AVS 45th International Symposium
    Plasma Science and Technology Division Tuesday Sessions
       Session PS1-TuM

Paper PS1-TuM1
Simulation of a Pulsed-Power Inductively Coupled Chlorine Plasma

Tuesday, November 3, 1998, 8:20 am, Room 314/315

Session: Pulsed Plasmas
Presenter: V. Midha, University of Houston
Authors: V. Midha, University of Houston
D.J. Economou, University of Houston
Correspondent: Click to Email
Low pressure high density plasmas are widely used for the fabrication of sub-micron semiconductor devices. Recently, pulsed power operation has emerged as a promising technique for reducing charge induced damage and etch profile distortion (e.g., notching) associated with conventional continuous wave discharges. This paper reports results of a fluid simulation of a pulsed-power inductively-coupled chlorine plasma. The mass, energy, and full momentum equations for the charged species are solved simultaneously with the Poisson equation and the Helmholtz equation for the electromagnetic power deposition profiles. A p-version, least-squares finite-element formulation of the glow discharge equations was developed which is capable of capturing sharp fronts in the sheath region without numerical diffusion. Also, this method is unconditionally stable circumventing the extremely short dielectric relaxation time constant of the system. Simulation results show spontaneous separation of the plasma into an ion-ion core and an electron-ion periphery, depending on the negative ion to electron density ratio. These results are in agreement with a semi-analytic model of the system. The influence of the rf bias frequency on the sheath dynamics and the ion flux and energy to the driven electrode during the afterglow was also examined. Significant oscillations of the ion flux were observed when the ion transit time through the sheath was about equal to the period of the applied field. Finally, the transition to a fully developed ion-ion plasma state and the dynamics of this new kind of plasma were studied.