XPS characterisation of neodymium gallate wafers

• Published in: Journal of alloys and compounds 2004-09, Vol.377 (1), p.259-267
• Main Authors: Talik, E., Kruczek, M., Sakowska, H., Ujma, Z., Gała, M., Neumann, M.
• Format: Article
• Language: English
• Subjects: Clean metal, semiconductor, and insulator surfaces; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron and ion emission by liquids and solids; impact phenomena; Electronic state; Exact sciences and technology; Photoelectron spectroscopy; Photoemission and photoelectron spectra; Physics; Single crystal
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2004.01.037

XPS examinations of NdGaO 3 single crystals were performed. A change of the chemical composition was found in wafers cut from the beginning, middle and end part of a crystal grown along the [0 1 1] direction. The existence of core level satellites at low binding energy related to defects was revealed. Unpolished, polished and substrates etched with H 3PO 4 show a decrease of gallium concentration in relation to a broken surface and to the nominal composition. Annealing of the substrates at different temperatures causes a decomposition due to escape of gallium not only from the surface but from inner parts as well. A comparison of the wafers from the crystals grown along different crystallographic direction reveals changes of the chemical composition and a variable level of defects. This was confirmed by etch pitch density measurements. The above measurements demonstrate the high sensitivity of gallium on processing.