Fabrication of Self-Aligned Enhancement-Mode $ hbox{In}_{0.53}hbox{Ga}_{0.47}hbox{As}$ MOSFETs With $ hbox{TaN/HfO}_{2}hbox{/AlN}$ Gate Stack

摘要

In this letter, we report the fabrication and characterization of self-aligned inversion-type enhancement-mode $hbox{In}_{0.53}hbox{Ga}_{0.47}hbox{As}$ metal–oxide–semiconductor field-effect transistors (MOSFETs). The $ hbox{In}_{0.53}hbox{Ga}_{0.47}hbox{As}$ surface was passivated by atomic layer deposition of a 2.5-nm-thick AlN interfacial layer. $hbox{In}_{0.53}hbox{Ga}_{0.47}hbox{As}$ MOS capacitors showed an excellent frequency dispersion behavior. A maximum drive current of 18.5 $muhbox{A}/muhbox{m}$ was obtained at a gate overdrive of 2 V for a MOSFET device with a gate length of 20 $muhbox{m}$ . An $I_{rm ON}/I_{rm OFF}$ ratio of $hbox{10}^{4}$ , a positive threshold voltage of 0.15 V, and a subthreshold slope of $sim$165 mV/dec were extracted from the transfer characteristics. The interface-trap density is estimated to be $sim !! hbox{7}{-} hbox{8} timesbreak hbox{10}^{12} hbox{cm}^{-2} cdot hbox{eV}^{-1}$ from the subthreshold characteristics of the MOSFET.