Cryogenic InGaAs HEMTs with Reduced On-Resistance using Strained Ohmic Contacts

We present InGaAs HEMTs with optimized cryogenic Ohmic contacts, for low-power qubit readout. We utilize tensile strained contact metals to reduce the barrier resistance, which is a major fraction of RSD, leading to ~50% reduction of RSD at low temperature. At 4 K, a ~50% lower RON is shown with tensile strained contacts and demonstrated contact resistance of 30.6 O • µm and RON of 290 O • µm at LG = 130 nm, among the lowest reported values for cryogenic HEMT technology. As a result, the InGaAs HEMTs exhibit a record-low value of the noise indication factorv IDS/gm = 0.18v V · mm/S, at the lowest DC power consumption reported in cryogenic low-noise HEMTs. RF measurements and small-signal model parameters are also presented. The results demonstrate that contact engineering is key to enhance the performance of cryogenic InGaAs HEMTs for future large-scale quantum computing applications.