Optimization of fabrication processes for Nb, NbN, NbTiN films and high-quality tunnel junctions for terahertz receiving circuits.

This paper describes the optimization of existing technology for fabrication superconducting films and high-quality tunnel junctions on a magnetron sputtering facility. To expand frequency range to 1.1 THz obtain limiting parameters elements, regimes production Nb, NbN, NbTiN were optimized. These are used fabricate superconductor-insulator-superconductor Nb/Al--AlN/NbN junctions. Al required create receiving elements at frequencies above 700 GHz (the cutoff niobium); such structures being developed radio astronomy array receiver located in Atacama Pathfinder Experiment telescope. Keywords: superconductivity, junctions, sputtering, thin films.