A novel process variation immune dopingless zero sub-threshold slope and zero impact ionization FET (DL-Z $$^{2}$$ 2 FET) based on transition metals

Abstract

Transition metal (TM) electrodes based dopingless zero sub-threshold slope and zero impact ionization FET (DL-Z$$^{2}$$2FET) is reported in this paper. The work-function engineering of TM electrodes is used for charge plasma based electrostatic pseudo doping. Work-function difference between TM electrodes and the undoped silicon film induces p$$^{+}$$+ and n$$^{+}$$+ regions in the film. TMs exhibit easy tunability of work-function and their CMOS fabrication compatibility pledges for their potential applications as these electrodes. A technology computer-aided design simulation study is performed to provide physical insight into its working mechanism and performance. It exhibits all the inherent characteristics of conventional Z$$^{2}$$2FET, viz. zero slope switching, high $$I_{ON}/I_{OFF}$$ION/IOFF ratio, lower operating voltages, immunity towards hot electron degradation and gate controlled hysteresis. The detrimental doping control issues, mobility degradation due to heavy doping and statistical random dopant fluctuations can no more obviate the device performance, it results in more process variations immune design. Hence it can be a potential fast switching transistor.