Etching Behavior and Damage Rejuvenation of Top Electrode and Bi_3.15Nd_0.85Ti₃O₁₂ Films Applied in Ferroelectric Random Access Memory Devices

Abstract

We report on high-T c ramp-edge junctions and dc superconducting quantum interference devices (SQUIDs) with a Ga-doped YBCO barrier. The interface resistances of the junctions were drastically reduced by in situ RF plasma cleaning treatment. The plasma gas and pressure were Ar, O 2 and 50-100 mTorr, respectively. The lattice images of the interface of the junctions were analysed by high-resolution transmission electron microscopy. The effects of RF plasma treatment and barrier layer material on the junction properties were systematically investigated. These junctions were fabricated uniformly and reproducibly, and they displayed clear RSJ-like I -V characteristics with high values of I c R n products at 65 K. Dc SQUIDs fabricated with the Ga-doped YBCO junctions exhibited excellent voltage modulations in response to applied fields at 65 K.