PHASE AND MICROSTRUCTURE INVESTIGATIONS OF BORON-NITRIDE THIN-FILMS BY SPECTROSCOPIC ELLIPSOMETRY IN THE VISIBLE AND INFRARED SPECTRAL RANGE

Spectroscopic ellipsometry over the spectral range from 700 to 3000 cm (-1) and from 1.5 to 3.5 eV is used to simultaneously determine phase and microstructure of polycrystalline hexagonal and cubic boron nitrid e thin films deposited by magnetron sputtering on (100) silicon. The r esults are obtained from a single microstructure-dependent model for b oth infrared and visible-light thin-film anisotropic dielectric functi ons. The optical behavior of high c-BN content thin films is described by an effective medium approximation. We obtain the amount of h-BN wi thin high c-BN content thin films. A thin oriented nucleation layer be tween the silicon substrate and the high c-BN content layer is demonst rated. The preferential arrangement of the grain c axes within the h-B N thin films are found to be dependent on the growth parameters. The r esults from the infrared and visible spectral range ellipsometry model are compared to each other and found to be highly consistent. (C) 199 7 American Institute of Physics.