Reference-free, depth-dependent characterization of nanolayers and gradient systems with advanced grazing incidence X-ray fluorescence analysis

摘要

Thin high-κ layers and stacks as well as ultra shallow dopant profiles arc technologically relevant nanoscaled systems for current and future electronic devices. The characterization of such systems presents several metrological challenges and requires further development of the available analytical techniques. Grazing incidence X-ray fluorescence (GIXRF) in combination with X-ray reflectometry (XRR) can significantly contribute to the characterization of nanoscaled samples by improved modeling of the X-ray standing wave (XSW) field induced by the incident X-rays. In conjunction with the in-house built radiometrically calibrated instrumentation of the Physikalisch-Technische Bundesanstalt, the method allows for reference-free quantitative in-depth analysis. The capabilities of the combined XRR-GIXRF method are shown on the example of several nanoscaled systems, including ultra-shallow Al dopant profiles in Si, HfO_2, and Al_2O_3 nano-laminates and self-assembled multilayers of organic tetralac-tam macrocycles.