R. Nilsson

Calibration of electron spectra

Abstract Energy calibration procedures, which have been used in ESCA, are reviewed. Binding energies of calibration lines suitable for solid and for gaseous samples have been determined. Charging effects of nonconducting samples have been investigated for different X-radiation, sample thickness and material. A calibration relative to lines from some insulating standard compound mixed into the sample was shown to be unreliable, while experiments indicated that in calibrating relative to a surface layer, the carbon line from the hydrocarbon contamination layer can be used as well as a line from a thick layer of a noble metal on a part of the sample.

Escape Depths of X-ray Excited Electrons

The escape depth of X-ray induced photoelectrons and Auger electrons has been measured for energies between 1 keV and 4 keV in metallic gold and aluminum oxide. The escape depth was found to be proportional to the square root of the electron energy and ranged from 19 ? (at 0.9 keV) to 37 ? (at 3.2 keV) in gold and from 13 ? (at 1.4 keV) to 22 ? (at 3.9 keV) in aluminum oxide.

Electron escape depth in silicon

Abstract The ESCA electron escape depth in silicon is determined from the peak areas in the electron spectra from evaporated thin films. For electron energies in the region 320 eV to 3.6 keV values from 13 to 83 A are obtained. The escape depth in silicon dioxide is determined for the energies 1.6 and 3.6 keV. Binding energies and Auger energies are determined in silicon and silicon oxides.

Ethene and the Chloroethenes Studied by ESCA

ESCA studies have been made of core and valence electrons in ethene and all the chloroethenes, using an instrument incorporating X-ray monochromatization. The orbitals are assigned according to calculated intensities and Extended Huckel type (EHT) calculations, as well as previously available data. Intensities are calculated from a model based on net atomic EHT populations and are found to agree well with experimental results. Also, CNDO calculations were performed.

An yttrium Mξ source for ESCA

Abstract A new source for producing YMξ radiation in an ESCA spectrometer is described. The system makes use of continuous evaporation of yttrium on a rotating anode. It is demonstrated that this scheme allows YMξ-excited electron spectra to be recorded without gradual loss of resolution and intensity due to anode oxidation. Electron spectra of Ar, Hg and N 2 excited by YMξ radiation are studied. Relative photoelectric cross-sections of the 5d 5 2 , 5d 5 2 and 6s orbitals in Hg and the four valence orbitals in N 2 are measured. The valence electron shake-up spectrum of N 2 is discussed.

Influence of doping on the electron spectrum of silicon

Abstract An energy difference of 1.0 eV has been found between the silicon 2 p electron peaks in the electron spectra from heavily doped silicon of n- and p-

Intermediate X-ray Sources for ESCA

The applicability of the YM? (hv = 132 eV) and the FK? (hv = 676 eV) X-ray lines for generating photoelectron spectra is demonstrated. The N2 valence electron spectra excited by YM? and A1K? are studied in regard to relative intensities and shake-up structure. Relative intensities of electron levels in Au excited by FK? and A1K? are measured. Cross-section ratios for FK? and A1K? excited spin-orbit components in Ar and Au are determined. Experimental and theoretical cross-section ratios of the Hg 5d spin-orbit components are reviewed for excitation energies between 21 eV and 2 700 eV.

Fluorine Kα radiation for the excitation of electron spectra

Abstract The applicability of the F K α X-ray line ( hv = 676 eV) from potassium fluoride for the excitation of electron spectra is demonstrated. Relative photoionization cross-sections in Au and gaseous Hg have been measured. The F K α radiation from KF, RbF and CsF has been studied. The Ba M ζ line ( hv = 602 eV) is found to be too broad for use in ESCA, even when emitted from metallic barium.