Microstructure and physical properties of nanofaceted antimony doped tin oxide thin films deposited by chemical vapor deposition on different substrates R. Outemzabet ⁎ , N. Bouras, N. Kesri U.S.T.H.B. Faculty of Physics Semiconductors Laboratory B.P. 32 El-Alia, Bab-Ezzouar, Algiers, Algeria Available online 30 January 2007 Abstract Antimony doped tin oxide SnO 2 : Sb thin films have been fabricated by atmospheric pressure chemical vapour deposition at substrate temperature varying between 350 °C and 420 °C in a horizontal reactor, from a mixture of hydrated SnCl 2 , SbCl 3 and O 2 gas. The films were grown on glass substrates and onto polished and porous n-type silicon. Doped films fabricated with various Sb (Sb/Sn %) contents ranging from undoped 0% to 4% were characterised employing different optical characterisation techniques, like X-ray diffraction, transmittance and reflectance in the wavelength range of 300 to 2500 nm and ellipsometry. The films exhibit the usual cassiterite diffraction pattern with high crystalline structure. Examination of the surface by scanning electron microscopy (SEM) showed that the films are textured made up of many pyramidal crystallites with nanofaceted surfaces, indicating highly stabilised material. The presence of inverted pyramids indicates that the crystallites grown by coalescence. The surface morphology was found to be independent on the kind of the substrate. From X-Ray spectra and SEM observations we get the texture the lattice constant and the grain size. The optical results provide information on film thickness, optical parameters and transmittance upon antimony concentration. The microstructure of the films, the grain growth topics (nucleation, coalescence…) depend strongly on deposition conditions and doping concentration. The observed variations of both the resistivity ρ and transmittance T are correlated to antimony atoms concentration which induced variation in the microstructure and in the size of SnO 2 nanograins (typically 20–40 nm). In this work, we have determined the feasibility of incorporating the correct amount of Sb atoms in tin oxide film by means of resistivity and transmission. SEM observations showed that the substrate do not affect the morphology. © 2007 Elsevier B.V. All rights reserved. Keywords: Microstructure; Physical properties; Nanofaceted; CVD 1. Introduction Photovoltaic, optoelectronic devices and other energy application require transparent conducting oxide (TCO) coat- ings of high transmission, low sheet resistance, high uniformity and larger substrate area. In this way tin oxide (SnO 2 ) film is one of the few electrical conductors that is optically transparent in the visible region in its undoped form. Transparent conducting tin oxide thin films either doped or undoped, are produced by several techniques [1] for various technological applications, as surface electrode for flat panel displays, solar cells, gas sensors and many more. In this work, we have fabricated electrically conductive and optically transparent tin oxide film, in their doped form by a home developed chemical vapor deposition (CVD) technique. We will first present the results on electrical properties and optical transmittance of doped films SnO 2 : Sb upon doping concentration of antimony atoms Sb than the results on surface morphology of doped films deposited on different substrates will follow. 2. Experimental The scheme of the experimental setup used has been reported elsewhere [2]. For preparation of tin oxide film a gas phase mixture of hydrated SnCl 2 and pure oxygen gas was used. Chemical doping with antimony can be achieved by adding the requisite amount of antimony trichloride (SbCl 3 ) to the started material. The Sb/Sn ratio was varied over a wide range, from 0.51% to 4%. The chemical vapours were carried away and Thin Solid Films 515 (2007) 6518 – 6520 www.elsevier.com/locate/tsf ⁎ Corresponding author. Fax: +213 21 50 00 98. E-mail address: oratiba@hotmail.com (R. Outemzabet). 0040-6090/$ - see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.tsf.2006.11.069