Gated Hall effect measurements on selectively grown InGaAs nanowires

InGaAs nanowires is one of the promising material systems of replacing silicon in future CMOS transistors, due to its high electron mobility in combination with the excellent electrostatic control from the tri-gate geometry. In this article, we report on gated Hall measurements on single and multiple In_0.85Ga_0.15As nanowires, selectively grown in a Hall bridge geometry with nanowire widths down to 50 nm and thicknesses of 10 nm. The gated nanowires can be used as junctionless transistors, which allows for a simplified device processing as no regrowth of contact layer or ion implantation is needed, which is particularly beneficial as transistor dimensions are scaled down. The analysis shows that the InGaAs layer has a carrier concentration of above 10¹⁹ cm^-3, with a Hall carrier mobility of around 1000 cm² V^-1 s^-1. The gated Hall measurements reveal an increased carrier concentration as a function of applied gate voltage, with an increasing mobility for narrow nanowires but no significant effect on larger nanowires.