The Tunnel Source (PNPN) n-MOSFET: A Novel High Performance Transistor

Abstract

As MOSFET is scaled below 90 nm, many daunting challenges arise. Short-channel effects (SCEs; drain-induced barrier lowering and V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">THmiddot</sub> rolloff), off-state leakage, parasitic capacitance, and resistance severely limit the performance of these transistors. New device innovations are essential to overcome these difficulties. In this paper, we propose the concept of a novel tunnel source (PNPN) n-MOSFET based on the principle of band-to- band tunneling. It is found that the PNPN n-MOSFET has the potential of steep subthreshold swing and improved Ion in addition to immunities against SCEs. Therefore, such a PNPN n-MOSFET can overcome the ever-degrading on-off characteristics of the deeply scaled conventional MOSFET. The design of the PNPN n-MOSFET was extensively examined using simulations. Devices with source-side tunneling junctions were fabricated on bulk substrates using spike anneal, and the experimental data is presented.