Silicon germanium thickness and composition determination using combined XPS and XRF technologies

摘要

Systems and approaches for silicon germanium thickness and composition determination using combined XPS and XRF technologies are described. In an example, a method for characterizing a silicon germanium film includes generating an X-ray beam. A sample is positioned in a pathway of said X-ray beam. An X-ray photoelectron spectroscopy (XPS) signal generated by bombarding said sample with said X-ray beam is collected. An X-ray fluorescence (XRF) signal generated by bombarding said sample with said X-ray beam is also collected. Thickness or composition, or both, of the silicon germanium film is determined from the XRF signal or the XPS signal, or both.

主权项

1. A method for characterizing a silicon germanium film, said method comprising:
generating an X-ray beam; positioning a sample in a pathway of said X-ray beam; collecting an X-ray photoelectron spectroscopy (XPS) signal generated by bombarding said sample with said X-ray beam; collecting an X-ray fluorescence (XRF) signal generated by bombarding said sample with said X-ray beam; determining a thickness of the silicon germanium film from the XRF signal and the XPS signal; and determining a composition of the silicon germanium film from the XRF signal and the XPS signal, wherein determining the composition of the silicon germanium film comprises comparing the XRF signal and the XPS signal to a realistic material layer mixing model that scales the predicted intensity of an XPS Ge signal and an XRF Ge signal relative to a pure germanium film, constraining the remaining fraction of the silicon germanium film to Si.