Title :
Small scale integrated technology for HTS RSFQ circuits
Author :
Huang, Mingqiang ; Komissinski, Philippe V. ; Kidiyarova-Shevchenko, Anna Yu ; Gustafsson, Marica ; Olsson, Eva ; Högberg, Björn ; Ivanov, Zdravko ; Claeson, Tord
Author_Institution :
Dept. of Biol. Sci., Carnegie Mellon Univ., Pittsburgh, PA, USA
fDate :
3/1/2001 12:00:00 AM
Abstract :
A technology for fabrication of YBCO ramp junctions on a superconducting ground plane is developed and evaluated. The technology is based on a two-layer, S-I, structure or on a four-layer, S-I-S-I, structure grown in situ with YBCO superconductor and with multilayer insulator of PBCO/STO/PBCO. Ramps for junctions, via connections and crossovers are formed by Ar ion milling under rotation and the ramp angle is less than 30° for all directions. A 20-25 nm thick Ga-doped PBCO was used as a barrier for Josephson junctions. One additional YBCO layer, for junction top electrodes and wiring, is deposited and patterned. Surface roughness of multilayers is characterized by AFM and is related to the junction parameters. Transport properties of junctions, via connections and crossovers are evaluated
Keywords :
Josephson effect; barium compounds; high-temperature superconductors; superconducting integrated circuits; yttrium compounds; AFM; Ar ion milling; Ga-doped PBCO barrier; PBCO/STO/PBCO multilayer insulator; PrBa2Cu3O7-SrTiO3 -PrBa2Cu3O7; PrBa2Cu3O7:Ga; RSFQ circuit; YBCO ramp Josephson junction; YBa2Cu3O7; crossover; fabrication; four-layer S-I-S-I structure; high Tc superconductor; small-scale integrated technology; superconducting ground plane; surface roughness; transport properties; two-layer S-I structure; via connection; Argon; Electrodes; Fabrication; High temperature superconductors; Insulation; Integrated circuit technology; Josephson junctions; Milling; Nonhomogeneous media; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
