HAL Id: jpa-00226883
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Submitted on 1 Jan 1987
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FIELD-ION ENERGY SPECTROSCOPY OF GOLD OVERLAYERS ON SILICON
W. Schmidt, A. Melmed, M. Lovisa, M. Naschitzki, J. Block
To cite this version:
W. Schmidt, A. Melmed, M. Lovisa, M. Naschitzki, J. Block. FIELD-ION ENERGY SPEC- TROSCOPY OF GOLD OVERLAYERS ON SILICON. Journal de Physique Colloques, 1987, 48 (C6), pp.C6-461-C6-461. �10.1051/jphyscol:1987675�. �jpa-00226883�
JOURNAL DE PHYSIQUE
Colloque C6, supplgment au n o l 1, Tome 48, novembre 1987
FIELD-ION ENERGY SPECTROSCOPY OF GOLD OVERLAYERS ON SILICON'
W.A. Schmidt, A.3. ~elrned*, M.F. Lovisa, M. Naschitzki and J.H. Block Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 1000 Berlin 33, F.R.G.
*~ational Bureau of Standards, Gaithersburg, MD 20899, U.S.A.
Abstract
By means of field-ion energy spectroscopy unoccupied localized states of the AulSi(ll1) contact have been observed. Gold overlayers of 3-5 monolayers and greater were prepared. Under these conditions, an interface of intermixed Si-Au structure was formed. The spectroscopic result in the form of an integral field-ion energy distribution proved the existence of empty electronic states beginning a t the Fermi level. A pronounced hump in the distribution was evaluated and resulted in a high density of states a t (0.95k0.2)eV above the top of the valence band edge. For methodical reasons the spectroscopy is carried out with p-type Si.
Using gold-covered n-type Si, Schottky barrier heights of the Auln-Si(ll1) contact can be determined.
Good agreement with our result can be seen from the spectroscopic data reported by Muret [ l ] which were obtained by capacitance spectroscopy of localized states of the AulSi(ll1) interface for a layer thickness of 200 nm. In this work the position of interface states was found with its lower edge a t 0.8 eV above the top of the valence band edge and extended up to 1.15 eV for its upper edge.
The highest density of states of - 10'6cm-2eV-1 was located a t 0.95 eV above valence band top, fitting exactly our data.
11 ] P.Muret, J. Appl. Phys. 53 (1982) 6300
The complete paper has been submitted to Surface Science
Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1987675
