Germanium-source tunnel field effect transistors with record high ION/IOFF

Tunnel field effect transistors (TFETs) with record high I_ON/I_OFF ratio (>10⁶) for low-voltage (0.5 V) operation are achieved by using germanium in the source region to achieve a small tunnel bandgap. The measured data are well explained by the theoretical band-to-band tunneling current model. Using the calibrated analytical model, the energy-delay performance of TFET-based technology is compared against that of conventional CMOS technology, at the 65 nm node. The TFET is projected to provide dramatic improvement in energy efficiency for performance in the range up to ~0.5 GHz.