Evaluation of the Si0.8Ge0.2-on-Si Epitaxial Quality by Inline Surface Light Scattering: A Case Study on the Impact of Interfacial Oxygen

Inline light scattering measurements are frequently used to determine wafer quality and cleanliness. In this paper we will show how this technique can be extended to determine the crystalline quality after hetero-epitaxy. Misfits on the surface of the epitaxial layer cause increased surface light scattering. The Si 0.8 Ge 0.2 -on-Si epitaxial quality has been evaluated by surface light scattering. A correlation is observed with the controlled variation of the interfacial oxygen between the Si substrate and epitaxial Si 0.8 Ge 0.2 .