Effect of Nitrogen Doping on Oxygen Precipitate Profiles in Czochralski Silicon Wafer

Abstract

The effect of nitrogen doping on the profiles of oxygen precipitates in Czochralski (CZ) silicon subjected to conventional annealing and rapid thermal annealing (RTA) has been investigated. After conventional high-low-high three-step annealing (1150 °C, 4 h + 650 °C, 128 h + 1050 °C, 16 h), it was found that an M-like oxygen precipitate profile existed in the cross section of a nitrogen-doped CZ silicon (NCZ-Si) wafer; however, this was not the case in conventional CZ silicon (CZ-Si) wafers. In contrast to conventional annealing, after rapid thermal annealing (RTA) followed by a low-high two-step annealing (800 °C, 8 h + 1050 °C, 16 h), an M-like oxygen precipitate profile existed in the cross section of the CZ-Si wafer but not in the NCZ-Si wafer. It is suggested that not only vacancies but also nitrogen doping have an influence on the oxygen precipitate profile. In addition, the relevant mechanism is discussed.