Diagnostics of thin semiconductor layers with spectroscopy of surface plasmon resonance using circularly polarized light

The paper presents the results of calculations of the ellipsometric parameters of reflected light from thin semiconductor layers under conditions of surface plasmon resonance. Layers of InSb and GaAs were used as objects of study. In the surface plasmon resonance spectroscopy method, the main parameter is the difference in angles at which the minimum reflection coefficients are achieved, respectively, with and without a layer. It is shown that in the case of an InSb layer, the characteristic minima in the angular spectra of the ellipsometric parameter ρ are spaced 6.1° from each other. The differences in the minima for the ellipsometric parameter Δ are 6.8°. For the case of GaAs, these differences have the following values: for the parameter ρ, the difference is 3.55°; for the parameter Δ, the difference is 3.90°. The analysis performed is an extension of the conventional method of surface plasmon resonance spectroscopy to the case of polarized light and shows the high efficiency of the proposed method for diagnosing thin layers of semiconductor materials.