Using a ferroelectric PbZrTiO3 gate stack, the range of the steep subthreshold swing in tunnel field-effect transistors was extended by 3.5 orders of magnitude demonstrating an improvement in the swing (by approximately double the slope). The drain conductance (gd) shows only 16% enhancement with large V DS (∼−1.5V) indicates internal voltage amplification with ferroelectric negative capacitance effect beneficial to small lateral drain-source bias voltages (−0.1 V). The concept of coupling the ferroelectric polarization is proposed. The power consumption is also discussed in low-power applications of steep subthreshold slope devices.
