Investigation of a single Ge dots layer and its evolution upon oxidation by spectroscopic ellipsometry

We present an ellipsometric investigation of a layer of Ge dots embedded in Si. Through dielectric function analysis, it is found that the layer containing Ge dots is actually constituted of a Si0.85Ge0.15 alloy containing Ge richer inclusions characterised by an additional contribution around View the MathML source. After oxidation of the Si layer, the SiGe alloy is pushed into the Si substrate by the growing oxide and the Ge rich inclusions are no longer detected.