Formation of oxide superconductor junction

Abstract

Abstract PURPOSE:To form an oxide superconductor junction with excellent reproducibility and controllability by a method wherein in a superconducting junction using a high Tc oxide superconductor as a material for an electrode, an extremely thin denatured layer formed by artificially processing the surface of a substratum electrode is used as a tunnel barrier. CONSTITUTION:A high Tc oxide superconducting material selected from (M11-XM 2X)YCuOZ(where 0<x<1, 1<=y<=2, 2<=z<=4; M1 is a group III metal; M2 is a group II metal) is used as a substratum electrode 2 and a counter electrode 4; an extremely thin denatured layer which has been formed by artificially processing the surface of the substratum electrode is used as a tunnel barrier 3. If the surface of the substratum electrode is etched by using a mixed gas rf plasma containing oxygen, a transition layer does not exist on the clean surface and this surface displays good superconductivity. Then, the tunnel barrier is obtained in the case where the substratum electrode is processed by the rf plasma in a gas where F, Cl and Br are substituted for N2 or H in CnHZn+Z and CnHZn+Z appropriately or in PCl3, BCl3 and SF3 or a gas where an inert gas is mixed with these. It is possible to control a film thickness and the quality of the tunnel barrier in accordance with a composition of the mixed gas, a gas pressure, a bias voltage and a processing duration.

Inventors

• 👤 Yujiro Kato
• 👤 加藤　雄二郎
• 👤 Hidefumi Asano
• 👤 秀文 浅野
• 👤 Keiichi Tanabe
• 👤 圭一 田辺
• 👤 Shugo Kubo
• 👤 衆伍 久保
• 👤 Osamu Michigami
• 👤 修 道上

Bibliographic Details