Analysis of Film Thickness Uniformity and Design of Correction Baffles for the Asynchronous Mass-Energy Thin Film Deposition System

To meet the high requirements for thickness uniformity of large-size optical thin films in space optical systems,this work conducts modeling and analysis of film thickness uniformity for a self-designed mass-energy asynchronous magnetron sputtering thin film deposition system. This system effectively suppresses nodule defects and thereby improves the laser damage threshold of the film by discretizing the thin film deposition process and introducing variable-angle auxiliary ion beam bombardment. On this basis,a calculation model of film thickness distribution suitable for this device is constructed,and the influence laws of structural parameters such as target width,target height,the distance between the target and the axis of the sample holder,and the radius of the sample holder on film thickness uniformity are systematically analyzed. The calculation results show that:the target width has a relatively small impact on film thickness uniformity;the larger the target height,the more uniform the film thickness distribution in the vertical direction;when the distance between the target and the sample holder is less than 1. 5 times the radius of the sample holder,the film thickness uniformity becomes worse as the distance increases;when this distance exceeds 1. 5 times,the uniformity is instead improved;in addition,the change in the radius of the sample holder has no significant effect on the film thickness distribution. When the optimization effect of adjusting the above structural parameters is limited,this paper designs a film thickness correction baffle,which uses the original film thickness distribution information obtained by simulation to regulate the effective working area of the target. The correction results show that the film thickness uniformity of the sample is significanty improved,and the initial difference coefficient decreased from more than 0. 35 to less than 0. 005,and the thickness difference corresponding to a 100 nm film thickness is only 0. 5 nm,which significantly improves the film thickness control accuracy. The research results provide theoretical guidance for the structural optimization of complex deposition systems and also provide technical support for the batch preparation of high-uniformity optical thin film components.