Kinetics of the formation of concentrational transitions between epitaxial layers of silicon in the process of growth from a molecular beam

Abstract

The doping kinetics of an epitaxial layer of silicon growing from a molecular beam is considered, taking mechanisms of impurity-atom capture by the growing layer into account: diffusional capture and immurement by atoms of the basic material. It is shown that, with increase in the growth rate, the thickness of the concentrational transition between regions with different levels of doping rises in the case of predominance of the first mechanism of impurity incorporation in the growing layer and decreases in the case of predominance of the second mechanism. Quantitative estimates of the thickness of the concentrational transition, taking account of the equilibrium coefficients of the impurity distribution between the surface region and the volume of the epitaxial layer, give satisfactory agreement with the experimental results.