On-wafer high frequency noise power measurements under cryogenic conditions: a new de-embedding approach

This work consist in an accurate estimation of the available noise power of the accesses of our cryogenic probe station in order to estimate precisely the on wafer Noise Figure or Noise Power of devices under cryogenic temperatures (until 78K). These available noise powers are estimated using a transmission line approach based on a consequent RLCG network associated to the temperatures distributions of the electrical accesses of the bench. These temperatures distributions along probes and cables during a measurement performed at low temperatures are obtained using a 3-D thermal modeling software (ANSYS) associated to thermal measurements and are carefully taking into account in our distribution network. This modeling has been validate by the measurement of the available noise power of a 50 Ω on-wafer resistance placed at several low temperatures (78K, 123K and 173K). This de-embedding approach is finally applied to the noise characterization of 100 nm gate??s length MM-HEMT at 77K and 173K.