应用于低功耗超导电路的Nb基Josephson结和SQUID的制备与测量(英文)  

FABRICATION AND MEASUREMENT OF Nb-BASED JOSEPHSON JUNCTION AND SQUID FOR LOW-POWER SUPERCONDUCTING CIRCUITS APPLICATION

作　　者：李浩[1] 李刚[1] 刘建设[1] 李铁夫[1] 陈炜[1] 

机构地区：[1]清华大学信息科学与技术国家实验室(筹),微纳电子学系,微电子学研究所,清华大学,北京100084

出　　处：《低温物理学报》2014年第3期161-166,共6页Low Temperature Physical Letters

基　　金：supported by the State Key Program for Basic Research of China(Grant No.2011CBA00304);the Chinese national science foundation(Grant Nos.60836001,11273023);the Tsinghua National Laboratory for Information Science and Technology(TNLIST)Cross-discipline Foundation~~

摘　　要：为了突破传统微电子芯片的散热限制和克服超级计算机运算能耗高的困难,低功耗电路已经成为信息计算领域研究的热点问题.近来,Nb基超导数字电路在低功耗电路中显现出比其它方案更有优势的前景.Josephson结的质量在超导数字电路的动态功耗中起着关键的作用.我们采用双层正胶光刻和NR9-3000PY负胶光刻,实现了适用于Nb基Josephson器件的自对准剥离工艺.性能稳定的Josephson结和直流超导量子干涉仪DC-SQUID被制备出来,在不同温度下进行了电学性能测试.不同面积的欠阻尼结具有一致的临界电流密度Jc,在2.54K时约400A/cm2.通过片上施加控制电流的方式,观测了DC-SQUID零电压态跳变电流随磁场的调制效应.Low-power circuits have been a main research issue in the field of information technology for solutions to the engineering limit of heat removal of micro-chip and the problem of high energy consumption of next generation supercomputers. Recently, Nb-based superconducting digital circuits have been demonstrated very promising results. The quality of the Josephson junctions plays an important role in determining dynamic consumption of these circuits. We implemented self-aligned lift-off process for fabricating Nb-based Josephson circuits, by photo- lithography using twoqayer positive resist and NR9-3000PY negative resist. High quality Josephson junctions and SQUID have been made. Underdamped junctions with different areas showed uniform critical current density Jc, about 400 A/cm^2 at 2. 54 K. Experiments on switching current of DC-SQUID based on unshunted Josephson junction periodically modulated by on-chip local magnetic field have been carried out.

关 键 词：低功耗超导电路 Nb基Josephson结 DC-SQUD 自对准剥离工艺 

分 类 号：TN405[电子电信—微电子学与固体电子学]