AVS 51st International Symposium
    Thin Films Thursday Sessions
       Session TF-ThM

Paper TF-ThM7
Inhomogeneous Transport of Energetic and Thermalized Neutrals in a Magnetron Sputter System

Thursday, November 18, 2004, 10:20 am, Room 303C

Session: Modeling & Fundamentals in Thin Film Deposition
Presenter: F.J. Jimenez, University of Alberta, Canada
Authors: F.J. Jimenez, University of Alberta, Canada
S. Leonard, Matrikon, Canada
P. Beatty, University of Alberta, Canada
S. Dew, University of Alberta, Canada
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Thermalization of energetic neutrals in a typical magnetron sputter deposition system occurs as energetic particles collide with background gas atoms. Most of these energetic neutrals are created at the cathode as a result of positive ions striking the target and causing sputter ejection/reflection. After a few collisions these energetic neutrals are greatly slowed until they reach thermal energies and their transport is believed to be governed by diffusion phenomena. This effect is responsible for reducing the energy of incoming particles to the substrate which in turn affects the characteristics of the film being deposited. It is known that island formation and coalescence stages of film growth strongly depend on temperature, angle of incidence and energy of neutrals. A coupled model that approximates transport of the thermalized particles in a typical magnetron sputter chamber is presented. The thermalized model follows a fluid approach to predict steady state spatial distributions of thermalized particles as a function of space. Transport equations are solved in a three dimensional space with a nonuniform grid and anisotropic transport coefficients. Particle diffusion is coupled with a temperature solver to consider the impact of gas heating. Shadowing effects due to the rather complex geometry of a common magnetron chamber are also taken into consideration in the model. Transport of energetic reflected neutrals and sputtered atoms from the target is simulated with a MonteCarlo approach which includes the gas rarefaction and heating effects. A study of the effect that power has on the steady state temperature of the gas is included. The simulation is performed assuming a typical aluminum deposition in an argon environment at constant voltage and pressure. Steady state temperature profiles and particle distributions in the whole chamber are presented indicating a clear temperature dependence on power as previous works have reported.