Progress in Study of Oxygen-Related Defects in Electron Irradiated CZ-Si

Electron irradiation on silicon results in the creation of vacancy (V) and silicon self-interstitial (I).Vacancy tends to integrate with oxygen and forms the complexes of vacancy and oxygen (VmOn)such as VO, VO2, and VO3. These complexes of vacancy and oxygen in silicon have been the subject of extended investigations by standard methods such as infrared absorption. In infrared spectrum, the different VmOnhas the corresponding peak. Irradiation induced defects as the core of oxygen precipitate can accelerate the oxygen precipitation. Oxygen precipitation plays an important role in the internal gettering (IG). In electron irradiated silicon, annealing at 300700 °C leads to the formation of two types of electrically active centers that are shallow thermal acceptors (TAs) and the well-known thermal donors (TDs). In this paper, the generation conditions, the infrared peaks of VmOn, the types of oxygen precipitation induced defects, the characters of TAs and TDs are studied.

Homogeneous and Heterogeneous Nucleation of Oxygen in Si-CZ

We present numerical simulations of nucleation kinetics of vacancies and interstitials during RTA and we study the impact of annealing temperature on bulk micro defect concentration. Since the concentration of vacancies and oxygen and also its diffusion kinetics are significantly different inside Czochralski silicon, we assume the nucleation of vacancies and oxygen independent on each other. We show that different populations of voids formed during RTA can influence formation of oxygen precipitate nuclei. According to classical nucleation theory the homogeneous nucleation dominates around temperatures 500 °C while the calculation of oxygen diffusion into the voids shows that the oxygen clusters over the critical size can be formed above temperatures 700 °C. The nuclei concentration of BMD is thus the superposition of homogeneous nucleation below 700 °C and heterogeneous one prevailing above 700 °C.