The effect of small doses of γ‐radiation from 60Co on concentration and mobility of majority carriers in n‐type Si and Ge is investigated. In the oxygen‐containing samples, the mobility is shown to grow anomalously with irradiation dose in the region of combined scattering. A model is proposed which is based on the neutralization of scattering center charges by those of the defects produced by irradiation mainly around the scattering centers. This model qualitatively accounts for the data obtained experimentally.

By means of Hall effect and EPR techniques, the behavior of phosphorus is investigated in single crystals of silicon subjected to heat treatment (HT) over a wide temperature range from 300 to 1200 °C; the HT is followed by cooling at different rates. The quenched samples exhibit a significant decrease of concentration of electrically active phosphorus in their volume. The following effects are shown to underlie this observation: 1) compensation of the donor impurity by quenching thermodefects; 2) loss of electrical activity of phosphorus atoms due to their transfer into inactive positons in the silicon lattice during the quenching. The influence of parameters of the parent substance on each of these effects is studied.

The effect of irradiation on the carrier mobility in inversion channels of MOS structures of thermally grown SiO2 as a function of band bending Ys and temperature T is studied. Possible physical models which explain the decreasing of carrier mobility both on the left‐and right‐hand side of the maximum of the μseff(Ys)‐dependence are discussed. New data on the formation of fast surface states at the Si–SiO2 interface by different types of irradiation are given.

No abstract