Silicon substrate having an epitaxial superconducting layer thereon and method of making same

US5173474A · kind A · utility

Assignees

• Xerox Corporation · US
• PRESIDENT AND BOARD OF TRUSTEES OF SANTA CLARA COLLEGE · US
• Board of Trustees of the Leland Stanford Junior University · US

Inventors

• George A. N. Connell · Cupertino, US
• David B. Fenner · Westford, US
• James B. Boyce · Los Altos, US
• David K. Fork · Mountain View, US

Key dates

• Filing date: Mar 11, 1991
• Grant date: Dec 22, 1992
• Expiry date: Mar 11, 2011

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S505/734
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

An HTSC material epitaxially deposited on a YSZ buffer layer on a surface of a monocrystalline silicon substrate has a zero resistance transition temperature of at least 85.degree. K., a transition width (10-90%) of no more than 1.0.degree. K., a resistivity at 300.degree. K. of no more than 300 micro-ohms-centimeter and a resistivity ratio (at 300.degree. K./100.degree. K.) of 3.0.+-.0.2. The surface of the silicon substrate is cleaned using a spin-etch process to produce an atomically clean surface terminated with an atomic layer of an element such as hydrogen with does not react with silicon. The substrate can be moved to a deposition chamber without contamination. The hydrogen is evaporated in the chamber, and then YSZ is epitaxially deposited preferably by laser ablation. Thereafter, the HTSC material, such as YBCO, is epitaxially deposited preferably by laser ablation. The structure is then cooled in an atmosphere of oxygen.