A Novel Metamorphic High Electron Mobility Transistors with (In(x)Ga(1-x)As)(m)/(InAs)(n) Superlattice Channel Layer for Millimeter-Wave Applications

Abstract

High performance MHEMTs using (In(x)Ga(1-x)As)(m)/(InAs)(n) superlattice structure as a channel layer have been fabricated successfully. These HEMTs with 80 nm gate length exhibit high drain current density of 392 mA/mm at drain bias 1.0 V and transconductance of 991 mS/mm at drain bias 1.2 V. Comparison with regular In(x)Ga(1-x)As channel, the superlattice channel HEMTs show an outstanding performance because of high electron mobility, and better carrier confinement in the (In(x)Ga(1-x)As)(m)/(InAs)(n) channel layer. The current gain cutoff frequency (f(T)) and maximum oscillation frequency (f(max)) were extracted to be 304 GHz and 162 GHz, respectively. The device demonstrated a 0.75 dB noise figure with an associated gain 9.6 dB at 16 GHz. The excellent device performance shows that the superlattice channel can be practically used for high-frequency and millimeter-wave application.