Stable preparation process of superconductor insulator multilayer films for HTS devices by off-axis magnetron sputtering

Abstract The preparation process for epitaxial multilayer films consisting of Y 0.9 La 0.2 Ba 1.9 Cu 3 O y (La-YBCO) and SrSnO 3 (SSO) for high- T c superconductor (HTS) electronic devices was developed. Four-layer films of SSO/La-YBCO/SSO/La-YBCO were deposited on BaZrO 3 -buffered MgO(1 0 0) substrates by off-axis magnetron sputtering. During deposition, the substrates were directly heated from backside by thermal radiation of a heater. No adhesive paste, such as Ag, for fixing the substrate was used in order to avoid contamination. Deposition conditions, especially the heater temperature profiles and atmosphere during elevating the temperature, were carefully controlled. The multilayer films with the average surface roughness R a around 2.0 nm were prepared with high reproducibility. Continuous production of the high-quality films throughout one year proved excellent stability of the preparation process.

[1]  Y. Ishimaru,et al.  High-temperature operation of oxide SFQ-circuit-elements , 2005, IEEE Transactions on Applied Superconductivity.

[2]  K. Tanabe,et al.  Progress in HTS sampler development , 2005 .

[3]  Keiichi Tanabe,et al.  Fabrication of HTS long-JTL circuits on La-YBCO ground plane , 2005 .

[4]  Keiichi Tanabe,et al.  Improvement in crystal orientation and in-plane alignment of La-doped YBCO thin film on BaZrO_3-buffered MgO substrate , 2005 .

[5]  S. Pandalai.  Recent research developments in physics , 2003 .

[6]  Y. Ishimaru,et al.  Fabrication and logic operation of oxide SFQ-circuit-components , 2005, IEEE Transactions on Applied Superconductivity.

[7]  K. Tanabe,et al.  Observation of 45 GHz current waveforms using HTS sampler , 2005 .

[8]  Fabrication and characteristics of SFQ circuit elements made of oxide thin films , 2005 .

[9]  T. Nagano,et al.  Analysis of I/sub c/ spreads in interface engineered junctions , 2001 .

[10]  K. Char,et al.  Properties of interface-engineered high Tc Josephson junctions , 1997 .

[11]  S. Tahara,et al.  High-temperature superconducting edge-type Josephson junctions with modified interface barriers , 1999 .

[12]  Masahiro Horibe,et al.  Preparation of La-doped Yb-123 thin films for high-Tc devices , 2002 .

[13]  Keiichi Tanabe,et al.  Development of Thin Film Multilayer Structures with Smooth Surfaces for HTS SFQ Circuits , 2005, IEICE Trans. Electron..

[14]  Y. Ishimaru,et al.  Improvement in reproducibility of multilayer and junction process for HTS SFQ circuits , 2005, IEEE Transactions on Applied Superconductivity.