Edge junction SQUIDs and multilayers using high T_c superconductors

Multilayer edge junction SQUIDs have been fabricated using epitaxial, laserablated films of YBaCuO for both elctrodes. The barrier region is defined by a low voltage plasma oxy-flouridation step. The SQUIDs are patterned using photolithography and ion milling and devices have been made with linewidths as small as 2μm. The edge junction SQUIDs have exhibited very low magnetic hysteresis values of ≤ 50 ppm. © 1990.