In0.7Ga0.3As/InAs/In0.7Ga0.3As composite-channel double-gate (DG)-HEMT devices for high-frequency applications

摘要

This paper reports the impact of barrier thickness TB and gate length L-g on the parameters of InAs quantum-well double-gate (DG) high-electron-mobility transistors (HEMTs) or DG-HEMT devices. It is shown that at drain-to-source voltage V-ds = 0.5 V, the In0.7Ga0.3As/InAs/In-0.7 Ga0.3As composite-channel DG-HEMTs with L-g = 50 nm and TB = 2 nm offer high positive threshold V-T = 0.26 V, record transconductance g(m) = 3.58 S/mm, with low short-channel effects (SCEs) such as drain-induced barrier lowering approximate to 58 mV/V, subthreshold slope approximate to 62 mV/dec, and an estimated logic gate-delay time of 0.77 ps along with high-frequency performance. This is the first report of 50 nm gate length and T-B = 2 nm In0.7Ga0.3As/InAs/In0.7Ga0.3 As DG-HEMTsachieving f(T) = 710 GHz and f(max) = 989 GHz at V-ds = 0.5 V. This is superior performance achieved by optimizing the device performance by introducing top and bottom gates, and reduced gate-to-channel distance with reduced barrier thickness TB. The present study clearly shows the great potential of InAs channel DG-HEMTs with reduced SCEs for low-loss, high-speed and high-frequency applications.