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

A simple method of uniaxial anisotropic media investigation by the mea surement of s- and p-polarized light reflectances near normal and graz ing angles as well as at the Brewster angle is proposed. The method is applied to thick films of porous silicon, the new potentially promisi ng microelectronic material. Our results support the hypothesis of a r ather high uniaxial optical anisotropy of the refractive index of poro us 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 morp hologies as a function of the geometrical shape of the pores is presen ted.