Beem and UHV-TEM Studies of PtSi/Si(001)

Abstract

AbstractRecent work using ballistic electron emission microscopy (BEEM) and ultra-high vacuum transmission electron microscopy (UHV-TEM) to study structure-property correlations of PtSi/Si(001) contacts is described. The spatial uniformity of the Schottky barrier height (SBH) for diodes grown at room temperature and 350°C was compared with the interface microstructure using TEM. Narrow SBH distributions with standard deviations of 7–12 meV were obtained independent of the deposition system and temperature. Analysis of the distributions compared well with standard current-voltage and capacitance-voltage measurements on the same diode. These low temperature depositions produced fine grained PtSi films (10–20 nm) with an interface roughness dependent on the cleaning process. Probable orientation effects on the SBH distribution were apparently screened out because of the low doping of the substrates that were used. As the deposition temperature is increased the PtSi tends towards polycrystalline epitaxy with island growth beginning at 700°C. Grains are rectangular and develop a large shape anisotropy of great interest for future investigations.