Epitaxial Si1−yCy alloys: The role of surface and gas phase reactions

Abstract

We have studied substitutional carbon incorporation in Si1−yCy alloys grown on Si (100) by ultrahigh vacuum chemical vapor deposition using silane and methylsilane as silicon and carbon precursors. Carbon incorporation has been studied in the growth temperature range of 550–650 °C. The total carbon content of the alloys increases linearly with the methylsilane partial pressure and a methylsilane sticking coefficient approximately two times higher than that of silane was determined from the data. Substitutional carbon content in the alloys tends to saturate at higher methylsilane flows. Our results, together with other previous reports, provide new insight into the roles of gas phase and surface reactions in determining growth rates and carbon incorporation efficiency.