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

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 (L-g), gate oxide thickness (t(ox)), channel thickness (t(ch)), and doping parameters are channel doping (N-ch), drain doping (N-d), and source doping (N-s). These parameters are varied to extract the RF parameters, cut-off frequency (f(t)), maximum oscillation frequency (f(max)), intrinsic gain, and admittance (Y) parameters. DG TFET with gate-drain overlap offers highest f(max) values of 977 GHz for drain doping of 1e20 cm(-3). Higher values of output resistance (R-o) 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 Y-11 and Y-22 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.