Impact of Quantum Confinement on Band-to-Band Tunneling of Line-Tunneling Type L-Shaped Tunnel Field-Effect Transistor

An L-shaped tunnel field-effect transistor (LTFET) employs an overlapped gate/channel/source architecture to maximize band-to-band tunneling (BTBT) area. The overlapped channel is very thin and suffers from the geometrical quantum confinement effect (QCE). The analysis of QCE in LTFET has been shown to significantly affect the BTBT in LTFET. As a consequence of QCE, conduction band in the overlapped channel becomes a discrete set of energy subbands, whereas the valence band in the source is continuous. The discretization of conduction band reduces the BTBT drain-source current (I
_ds
) of LTFET. QCE also forces the lateral and parasitic component of BTBT to dominate for a significant portion of the gate-bias swing.