50-nm gate Schottky source/drain p-MOSFETs with a SiGe channel

We propose new SiGe channel p-MOSFETs with germano-silicide Schottky source/drains (S/Ds). The Schottky barrier-height (SBH) for SiGe is expected to be low enough to improve the injection of carriers into the SiGe channel and, as a result, current drivability is also expected to improve. In this letter, we demonstrate the proposed Schottky S/D p-MOSFETs down to a 50-nm gate-length. The drain current and transconductance are -339 muA/mum and 285 muS/mum at V-GS = V-DS = -1.5 V, respectively. By increasing the Ge content in the SiGe channel from 30% to 35%, the drive current and transconductance can be improved up to 23% and 18%, respectively. This is partly due to the lower barrier-height for strained Si0.66Ge0.35 channel than those for strained Si0.7Ge0.3 channel device and partly due to the lower effective mass of the holes.