Fabrication of Nb/Al(AlOx)/Nb DC SQUID by focused ion beam sculpturing


  D. Yuvaraj  ,  Gil Bachar  ,  Oren Suchoi  ,  Oleg Shtempluck  ,  Eyal Buks  
Technion Israel Institute of Technology

Highly reproducible Nb/Al(AlOx)/Nb Josephson junction based direct current superconducting quantum interference devices (DC SQUID) were fabricated by three dimensional etching using focused ion beam. Hysteretic and non-hysteretic DC SQUID with critical current ranging from 25 to 1100 µA were fabricated by varying the Al barrier and oxygen exposure time. The fabricated DC SQUIDs have shown periodic flux dependence with high modulation factor reaching a value of 92% at 4.2K.