AVS 47th International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS1+MS-WeA

Paper PS1+MS-WeA8
Source Optimization for Magnetron Sputter-Deposition of NbTiN Tuning Elements for SIS THz Detectors

Wednesday, October 4, 2000, 4:20 pm, Room 310

Session: Sensors and Control in Plasma Processing
Presenter: N.N. Iosad, Delft University of Technology, The Netherlands
Authors: N.N. Iosad, Delft University of Technology, The Netherlands
B.D. Jackson, Space Research Organization of the Netherlands
J.R. Gao, Space Research Organization of the Netherlands
S.N. Polyakov, Moscow State University
P.N. Dmitriev, Russian Academy of Sciences
T.M. Klapwijk, Delft University of Technology, The Netherlands
Correspondent: Click to Email
NbTiN is one of the most promising materials for use in the tuning circuits of Nb-based superconductor-isolator-superconductor (SIS) mixers for operating frequencies above the gap frequency of Nb (about 700 GHz). Device development requires stable and reproducible film properties. In this manuscript we compare the properties of NbTiN and NbN films obtained with a DC magnetron sputtering source using balanced and unbalanced magnetic trap configurations. This experiment shows that reducing the effectiveness of the magnetic trap by changing the magnet configuration is equivalent to reducing the sputtering pressure from the prospective of the film properties. We find that the properties of the films are not stable throughout the target life-time. Sputtering source with balanced configuration shows degradation of the NbN film properties as the target gets grooved for the fixed applied power and sputtering pressure. In contrast unbalanced sputtering source shows opposite behavior for the NbTiN films. We also show that it is possible to optimize the configuration of the magnetron magnets to produce stable and reproducible NbTiN films under the same gas pressure and applied power throughout the target lifetime.