On epitaxial [formula omitted] thin film growth by chemical vapour deposition from a silane, germane, hydrogen chloride and hydrogen gas mixture

Abstract

Epitaxial Si 1−x Ge x layers were deposited in a conventional atmospnheric pressure process from silane, germane, hydrogen chloride and hydrogen gas mixtures in the temperature range from 1070 to 730°C. A clear transition from strong to weak temperature dependence is observed at about 870 °C as typical fure silicon depositionn from silane. So a transport-reaction limited mechanism is deduced for SiGe layer growth. The theoretical consideration of growth mechanism is based on the assumption of three partial growth rates, the sum of which is equal to total layer growth rate. The partial growth rates consist of the silicon growth rate observed without germane in the gas, the germanium growth rate observed by the presence of germane in the gas, and the rate of additional silicon deposition caused by the presence of germane, too. Germanium partial growth rate is also characterized by a strong and weak region of temperature dependence; however, the transition is observed at about 980 °C.