AVS 47th International Symposium
    Thin Films Thursday Sessions
       Session TF-ThM

Paper TF-ThM7
Studies of Pulsed DC Power in Magnetron Sputtering Systems

Thursday, October 5, 2000, 10:20 am, Room 203

Session: Optical Films
Presenter: P.J. Kelly, University of Salford, UK
Authors: P.J. Kelly, University of Salford, UK
J. O'Brien, University of Salford, UK
J.W. Bradley, UMIST, UK
R. Hall, Advanced Energy Industries Inc.
G. Roche, Advanced Energy Industries Inc.
R.D. Arnell, University of Salford, UK
Correspondent: Click to Email
The application of pulsed DC power has proved to be highly advantageous in magnetron sputtering processes. Indeed, reactive pulsed magnetron sputtering is now amongst the leading techniques for the deposition of dielectric films. When the magnetron discharge is pulsed in the mid-frequency range (20-350kHz), the periodic voltage reversals effectively discharge poisoned regions on the target. This significantly reduces the occurrence of arc events at the target and stabilises the deposition process. As a consequence, substantial improvements have been observed in film structure and properties, compared to films produced by continuous DC processing. More recently, interest has also focused on the effects which can arise when pulsed DC power is applied to the substrate. Pulsing the bias voltage appears to significantly increase the substrate ion current. For example, when compared to DC biasing, preliminary results have shown that a three-fold increase can be achieved in the current drawn at the substrate if the bias voltage is pulsed at 350kHz. However, despite these successes, aspects of this technology are not yet well understood. Consequently, detailed studies of the application of pulsed DC power, both to the magnetron and to the substrate, in a dual, variable field strength closed-field unbalanced magnetron sputtering system, are now in progress. Initial findings are reported here.