Terahertz In0.8Ga0.2As quantum-well HEMTs toward 6G applications

초록

We present the systematic analysis of Lg scaling behavior and the impact of the side-recess spacing (L-{side}) on DC and high-frequency characteristics of In0.8 Ga0.2 As QW HEMTs with Lg from 10 mu mathrm{m} to 20 nm, aiming to explore the scaling limit of fmax and thereby demonstrate THz devices. The fabricated L-{g}= 20 nm device with L-{side} = 150 nm exhibited {DIBL}=60 mV/V and f-{T}/ f-{max} quad =0.75 /1.1 THz, while the device showed with L-{side}=50 nm {DIBL}=110 mV/V and f-{T}/ f-{max}=0.72 /0.53. Strict control of short-channel effects from the viewpoint of DIBL was central to maximize the enhancement of fmax as Lg scaled down aggressively. Moreover, we explained the physical mechanism of the decrease in fmax for HEMTs with Lg scaled down to sub-50 nm. The results in this work represent the best balance of fT and fmax in any transistor technology and the highest fT in any FET technology. © 2022 IEEE.