MODEL FOR DOPANT INCORPORATION INTO GROWING SILICON EPITAXIAL-FILMS .1. THEORY

A physicochemical model is presented describing the incorporation of dopant atoms into silicon epitaxial films during deposition from a SiH4-AsH8-H2 mixture in a horizontal atmospheric-pressure, epitaxial reactor. The model considers a sequence of processes occurring in the gas phase and at the surface. In order to properly describe the doping process under both transient and steady-state conditions, mass-balance of the As-containing species is considered at each important point in the epitaxial system. The detailed representation of these mass-balance equations is obtained, and seven, firstorder linear differential equations containing the mathematical description of the doping process result. In order to conveniently handle this set of equations, an equivalent electric circuit represented by an analogous set of equations is found. This circuit representation provides insight into the different mechanisms taking part in the doping process and their relative importance. A comparison between this model and experimental results reported earlier is presented in the following paper. © 1979, The Electrochemical Society, Inc. All rights reserved.