Positron annihilation study of vacancy-like defects related to oxygen precipitates in Czochralski-type Si

We report the direct measurement of vacancy-like defects related to oxygen in the oxygen precipitation process in Czochralski Si. The vacancy-like def ects were detected by measuring the positron lifetime and narrowing of the positron-electron annihilation momentum distribution. Oxygen atoms surround ing the vacancy-like defects were detected by analyzing the high-momentum p art of the positron-electron momentum distribution measured by a Doppler br oadening coincidence technique. It was found that the majority of the defec ts associated with oxygen have an effective open volume smaller than that o f a silicon monovacancy. (C) 2001 American Institute of Physics.