Development of NbTiN constriction junctions and superconducting quantum interference devices

Superconducting Quantum Interference Devices (SQUIDs) have become a leading tool for magnetometry with a wide range of applications. In this work, we investigate the properties of NbTiN SQUIDs created with a patterned constriction junction. The NbTiN film was grown through reactive sputtering, and then patterned using e-beam lithography and ion milling. SQUIDs were fabricated with constrictions as narrow as 50nm across, and loop areas of approximately 1μm². At 250mK, field dependent voltage oscillations were observed up to .3T, with an effective area consistent with the physical dimensions of the device.