Influence of trap-assisted tunneling on Subthreshold Slope of Ge/Si heterojunction L-shaped TFETs

The influences of interface traps on the performance of Ge/Si heterojunction L-shaped tunneling field-effect transistors (L-TFETs) are investigated in terms of trap location, trap concentration, temperature, and source doping profile. Simulation results show that the traps at tunneling junction between source and vertical channel degrade subthreshold swing (SS) more severely than the traps at tunneling junction between source and horizontal channel. In addition, it also shows that a sub-thermal SS requires at least D
_it
≤ 10
¹⁰
cm
^-3
at Ge/Si interface and confirms that SS degradation caused by TAT and OFF-currents caused by Shockley-Read-Hall generation will increase with rising of temperature. Furthermore, the existence of gradient in doping profile with traps cannot be neglected for its degradation on SS of Ge/Si L-shaped TFET.