Effect of 60Co Y Rays on High-Resistivity p-Type Si

Abstract

Defects created by γ rays in high‐resistivity (1000 to 10 000 Ω·cm) boron‐doped silicon have been studied by Hall effect and resistivity measurements. Only one energy level is observed at 0.268 eV above the valence band by irradiation at 300°K. Its statistical weight is equal to ½. The defect annealing between 100° and 200°C occurs by the agency of another defect. In some special cases, a more complex association with a third defect can be observed, which introduces another level at 0.21 eV above the valence band. All the results obtained are compatible with the divacancy assuption. Furthermore, we observe, by irradiation at 77°K, the formation of unstable defects, which disappear at 170°K.