- Method for in-situ fabrication of intrinsic-Josephson-junction mesa of high temperature superconducting single crystals and ion-beam etching apparatus used therein

摘要

PURPOSE: A method for fabricating an intrinsic Josephson junction platform is provided to accurately control the number of intrinsic Josephson junctions formed in a high-temperature superconductor platform structure by etching a high-temperature superconductor single crystal in a condition of low vacuum and low temperature and by performing an in-situ process for measuring the electrical characteristic of the intrinsic Josephson junction in the platform structure. CONSTITUTION: The c-axis direction of a unit cell is made vertical to a substrate to fix a high temperature superconductor single crystal(14) to the substrate. The ab surface of the single crystal is exposed. A conductive metal thin film(16) is deposited on the ab surface of the single crystal. A plurality of platform structures are formed in which the metal thin film is stacked on the single crystal. The gap between the plurality of platform structures is filled to insulate the side surface of the platform structure and the exposed surface of the single crystal and to form an insulation layer pattern(18) for separating the metal thin films on the plurality of platform structure. A plurality of mutually-separated electrode patterns are formed on the separated metal thin film. The electrode pattern and the metal thin film under the electrode pattern that are stacked on at least one platform structure among the plurality of platform structures are etched and separated so that a curve of a voltage characteristic with respect to a transmission current on the platform to be measured can be obtained by a four terminal method.