Oxidation of preferentially (1 1 1)-oriented Au films in an oxygen plasma investigated by scanning tunneling microscopy and photoelectron spectroscopy

• Published in: Surface science 2001-03, Vol.475 (1), p.1-10
• Main Authors: Koslowski, B., Boyen, H.-G., Wilderotter, C., Kästle, G., Ziemann, P., Wahrenberg, R., Oelhafen, P.
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Clean metal, semiconductor, and insulator surfaces; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; Gold; Photoelectron spectroscopy; Photoemission and photoelectron spectra; Physics; Scanning tunneling microscopy; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; X-ray photoelectron spectroscopy
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(00)00986-9

The effect of an oxygen plasma and a consecutive thermal treatment on the chemical state and morphology of a gold(1 1 1) surface has been investigated by photoelectron spectroscopy (XPS, UPS) and scanning tunneling microscopy. An initially atomically flat Au(1 1 1) surface is oxidized to a depth of about 4 nm in an oxygen plasma resulting in a characteristic rough surface morphology. The oxidation of the gold surface can be unequivocally determined from XPS by the chemical shift of the 4f levels. After reduction of such an oxidized gold surface by a thermal treatment, its initial spectroscopic state is completely restored, while the resulting morphology exhibits a pattern of nanometer-sized Au islands.