InAs/In(1-x)Ga(x)As Composite Channel High Electron Mobility Transistors for High Speed Applications

Abstract

80-nm InAs channel HEMTs with different lattice matched sub-channels, In(0.53)Ga(0.47)As and In(0.7)Ga(0.3)As, have been fabricated. The device with InAs/In(0.7)Ga(0.3)As composite channel exhibits high drain current density (1101 mA/mm), and high transconductance (1605 mS/mm) at drain bias V(DS) = 0.8 V. The high current gain cutoff frequency (f(t)) of 360 GHz and maximum oscillation frequency (f(max)) of 380 GHz of the device with InAs/In(0.7)Ga(0.3)As were obtained at V(DS) = 0.7 V in comparison to the InAs/In(0.53)Ga(0.47) As channel HEMTs with f(t) = 310 and f(max) = 330 GHz. This is due to the high electron mobility and electron confinement in the InAs/In(0.7)Ga(0.3)As channel. In addition, a low gate delay time 0.84 psec was obtained at V(DS) = 0.5 V. The excellent performance of the InAs channel HEMTs demonstrated in this study shows great potential for high speed and very low power logic applications with the optimal design of In(0.7)Ga(0.3)As/InAs/In(0.7)Ga(0.3)As composite channel.