IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Thin Films Thursday Sessions
       Session TF-ThA

Invited Paper TF-ThA1
Ionized-PVD with Quasi-Stationary High Power Magnetron Sputtering

Thursday, November 1, 2001, 2:00 pm, Room 123

Session: Emerging Thin Film Techniques
Presenter: U. Helmersson, Linköping University, Sweden
Authors: U. Helmersson, Linköping University, Sweden
J. Alami, Linköping University, Sweden
A.P. Ehiasarian, Sheffield Hallam University, UK
K.M. Macák, Sheffield Hallam University, UK
J.T. Gudmundsson, University of Iceland
Correspondent: Click to Email
The development of ionized-PVD by sputtering over the last few years is based on the production of a high-density plasma (10@super 18@ - 10@super 19@ m@super -3@) in front of the source. As the atoms pass through this dense plasma, a large fraction becomes ionized. The high plasma densities can be achieved in several ways, by using an rf-coil, a hollow cathode arrangement, or as in the present case, simply by increasing the power supplied to the magnetron source. To avoid extensive heating of the cathode as well as the development of arcs, in the latter case, the power is pulsed with a duty factor of around 1 %, which maintains the average power at an acceptable level. In the present work, peak power densities of several kW cm@super -2@ with a repetition frequency of 50 Hz was used. This technique has been demonstrated for sputtering a range of different metals, yielding a degree of ionization of 30 to 70 % depending on cathode material and applied power as measured for Cu, Ta, and Cr cathodes. Optical emission studies demonstrate a temporal development of the plasma during the pulse. Initially the emission is dominated by Ar-lines, but later in the pulse lines from cathode-metal ions dominate the emission. This may indicate a transition from Ar-sputtering to self-sputtering during the pulse. That self-sputtering occurs is also supported by the observation that the relative deposition rate (pulsed rate as compared with normal dc rate) scales with self-sputtering yield giving low relative deposition rate for low-yield materials. Film growth by this sputtering technique is demonstrated in trench-filling applications, reactive sputtering of chromium nitrides, and for carbon films.