PtSi dominated Schottky barrier heights of Ni(Pt)Si contacts due to Pt segregation

Temperature dependent current-voltage measurements show that the addition of only 10% Pt to NiSi causes an increase of Schottky barrier height (SBH) from 0.65 eV for NiSi to 0.78 eV for the 10% Pt alloy. Internal photoemission measurements resolve two SBHs in all alloyed samples with ≥5% Pt incorporation corresponding to NiSi and PtSi (∼0.68 eV and ∼0.80 eV), proving that each contributes independently to junction current. High angle annular dark field imaging with scanning transmission electron microscopy confirms Pt segregation to the Ni(Pt)Si/Si interface. The resulting increased SBH may therefore be detrimental to contact resistivity in future technology nodes.