Carbon Nanotube Radiofrequency Transistors With fT/fMAX of 376/318 GHz

Aligned carbon nanotube (ACNT) array was regarded as an excellent channel material to build radio frequency (RF) field-effect transistors (FETs) with an ultra-high frequency of up to THz regime due to the electrical performance advantages of high carrier mobility and saturation velocity, as well as low intrinsic capacitance. However, ACNT FET with extrinsic current-gain (f(T)) and maximum oscillation (f(MAX)) cut-off frequencies of simultaneously over 300 GHz has not yet been reported. In this letter, we report ACNT based RF FETs with record high dc performance of on-state current about 2.2 mA/mu m and peak transconductance about 1.9 mS/mu m at a bias of -1 V. Especially, the ACNT based FETs show f(T) and f(MAX) of up to 376 and 318 GHz by scaling down gate length to 35 nm, indicating the actual RF performance into the THz regime. Radio-frequency amplifiers that exhibit power gain of over 24 dB operating in K band is also demonstrated.

Automated summary

Aligned carbon nanotube (ACNT) array is an excellent channel material for building radio frequency (RF) field-effect transistors (FETs) with an ultra-high frequency. In this study, ACNT based RF FETs with record high dc performance and f(T) and f(MAX) frequencies up to 376 GHz and 318 GHz were demonstrated, indicating their potential for actual RF performance in the THz regime.