Numerical Investigations of Nanowire Gate-All-Around Negative Capacitance GaAs/InN Tunnel FET

Abstract

We demonstrated a nanowire gate-all-around (GAA) negative capacitance (NC) tunnel field-effect transistor (TFET) based on the GaAs/InN heterostructure using TCAD simulation. In the gate stacking, we proposed a tri-layer HfO2/TiO2/HfO2 as a high-K dielectric and hafnium zirconium oxide (HZO) as a ferroelectric (FE) layer. The proposed GAA-TFET overcomes the thermionic limitation (60 mV/decade) of conventional MOSFETs’ subthreshold swing (SS) thanks to its improved electrostatic control and quantum mechanical tunneling. Simultaneously, the NC state of ferroelectric materials improves TFET performance by exploiting differential amplification of the gate voltage under certain conditions. The most surprising discoveries of this device, which outperforms all previous results, are the very high $I_{ON}/I_{OFF}$ ratio on the order of 1011 and the enormous on-state current of 135 $\mu \text{A}$ . The incorporation of the NC effect with a 9 nm HZO results in the lowest SS of 20.56 mV/dec (52.38% lower than baseline TFET) and the highest voltage gain of 6.58. Furthermore, the output characteristics revealed a large transconductance ( $g_{m}$ ) of 7.87 mS (103 order higher than the baseline TFET), drain-induced barrier lowering (DIBL) of 9.7 mV, and a threshold voltage of 0.53 V (37.65% lower than baseline TFET), all of which are significant. Thus, all of the results indicate that the proposed device structure may lead to a new route for electronic devices, creating higher speed and lower power consumption.

Keywords

• BTBT
• gate-all-around structure
• heterojunction
• nanowire tunnel-FET
• negative capacitance