Digital Interferogram Processing in Nanometer Thickness Measurement of Films by Microinterferometer MII-4
Measuring potential of microinterferometer MII-4 has been spread on the nanometer thickness region by application of digital data processing. The upgraded microinterferometer with an adapted web camera for interference pattern registration as well as the developed software Optic Meter make it possible not only to measure the nanometer thickness, but also to significantly reduce the error of thickness measurements. Application of the digital interferogram processing using the developed software Optic Meter allows for the measurement of thickness up to 20 nm with a resolution of 5 nm, which is practically impossible to achieve by using the visual method. Comparison of the results of thickness measurements by atomic force microscopy and with the upgraded microinterferometer showed a difference of 2 nm, which proves the reliably of the proposed method.