Electrical characterizations of InGaAs nanowire-top-gate field-effect transistors by selective-area metal organic vapor phase epitaxy

Single InGaAs nanowire-top-gate metal-semiconductor field-effect transistors (MESFETs) were fabricated and characterized. Silicon-doped n-InGaAs nanowires (with a typical diameter of 100nm) were grown by catalyst-free selective-area metalorganic vapor-phase epitaxy (SA-MOVPE). The FETs of single nanowires on SiO2-coated Si substrates were fabricated by defining metal contacts at both ends of the nanowires and the metal top gate between contacts. According to the measurements of drain current-voltage and gate transfer characteristics, the top-gate MESFETs exhibited significant enhancements in device performance characteristics compared with FETs under back-gate operation; that is, a peak transconductance of 33 mS/mm and a current on-off ratio of 10(3) were obtained. A possibility for further improvements in FET characteristics was also considered.