Integration of PtSi-based Schottky-barrier p-MOSFETs with a midgap tungsten gate

This paper demonstrates the successful integration of Schottky barrier (SB) MOSFETs that feature platinum silicide (PtSi) source/drain and a tungsten midgap gate down to a length of 40 mn. SB MOSFETs are shown to steadily progress with respect to conventional highly doped source/drain with a current drive (I-on) of 325425 mu A/mu m, an off-state current (I-off) of 14-368 nA/mu m at -2 V for 100-40 nm physical gate lengths, respectively. Post-silicidation thermal treatments necessary to passivate defects at the silicon/silicon dioxide interface are shown to negatively impact electrical performance of short channel devices due to an increase of the SB to holes. Device simulation corroborates the increased sensitivity of the current drive to the modulation of the SB as the gate length is scaled down.