REFLECTION SPECTRUM FOR A THIN-FILM WITH NONUNIFORM THICKNESS

The analytical expression for the reflectance of a weakly absorbing we dge shaped thin film supported on a thick transparent substrate has be en obtained. The envelopes of reflectance maxima and minima derived fr om that expression together with known formulae for envelopes of trans mission spectrum enable calculation of optical constants and thickness non-uniformity of the film. The calculations have been applied to thi n films of amorphous silicon and the results obtained have been compar ed with those for films considered uniform.