Differential charging in SiO2/Si system as determined by XPS

Karadas, F
Ertaş, Gülay
Suzer, S
The Si2p binding and the Si-KLL kinetic energy difference between the SiO2 layer and Si substrate is shown to be influenced by application of external voltage bias to the sample holder due to the differential charging as was already reported earlier (Ulgut, B.; Suzer, S. J. Phys. Chem. B 2003, 107, 2939). The cause of this bias induced (physical)-shift is now proven to be mostly due to partial neutralization by the stray electrons within the vacuum system by (i) introducing additional stray electrons via a filament and following their influence on the measured binding energy as a function of the applied voltage, (ii) measuring the Auger parameter. It is also shown that citrate-capped gold nanoclusters deposited on the SiO2/Si system experience differential charging similar to that of the oxide layer rather than the silicon substrate.


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...
Time-resolved XPS analysis of the SiO2/Si system in the millisecond range
Demirok, UK; Ertaş, Gülay; Suzer, S (American Chemical Society (ACS), 2004-04-29)
By applying voltage pulses to the sample rod while recording the spectrum, we show, for the first time, that it is possible to obtain a time-resolved XPS spectrum in the millisecond range. The Si 2p spectrum of a silicon sample containing a ca. 400-nm oxide layer displays a time-dependent charging shift of ca. 1.7 eV with respect to the Au 4f peaks of a gold metal strip in contact with the sample. When gold is deposited as C-12-thiol-capped nanoclusters onto the same sample, this time the Au 4f peaks also d...
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ARIK, Enis; Altan, Hakan; Esentürk, Okan (American Chemical Society (ACS), 2014-05-01)
Investigation of frequency dependent permittivity of mixture solutions provides information on the role of intermolecular interactions on relaxation processes of solvent and solute molecules. In this study the dielectric properties of ethanol/gasoline mixtures in the terahertz spectral region are investigated. Frequency dependent absorption coefficients, refractive indices, and complex permittivities of pure ethanol and gasoline, and their mixtures at varying ethanol volume percentages (v/v %) are reported....
Current conduction mechanism in Al/p-Si Schottky barrier diodes with native insulator layer at low temperatures
ALTINDAL, ŞEMSETTİN; Kanbur, H.; Yildiz, D. E.; Parlak, Mehmet (Elsevier BV, 2007-03-30)
The forward bias current-voltage (I-V) characteristics of Al/p-Si (MS) Schottky diodes with native insulator layer were measured in the temperature range of 80-300 K. The obtained zero bias barrier height Phi(B0)(I-V), ideality factor (n) and series resistance (R-s) determined by using thermionic emission (TE) mechanism show strong temperature dependence. There is a linear correlation between the Phi(B0)(I-V) and n because of the inhomogeneties in the barrier heights (BHs). Calculated values from temperatur...
Enhanced peak separation in XPS with external biasing
Ertaş, Gülay; Suzer, S (Elsevier BV, 2005-08-15)
We have demonstrated that the An 4f peaks of the capped gold nanoparticles deposited on a SiO2 (20 nm)/Si substrate can be separated form the An 4f peaks of a gold metal strip, in contact with the same sample, by application of an external voltage bias to the sample rod while recording the XPS spectra. The external bias controls the flow of low-energy electrons falling on to the sample which in-turn controls the extent of the differential charging of the oxide layer leading to shifts in the binding energy o...
Citation Formats
F. Karadas, G. Ertaş, and S. Suzer, “Differential charging in SiO2/Si system as determined by XPS,” JOURNAL OF PHYSICAL CHEMISTRY B, pp. 1515–1518, 2004, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/36096.