Fabrication of high-quality submicron Nb/Al-AlOx/Nb tunnel junctions

• 来源期刊: 中国物理B(英文版)
• 关键词: Nb junctions fabrication superconducting qubit macroscopic quantum phenomena
• 年，卷（期）: 2008,（8）
• 页码范围: 3083-3086
• 页数: 4页
• 语种: 英文

摘要

Nb/Al-AlOx/Nb tunnel junctions are often used in the studies of macroscopic quantum phenomena and supercon-ducting qubit applications of the Josepheon devices. In this work, we describe a convenient and reliable process using electron beam lithography for the fabrication of high-quality, submicron-sized Nb/Al-AlOx/Nb Josephson junctions.The technique follows the well-known selective Nb etching process and produces high-quality junctions with Vm=100 mV at 2.3 K for the typical critical current density of 2.2 kA/cm2, which can be adjusted by controlling the oxygen pressure and oxidation time during the formation of the tunnelling barrier. We present the results of the temperature depen-dence of the sub-gap current and in-plane magnetic-field dependence of the critical current, and compare them with the theoretical predictions.