Dual source negative capacitance GaSb/InGaAsSb/InAs heterostructure based vertical TFET with steep subthreshold swing and high on-off current ratio

Abstract

Continuous downscaling of CMOS technology at the nanometer scale with conventional MOSFETs leads to short channel effects (SCE), increased subthreshold slope (SS), and leakage current, degrading the performance of ICs. We proposed a dual-source vertical tunnel field-effect transistor (TFET) with a steeper subthreshold swing (SS) and superior electrostatic control thanks to quantum mechanical band-to-band tunneling. We show that the use of GaSb/InGaAsSb/InAs heterostructure boosts the band-to-band tunneling rate in TFETs, resulting in higher on-state current. Incorporating the negative capacitance effect using ferroelectric materials further enhances the performance of the proposed device greatly. The lowest SS of 21.94 mV/dec and an on–off current ratio of 4.3267 × 1011 were obtained for dual source GaSb/InGaAsSb/InAs heterostructure based vertical TFET. The lowest subthreshold swing was found as 17.37 mV/dec after integrating Hf1–xZrxO2 ferroelectric material into the gate stack. The negative capacitance effect also increases the on-state current tenfold, resulting in an incredible ION/IOFF ratio of 1012. The suggested device focuses on low power consumption applications by assuring a very low leakage current and a reduced subthreshold swing.

Keywords

• Vertical tunnel FET
• Dual source
• Ferroelectric material
• Negative capacitance
• Heterojunction