Optical Constants Determination of Pseudomorphic Si1-XGex Layers on Si(001), with 0<x<0.54

The optical constants of fully strained Si 1-x Ge x layers (0< x <0.54) alloys grown by Reduced Pressure Chemical Vapor Deposition on bulk Si(001) wafers were determined in the 0.73 to 6.48 eV spectral range using variable-angle spectroscopic ellipsometry. The robustness of the deduced optical functions relies on an appropriate management of surface effects together with a rigorous combination of X-ray based and optical-based analysis so as to build the required alloy model. This model was extensively tested, demonstrating a 0.5-1 at.% accuracy concerning the Ge content in fully-strained Si 1-x Ge x epitaxial layers.