Visible light shines vertically on the measured film, and part of the light is reflected on the film surface, and the other part penetrates the film, and then reflected at the interface between the film and the bottom layer, so that the light reflected on the film surface and the light reflected on the film bottom interfere with each other. Based on the principle of white light interference, it uses broadband light source to measure reflection data of different wavelengths. Because the reflectivity n and k vary with different films, the film thickness can be obtained by curve fitting according to this characteristic. Parameters corresponding to different types of materials are described by different models, which ensures the accuracy of film thickness measurement of different types of materials.
Dacheng precision equipment film thickness meter adopts non-radioactive advanced measurement technology, which is an ideal solution to measure the thickness of diaphragm.