Future prospects for tunneling transistors
This article introduces the operating principles and device/material technologies of tunneling FETs (TFET), which could be one of the promising steep slope transistors to realize a steep change in the drive current under low voltage changes. TFETs are composed of reverse-biased pn junctions in semiconductors with MOS structures, allowing the flow of tunneling currents, which can be controlled by a gate voltage. Since the current switching is controlled by the overlap of density-of-states between the conduction and the valence band, a steeper slope than in MOSFETs is expected. On the other hand, low drive current based on a tunneling mechanism is a critical issue. A variety of engineering approaches to improve the electrical characteristics of TFETs and their future prospects are described.
- 1 School of Engineering, The University of Tokyo