Optical metrology of thin films using high-accuracy spectro-photometric measurements with oblique angles of incidence

摘要

Oblique-incidence spectrophotometric measurements are considered for reliable determination of the refractive index and thickness of thin-film coatings. By using a model of the spectral transmittance of thin film samples, the effect of systematic factors on the determined thin-film parameters is analyzed. The optical parameters of a silicon-dioxide sample determined from the experimental results obtained with the HUT spectrophotometer are consistent for the incidence angles between 0 and 56.4 degrees, demonstrating high accuracy of film-parameter determination.