High-performance indium arsenic (InAs) channel-based quantum well field-effect transistors (QWFETs) have been fabricated. A superior drain-source current density of 1015 mA/mm was achieved, with a high transconductance of 1900 mS/mm when the drain (V-DS) was biased at 0.5 V. The current gain cutoff frequency (f(T)) and maximum oscillation frequency (f(max)) were extracted to be 393 and 260 GHz, respectively. A very low gate delay of 0.54 ps was also achieved at a 0.5 V drain bias. Compared to a silicon n-channel metal-oxide semiconductor field-effect transistor, the QWFETs exhibited a better radio-frequency performance with lower dc power consumption, which indicates the great potential for high-speed and low-voltage digital applications. (C) 2008 The Electrochemical Society.