Ellipsometry studies of Si/Ge superlattices with embedded Ge dots

In this paper, we present an analysis for treating the spectroscopic ellipsometry response of Si/Ge superlattices (SLs) with embedded Ge dots. Spectroscopic ellipsometry (SE) measurement at room temperature was used to investigate optical and electronic properties of Si/Ge SLs which were grown on silicon (Si) wafers having aOE (c) 111 > crystallographic orientation. The results of the SE analysis between 200 nm and 1000 nm indicate that the SL system can effectively be described using an interdiffusion/intermixing model by assuming multicrystalline Si and Si1-x Ge (x) intermixing layers. The electronic transitions deduced from the analysis reveal Si-, Ge- and alloying-related critical energy points.