Tunnel junction type josephson element and manufacture thereof

Abstract

Abstract PURPOSE:To eliminate the breakdown of an insulating film by a temperature cycle between a room temperature and a cryogenic temperature by reducing the difference of the thermal expansion coefficient of component metal particles of a thin superconductive film and an insulating film. CONSTITUTION:A thin superconductive film 15 which is formed of a mixture 14 of ultrafine lead particles 12 and ultrafine dioxidized silicon or silicon particles 13 is formed on an insulating substrate 11 made of silicon. Then, an insulating film 16 of lead oxide is formed on a region faced with the film 15 on the surface of the particles 12 at the surface side of the film 15. Subsequently, a thin superconductive film 20 made of a mixture 19 of ultrafine lead particles 17 and ultrafine dioxidized silicon or silicon particles 18 for covering the film 16 is formed on the film 15. Since the thermal expansion coefficients of the particles 12, 17 and 13 are respectively 30X10<6>/ deg.C and 2.5X10<6>/ deg.C, while the film 16 has 10X10<6>/ deg.C, the difference of the thermal expansion coefficient between the films 15 and 20 becomes small.

Inventors

• 👤 Takashi Inukai
• 👤 犬飼　隆
• 👤 Yoichi Enomoto
• 👤 陽一 榎本
• 👤 Toshiaki Murakami
• 👤 敏明 村上

Bibliographic Details