Investigation of geometrical and doping parameter variations on GaSb/Si‐based double gate tunnel FETs: A qualitative and quantitative approach for RF performance enhancement

Abstract

This paper compares the radio frequency (RF) performance enhancement of GaSb/Si‐based double gate (DG) tunnel field‐effect transistors (TFETs) and DG TFETs with gate‐drain overlap devices using technology computer‐aided design (TCAD) simulations. The geometrical parameters taken under consideration are gate length (Lg), gate oxide thickness (tox), channel thickness (tch), and doping parameters are channel doping (Nch), drain doping (Nd), and source doping (Ns). These parameters are varied to extract the RF parameters, cut‐off frequency (ft), maximum oscillation frequency (fmax), intrinsic gain, and admittance (Y) parameters. DG TFET with gate‐drain overlap offers highest fmax values of 977 GHz for drain doping of 1e20 cm−3. Higher values of output resistance (Ro) results in high intrinsic gain values for DG TFET with gate‐drain overlap. In terms of Y parameters, DG TFET with gate‐drain overlap shows better Y11 and Y22 values compared with DG TFET. A quantitative model as a function of geometrical and doping parameters is modelled for all the RF parameters that validate the simulated values and predicted values.