50 nm metamorphic GaAs and InP HEMTs

This paper reviews some of the recent work at the Nanoelectronics Research Centre at the University of Glasgow on the optimisation of 50 nm metamorphic GaAs and InP HEMTs. Typical DC and RF figures of merit obtained from 50 nm metamorphic GaAs HEMTs include Idss of 800 mA/mm, gm of 1100 mS/mm, threshold voltage standard deviation of 5 mV across a 25 mm × 25 mm area, fT of 440 GHz and fmax of 400 GHz, all at a drain bias of 1.0 V. To our knowledge, these are the highest operating frequency GaAs-based transistors to date. At Vd = 0.8 V and Vg = − 0.6 V, a NFmin and Gass of 0.7 dB and 13 dB respectively at 26 GHz have been demonstrated.For similar geometry InP HEMTs, DC and RF figures of merit are the following: Idss of 900 mA/mm, gm of 1600 mS/mm, fT of 550 GHz, fmax of 440 GHz, and NFmin and Gass of 0.9 dB and 14 dB respectively at 26 GHz. The highest performance 50 nm HEMTs reported to date. Using these technologies, single stage MMMICs with gain of at least 7 dB and a return loss of better than − 5 dB across a 24 GHz bandwidth from 71 GHz to 95 GHz have been realised. Noise figure of 2.5 dB and associated gain of 7.3 dB at 90 GHz have been achieved with a DC power consumption of 20 mW.