MIS-nano-structure creation by the ion bombardment of HTSC-surfaces

A new way of controlled fabrication of "metal/insulator/superconductor" (MIS) structures with nano- and subnanometer thickness of layers and interfaces is suggested. The way is based on the effect of ion-induced self-organizing restructuring of the near surface region of high temperature superconductors (HTSC). The chemical bond breaking of metal atoms with oxygen stimulated by the bombarding ions is the first stage of the effect. Then the metal atoms diffuse to the surface and form a metallic segregate in the form of a film or a cluster ensemble depending on the ion energy and irradiation dose. The irradiated region loses its superconductivity and is transformed into insulator. The thickness of the dielectric layer is determined by the penetration depth of ions which can be regulated by variation of their energy. The processes pointed out and the properties of the created structures have been studied using electron spectroscopy. As compared to the known structures, the discovered ones are characterized by qualitatively thinner layers and interfaces.