EVAPORATED AND IMPLANTED REFERENCE LAYERS FOR CALIBRATION IN SURFACE-ANALYSIS

The potential of thin reference layers prepared by the Central Bureau for Nuclear Measurements, especially for calibration puposes in surface analysis, is presented. Our special preparation procedure is outlined, making use of an ultrahigh vacuum microbalance with the substitution principle of weighing applied. Our procedure of characterizing the areal density of the evaporated layers is unique in that it provides for an optimal traceability to the SI unit of mass. Besides thin metal layers evaporated onto vitreous carbon substrates, which can serve for yield calibration in surface analysis, we are making use of thin layers as internal standards on implanted samples in order to perform high-accuracy determinations of the retained dose through Rutherford backscattering spectroscopy. After sensitive tests of the thickness uniformity, evaporated and implanted thin layers are made available as reference samples.