XPS measurements for probing dynamics of charging

Suzer, Sefik
Sezen, Hikmet
Ertaş, Gülay
Dana, Aykutlu
The technique of recording X-ray photoemission data while the sample rod is subjected to +/- 10.0V (dc) or square-wave pulses (ac) with varying frequencies in the range of 10(-3) to 10(3) HZ for probing charging/discharging dynamics of dielectric materials, is reviewed. Application of this technique introduces charging shifts as well as broadening of the peaks, which depend non-linearly on the polarity, as well as on the frequency of the pulses applied. These changes have been measured on: (i) an artificially created dielectric sample consisting of a Au metal strip connected externally to a series resistor of 1 M Omega and a parallel capacitor of 56 nF, and two real dielectric films; (ii) a 20 nm organic polystyrene film spin-coated on a silicon substrate; (iii) a 10 nm SiO(2) inorganic layer thermally grown on silicon. A simple circuit model is introduced to simulate the charging shifts and the peak broadenings. Although this simple model faithfully reproduces the charging shifts in all three cases, and also some of the broadenings for the artificial dielectric and the polystyrene film, the additional broadening in the negatively charged peaks of the SiO(2) dielectric film cannot be accounted for. It is also claimed that these experimental findings can be used for extracting material-specific dielectric properties.


XPS characterization of Bi and Mn collected on atom-trapping silica for AAS
Suzer, S; Ertas, N; Ataman, Osman Yavuz (1999-04-01)
The chemical state of analyte species collected on a water-cooled silica tube during atom-trapping atomic absorption spectrometric determination is investigated with the use of X-ray photoelectron spectroscopy (XPS) for Bi and Mn. Analysis of the Bi 4f(7/2) peak reveals that the chemical state of Bi is +3 during initial trapping (before the atomization stage), but an additional 0-valence state of Bi is also observed after the atomization stage. With the use of the measured Mn 2p(3/2) binding energy together...
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Harmonic Motion Microwave Doppler Imaging method, which was proposed as an alternative method for breast tumor detection, is a combination of microwave radar and focused ultrasound techniques yielding data depending on electrical and mechanical properties of the tissue. In this study, Harmonic Motion Microwave Doppler Imaging data from a small tumor inside homogeneous fat is analyzed as a function of tumor location on three orthogonal planes using Finite Difference Time Domain simulations. The results show ...
XPS study of pulsed Nd : YAG laser oxidized Si
Aygun, G.; Atanassova, E.; Kostov, K.; Turan, Raşit (Elsevier BV, 2006-08-15)
X-ray photoelectron spectra (XPS) of thin SiO2 layers grown by pulsed Nd:YAG laser at a substrate temperature of 748 K are presented, The peak decomposition technique combined with depth profiling is employed to identify the composition and chemical states of the film structure. It is established that the oxide is non-stoichiometric, and contains all oxidation states of Si in different amounts throughout the film. The interface Si/laser-grown oxide is not abrupt, and the coexistence of Si2O3 and Si2O suboxi...
XPS analysis with external bias: a simple method for probing differential charging
Ertaş, Gülay (Wiley, 2004-07-01)
The XPS spectra of thermally grown oxide layers on Si, Al, W and Hf substrates have been recorded while the samples were subjected to external d.c. voltage bias. The bias induces additional shifts in the measured binding energy differences between the XPS peaks of the oxide and that of the metal substrate in Si and Al (as probed both in the 2p and the KLL Auger regions), but not in W and Hf (as probed in the 4f region). These bias induced shifts are attributed to differential charging between the oxide laye...
Optical characterization of Ga2SeS layered crystals by transmission, reflection and ellipsometry
IŞIK, MEHMET; Hasanlı, Nızamı (2015-07-10)
Optical properties of Ga2SeS crystals grown by Bridgman method were investigated by transmission, reflection and ellipsometry measurements. Analysis of the transmission and reflection measurements performed in the wavelength range of 400-1100 nm at room temperature indicated the presence of indirect and direct transitions with 2.28 eV and 2.38 eV band gap energies. Ellipsometry measurements were carried out in the 1.2-6.0 eV spectral region to get information about optical constants, real and imaginary part...
Citation Formats
S. Suzer, H. Sezen, G. Ertaş, and A. Dana, “XPS measurements for probing dynamics of charging,” JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA, pp. 52–57, 2010, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47059.