Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-12-01T00:05:56.338Z Has data issue: false hasContentIssue false
  • English
  • Français

CeO2 insulating films for application to high-temperature superconducting digital devices

Published online by Cambridge University Press:  01 January 2006

Ai Kamitani ,
H. Wakana ,
A. Ogawa ,
S. Adachi ,
K. Higuchi ,
H. Yamamoto  and
K. Tanabe
Ai Kamitani*
Affiliation:
Superconductivity Research Laboratory-International Superconductivity Technology Center (SRL-ISTEC), Koto-ku, Tokyo 135-0062, Japan
H. Wakana
Affiliation:
Superconductivity Research Laboratory-International Superconductivity Technology Center (SRL-ISTEC), Koto-ku, Tokyo 135-0062, Japan
A. Ogawa
Affiliation:
Superconductivity Research Laboratory-International Superconductivity Technology Center (SRL-ISTEC), Koto-ku, Tokyo 135-0062, Japan
S. Adachi
Affiliation:
Superconductivity Research Laboratory-International Superconductivity Technology Center (SRL-ISTEC), Koto-ku, Tokyo 135-0062, Japan
K. Higuchi
Affiliation:
Superconductivity Research Laboratory-International Superconductivity Technology Center (SRL-ISTEC), Koto-ku, Tokyo 135-0062, Japan; and Nihon University, Funabashi-city, Chiba 274-8501, Japan
H. Yamamoto
Affiliation:
Superconductivity Research Laboratory-International Superconductivity Technology Center (SRL-ISTEC), Koto-ku, Tokyo 135-0062, Japan; and Nihon University, Funabashi-city, Chiba 274-8501, Japan
K. Tanabe
Affiliation:
Superconductivity Research Laboratory-International Superconductivity Technology Center (SRL-ISTEC), Koto-ku, Tokyo 135-0062, Japan
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

CeO2 thin films as insulating layers for high-temperature superconducting digital devices were studied. The dependence on substrate temperature and oxygen pressure of the surface morphology and crystallinity of CeO2 thin films prepared by pulsed laser deposition were investigated. CeO2 thin films with a flat and closely grained surface were obtained at a relatively low oxygen pressure of 3.6 Pa, whereas higher oxygen pressure led to CeO2 thin films with a rough surface and columnar grains. The recovery of oxygen content in superconducting layers was examined for multilayer structures with CeO2 thin films. Enough oxygen was supplied to the upper and lower superconducting layers when the multilayer was cooled slowly in 3 × 10−4 Pa oxygen pressure after deposition. Resistively shunted junction type I-V characteristics were confirmed for interface-engineered ramp-edge junctions in a multilayer structure including four superconducting layers with CeO2 thin films.

Keywords

SuperconductingFilm
Type
Articles
Information
Journal of Materials Research , Volume 21 , Issue 1 , January 2006 , pp. 263 - 269
Copyright
Copyright © Materials Research Society 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1.Likharev, K.K. and Semenov, V.K.: RSFQ logic/memory family: A new Josephson-junction thechnology for sub-terahertz-clock-frequency digital systems. IEEE Trans. Appl. Supercond. 1, 3 (1991).Google Scholar
2.Soutome, Y., Fukazawa, T., Saito, K., Tsukamoto, A. and Takagi, K.: HTS surface-modified junctions with integrated ground-planes for SFQ circuits. IEICE Trans. Electron. E85–C:3, 759 (2002).Google Scholar
3.Katsuno, H., Inoue, S., Nagano, T. and Yoshida, J.: A novel multilayer process for HTS SFQ circuit. IEEE Trans. Appl. Supercond. 13, 809 (2003).CrossRefGoogle Scholar
4.Wakana, H., Adachi, S., Sugiyama, H., Takahashi, Y., Sugano, T., Horibe, M., Ishimaru, Y., Tarutani, Y. and Tanabe, K.: Ramp-edge junctions with interface-modified barriers fabricated on YBCO thick films. IEEE Trans. Appl. Supercond. 13, 595 (2003).CrossRefGoogle Scholar
5.Katsuno, H., Nagano, T., Inoue, S., Yoshida, J.: Development of the fabrication process for HTC SFQ circuits (2). Extended Abstracts, 49th Spring Meeting, Jpn. Soc. Appl. Phys. 28a-ZD-2 (in Japanese).Google Scholar
6.Kamitani, A., Wakana, H., Adachi, S. and Tanabe, K.: Investigation of BaZrO3 and SrZrO3 insulating layers on La-YBCO ground plane for high-T c devices. Physica C 412, 1414 (2004).Google Scholar
7.Kamitani, A., Wakana, H., Adachi, S., Nakajima, Y., Higuchi, K., Yamamoto, H. and Tanabe, K.: Examination of MgO insulator thin films for high-Tc superconducting devices. Physica C (in press).Google Scholar
8.Hidaka, M., Maruyama, M. and Sato, T.: Single flux quantum (SFQ) sampler made of high-T c superconductor. Ins. Electron. Inf. Commun. Eng. J86–C, 1128 2003 , (in Japanese).Google Scholar
9.van Wijck, M.A.A.M., Verhoeven, M.A.J., Reuvekamp, E.M.C.M., Gerritsma, G.J., Blank, D.H.A. and Rogalla, H.: CeO2 as insulating layer in high Tc superconducting multilayer and crossover structures. Appl. Phys. Lett. 68, 553 (1996).CrossRefGoogle Scholar
10.Sato, H., Miyakawa, R., Nakamura, N., Gjoen, S.R., Akoh, H. and Takada, S.: YBa2Cu3Ox crossover structures using CeO2 film as insulating layer. Jpn. J. Appl. Phys. 35, L311 (1996).CrossRefGoogle Scholar
11.Tsukamoto, A., Fukazawa, T., Soutome, Y., Tarutani, Y. and Takagi, K.: Faburication of YBCO/CeO2/YBCO crossover and via structures for digital circuit and integrated SQUID applications. Supercond. Sci. Technol. 12, 1001 (1999).CrossRefGoogle Scholar
12.Wakana, H., Adachi, S., Kamitani, A., Nakayama, K., Ishimaru, Y., Tarutani, Y. and Tanabe, K.: Development of thin film multilayer structures with smooth surface for HTS SFQ circuits. IEICE Trans. Electron. E88–C.2, 208 (2005).Google Scholar
13.Adachi, S., Wakana, H., Horibe, M., Inoue, N., Sugano, T. and Tanabe, K.: Preparation of La-doped Yb-123 thin films for high-T c devices. Physica C 378–381, 1213 (2002).CrossRefGoogle Scholar
14.Kamitani, A., Adachi, S., Wakana, H. and Tanabe, K.: Improvement in crystal orientation and in-plane alignment of La-doped YBCO thin film on BaZrO3-buffered MgO substrate. J. Mater. Res. 20, 1529 (2005).Google Scholar
15.Moeckley, B.H. and Char, K.: Properties interface-engineered high T c Josephson junctions. Appl. Phys. Lett. 71, 2526 (1997).CrossRefGoogle Scholar
16.Sato, T., Hidaka, M. and Tahara, S.: High-temperature superconducting edge-type Josephson junctions with modified interfaces. IEEE Trans. Appl. Supercond. 9, 3141 (1999).Google Scholar
17.Wakana, H., Adachi, S., Horibe, M., Ishimaru, Y., Horibe, O., Tarutani, Y. and Tanabe, K.: Influence of counter-layer deposition condition on critical current spread in interface-modified ramp-edge junction arrays. Jpn. J. Appl. Phys. 2 Lett. 41, L239 (2002).CrossRefGoogle Scholar
18.Lichtenwalner, D.J., Auciello, O., Dat, R. and Kingon, A.I.: Investigation of the ablated flux characteristics during pulsed laser ablation deposition of multicomponent oxides. J. Appl. Phys. 74, 7497 (1993).CrossRefGoogle Scholar
19.Fang, X., Tachiki, M. and Kobayashi, T.: Excimer-laser abration of RuO2 observed by a streak camera. J. Appl. Phys. 85, 2492 (1999).CrossRefGoogle Scholar