Characterization of Defects in CZ-grown Si Crystals with OSF Ring

Abstract

ABSTRACTThe nature and radial distribution of crystallographic micro-defects in CZ-grown silicon crystal wafers which exhibit OSF ring were investigated. With the difference in copper decoration XRT image and in temperature dependence of oxgen precipitation, four coaxial ring regions were clearly identified. In the OSF ring region, oxgen precipitation takes place even at relatively high temperatures around 1, 100°C. Gold diffusion experiments were also carried out, for which the ‘kick-out mechanism’ was considered to reveal the density distribution of sinks for interstitial silicon. A semi-quantitative schematic model describing the density distribution of the precipitation nuclei as a function of critical size of the nuclei for each of the four ring regions is derived. The nuclei that are stable at high temperature act as sinks for interstitial silicon atoms, generating stacking faults.