Vertical nanowire InGaAs MOSFETs fabricated by a top-down approach

Vertical In_0.53Ga_0.47As Gate-all around (GAA) nanowire (NW) MOSFETs fabricated by a top-down approach are demonstrated experimentally for the first time. The fabrication process features a new III-V dry etch process capable of sub-20 nm diameter NWs with an aspect ratio greater than 10. It also includes a digital etch technique to controllably reduce nanowire diameter and remove dry etch damage. With a channel length L_ch=80 nm and EOT=2.2 nm, we obtain a transconductance of 730 μS/μm at 0.5 V in a 50 nm diameter NW MOSFET. The digital etch increases the transconductance by 20% and improves the subthreshold characteristics of the devices. In terms of balance of transport and short-channel effects, our MOSFETs match the best vertical nanowire devices fabricated by bottom-up techniques.