  In the present work, we have investigated the performances of p plus minus
Al0.3Ga0.7Sb Pocket Implanted L shaped GaSb InAs staggered bandgap SG
heterojunction vertical n channel tunnel field effect transistors TFETs of 4 nm
thin channel structures with the gate lengths of 20 nm. In this L shaped
nonlinear geometry the gate electric field and tunnel junction internal field
are oriented in same direction. We have used a 3 D full band atomistic sp3d5s
spin orbital coupled tight binding method based quantum mechanical simulator.
We have investigated current voltage characteristics, ON current, OFF current
and subthreshold swing as functions of equivalent oxide thickness Tox, gate
length LG, drain length LD, gate undercut LUC, dielectric constant and drain
thickness TInAs in nonlinear L shaped TFETs for low subthreshold swing and low
voltage operation.
