Double-masking technique for increasing fabrication yield in superconducting electronics

摘要: A new technique is presented for improving the microfabrication yield of Josephson junctions in superconducting integrated circuits. This based on use a double-layer lithographic mask partial anodization side-walls and base electrode junctions. The top layer resist material, bottom dielectric material chosen so as to a) maximize adhesion between underlying layer, b) be etch-compatible with c) insoluble processing chemistries. In preferred embodiment invention, superconductor niobium, this silicon dioxide, conventional photoresist or electron-beam resist. combination results substantial increase fabrication high-density circuits due junction uniformity reduction defect density. An additional improvement over prior art involves replacement wet-etch step dry etch more compatible microlithography.