Estimation of the dielectric properties of low-k materials using optical spectroscopy

The dielectric function spectra of low dielectric constant (low-k) materials have been determined using spectroscopic ellipsometry, near-normal incidence spectroscopic reflectometry, and Fourier transform infrared transmission spectrometry over a wide spectral range from 0.03 to 5.4 eV (230 nm to 40.5 mum wavelength region). The electronic and ionic contributions to the overall static dielectric constant were determined for representative materials used in the semiconductor industry for interlayer dielectrics: (1) FLARE-organic spin-on polymer, (2) HOSP-spin-on hybrid organic-siloxane polymer from the Honeywell Electronic Materials Company, and (3) SiLK-organic dielectric resin from the Dow Chemical Company. The main contributions to the static dielectric constant of the low-k materials studied were found to be the electronic and ionic absorptions. (C) 2001 American Institute of Physics.