Impact of channel doping on Schottky barrier height and investigation on p-SB MOSFETs performance

This paper proposes to study the impact of a moderate variation of the channel doping level on the electrical performance of p-type Schottky-barrier (SB) MOSFETs. First, it has been found that a moderate increase of the acceptors doping level leads to a reduction of the Schottky-barrier height (SBH) but does not affect the silicide reaction. In the case of PtSi, the SBH on p-type silicon at 5 x 10(15) cm(-3) is 0.15 eV whereas an increase of the doping level by two decades decreases the barrier by 60 meV. The integration of PtSi MOSFETs on moderately doped channel (5 x 10(17) cm(-3)) Was successfully achieved, demonstrating an overall 60% improvement in current drive at L-g = 100 nm. This enhanced performance is attributed to the barrier height reduction related to the beneficial band bending induced by p-type dopants. The considered doping levels are still in a sufficiently low range not to affect the carrier mobility in the channel. A complete study, including comparison of I-on, I-off, immunity against short channel effects (Swing and DIBL), is presented. (C) 2008 Elsevier B.V. All rights reserved