Analysis And Research Of Reactive Sputtering Control In The Vacuum Coating System

Vacuum coating is a promising surface coating application technology, it has a certainseries of excellent characteristics that other craft can’t be replaced: free from influence ofcoating component materials and the status quo; thickness of the coating can be controlled,typically a few tenths or a few microns percent of a micron. Thus, it is widely used inelectronic equipment, astronomical instruments, meters and other industries. In vacuumcoating system the reactive sputtering coating is a common method used for the preparation ofcompound thin film. The control of the sputtering process is particularly important to obtainbetter quality films. This paper focuses on the analysis and research of reactive sputteringprocess control.This paper first introduces the background, purpose and significance of the thesis. At thesame time, it introduces several reactive sputtering methods commonly used, such as DCreactive sputtering, reactive sputtering and reactive magnetron sputtering. Reactive magnetronsputtering, the most promising development in a coating method, has been widely applied tovarious areas of the industry.Then the paper analysis the Speedflo reactive sputtering controller of the Genconcompany in British. This controller is more flexible and powerful, also can get the best resultfrom the deposition and plasma processes. It is a sensor feedback system, monitors the outputof the sputtering process, and startups the automatic input of the process, thus improvesefficiency and maintains quality and stability of the product. The working principle ismonitoring and controlling the plasma intensity by adjusting the reaction gas input. Thecharacteristics of the Speedflo reactive sputtering controller is that using the spectral feedbackcompatible with voltage feedback, using the the PDF algorithm rather than the conventionalPID algorithm, multi-channel feedback information, multi-channel input and output.the control algorithm plays a key role in the control process. While the controller has theadvantages of using a PDF control algorithm in the control process, but there is stillinsufficient, especially chemical stability of the film. By reactive sputtering process modelingand simulation, it obtains that when the system reaches a steady state, there will be lessvolatile. This will affect the chemical properties of the film stability, the required film qualityhigh places below standard. Thus, according to this shortcoming, this paper proposes animproved control algorithm, namely fuzzy PDF control algorithm. Among them, the main useof adaptive fuzzy control fuzzy control, real-time adjustment of the control parameters. UsingMatlab software algorithm simulation, it concludes that the fuzzy PDF control strategy cannot only enhance the anti-jamming performance, but also to eliminate the static error. Thismakes compound film more uniform in thickness, and more stable in chemical in the sputter-coating process, and also improves the application of the product value. PDF fuzzycontrol algorithm in a vacuum coating technology has a strong practical, making it towardmore refined direction.