Kinetics of epitaxial Si1−xGex growth using SiH2Cl2–GeH4–H2 mixture in reduced-pressure chemical vapor deposition

Abstract

The dependences of the Ge/Si ratio in epitaxial Si1−xGex layers grown using a SiH2Cl2–GeH4–H2 mixture by reduced-pressure chemical vapor deposition on the flow rate ratio of GeH4/SiH2Cl2 and on the total flow rate have been examined in the temperature range from 480 to 600 °C. As previously reported, the Ge/Si ratio does not increase linearly with the flow rate ratio; instead, the rate of increase decreases at high flow rate ratios. Additionally, it increases with increasing total flow rate when the ratio of GeH4/SiH2Cl2 is fixed. It is found that these flow rate dependences are well accounted for by assuming that the reaction order for SiH2Cl2 adsorption is twice as large as that for GeH4 adsorption.