Stability and uniformity of planar high temperature Josephson junctions fabricated using nanolithography and ion damage

• Published in: IEEE transactions on applied superconductivity Vol. 9; no. 2; pp. 3005 - 3007
• Main Authors: Katz, A.S., Woods, S.I., Dynes, R.C., Sun, A.G.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.06.1999; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Critical current; Damage; Devices; Direct current; Electron beam lithography; ELECTRONIC PRODUCTS; Electronics; ELEVATED TEMPERATURE; Exact sciences and technology; FABRICATION; ION IMPLANTATION; Josephson junctions; Lithography; MICROSTRUCTURES; Nanolithography; Nanostructure; Plasma temperature; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Space technology; Stability; Superconducting devices; Superconducting transition temperature; THIN FILMS; Variability; Yttrium barium copper oxide; YTTRIUM OXIDE; Critical current; Josephson junction; Electron beam lithography; Stability criterion; Planar device; Nanotechnology; High temperature superconductor; Room temperature; Uniformity; Thin film; Production process
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/77.783661

We have investigated the room temperature stability and the critical current uniformity of planar thin film YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// Josephson junctions. The junctions were fabricated using electron-beam lithography to define a stencil structure followed by ion damage from a conventional 200 keV ion implanter. Using this technique, we have fabricated junctions with weak link lengths of 20-100 nm that showed classical dc and ac Josephson effects at 77 K. By a suitable choice of damage and stencil width, these devices may be tuned to operate at any temperature between 1 K and the bulk transition temperature, and they may be placed anywhere on a wafer, providing a high degree of flexibility for circuit applications. Results obtained over several months showed a high level of room temperature stability, and the uniformity of the junctions was maintained.