$\hbox{In}_{0.7}\hbox{Ga}_{0.3}\hbox{As}$ Tunneling Field-Effect Transistors With an $I_{\rm on}$ of 50 $\mu\hbox{A}/\mu\hbox{m}$ and a Subthreshold Swing of 86 mV/dec Using $\hbox{HfO}_{2}$ Gate Oxide

Abstract

Vertical In_0.7Ga_0.3As tunneling field-effect transistors are demonstrated with a high on-current of 50 μA / μm (in comparison to reported values) and a minimum subthreshold swing (SS) of 86 mV/dec using atomic-layer-deposited HfO₂ gate oxide. The tunneling diodes exhibit the gate-bias-dependent Esaki diode behavior with a negative differential resistance under the forward diode bias at various temperatures, which confirms that the conduction mechanism is, indeed, band-to-band tunneling. The effects of equivalent oxide thickness scaling and various temperatures on the on-current and the SS are also investigated.