OPTICAL FUNCTIONS OF CHEMICAL-VAPOR-DEPOSITED THIN-FILM SILICON DETERMINED BY SPECTROSCOPIC ELLIPSOMETRY

The optical functions of several forms of thin-film silicon (amorphous Si, fine-grain polycrystalline Si, and large-grain polycrystalline Si ) grown on oxidized Si have been determined using 2-channel spectrosco pic polarization modulation ellipsometry from 240 to 840 nm (approxima tely 1.5-5.2 eV). It is shown that the standard technique for simulati ng the optical functions of polycrystalline silicon (an effective medi um consisting of crystalline Si, amorphous Si, and voids) does not fit the ellipsometry data.