Comparative analysis of the performance of InAs lateral and vertical band-to-band tunneling transistors

To summarize, we have shown that in comparison to a lateral device, a vertical structure may provide a larger ON current for similar OFF current. However, the subthreshold swing is degraded due to weaker gate control. We also show that there is a critical body thickness below which the vertical tunneling is greatly minimized. We find that significant vertical tunneling only starts at a large gate voltage and lateral tunneling almost acts as a leakage mechanism until this point. These facts indicate that (i) with a shallow pocket (ii) with right choice of doping densities in the source and pocket (iii) by effectively controlling the transport in lateral and vertical directions, e.g. by strain or by heterostructures, large ON currents with reasonable substreshold may be achieved.