Properties of DC magnetron sputtered Nb and NbN films for different sourceconditions

Citation
Nn. Iosad et al., Properties of DC magnetron sputtered Nb and NbN films for different sourceconditions, IEEE APPL S, 9(2), 1999, pp. 1720-1723
Citations number
16
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
ISSN journal
10518223 → ACNP
Volume
9
Issue
2
Year of publication
1999
Part
2
Pages
1720 - 1723
Database
ISI
SICI code
1051-8223(199906)9:2<1720:PODMSN>2.0.ZU;2-K
Abstract
We have compared the quality of Nb and NbN films obtained by de magnetron s puttering from a new and a fully eroded Nh target. Since current supercondu cting electronic devices such as SIS mixers, RSFQ digital circuits and hot electron bolometers are produced by reactive sputtering, we are interested in optimum source operating conditions over the target life time. We find t hat stress-free Nb films can, at any state of the target, be obtained under the same Ar pressure and de power applied to the sputtering source. We sho w that this approach also works for NbN reactive sputtering if the nitrogen flow rate is maintained proportional to the deposition rate of Nh In both cases the zero-stress point shifts to lower cathode de voltage as the targe t erodes. Additionally we find that the effectiveness of the magnetic trap of the magnetron influences the normal state resistivity of the NbN films.