AVS 45th International Symposium
    Vacuum Metallurgy Division Monday Sessions
       Session VM+TF-MoM

Paper VM+TF-MoM7
Combined Monte Carlo and Fluid Sputter Transport Model in an Ionized PVD System with Experimental Plasma Characterization

Monday, November 2, 1998, 10:20 am, Room 328

Session: Ionized-PVD: Processes, Properties, and Applications
Presenter: D.R. Juliano, University of Illinois, Urbana
Authors: D.R. Juliano, University of Illinois, Urbana
D.B. Hayden, University of Illinois, Urbana
M.M.C. Allain, University of Illinois, Urbana
D.N. Ruzic, University of Illinois, Urbana
Correspondent: Click to Email
A code has been developed to model the transport of sputtered material in a modified industrial-scale magnetron. The device has a target diameter of 355 mm and was designed for 200 mm substrates. The chamber has been retrofitted with an auxilliary RF inductive plasma source located between the target and substrate. The source consists of a water-cooled copper coil immersed in the plasma, but with a diameter large enough to prevent shadowing of the substrate. The RF plasma, target sputter flux distribution, background gas conditions, and geometry are all inputs to the code. The plasma is characterized via a combination of a Langmuir probe apparatus and the results of a simple analytic model of the ICP system. A Monte Carlo routine in the code then tracks high energy atoms emerging from the target as they move through the chamber and undergo collisions with the electrons and background gas. The sputtered atoms are tracked by this routine whatever their electronic state (neutral, ion, excited). If the energy of a sputtered atom decreases to near-thermal levels, then it exits the Monte Carlo routine as is tracked with a simple diffusion model. In this way, all sputtered atoms are followed until they hit and stick to a surface, and the velocity distribution of the sputtered atom population (including state information) at each surface is calculated, especially the substrate. Through the use of this simulation the coil parameters and geometry can be tailored to maximize deposition rate and sputter flux uniformity.