DETERMINATION OF POROUS SILICON FILM PARAMETERS BY POLARIZED-LIGHT REFLECTANCE MEASUREMENTS

A simple method of uniaxial anisotropic media investigation by the measurement of s- and p-polarized light reflectances near normal and grazing angles as well as at the Brewster angle is proposed. The method is applied to thick films of porous silicon, the new potentially promising microelectronic material. Our results support the hypothesis of a rather high uniaxial optical anisotropy of the refractive index of porous silicon films of moderate porosity. As an illustrative example, the theoretical relationship between measurable birefringence (anisotropy) and the porosity of thin porous films with different structural morphologies as a function of the geometrical shape of the pores is presented.