Analysis of Optical Constants for Sputter-Deposited InSb Films Based on the Interband-Transition Model

The dielectric-function spectra for InSb films rf-sputter-deposited on (0001) and (011̄0) sapphire substrates have been analyzed by using a simplified interband transition model. The film deposited on (0001) sapphire is epitaxial, while the film on (011̄0) sapphire is polycrystalline in structural properties. The model based on the Kramers-Kronig transformation includes the E 0, E 0+Δ0, E 1, E 1+Δ1, E 0 ′, E 0 ′+Δ0 ′, E 2, E 1 ′ gaps and indirect gap (E g L ) as the main dispersion mechanisms. The analysis suggests that the sputter-deposited InSb films include a small and a large number of void networks in the film medium for epitaxial and polycrystalline films, respectively. Dielectric-function-related optical constants, such as the refractive index and extinction coefficient, of the InSb films are also presented and analyzed.