Analysis of non-uniform hetero-gate-dielectric dual-material control gate TFET for suppressing ambipolar nature and improving radio-frequency performance

A tunnel field-effect transistor (TFET) is proposed by combining various advantages together, such as non-uniform gate-oxide layer, hetero-gate-dielectric (HGD), and dual-material control-gate (DMCG) technology. The effects of the length of non-uniform gate-oxide layer and dual-material control-gate on the on-state, off-state, and ambipolar currents are investigated. In addition, radio-frequency performance is studied in terms of gain bandwidth product, cut-off frequency, transit time, and transconductance frequency product. Moreover, the length of non-uniform gate-oxide layer and dual-material control-gate are optimized to improve the on-off current ratio and radio-frequency performances as well as the suppression of ambipolar current. All results demonstrate that the proposed device not only suppresses ambipolar current but also improves radio-frequency performance compared with the conventional DMCG TFET, which makes the proposed device a better application prospect in the advanced integrated circuits.