Ellipsometry of Metal Films under the Condition of Anomalous Skin Effect

Fredholm integral equations of the second kind, which describe the fields of TE and TM polarized waves in metal films with allowance for the anomalous skin effect, are formulated. The equations can be solved numerically by the quadrature method. The electric fields in gold and aluminum films deposited on a silicon substrate and the angular dependences of the polarization angles of light reflected from these films are investigated. It is found that the solution of the inverse problem of multiangle ellipsometry of metal films within the approximation of the normal skin effect is characterized by the instability of the reconstructed complex refractive index of the metal with a change in the thickness of the metal film.