Wüest M. 51 Wykes M. 82 Yamaguchi M. 17 Ybarra G. 129 Yubero F ...
Wüest M. 51 Wykes M. 82 Yamaguchi M. 17 Ybarra G. 129 Yubero F ...
Wüest M. 51 Wykes M. 82 Yamaguchi M. 17 Ybarra G. 129 Yubero F ...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
JUNE 26 MONDAY AFTERNOON<br />
RIVA-TF-MoA-OR.10 THE INFLUENCE OF MAGNETIC CONFINEMENT IN DI-<br />
RECT ABNORMAL GLOW DISCHARGES. Y. Nunes, A. Wemans, P. R. Gordo and M. J. P.<br />
Maneira. Cefitec - Department of Physics, Faculty of Sciences and Technology, New University of<br />
Lisbon, P-2<strong>82</strong>9-<strong>51</strong>6, Caparica, PORTUGAL.<br />
In this work an experimental study of the magnetic field influence on planar magnetron abnormal<br />
glow discharges of argon on copper targets is presented. A magnetron cathode that allows the control<br />
of the magnetic configuration was developed, and its magnetic circuit characterized.<br />
To quantify the magnetic field influence in the discharge, a confinement power parameter C B , was<br />
defined. This parameter, takes into account simultaneously the useful volume of the field, V C , and<br />
the average of the parallel component of the magnetic induction to which the plasma is subjected.<br />
For a planar magnetron cathode with cylindrical symmetric magnetic field, where r and z are the radial<br />
and height coordinates, and B || the parallel component of the magnetic field in this coordinate.<br />
The confinement power parameter is:<br />
C<br />
∫∫<br />
B<br />
= 2 π<br />
||<br />
)<br />
V C<br />
B ( r,<br />
z rdrdz<br />
Current-voltage-pressure characteristics were measured and the influence of the confinement power<br />
is mapped through current-voltage curves at constant confinement power values, displayed at several<br />
pressures. It was showed that at higher confinement power values the behaviour of the I-V characteristics<br />
is in general well described by the Thornton empirical law, I=kV n .<br />
Systematic study of k and n Thornton parameters with confinement power will be presented. The results<br />
show that above certain value of C B, the Thornton parameter, n, that is considered to characterise<br />
the entrapment efficiency of the electrons, converges to a constant for pressures from 1 to 8 Pa, as<br />
can be seen in Fig1.<br />
Fig.1 – Thornton parameter<br />
n as function of confinement<br />
power C B.<br />
The data shows also that there is dependence between n and k, Thornton parameters.<br />
42
Change language