Metal Gate Work Function Engineering: Sub-Nano Regime Double Gate MOSFETs

Abstract

The effect of metal gate (MG) work function (WF) on MOSFETs having double gate has been researched for the next generation logic applications. GaN-based Double-Gate MOSFETs, by tuning the value of work functions (WF) are investigated by simulation to establish the transport characteristics to mitigate SCEs (short channel effects). The metal gate (MG) work functions (WF) is varied between 3.5 eV and 4.8 eV and the device performance is evaluated. The reduction of SCEs is observed for multiple metal gate (MG) work functions (WF). The simulation results apprise that by tuning the work function of GaN-based double-gate MOSFETs, the threshold voltage tuning can be possible. The reduction of short channel effects (SCEs) can be possible by fixing the congenial value of the threshold voltage (VT). The simulations have been performed for GaN-based DG-MOSFETs considering 9.7 nm (ITRS- Year: 2021) length of the gate (L G ). The device turn on and turn off voltage (Gate-Source) is respectively, V GS =1 V and V GS = 0 V. The effective oxide thickness (EOT) is considered as 0.56 nm for a gate length of 9.7 nm. In the device simulation focus has been set on V TH , ION, I OFF , DIBL and SS, this metrics has been done for multiple metal gate work functions. The value of drain induced barrier lowering (DIBL) and subthreshold leakage current is reduced and threshold voltage (VT) is increased with tuning the metal gate work functions. The proposed GaN-based DG-MOSFETs suggests that the reduction of short channel effects (SCEs) can be possible by tuning the MG-WF (metal gate-work function).