature range 103-322° K in the resistivity range 1-135 ohm-cm. Or the other hand, the mobility by the spherical model deviated considerably from the experimental results, especially in the low temperature range. The mobility due to the cluster scattering in the empirical model slightly depended on the temperature and had a tendency to saturate as the temperature decreased in the temperature range 103-157° K, while it depended on T in the temperature range 164-322° K, which could be explained qualitatively by the cluster-space charge region model. This situation was not true for the spherical model.