Jpn. J. Appl. Phys. 28 (1989) pp. 1367-1372  |Next Article|  |Table of Contents|
|Full Text PDF (1315K)| |Buy This Article|

Microstructure and Superconductivity in Epitaxial MgO/NbN Multilayers

Shiro Nagaoka, Katsuyoshi Hamasaki¹, Tsutomu Yamashita¹ and Toranosuke Komata²

(Received July 20, 1989; accepted for publication May 20, 1989)

The aim of this investigation is to achieve high transition temperature, low resistivity films under conditions suitable for use in all-NbN Josephson junction fabrication. For this purpose, the heteroepitaxy of NbN on MgO films is investigated. For substrate temperature of 200°C or thereabouts, polycrystalline MgO films of (200) orientation were formed on (100) silicon, (1102) α-Al₂O₃, and fused silica. Based on XTEM, HEED and X-ray data, heteroepitaxial growth ((100)_NbN//(100)_MgO) was obtained in NbN films and NbN/MgO/NbN trilayers deposited on (200) oriented MgO films. The epitaxial NbN films of 10 nm thickness had high transition temperatures of about 14 K, and relatively low residual resistivities of less than 200 µΩ·cm. Using the GL relationships, we calculated the Ginzburg-Landau parameters, λ(0) and ξ, of our NbN films in the dirty limit. The calculated ξ(4.2 K) and λ(0) are ∼4.5 nm and ∼300 nm, respectively.

URL: http://jjap.jsap.jp/link?JJAP/28/1367/
DOI: 10.1143/JJAP.28.1367

References | Citing Articles (6)

1. A. I. Braginski, J. R. Gavaler, M. A. Janocko and J. Talvacchio: SQUID 85, eds., H. D. Hahlbohm and H. Lubbig, (Walter de Gruyter, Berlin 1985) p. 591.
2. G. Oya and Y. Onodera: Jpn. J. Appl. Phys. 10 (1971) 1485[JSAP].
3. G. Oya and Y. Onodera: J. Appl. Phys. 45 (1974) 1389[AIP Scitation].
4. Y. M. Shy, L. E. Toth and R. Somasundaram: J. Appl. Phys. 44 (1973) 5539[AIP Scitation].
5. S. Kosaka and Y. Onodera: Proc. 6th Int. Vaccum Congress, Kyoto, 1974, Jpn. J. Appl. Phys. 13 (1974) Suppl. 2, Pt 1, [JSAP]p. 613.
6. J. R. Gavaler, A. I. Braginski, M. A. Janocko and J. Talvacchio: Physica 135B (1985) 148.
7. K. Ueda, K. Hamasaki, I. Yamada, T. Yamashita, T. Komata and Y. Hirukawa: Shinku 28 (1985) 796 (in Japanese).
8. T. Yamashita, K. Hamasaki and T. Komata: Adv. Cryog. Eng. 32 (1986) 617.
9. J. Talvacchio, J. R. Gavaler and A. I. Braginski: to be published in Proc. TMS-AIME: Metallic Multilayers and Epitaxy, eds. H. Hong and S. A. Wolf (1987).
10. J. Talvacchio and A. I. Braginski: Extended Abstracts of the 1987 Int. Superconductivity Electronics Conference (ISEC), (1987) p. 66.
11. W. R. Sinclair and C. J. Calbick: Appl. Phys. Lett. 10 (1967) 214[AIP Scitation].
12. S. Nagaoka, K. Hamasaki, T. Yamashita and T. Komata: IEICE Tech. Rep. SCE86-12 (1986) 1 (in Japanese).
13. K. Sugiyama, K. Akazawa, M. Oshima, H. Miura, T. Matsuda and O. Nomura: Plasma Chem. & Plasma Processing 6 (1986) 179.
14. L. Hochard, A. Plain and A. Ricard: Proc. 4th Int. Symp. Plasma Chem., ed. by S. Veprek (University Zurich) (1979) p. 545.
15. K. Hamasaki, S. Nagaoka, T. Komata and T. Yamashita: Superconducting Materials, Extended Abstracts, eds. J. Beuk and A. I. Braginski (Materials Res. Soc, Pittsburg, 1986) p. 10.
16. K. Yachi, K. Hamasaki, T. Yamashita and S. Nagaoka: IEICE Tech. Rep. SCE86-39 (1986) 41 (in Japanese)
17. J. R. Gavaler, J. Talvacchio and A. I. Braginski: Adv. Cryog. Eng. 30 (1984) 535.
18. M. Igarashi, M. Hikita and K. Takei: Adv. Cryog. Eng. 30 (1984) 627.
19. T. P. Orlando, E. J. McNiff, S. Foner and M. R. Beasley: Phys. Rev. B19 (1979) 4545[APS].
20. T. R. Gheewala: IBM J. Res. & Develop. 24 (1980) 130.
21. K. Ueda, I. Yamada, K. Hamasaki, T. Komata and T. Yamashita: IEICE Tech. Rep. SCE85-2 (1985) 7 (in Japanese).
22. H. H. Zappe and B. S. Landman: J. Appl. Phys. 49 (1978) 344[AIP Scitation].
23. J. Clarke: IEEE Trans. Electron Devices ED-27 (1980) 1896.
24. F. E. Harper and M. Tinkham: Phys. Rev. 172 (1968) 441[APS].
25. E. J. Kramer: J. Appl. Phys. 44 (1973) 1360[AIP Scitation].
26. J. Y. Juang, D. A. Rudman, R. B. van Dover, W. R. Sinclair and D. D. Bacon: Adv. Cryog. Eng. 32 (1986) 651.