Self‐aligned contact process for Nb/Al‐AlOx/Nb Josephson junctions
Self‐aligned contact process for Nb/Al‐AlOx/Nb Josephson junctions
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Nb/Al-AlOx/Nb 约瑟夫森结的自对准接触工艺
DOI：
10.1063/1.96573
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发表时间：
1986
影响因子：
4
通讯作者：
T. Yamaoka
中科院分区：
文献类型：
--
作者：
S. Morohashi;S. Hasuo;T. Yamaoka
高质量的Nb/Al-AlOx/Nb约瑟夫森结已经通过称为自对准接触工艺的新工艺制造。在通过反应离子蚀刻（RIE）技术限定结区域之后，对暴露的Nb层和结边缘进行阳极氧化以防止电短路，并且沉积Al膜作为蚀刻停止层。在通过RIE形成基极图案之后，沉积绝缘层。由于淀积的Al膜，用于连接对电极和布线层的具有结直径的接触孔可以不对准地制造。通过该工艺制造的结表现出优异的电流-电压特性（在临界电流密度jJ =1.8 kA/cm 2时Vm =70 mV，在jJ =20 kA/cm 2时Vm =11 mV）。
High quality Nb/Al‐AlOx/Nb Josephson junctions have been fabricated by a novel process named the self‐aligned contact process. After the definition of the junction area by a reactive ion etching (RIE) technique, the exposed Nb layer and the junction edge are anodized to protect against electrical shorts and an Al film is deposited as the etching stopper layer. After base electrode patterning by RIE, an insulation layer is deposited. The contact hole, with the diameter of the junction, for connecting a counter electrode and a wiring layer, can be made without registration because of the deposited Al film. The junctions fabricated by this process have exhibited excellent current‐voltage characteristics (Vm =70 mV at the critical current density jJ =1.8 kA/cm2, Vm =11 mV at jJ =20 kA/cm2).