Heat-treatment-induced defects in low-resistivity silicon

Czochralski-grown silicon has been investigated with doping levels up to 5×1018 cm−3 of boron or phosphorus by positron annihilation. For the highly boron-doped samples vacancies could be created upon heat treatment in the 700–1000 °C range up to a concentration of 1017 vacancies cm−3. Reducing either the boron concentration or the interstitial oxygen concentration (by prolonged heat treatment at 1200 °C) reduced the amount of created …