| 摘要 |
A method for measuring the film element using optical multi-wavelength interferometry is revealed. The invention uses reflection coefficients of thin films at different wavelengths to measure the thickness and optical constants of thin films. The phase difference coming from the phase difference between test and reference surfaces is distinguished from the phase difference from the spatial path difference between reference and test beams by doing measurements on different wavelengths, because they change in different ways as the measuring wavelength changes. The phase is then acquired. Combining with the measured reflectance of thin film, the reflection coefficient of thin film is obtained. Collecting the reflection coefficients of each point, the thin film thickness and optical constants distribution in 2 dimensions are calculated. The surface profile is known through the spatial path differences between reference and test beams. These can be measured in a interferometer to avoid the vibration influence. |
