INTERPRETATION OF INPLANE AND OUT-OF-PLANE ANISOTROPIC SURFACE-INTERFACE REFLECTANCE AND TRANSMITTANCE DIFFERENCE SPECTROSCOPY

A numerical method developed previously [J. Appl. Phys. 80, 4621 (1996 )] has been extended to simulate the nonnormal-incidence reflectance-d ifference spectroscopy and transmittance-difference spectroscopy spect ra of biaxial anisotropic (epsilon(x) not equal epsilon(y) not equal e psilon(z)) multilayer systems with finite thickness. It is demonstrate d that, when the principal axes of the anisotropy layer are at certain orientations, a reflectance-difference spectrum can be separated into two spectra, namely, an in-plane anisotropic spectrum and an out-of-p lane anisotropic spectrum. It is shown that the separation is valid fo r large in-plane anisotropy, i.e., \epsilon(x) - epsilon(y)\ approxima te to \epsilon(x)\, and an incident angle of less than or equal to 20 degrees. (C) 1998 Optical Society of America [S0740-3224(98)01203-X].