Growth of Si1 − x − yGexCy multi-quantum wells: structural and optical properties

Abstract We have studied the optical properties and growth by rapid thermal chemical vapour deposition of multi-quantum well heterostructures based on the group IV elements Si, Ge and C. Si 1 − x Ge x Si , Si 1 − x − y Ge x C y Si , Si 1 − x Ge x Si 1 − y C y and Si 1 − y C y Si heterostructures were investigated by X-ray diffraction (XRD), secondary ion mass spectroscopy (SIMS), photoluminescence and Raman spectroscopy. Different features are observed depending on the growth temperature. At 575 °C, carbon and germanium are incorporated as expected, whereas at lower temperatures (550 °C), strong segregation occurs, as indicated by the decrease in the number of periods of the heterostructure observed by SIMS and XRD. Photoluminescence identifies a defect line associated with carbon and oxygen. Raman spectroscopy shows that, although carbon compensates for the external strain, the energy of the Si-Ge vibration mode is only weakly modified.