Scalability of sub-100 nm thin-channel InAs PHEMTs

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 t<inf>ch</inf> = 10 nm, together with reference In<inf>0.7</inf>Ga<inf>0.3</inf>As PHEMTs with t<inf>ch</inf> = 13 nm. In comparison with reference In<inf>0.7</inf>Ga<inf>0.3</inf>As ones, InAs PHEMTs with t<inf>ch</inf> = 10 nm exhibit excellent electrostatic integrity of the device down to L<inf>g</inf> = 30 nm regime, such as subthreshold swing (S=75 mV/dec), DIBL = 84 mV/V and g<inf>m_max</inf> = 1.9 mS/mm at V<inf>DS</inf> = 0.5 V. Besides, InAs PHEMTs with L<inf>g</inf> = 30 nm show outstanding f<inf>T</inf> = 600 GHz and f<inf>max</inf> = 490 GHz at V<inf>DS</inf> = 0.5 V. More importantly, InAs PHEMTs exhibit a far better scaling behaviors, down to L<inf>g</inf> = 30 nm regimes. Indeed, InAs is a promising choice of the channel material for future THz and logic applications.