IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Engineering Monday Sessions
       Session SE-MoA

Paper SE-MoA1
Multi-Level Control for Reactive Sputtering

Monday, October 29, 2001, 2:00 pm, Room 132

Session: Surface Engineering I: Graded, Multicomponent, and Complex Coatings
Presenter: W.D. Sproul, Reactive Sputtering, Inc.
Authors: W.D. Sproul, Reactive Sputtering, Inc.
B.E. Sylvia, Reactive Sputtering, Inc.
Correspondent: Click to Email

Pulsed dc power combined with partial pressure control of the reactive gas has made it possible to reactively sputter deposit non-conducting films such as aluminum oxide at relatively high deposition rates. Most reactive sputtering control systems rely on a single feedback signal for process control. However controlling on a single variable can affect the quality and repeatability of the deposited films. For example when the target voltage is used as the feedback signal, it can change for reasons other than a change in the reactive gas partial pressure such as outgassing or a disappearing anode. Another signal is needed to remove the ambiguity in the control process. Similarly if a mass spectrometer is used to provide the primary feedback control signal, the control signal can change with time due to drift in the mass spectrometer. A new system has been built that overcomes the problem of controlling on a single feedback signal. This new system, called IRESS, controls on a primary signal and then makes on-line adjustments to this primary signal based on secondary feedback signals. Examples of how this works for aluminum oxide and aluminum oxynitrides coatings will be given.