Tuning of the Platinum Silicide Schottky Barrier Height on n-Type Silicon by Sulfur Segregation

The Schottky barrier height PhiB of platinum silicide (PtSi) contacts on n-type silicon was tuned by sulfur segregation at the PtSi/Si interface. Sulfur was implanted prior to Pt deposition and segregated at the interface during PtSi formation. It was observed that the barrier height could be tuned by changing the sulfur dose. A minimum barrier height of 0.12 eV was obtained on n-type (100) Si substrates. Since PtSi naturally provides a small PhiB of 0.2 eV on p-type Si, it carries the potential to serve as the single metal source/drain contact metal in a CMOS integrated circuit with PhiB tuning on n-channel transistors.