Fabrication of Sub-Micrometer SIS Junctions for Radio Astronomy

• Published in: IEEE transactions on applied superconductivity Vol. 17; no. 2; pp. 191 - 193
• Main Authors: Krebs, N., Barbier, A., Billon-Pierron, D., Halleguen, S., Schicke, M., Schuster, K.F.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01-06-2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Chemical products; Circuit properties; Compound structure devices; Contact; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Etching; Exact sciences and technology; Fabrication; Inductively coupled plasma; Lithography; Microelectronic fabrication (materials and surfaces technology); Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Millimeter wave mixers; Niobium; Plasma applications; Plasma chemistry; Plasma devices; Production; Radio astronomy; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Signal convertors; Silicon dioxide; Sputter etching; superconducting device fabrication; Superconductivity; thin films; High resolution; Electron beam lithography; Microwave; Superconductor device; Chemical etching; Sputter coating; Thin film; thin films; Millimetric wave; Microelectronic fabrication; Engraving; Inductively coupled plasma; Radio astronomy; SIS junctions; Millimeter wave mixers; Manufacturing process; Spin-on coatings; superconducting device fabrication; Chemical mechanical polishing
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2007.898717

We present a new fabrication scheme for high quality Nb-AlO x -Nb junctions as used for mm-wave mixers in radio astronomy. The key features of the fabrication process are high-resolution e-beam lithography for junction and contact definition as well as highly selective Niobium and SiO 2 inductively coupled plasma etching. Chemical-mechanical polishing, which is difficult to control for low volume production is not required. We further show that a new type of spin-on glass can be used as a reliable replacement for sputtered SiO 2 . We present yield and parameter scattering of these devices.