OPTICAL-PROPERTIES OF BULK AND MULTIQUANTUM-WELL SIGE-C HETEROSTRUCTURES

We have investigated optical properties of SiGe:C layers deposited on Si(100). Bulk and multi-quantum well heterostructures were grown by ra pid thermal chemical vapor deposition using methylsilane as carbon pre cursor, The optical properties are analyzed as a function of the struc tural properties of the alloys. The photoluminescence of these structu res exhibits two features: deep level photoluminescence associated wit h localized states and band-edge recombination which gives an indicati on of the band gap variation due to carbon incorporation in substituti onal sites, in the case of multi-quantum well heterostructures, we rep ort on an enhancement of the radiative recombination associated with s ilicon at room temperature in presence of Si1-xCx layers. The strain c ompensation induced by carbon in SiGe, which is evidenced by X-ray dif fraction, is compared to the Raman spectroscopy of the vibration modes of the alloy.