EPITAXIAL-GROWTH OF SI1-X-YGEXCY ALLOY LAYERS ON (100)SI BY RAPID THERMAL CHEMICAL-VAPOR-DEPOSITION USING METHYLSILANE

High quality pseudomorphic Si1-yCy and Si1-x-yGexCy layers were grown on (100) Si between 530 and 650 degrees C by rapid thermal chemical va por deposition in the SiH4/GeH4/SiH3CH3/H-2 system. These layers conta ined up to 30 at. % Ge and up to 2.2 at. % C. Strain engineering was a chieved. The strain could be tailored continuously from compressive (u p to 2.2% in Si1-xGex) to tensile (up to -0.8% in Si1-yCy and -0.35% i n Si1-x-yGexCy). The relationship between the process parameters and t he physical properties of the layers was investigated. A process windo w for growing high quality layers was defined in terms of the partial pressures of SiH4 and SiH3CH3. It was found to be independent of Ge co ntent, growth temperature, and growth rate. No carbon contamination wa s observed. No interference between Ge and C incorporation was observe d. A model for the incorporation of substitutional C in the films whic h is based on the chemical reaction of SiH4 and SiH3CH3 on the surface is proposed. (C) 1996 American Vacuum Society.