Research On Nano Film Thickness Measurment And Traceability Based On Mueller Ellipsometry

With the rapid development of nano-fabrication technology,nano-film technology has been widely used.Rapid,low-cost,non-destructive and accurate measurement of nano-film thickness and traceability of film thickness values are of great significance in ultra-precision processing such as advanced manufacturing and integrated circuit industries.In view of this development status,this paper studies the measurement of the geometric parameter of film thickness.Through the construction of ellipsometry measurement system,the preparation and calibration of film thickness standard samples,the solution method of film thickness and the traceability system of film thickness value,to achieve high-precision measurement of nano-film thickness.Firstly,this paper analyzes the optical path composition and system model of the Mueller matrix ellipsometry system,selects the components with appropriate indexes,determines the optical hardware composition,and builds a set of wide-spectrum dualrotation compensator Mueller matrix ellipsometry system.The key technologies in the system are mainly introduced: the synchronous motion of the dual-rotation compensator triggers the detector to collect the spectral signal,and the synchronous acquisition of the spectral signal of the measuring optical path is completed.After the system is built,the air medium and the silica standard sample are used as the measurement objects to test the performance of the entire measurement device.Secondly,in order to solve the problem of traceability and calibration of measuring instruments in the process of nanometer measurement,and to study the characteristics of different oxidation processes,a set of 5 nm～ 500 nm composite structure film thickness standard sample,including composite model structure design of physical film structure and geometric film structure,to meet the film parameter calibration requirements of optical and non-optical nano-film measuring instruments.Finally,based on the structural characteristics of the nano-film,the ellipsometry process is analyzed,the ellipsometry film thickness measurement model of the film material is established,and the double-rotation Muller ellipsometry system is used to measure the physical properties of the film area to realize the effective nano-film thickness template.Characterization and uncertainty evaluation of measurement results.According to the structural characteristics of the samples,a quantitative atomic force microscope was used for comparative analysis to establish a film thickness measurement system with a composite film thickness standard sample as the standard material,and the overall performance and traceability of the nanometer measurement system were verified through laboratory comparison analysis.