Details of below band-gap uniaxial dielectric function of SiC polytypes studied by spectroscopic elipsometry and polarized light transmission spectroscopy

An experiment was conducted, by using standard phase modulated spectroscopic elipsometry (PMSE), to measure the ordinary dielectric function of common SiC poly-types 15R, 21R, 6H, and 4H. The result reveals that the effective oscillator strength of the dielectric difference function varies as a cubic polynomial with a turning point at the degree of hexagonality of 50 percent.