| Plasma processes are gaining an increasing role in materials processing for deposition and etching of thin films. However, plasma processing is still at a state of the art as a technology and more comprehensive modeling studies are needed. The considerable interest in plasma deposition is driven by the ability to grow films at relatively low process temperatures combined with special material properties that can not be realized in conventional thermally driven processes.; In order to understand the behavior of plasma reactors, knowledge of discharge physics and chemistry is required. For a complete understanding of discharge reactor performance, it is necessary to develop models with predictive capabilities over a wide range of operating parameters. The objective of this research is to establish quantitative relationships between deposition/etch rates and process variables in order to, obtain desired film uniformity and materials properties, and develop workable set of design criteria.; A detailed mathematical model for dc plasma reactors is presented in this thesis. The overall model consists of two parts. In part one, given an electron distribution function, a mass transfer model will predict the deposition rates of desired thin films. Part two consists of a rigorous model for the discharge physics which predicts the electron density function. This model is based on the continuum conservation equations. Planar geometry is assumed, and the model includes continuity equations for all charged particles, Poisson's equation to determine the local electric fields, and an energy balance to determine the ionization and energy loss rates. Combination of models proposed in parts one and two are expected to result in a more quantitative understanding of dc plasma. |
