Optical functions of chemical vapor deposited thin-film silicon determined by spectroscopic ellipsometry

Abstract

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 spectroscopic polarization modulation ellipsometry from 240 to 840 nm (∼1.5–5.2 eV). It is shown that the standard technique for simulating the optical functions of polycrystalline silicon (an effective medium consisting of crystalline Si, amorphous Si, and voids) does not fit the ellipsometry data.