Vacancy model of micropipe annihilation in epitaxial silicon carbide layers

Abstract

Kinetic processes of annihilation (healing) of a micropipe threading into a growing layer from a substrate-seed are considered in terms of the vacancy model of heteropolytype epitaxy of silicon carbide we previously suggested (Fiz. Tekh. Poluprovodn., 39, 296 (2005); 41, 641 (2007)). A relationship is found between the growth rate of an epitaxial film, vacancy lifetime, and defect layer width at which the micropipe is healed. Both kinds of vacancies, of carbon and silicon type, are taken into account. In addition, a simplified linear model of the process of micropipe healing is suggested. The relationship between the micropipe diameter r ₀ and the defect layer width l* is determined in terms of this model: l* = r ₀(G/g), where G is the layer growth rate and g is the vacancy velocity, which yields l* ≈ 6r ₀ for actual growth conditions.