Single-charge devices with ultrasmall Nb/AlOx/Nb trilayer Josephson junctions
Single-charge devices with ultrasmall Nb/AlOx/Nb trilayer Josephson junctions
复制标题
具有超小型 Nb/AlOx/Nb 三层约瑟夫森结的单电荷器件
DOI：
10.1063/1.1855399
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发表时间：
2004
影响因子：
3.2
通讯作者：
J. Niemeyer
中科院分区：
文献类型：
--
作者：
R. Dolata;H. Scherer;A. Zorin;J. Niemeyer
用标准的Nb/AlOx/Nb三层膜制作了约瑟夫森结晶体管和50结阵列，其线性结尺寸从200 nm到70 nm。制作过程包括电子束光刻、干法刻蚀、阳极氧化和化学机械抛光平坦化。样品在25mK以下的温度下进行了表征。总的来说，所有的结都是高质量的，它们的I-U特性显示出低的漏电流和高的超导能隙值Δ≈1.35 meV。由于结之间偏置电压的重新分布，晶体管和阵列的特性在与库珀对、准粒子和它们的组合的隧穿有关的子隙区域中表现出一些特征。晶体管样品的总岛电容从1.5fF到4fF不等，具体取决于结的大小。由线性尺寸小于100 nm×100 nm的结制成的器件在超导和非超导材料中都表现出显著的单电子行为。
Josephson junction transistors and 50-junction arrays with linear junction dimensions from 200nm down to 70nm were fabricated from standard Nb∕AlOx∕Nb trilayers. The fabrication process includes electron beam lithography, dry etching, anodization, and planarization by chemical-mechanical polishing. The samples were characterized at temperatures down to 25mK. In general, all junctions are of high quality and their I-U characteristics show low leakage currents and high superconducting energy gap values of Δ≈1.35meV. The characteristics of the transistors and arrays exhibit some features in the subgap area, associated with tunneling of Cooper pairs, quasiparticles, and their combinations due to the redistribution of the bias voltage between the junctions. Total island capacitances of the transistor samples ranged from 1.5fF to 4fF, depending on the junction sizes. Devices made of junctions with linear dimensions below 100nm×100nm demonstrate a remarkable single-electron behavior in both superconducting and n...