OPTICAL-PROPERTIES OF BORON-CARBIDE (B5C) THIN-FILMS FABRICATED BY PLASMA-ENHANCED CHEMICAL-VAPOR-DEPOSITION

Variable angle of incidence spectroscopic ellipsometry was used to det ermine the optical constants near the band edge of boron carbide (B5C) thin films deposited on glass and n-type Si(111) via plasma-enhanced chemical-vapor deposition. The index of refraction n, the extinction c oefficient k, and the absorption coefficient are reported in the photo n energy spectrum between 1.24 and 4 eV. Ellipsometry analysis of B5C films on silicon indicates a graded material, while the optical consta nts of B5C on glass are homogeneous. Line shape analyses of absorption data for the films on glass indicate an indirect transition at approx imately 0.75 eV and a direct transition at about 1.5 eV. (C) 1996 Amer ican Institute of Physics.