  Using a fully automated cryogenic wafer prober, we measured superconductor
fabrication process control monitors and simple integrated circuits on 200 mm
wafers at 4.4 K, including SQIF-based magnetic field sensors, SQUID-based
circuits for measuring inductors, Nb/Al-AlOx/Nb Josephson junctions, test
structures for measuring critical current of superconducting wires and vias,
resistors, etc., to demonstrate the feasibility of using the system for
characterizing niobium superconducting devices and integrated circuits on a
wafer scale. Data on the wafer-scale distributions of the residual magnetic
field, junction tunnel resistance, energy gap, inductance of multiple Nb
layers, critical currents of interlayer vias are presented. Comparison with
existing models is made. The wafers were fabricated in the SFQ5ee process, the
fully planarized process with eight niobium layers and a layer of kinetic
inductors, developed for superconductor electronics at MIT Lincoln Laboratory.
The cryogenic wafer prober was developed at HPD/ FormFactor, Inc.
