Co-fabrication of planar Gunn diode and HEMT on InP substrate

We present the co-fabrication of planar Gunn diodes and high electron mobility transistors (HEMTs) on an Indium Phosphide (InP) substrate for the first time. Electron beam lithography (EBL) has been used extensively for the complete fabrication procedure and a 70 nm T-gate technology was incorporated for the enhancement of the small-signal characteristics of the HEMT. Diodes with anode-to-cathode separation (Lac) down to 1 μm and 120 μm width where shown to oscillate up to 204 GHz. The transistor presents a cut-off frequency (fT) of 220 GHz, with power gain up to 330 GHz (f<sub>max</sub>). The integration of the two devices creates the potential for the realisation of high-power, high-frequency MMIC Gunn oscillators, circuits and systems