INTEGRATED CONTACT SILICIDE WITH TUNABLE WORK FUNCTIONS

Methods for reducing interface resistance of semiconductor devices leverage dual work function metal silicide. In some embodiments, a method may comprise selectively depositing a metal silicide layer on an Epi surface and adjusting a metal-to-silicon ratio of the metal silicide layer during deposition to alter a work function of the metal silicide layer based on whether the Epi surface is a P type Epi surface or an N type Epi surface to achieve a Schottky barrier height of less than 0.5 eV. The work function for a P type Epi surface may be adjusted to a value of approximately 5.0 eV and the work function for an N type Epi surface may be adjusted to a value of approximately 3.8 eV. The deposition of the metal silicide layer on the Epi surface may be performed prior to deposition of a contact etch stop layer and an activation anneal.