Effects of substrate crystallinity and dopant on the growth kinetics of platinum silicides

The growth kinetics of platinum silicides have been studied on four substrate categories: single-crystal, amorphous, undoped polycrystalline, and phosphorus-doped (8×10²⁰ at./cm³) polycrystalline silicon. The sequential growth of Pt₂Si and PtSi were analyzed by Rutherford backscattering spectroscopy (RBS), Seeman-Bohlin x-ray diffraction, and cross-section transmission electron microscopy. Phosphorus depth profiles were measured by secondary ion mass spectroscopy (SIMS). Our results conclude that the activation energies for the growth of Pt₂Si and PtSi are not affected by substrate crystallinity and doping of phosphorus. Analysis of the phosphorus profile by SIMS clearly showed that phosphorus atoms are segregated near the interface between PtSi and polycrystalline silicon, but not at the Pt₂Si/polycrystalline silicon interface.