EXAMINATION OF LAYERED STRUCTURES BY TOTAL-REFLECTION X-RAY-FLUORESCENCE ANALYSIS

The merits and the limitations of total-reflection X-ray fluorescence (TXRF) surface analysis are discussed using selected examples that pose different demands on the technique. The first example is the perpendicular localization of impurities in the uppermost surface zone of a silicon wafer. Greater difficulties arose in the case of an argon sputtered nickel-wafer, in which not only the Ni load was to be determined but also the dose and the depth distribution of the argon atoms. In order to demonstrate the ability of TXRF for density determination, optical flats were examined, which serve as sample carriers for trace element analysis and which consist of quartz, boron nitride and acryl respectively. The determination of the surface density is described because it appears to be a precondition for the characterization of layered structures. The most complex example presented consists of a very thin Co layer that has to be characterized within a Cu layer.