| AVS 56th International Symposium & Exhibition | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS-ThP |
| Session: | Plasma Science Poster Session |
| Presenter: | M.M. Turner, Dublin City University, Ireland |
| Authors: | B.J. Keville, Dublin City University, Ireland M.M. Turner, Dublin City University, Ireland |
| Correspondent: | Click to Email |
Real time, closed loop control of certain plasma species may potentially improve reproducibility and increase process yields. In order to investigate the feasibility of applying closed loop control to a plasma process, closed loop control of a plasma simulation was studied. This presentation concentrates solely on control issues, since the simulation was described in a companion presentation. The design of real time control algorithms is facilitated by simple, dynamical process models. The derivation of such a model from a much more complex simulation is presented, together with a stability analysis which indicates how the parameters of a real time control algorithm may be determined from such a model (model-based control). Process measurements may be indirect and, in addition, corrupted by process and measurement noise. Simple dynamical models may be used to construct model-based estimators such as the Kalman filter. The construction of such a filter to improve estimates obtained from optical emission spectroscopy is described in this presentation. Finally, the application of adaptive control to maintain closed loop stability despite changes in process parameters such as wall sticking coefficient due to chamber seasoning is presented.