Carbon incorporation in Si_(1-y)C_y alloys grown by ultrahigh vacuum chemical vapor deposition

摘要

Thin heteroepitaxial Si_(1-y)C_y films have been grown on Si (100) by Ultrahigh Vacuum Chemical Vapor Deposition (UHV/CVD) using silane and methlsilane as silicon and carbon precursors. Carbon incorporation has been studied in the growth temperature range of 550 deg C to 650 deg C. The layers have been characterized using high resolution X-ray diffraction and secondary ion mass spectrometry. The total carbon content of the alloys increases linearly with the methylsilane partial pressure and a methylsilane sticking coefficient approximately 2 times higher than that of silane was extracted. Layers with up to 1.34 percent substitutional carbon have been obtained at the lowest growth temperature. Fully substitutional carbon can be obtained for levels up to 0.65percent. Variations of the growth rate with temperature and carbon content are also discussed.