In-line metrology capability for epitaxial multi-stack SiGe layers

This paper describes a study performed to evaluate inline metrology techniques for the monitoring of multiple SiGe layers in a manufacturing environment. Comparative measurements between High Resolution X-Ray Diffraction (HRXRD), X-Ray Reflectometry (XRR) and spectroscopic ellipsometry (SE) optical technique were carried out on a specifically-design wafer set. Strength and drawback of each technique are presented. An innovative approach of combining techniques for such application is explored and the results confirm the benefit of this strategy.