Defect Dynamics in the Presence of Oxygen in Growing Czochralski Silicon Crystals

Abstract

Modern Czochralski (CZ) silicon crystals contain various large defects known as microdefects that affect the yield and the performance of microelectronic devices. These microdefects are primarily the agglomerates of the intrinsic point defects of silicon, vacancies and self-interstitials, and of oxygen (silicon dioxide). The distribution of microdefects in a CZ crystal is determined by the complex dynamics influenced by various reactions involving the intrinsic point defects and oxygen, and their transport. Two-dimensional oxygen influenced transient defect dynamics in growing CZ crystals is quantified and solved. The Frenkel reaction and the reactions between vacancies and oxygen are considered. The formation of all microdefects is described by the classical nucleation theory. Microdefects are assumed to be spherical clusters that grow by a diffusion-limited kinetics. The predictions of the model agree well with experimental data. Various predictions of the model and experimental results are discussed.