Epitaxial growth of Si1−x−yGexCy alloy layers on (100) Si by rapid thermal chemical vapor deposition using methylsilane

Abstract

High quality pseudomorphic Si1−yCy and Si1−x−yGexCy layers were grown on (100) Si between 530 and 650 °C by rapid thermal chemical vapor deposition in the SiH4/GeH4/SiH3CH3/H2 system. These layers contained up to 30 at. % Ge and up to 2.2 at. % C. Strain engineering was achieved. The strain could be tailored continuously from compressive (up to 2.2% in Si1−xGex) to tensile (up to −0.8% in Si1−yCy and −0.35% in Si1−x−yGexCy). The relationship between the process parameters and the physical properties of the layers was investigated. A process window 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 content, growth temperature, and growth rate. No carbon contamination was observed. No interference between Ge and C incorporation was observed. A model for the incorporation of substitutional C in the films which is based on the chemical reaction of SiH4 and SiH3CH3 on the surface is proposed.

Induction of the surface plasmon resonance from C-incorporated Au catalyst in Si1−xCx nanowires

“…The main difference between the Si 1Àx C x film and the Si 1Àx C x wire is the existence of Au as a catalysti.e., the Au catalyst is an important factor that inhibits the chemical state of C from bonding with Si atoms. In the case of Si 1Àx C x film growth without the Au catalyst, C atoms can be substitutionally incorporated into Si sites with connecting Si-C bonds because the CH 3 SiH 3 precursor maintains its Si-C bonds at temperatures below 600 C. 29,30 The following thermal decomposition mechanisms are generally invoked for explaining Si 1Àx C x film growth using SiH 4 and CH 3 SiH 3 :…”

“…Since the formation of HSiCH 3 is dominant at temperatures below 700 C and the H 2 Si]CH 2 formation is relatively minor, SiCH 4 is needed as the main radical for C incorporation since it can diffuse across the surface of H-covered sites such as SiH 2 and can be inserted into Si-H or C-H surface bonds. 29,30 Hence, step (iii) is decisive for the incorporation of C in Si 1Àx C x films by forming SiCH 4 radicals. Yet, for Si 1Àx C x NWs, the growth mechanism by the VLS method using a Au catalyst has not been studied extensively until now.…”

Application of high-resolution x-ray diffraction for detecting defects in SiGe(C) materials

“…where υ is the Poisson ratio (υ = 0.278) for Si 1−x Ge x /Si and the incorporation of C in these heterostructures is believed to have only a minor effect on the Poisson value [4]. The widths of the layer and substrate peaks and the low-intensity broadening can provide valuable information about the density and the structure of the defects.…”