AVS 47th International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS+MS-WeM

Paper PS+MS-WeM8
Transient Charging Effects of Insulating Surfaces Exposed to a Plasma During Pulse Biased DC Magnetron Sputtering.

Wednesday, October 4, 2000, 10:40 am, Room 311

Session: Plasma-Induced Damage
Presenter: E.V. Barnat, Rensselaer Polytechnic Institute
Authors: E.V. Barnat, Rensselaer Polytechnic Institute
T.-M. Lu, Rensselaer Polytechnic Institute
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The ability to control the charging of thin dielectric films exposed to ionized discharges, using a pulsed bias, is studied experimentally and theoretically. A dielectric film is exposed to the discharge and the transient currents associated with the dielectric's charging are measured after each pulse. Factors effecting the time scale the film undergoes charging, including the dielectric constant, the dielectric's thickness, the plasma density, and the amount of potential applied during each pulse are explored. By constructing a simple model based on the plasma's impedance to the pulsed bias and the capacitive coupling between the electrode and the surface of the dielectric where the charge accumulates, the observed transient currents are explained. Calculations are then made to determine the energy distribution of the ions extracted from the plasma and how both the pulse of the electrode and the charging of the dielectric influence the ion energy distributions. To demonstrate an application of the pulse bias technique, it is shown that we can dramatically control the film morphology and microstructure by pulse biasing the electrode. Also, by properly setting the pulse bias, the pulse frequency or the pulse duty, damage to thin dielectric films, such as electrical breakdown, is prevented during metallization.