The accuracies of photometric, polarimetric and ellipsometric methods for the optical constants of thin films

The inherent accuracies of various techniques for determining the optical constants of thin films have been assessed by computing the errors produced in n and k by known experimental errors in the optical functions being measured. The results are presented as arrays of error parallelograms in the n–k plane covering d/λ from 0.001 to 0.20 and θ from 5° to 85°.The largest regions of accuracy, in the form of annular quadrants, were obtained using the mixed photometric and polarimetric functions at small angles of incidence. Ellipsometry gives similar results at large angles of incidence but for photometry and for polarimetry the accurate regions were in the form of two lobes.The effects of errors in x and θ were also considered.