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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 18:34 |
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Conference: Bucharest University Faculty of Physics 2014 Meeting
Section: Solid State Physics and Materials Science
Title:
Study of the Surface modification of GaAs with Angular Resolved X-Ray photoelectron spectroscopy (ARXPS)
Authors:
D. DRAGOMIR (1), C. LOGOFATU (2), D. BALAN (1), Georgiana DUMITRACHE (1), C. BERBECARU (1)
Affiliation:
1) Faculty of Physics, University of Bucharest, Bucharest – Magurele, 077125, Romania
2) Laboratory of Chemical Analysis of Advanced Materials, National Institute for Material Physics, POBox MG7, 77125 Bucharest Romania
E-mail
adrianrider91@yahoo.com, constantinlogofatu@yahoo.com, danutz_nightshot@yahoo.com, georgianaa.dumitrache@yahoo.com, berbecaru2ciceron@yahoo.com
Keywords:
XPS, thermal heating of GaAs, stoichiometry of GaAs surface
Abstract:
Gallium Arsenide is an important III-V semiconductor material, for micro and optoelectronic applications. For obtaining good ohmic contact and Schottky barriers it requires a very clean surface. In this work, the cleaning of GaAs surface has been investigated by Angular Resolved X-ray photoelectron spectroscopy (ARXPS). The surface sensitivity of XPS (typically 40-100 Å), makes the technique to be ideal for the measurements of oxidation states and oxide layer thickness. ARXPS study has been performed in order to investigate the effects of the thermal heating of GaAs surfaces, up to a temperature of maximum 700 oC. The studies has been performed at 0o, 40o, 60o, 70o and 75o Take-off Angle (TOA). Desorption of the arsenic oxidized, phase under ultrahigh-vacuum conditions, occurs between 150 and 400 oC (complete desorption). The gallium oxidized phase, is removed by desorption of both gallium and oxygen atoms, between 550 and 600 oC. With thermal heating the Ga/As concentration ratio is almost 1, therefore obtaining the stoichiometry for GaAs surface.
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