| AVS 54th International Symposium | |
| Plasma Science and Technology | Monday Sessions |
| Session PS1-MoM |
| Session: | Plasma Modeling |
| Presenter: | J.J. Munro, University College London, England |
| Authors: | J.J. Munro, University College London, England J. Tennyson, University College London, England |
| Correspondent: | Click to Email |
Extensive molecular data is a key requirement in understanding modern technical plasmas. Here we present a method for coupling molecular data with chemical models and a global plasma simulation to enable rapid testing and evaluation of new plasmas. A global plasma model (GLOBAL_KIN1) is extended using an expert system 'Quantemol-P' to enable ad-hoc simulations using new plasma recipes. A set of atomic and molecular species to be considered in the plasma simulation is specified by the user. The expert system generates a complete set of reaction pathways for both the gas and surface reactions in a plasma. This set is pruned by discarding un-physical reactions and reaction data not appropriate to technical plasmas. Where data exists, a rate is calculated for the reaction at the plasma temperature so its importance can be evaluated. Where no data exists, a set of heuristics is used (based upon reaction type) to evaluate the reaction's importance. A user can adjust the species, gas phase reactions, surface reactions and plasma properties to control the simulation. The reaction list is populated with a database of molecular parameters and cross-sections; missing data can be calculated using a further expert system 'Quantemol-N'.2 This applies the R-Matrix method, which has proven highly accurate for electron-molecule interactions.3 In instances where this R-Matrix method does not apply, other methods such as the Binary Encounter Bethe model4 maximize the range of cross-section data available. The method allows for rapid investigation of new plasma recipes with a greater level of flexibility than previously achievable. A simple plasma-etch example is presented to demonstrate the system.
1D.S. Stafford and M.J. Kushner, O2(1-delta) Production in He/O2 Mixtures in Flowing Low Pressure Plasmas, J. Appl. Phys. 96, 2451(2004).
2J. Tennyson, D.B. Brown, J.J. Munro, I. Rozum, H.N. Varambhia and N. Vinci, Quantemol-N: an expert system for performing electron molecule collision calculations using the R-matrix method, J. Phys. Conf. Series, (in press).
3H.N. Varambhia and J. Tennyson, Electron collision with HCN and HNC molecules using the R-matrix method, J. Phys. B: At. Mol. Opt. Phys. 40, 1211-1223 (2007).
4W. Hwang, Y.-K. Kim and M.E. Rudd, New model for electron-impact cross sections of molecules, J. Chem. Phys. 104(8), 2956-2966 (1996).