CHARACTERIZATION OF THE VG ESCALAB INSTRUMENTAL BROADENING FUNCTIONS BY XPS MEASUREMENTS AT THE FERMI-EDGE OF SILVER

A mathematical algorithm is presented to determine the broadening func tion of an XPS spectrometer using smoothed first derivatives of experi mental Fermi edges for the VG ESCALAB 220i-XL instrument at various pa ss energies. Different smoothing algorithms were applied and optimal p arameter sets are discussed, as this has not been done before. The sma llest error in the determination of the broadening function occurred w ith the usage of spline functions. It is shown that the broadening fun ction of the spectrometer can be well described by a symmetrical Gauss ian function. The resolution and the intensity dependence on the pass energy is determined for the spectrometer, as well a.s the linewidth o f the monochromated X-rays. (C) 1997 Elsevier Science B.V.