Optical response of Si/Ge superlattices with embedded Ge dots

Abstract

A method was provided for treating the optical response of Si/Ge superlattices (SL) with embedded Ge dots. Spectroscopic ellipsometry (SE) measurement at room temperature was used to investigate optical and electronic properties of Si/Ge SL which were grown on silicon (Si) wafers having <111> crystallographic orientation. The results of the SE analysis between 1.2 eV and 5.2 eV indicate that the SL system can effectively be described using interdiffusion/intermixing model by assuming a multicrystalline Si and Si 1−x Ge x intermixing layers. The optical transitions exhibit Si, Ge and alloying related critical points.