[20p-W834-1~12] 11.5 Junction and circuit fabrication process, digital applications

△ [20p-W834-5] Study on Subgap Current in Nb/Al/AlO_x/Al/Nb Junctions

〇(M2)mizuki ikeya¹, takeshi sakai¹, takafumi kojima², takashi noguchi² (1.The Univ. Electro-Communications, 2.National Astronomical Observatory of Japan)

Keywords:SIS Junction,leakage current

High current density SIS mixers are most important components for an Ultra-wideband receiver in radio astronomy. Such mixers need SIS junctions with a very thin Insulator. However, in the case of conventional Nb/Al/AlO_x/Nb junctions, it is likely that leakage current increase with a very thin insulator. In this research, adding an extra Al layer, reduction of leakage current is expected. We obtained studies with respect to these junctions by calculation of IV character, observation by TEM, EDX analysis.