Title :
Investigation of properties of stacked-type interface-treated Josephson junctions fabricated with PrGaO3 doping process
Author :
Yoshinaga, Y. ; Izawa, S. ; Wakita, K. ; Kito, T. ; Inoue, M. ; Fujimaki, A. ; Hayakawa, H.
Author_Institution :
Dept. of Quantum Eng., Nagoya Univ., Japan
fDate :
6/1/2003 12:00:00 AM
Abstract :
We have investigated how surface morphology of base YBa2Cu3O7-δ (YBCO) films affects the properties of the stacked-type interface-treated junctions (ITJ) with the PrGaO3 (PGO) doping process. In the ITJs, the junction barriers are formed by Ar ion milling and subsequent annealing, without depositing artificial barriers. The PGO doping process was carried out for eliminating excess currents of the junctions. Our results suggest that the YBCO films suitable for the junctions should consist of similar size grains, and do not contain any precipitates. Furthermore, the morphology should not be changed after the Ar ion milling. The nine junctions fabricated on such a film exhibit the averaged critical current density (Jc) on the chip of 9.0×103 A/cm2, the small 1σ spread of 5.6% in the Jc, and the averaged IcRn product on the chip of 1.5 mV with overdamped characteristics at 4.2 K.
Keywords :
Josephson effect; annealing; barium compounds; critical current density (superconductivity); grain size; high-temperature superconductors; praseodymium compounds; superconducting thin films; yttrium compounds; 4.2 K; Ar ion milling; PGO doping; YBCO film; YBa2Cu3O7:PrGaO3; annealing; critical current density; grain size; high temperature superconductor; stacked-type interface-treated Josephson junction; surface morphology; Annealing; Argon; Critical current density; Doping; High temperature superconductors; Josephson junctions; Milling; Superconducting integrated circuits; Surface morphology; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2003.814049
