High quality Si1−<i>x</i>−<i>y</i>Ge<i>x</i>C<i>y</i> epitaxial layers grown on (100) Si by rapid thermal chemical vapor deposition using methylsilane

Abstract

We have produced epitaxial Si1−x−yGexCy/Si heterostructures by rapid thermal chemical vapor deposition using methylsilane SiCH6). These layers were grown in the SiH4/GeH4/SiCH6/H2 system between 550 and 600 °C at 1.5 Torr. Suitable process conditions were found that allow very efficient substitutional carbon incorporation. No carbon cross contamination was observed. Crystal quality, chemical composition, and lattice strain were deduced from Nomarski microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, secondary ion mass spectrometry, and x-ray diffraction. Defect-free alloy layers with compositions of up to 20 at.% Ge and 2.2 at. % C were produced. The lattice parameter was tailored so that the strain in these layers gradually moved from compressive to tensile. A tensile strain of up to 0.35% was achieved.