| The two- and three-dimensional simulation of plasma machines used for materials processing has been investigated. The issues arising when doing self-consistent electromagnetic field/particle type simulations include numerical instabilities, large computer memory requirements and long computer simulation times. Two simulation models were developed to investigate these issues.; For the first model, a self-consistent 3D3V plasma-EM numerical model was developed to simulate discharges inside a compact microwave plasma source. The model coupled an electromagnetic field model and a particle plasma model to simulate plasma production and heating in low pressure ECR plasmas. A grid system was developed to improve numerical stability in cylindrical coordinate system structures. The input parameters to the simulation included operating pressure, gas type and magnetic field pattern. Characteristics of the plasma simulated included plasma temperature, charge density, plasma potential, radial electric field distribution near the walls and power absorption patterns.; For the second model, a 2D3V simulation of the downstream region of plasma processing machines was conducted assuming {dollar}phi{dollar} symmetry. The plasma source was assumed to provide a constant or spatially variable flux of particles to the downstream region. The plasma potential and the charge densities across the simulation volume were resolved. A non-uniform particle weighting scheme was implemented to aid stability at the grid points close to the origin.; Simulation models were redesigned to achieve some measure of parallelism. This was done by observing that the movement of particles in particle type plasma simulations are essentially independent of each other once the governing forces have been self-consistently determined. Implementations of 2D3V and 3D3V plasma simulations on a MasPar MP2 massively parallel processor were achieved. Speed-up of over 13 times the fastest locally available serial machine was achieved demonstrating the promise of parallel simulations. Further, the simulation of problem sizes beyond the computing and storage capability of desktop workstations was also demonstrated.; The concept of parallel simulations was modified to spread the computation load across a set of networked desktop workstation machines in a distributed manner. A distributed simulation using PVM was designed to be run across 2, 4 and 8 workstations. The two processor implementation was shown to provide considerable speed up over a single desktop case. However, communication bottlenecks reduced the computational speed-up considerably for the four processor implementation. |
