Scalability of sub-100 nm thin-channel InAs PHEMTs

Abstract

We have experimentally investigated the role of thinning down the channel thickness and using high InAs composition as a channel material, which aims to improve the electrostatic integrity of the device as well as high frequency characteristics of the device. To do so, we have fabricated InAs PHEMTs with tch = 10 nm, together with reference In0.7Ga0.3As PHEMTs with tch = 13 nm. In comparison with reference In0.7Ga0.3As ones, InAs PHEMTs with tch = 10 nm exhibit excellent electrostatic integrity of the device down to Lg = 30 nm regime, such as subthreshold swing (S=75 mV/dec), DIBL = 84 mV/V and gm_max = 1.9 mS/mm at VDS = 0.5 V. Besides, InAs PHEMTs with Lg = 30 nm show outstanding fT = 600 GHz and fmax = 490 GHz at VDS = 0.5 V. More importantly, InAs PHEMTs exhibit a far better scaling behaviors, down to Lg = 30 nm regimes. Indeed, InAs is a promising choice of the channel material for future THz and logic applications.