Title :
Critical current control and microwave-induced characteristics of (NbN/TiNx)n/NbN stacked junction arrays
Author :
Ishizaki, M. ; Yamamori, H. ; Shoji, A. ; Benz, S.P. ; Dresselhaus, P.D.
Author_Institution :
Nat. Inst. of Adv. Ind. Sci. & Technol., Japan
fDate :
6/1/2003 12:00:00 AM
Abstract :
Stacked double and triple Josephson junctions with NbN electrodes and TiNx barriers were fabricated for the next-generation 10 V programmable Josephson voltage standard. Because of difficulties in the growth of uniform junctions in a stack with a constant barrier thickness, a stack with carefully engineered thicknesses was grown that exhibited uniform junction properties. The junction arrays on these chips were biased with microwave power at 16 GHz resulting in constant-voltage steps consistent with the total number of junctions in the array, including the multiple junctions in the stacks. The steps had a current range greater than 1 mA at 4.2 K.
Keywords :
critical current density (superconductivity); measurement standards; niobium compounds; superconducting junction devices; superconducting microwave devices; titanium compounds; voltage measurement; (NbN-TiNx)n-NbN; (NbN/TiNx)n/NbN; 10 V; 16 GHz; 4.2 K; constant-voltage steps; critical current control; double Josephson junctions; microwave power; microwave-induced characteristics; programmable Josephson voltage standard; stacked junction arrays; triple Josephson junctions; uniform junction properties; Critical current; Electrodes; Fabrication; Helium; Josephson junctions; Microwave antenna arrays; Sputter etching; Sputtering; Tin; Voltage;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2003.814163
