PEM Automatic Control System of Reactive Sputtering Coating Equipment
|Course||Fluid Machinery and Engineering|
|Keywords||the reactive sputtering coating equipment plasma PEM single neuron adaptive PID|
Based on the principle of reactive magnetron sputtering, what we can see from the hysteresis effect of reactive sputtering, we aim at getting high-grade film with high sputtering rate and optimum stoicheiometry, so we should set the reactive point in the transition region of the hystersis effect, which is between metallic mode and oxide mode. We know that hystersis effect is inerversible, so a fast control system is needed to make-up a closed loop to control the reactive gas flow. There are many signals can be used, we choose the PEM as the signal because of its adaptability.The PEM automatic control system of reactive sputtering coating equipment is monitoring the plasma with its emissions, and through the spectrogram the density of the different particles can be known and the state of reaction can be known too, than to control the reacting gas flow. On theory, we can compute the density of all the different particles exactly through the spectrogram with Stark manner etc. But because of the complexity and indeterminacy of parameters in reaction, with direct proportion between intensity of spectrum and density of particals, we choose the relative intensity of spectrum to agent the density of particals. And spectrometer, fiber, photoelectric conversion elements will be used in the system.Based on the principle of reactive magnetron sputtering and emission spectra diagnosing the plasma, I design an automatic system for reactive sputtering coating equipment which can adjust the react gas quickly. The equipments used in system are analysed, than the main equipments’brand and model number are chosen. The position of probe and interface of equipments are introduced.Furthermore, it formulates the regulation signal control algorithm and manners are studied. Two regulation signal modes are brought out with using the same or different spectral lines in different states. It designs a single neuron adaptive PID controller for PEM system of reactive sputtering coating equipment, and then simulates the control algorithm PID with software Matlab. By comparison simulation of classical PID without a single neuron adaptive controller, we can see it get a more ideal effect.Because of the PEM control system, the reactive sputtering coating equipment can work at the point with a high sputtering rate and get good compound thin film.Besides, the system is a fessible plan.