Application of femtosecond frequency combs in the Measurement of Film thickness

摘要

In this paper, a method to measure the thickness of TiO_2 is developed based on the Micklson interferometer. Through aspectral domain analysis of multiple interferograms obtained using a femtosecond pulse laser, accroding to theinterferance signals appear in the interferograms the thickness of film can be measured at high speed. We developed asimple method to measure the film thickness and for a sample we use the silicon wafer and coated TiO2 silicon wafer.Thickness of silicon wafer and coated TiO_2 silicon wafer were measured respectivly, then from the thickness of coatedTiO_2 silicon wafer minus the thickness of silicon wafer. Result shows that the avarege thickness of TiO_2 is 75.00μm