Scaled-footprint ultra-low power cryogenic InGaAs/InP HEMTs with record-high combination of low-noise and high-frequency performance

In this work we demonstrate cryogenic $In_x Ga_{1-x} As / InP$ HEMTs with highly scaled gate footprints, down to $380\times40 nm^2$ for a single gate finger, and investigate the impact of footprint scaling on device performance. The $80\%$ In channel devices show $f_T = 622\ GHz$ and $f_{MAX} = 733\ GHz$ together with a noise indication factor $√(I\_D)/gm = 0.17 √(V\times mm/S)$ at $4\ K$, which is a record-high combination of high-frequency and low-noise performance. The performance is enabled by heterostructure engineering, resulting in ultra-low $R_{ON} = 250\ Ω \times µm$ together with a minimum subthreshold swing $SS < 10 mV/decade$. These results show that cryogenic III-V HEMT technology can provide excellent performance at scaled footprints for readout in future high-density quantum systems.