在氧化鈦緩衝層上蒸鍍釔鋇銅氧高溫超導薄膜之特性研究

Abstract

本論文敘述以脈衝雷射在鈦酸鍶基板及矽(100)基板上蒸鍍氮化鈦(TiN)薄膜之方法。以此法所得之TiN薄膜具有 (100) 晶向，且擁有平整的表面以及極佳之金屬性。我們嘗試在TiN 薄膜上蒸鍍YBCO超導薄膜，發現TiN(100) 在YBCO 成長的過程中會氧化成絕緣之TiO2(110)。此TiO2 薄膜可被利用作為一緩衝層，在矽基板上成長 YBCO 超導薄膜。如此得到之YBCO 超導薄膜，其臨界溫度可達80.6K。最後，我們比較以連續性脈衝雷射蒸鍍及選擇性磊晶成長所得到之YBCO/TiO2 多層薄膜結構，探討YBCO在不同方法所得到之TiO2上之超導性。

Titanium nitride thin films have been deposited on SrTiO3 and Si (100) substrates by pulsed laser deposition. The films were found to possess excellent electrical properties and the complete epitaxy. We have verified that the TiN (100) thin film would transform into TiO2 (110) in fabricating the YBCO/TiN/substrate multilayer structure and made it the YBCO/TiO2/substrate structure in reality. We have utilized this TiO2 (110) thin film as a buffer layer for deposition of the superconducting YBCO thin film on Si substrate. Zero-resistance temperature of 80.6 K was measured. In addition, we put forth a large contradiction between the in-situ pulsed laser deposition and selective epitaxial growth of YBCO/TiO2/substrate structures.