Structural properties of SnxSy thin films prepared by plasma-enhanced chemical vapor deposition
Por:
Sanchez-Juarez A., Ortiz A.
Publicada:
1 ene 2000
Resumen:
The growth and structural properties of SnxSy (SnS2, Sn2S3) prepared by the plasma-enhanced chemical vapor deposition process have been studied systematically. SnxSy thin films were prepared by the decomposition of H2S and SnCl4 vapors mixture in a capacitively coupled 13.56 MHz radio frequency glow discharge chamber with a radially symmetric flow pattern. Hydrogen was used as a diluent gas and for removing chlorine radicals generated by the SnCl4 decomposition. The deposition pressure, substrate temperature, and plasma power density were kept constant at 50 mTorr, 150°C, and 25 mW/cm2, respectively. The relative concentration of the precursor materials, g, defined as the ratio of tin chloride mass flow rate to the sum of tin chloride and hydrogen sulfide mass flow rates, was varied from 0 to 1.0. A total mass flow rate of 25 standard cubic centimeter per minute for the precursor materials and the diluent gas was used in all the cases. It was found that (i) For g < 0.2, the deposited thin films contain only the 2H-SnS2 phase, and show a hexagonal crystalline structure with a preferential growth of the c axes perpendicular to the plane of the substrate; (ii) For 0.2 ? g < 0.5, and g > 0.6, the deposited films contain a mixture of hexagonal SnS2 and orthorhombic Sn2S3 compounds; and (iii) For g close to 0.5, the deposited material has only the Sn2S3 compound. In all the samples, the size of the crystallites and the lattice parameters were estimated from the width of the X-ray diffraction peaks and the interplanar distances. It was found that the chemical composition, the crystallinity, and the preferential growth of the deposited material are well controlled by adjusting the value of g.
Filiaciones:
Sanchez-Juarez A.:
Department of Solar Materials, Energy Research Center, Unive Rsidad Nacional Autonoma de Mexico, Temixco, Morelos, 62580, Mexico
Materials Research Institute, Universidad National Autonoma de Mexico, Coyoacan, D.F. 04510, Mexico
Ortiz A.:
Department of Solar Materials, Energy Research Center, Unive Rsidad Nacional Autonoma de Mexico, Temixco, Morelos, 62580, Mexico
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