| AVS 55th International Symposium & Exhibition | |
| Plasma Science and Technology | Tuesday Sessions |
| Session PS-TuP |
| Session: | Plasma Science Poster Session |
| Presenter: | F.J. Jimenez, University of Alberta, Canada |
| Authors: | F.J. Jimenez, University of Alberta, Canada D. Field, NuCryst Pharmaceuticals, Canada S. Ekpe, University of Alberta, Canada S.K. Dew, University of Alberta, Canada |
| Correspondent: | Click to Email |
Sputter deposition is a well established technique underlying a wide range of technological applications. However, the system is complex, involving coupled interactions of plasma, target, transport and substrate. Several models have been developed to explain and to optimize the process conditions. Nevertheless, the majority of these models excluded or simplify some key parameters missing the benefits that may arise using a detailed model. We present a comprehensive 3D coupled model where each part of the process is isolated in modules. Transport of charged and neutral particles is solved using a hybrid algorithm where energetic particles are followed individually using a Direct Monte Carlo (DMC) approach and thermalized particle transport is described by a computational fluid dynamics model modified to account for the nonuniform magnetic field. The plasma model is solved self-consistently using an octree grid with local refinement in the region next to the cathode to resolve the thin sheath typical of magnetron sputter systems. The highly coupled system of partial differential equations is numerically solved using a modified Newton method. An iterative approach is used to surmount the coupling arising between the glow discharge and the rarefaction and heating of the background gas. For experimental verification, a planar magnetron with an Aluminum target has been used as the reference system. The discharge has been characterized using a custom Langmuir probe. Plasma densities are shown to increase with power and pressure as would be expected. Electron temperature on the other hand decreases with pressure and power for the process conditions studied (5-40 mTorr, 75-300 W). At high pressures and/or high powers, the rate of reduction in electron temperature decreases, suggesting the effect of process gas rarefaction. At these pressures and powers significant rarefaction has been observed indicating a trend between this effect and plasma parameters. This may suggest a more decisive role of the gas-plasma interaction when modeling magnetron sputtering systems in this pressure regime.