Very low Schottky barrier to n-type silicon with PtEr-stack silicide

We investigate Er silicide formed on n-type silicon. In order to protect the Er from oxidation during the formation of Er silicide in non-UHV conditions, a Pt layer is deposed successively on top of Er layer. Surprisingly, we observe that Pt remains essentially unaffected in the formation of Er silicide at temperatures lower than 700 °C. We find that silicidation process is fully completed by rapid thermal annealing at 500 °C. A simplified method of analysis considering the final Schottky barrier MOSFET application has been used to characterize the Schottky barrier of the PtEr-stack silicide system. A very low apparent Schottky barrier (smaller than 0.1 eV) on a n-type silicon substrate with a concentration of 1.4×10 cm in the active region has been obtained.