XPS and XRD study of crystalline 3C-SiC grown by sublimation method

Preliminary XPS and XRD studies of the 3C-SiC polycrystals (with the grain size of order of 100 mu m) grown by the sublimation method were performed. The XRD data proved a dominant 3C-SiC structure accompanied by an admixture of the residual 6H-SiC phase. The main core-level photoelectron spectra we re analysed in detail. In particular, the C Is level spectrum revealed a th ree peaks structure containing the peak indicative of free carbon as well a s the remaining two identified as the carbidic components, centered at E-B( a)=282.3 eV and E-B(b)=283.4 eV. The fact, that the most intensive peak 'a' was found especially well resolvable in the acquired spectrum las not obse rved in the earlier reports) was linked with a dominance of 3C-SiC phase an d a relatively high lattice perfection of the crystals studied. Therefore, it enabled us a reliable identification of the main C Is line component (pe ak 'a') as related to the C-Si bond in cubic Si1-xCx crystal with slight de viation from stoichiometry (0.5<x equal to or less than 0.54). On the other hand, the minor carbidic component (peak 'b') was ascribed to the C-Si bon d in the highly C-saturated cubic Si1-xCx (x similar or equal to 0.6) compo und that is present in the surface region. (C) 1999 Elsevier Science S.A. A ll rights reserved.