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_ch = 10 nm, together with reference In_0.7Ga_0.3As PHEMTs with t_ch = 13 nm. In comparison with reference In_0.7Ga_0.3As ones, InAs PHEMTs with t_ch = 10 nm exhibit excellent electrostatic integrity of the device down to L_g = 30 nm regime, such as subthreshold swing (S=75 mV/dec), DIBL = 84 mV/V and g_{m_max} = 1.9 mS/mm at V_DS = 0.5 V. Besides, InAs PHEMTs with L_g = 30 nm show outstanding f_T = 600 GHz and f_max = 490 GHz at V_DS = 0.5 V. More importantly, InAs PHEMTs exhibit a far better scaling behaviors, down to L_g = 30 nm regimes. Indeed, InAs is a promising choice of the channel material for future THz and logic applications.