A novel MOSFET structure with asymmetric Schottky and P-N junction source/drain on bulk silicon substrate

An asymmetric Schottky and P-N junction source/drain MOSFET contains a conventional P-N junction and a hybrid junction for the source and drain or vice versa. Owing to the asymmetric source/drain structure, this device could be used in two different situations: Schottky-junction source MOSFETs and Schottky-junction drain MOSFETs. Performances of MOSFETs featuring a gate length of 100 nm with Schottky-junction source, Schottky-junction drain, Schottky-junction source/drain and conventional P-N junction have been obtained via numerical simulation by using Silvaco software package. The Schottky-junction source MOSFET exhibits significantly lower GIDL leakage current compared with the pure Schottky-barrier MOSFETs and slightly lower drive current compared with conventional P-N junction MOSFETs when the Schottky barrier height is set at 0.13 eV. For the Schottky-junction drain MOSFET, its drive current is found to be similar to that of conventional P-N junction MOSFETs and less sensitive to variations of Schottky barrier height compared with pure Schottky-barrier MOSFET.