Session D40 - Poster Session I.
POSTER session, Monday afternoon, March 12
Exhibit Hall, Washington State Convention Center
PtSi films on Si (and precursor samples of Pt on Si) have been characterised using a novel, variable temperature (ambient to 85K), in-vacuo prism coupler - this couples IR radiation (\lambda = 3.39 \mu m here) to surface plasmons on the sample via an evanescent field across a uniform, remotely adjustable gap between prism and sample. The resulting attenuated total reflection (ATR) curves for Pt films decrease in half-width with decreasing temperature, as anticipated due to decreased electron-phonon scattering. The formation of PtSi by thermal annealing of the Pt films is revealed by XRD and AFM to be partial and less uniform than commonly supposed. However, even for PtSi films of uniform composition and smooth morphology on p-Si substrates, the shape of the ATR curves remain defiantly constant between ambient temperature and 85K. Consideration of increased carrier scattering due to the preclusion of thermionic emission over the low Schottky barrier with reduced temperature is set against decreased electron-phonon scattering to explain the observation.