STABILITY OF HIGH-QUALITY NB/ALOX/NB JOSEPHSON-JUNCTIONS
STABILITY OF HIGH-QUALITY NB/ALOX/NB JOSEPHSON-JUNCTIONS
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DOI：
10.1063/1.349496
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发表时间：
1991-08-01
影响因子：
3.2
通讯作者：
HASUO, S
中科院分区：
文献类型：
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作者：
MOROHASHI, S;YOSHIDA, A;HASUO, S
我们制备的Nb/AlO（x）/NbJosephson结显示出良好的I-V特性（在1500 A/cm ~ 2的临界电流密度下V（m）= 80 mV）。 我们将这些特性归因于清晰的结界面，通过沉积Nb和Al层以最小的热和物理损伤获得。 我们制造了10（4）结串联连接在一个单一的芯片上的面积为5 × 5平方毫米。 每个结点为10 × 10-mu-2。 这些结具有优异的均匀临界电流，没有失败，并且在室温下储存4年后没有变化。 这些结果表明，Nb/AlO（x）/Nb结在约瑟夫森大规模集成电路中具有良好的应用前景。 然而，如果Al和Al氧化物层用于实际的大规模集成电路中，其中包含多于10（5）个结，则可能进一步需要改善Al和Al氧化物层的均匀性。 磁通阱对电流均匀性的影响和退火引起的I-V特性的恶化对于大规模集成可能是至关重要的。
We fabricated Nb/AlO(x)/Nb Josephson junctions which showed excellent I-V characteristics (V(m) = 80 mV at the critical-current density of 1500 A/cm2). We attribute these characteristics to the clear junction interface, obtained by depositing Nb and Al layers with a minimum of thermal and physical damage. We fabricated 10(4) junctions connected in series on a single chip with an area of 5 x 5 mm2. Each junction is 10 x 10-mu-2. These junctions have excellent uniform critical currents, have not failed, and have not changed after room-temperature storage for 4 years. These results indicate that Nb/AlO(x)/Nb junctions are excellent for use in Josephson LSI circuits. However, it may be further necessary to improve the uniformity of Al and Al-oxide layers if they are used in an actual large-scale integrated circuit, where more than 10(5) junctions are contained. The influence of the flux trap on current uniformity and deterioration of the I-V characteristics by annealing may be critical for large-scale integration.