New structural approach for reducing punchthrough current in deep submicrometre MOSFETs and extending MOSFET scaling

A heterojunction MOSFET structure is proposed in which the energy band offset of a heterojunction provides an additional potential energy barrier at the source in order to improve the turn-off characteristics in extremely small MOSFETs. Initial numerical simulations of this device show that the heterojunction MOSFET yields a substantial improvement in off-state leakage current compared to a conventional all-Si (homojunction) MOSFET. An additional design technique such as this is believed to be able to allow devices to be scaled more effectively to x 0.1 μm technology.