The optical functions of low dielectric constant (low-k) materials have bee
n determined using a high-precision four-zone null spectroscopic ellipsomet
er in the spectral range from 1.5 to 5.4 eV (230-840 nm wavelength region).
The ellipsometric data were fitted simultaneously with near-normal inciden
ce reflectivity spectra (ranging from 0.5 to 6.5 eV). A general method of s
imultaneous treatment of ellipsometric and reflectivity data is demonstrate
d on representative materials used in the semiconductor industry for interl
ayer dielectrics: (1) SiLK-organic dielectric resin from the Dow Chemical C
ompany, (2) Nanoglass-nanoporous silica from the Honeywell Electronic Mater
ials Company, and (3) tetra-ethyl-ortho-silicate (TEOS) (SiO2)-the standard
dielectric material. The low-k materials (SiLK and Nanoglass) were prepare
d by a standard spin-coating process, while the SiO2 layer was prepared by
thermal decomposition from TEOS onto single-crystal silicon wafers. (C) 200
1 American Institute of Physics.