Investigation of Analog Parameters and Miller Capacitance Affecting the Circuit Performance of Double Gate Tunnel Field Effect Transistors

Abstract

AbstractTCAD Simulations for 30 nm double gate tunnel field effect transistor (DGTFET) reports steeper subthreshold swing, SS ~ 15 mV/dec, ION ~ 10–4 A/µm, and low off-state current IOFF ~ 10−15A/µm as desirable parameters for low voltage applications. The unity gain frequency (fT) increases with Vgs and maximizes at 5.2 × 1011 Hz for Vgs = Vds = 0.7 V. It is investigated that the gain-bandwidth product (GBP) also increase with Vgs and maximized at 2.63 × 1011 Hz for Vds = 0.7 V at Vgs = 0.6 V. Transconductance frequency product (TFP) increases initially with Vgs (0–0.7 V) and maximizes at 4.46 × 1011 Hz/V for Vds = 0.7 V. Higher value of Vds results in better response time of the DGTFETs, i.e., increasing Vds from 0.1 to 0.8 V, the transit time (tr) of the electron decreases from 4 to 0.1 ps resulting faster switching operation. Transient performance of DGTFETs reports that at supply voltage (VDD) = 0.7 V, increasing the load capacitance (CL, 10–200 pF) the total delay increases from 0.18 to 1.9 ns. It is also noticed that the % peak voltage overshoot (% Vp) decreases from 42.8 to 2.14% due to decrease in computed values of miller capacitance (CMIL) from 11.27 to 4.32 fF. Maintaining CL = 15 fF, increasing VDD reports significant variation in voltage peak overshoot from 35 to 26.25% and total delay also decreases from 8 to 0.2 ns for VDD = 0.1–0.8 V.KeywordsBand-to-band tunneling (BTBT)AnalogTransientTFETMiller capacitanceVerilog A modelSymica D