Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5364989 | Applied Surface Science | 2007 | 6 Pages |
Abstract
The electrical properties of the Cu/n-InP and Al/n-InP Schottky barrier diodes (SBDs) with and without the interfacial oxide layer have been investigated by using current-voltage (I-V) measurements. The oxide layer on chemically cleaned indium phosphide (InP) surface has been obtained by exposure to water vapor at 1 ml/min at 200 °C before metal evaporation. The chemical composition of surface oxides grown on the InP is investigated using X-ray photoelectron spectroscopy (XPS). Phosphorus is present as In(PO3)3, InPO4, P2O5 and P4O10. The values of 0.437 ± 0.007 and 0.438 ± 0.003 eV for the barrier height of the reference Cu/n-InP and Al/n-InP SBDs were obtained, respectively. Furthermore, the values of 0.700 ± 0.030 and 0.517 ± 0.023 eV for the barrier height of the oxidized Cu/n-InP and Al/n-InP SBD were obtained, respectively. The transport properties of the metal-semiconductor contacts have been observed to be significantly affected by the presence of the interfacial oxide layer. Devices built on the oxidized surfaces show improved characteristics compared with those built on chemically cleaned surfaces. The chemical reactivity of the metal with oxide and n-InP is important to the formation of the Schottky barriers. The reactive metal Al gave a low barrier height due to the reduction of oxide and reaction with InP. The transmission coefficients for the oxidized Cu/n-InP and Al/n-InP are equal to 2.23 Ã 10â5 and 4.60 Ã 10â2, respectively.
Related Topics
Physical Sciences and Engineering
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Physical and Theoretical Chemistry
Authors
H. Ãetin, E. Ayyildiz,