Optical Characterization Group

Universitat de Barcelona

Characterization Programs

Three programs are presented here. NKDGen is a direct calculation program while NKDMatl and NKDStack are for inverting spectorcopic data. NKDMatl and NKDStack are intended for users involved in Researh and Development tasks, to help in the optical analysis of their samples.

          
    • NKDGen: simulation of optical spectra

      This program can be used to calculate optical spectra for a sample defined by the user. It illustrates the variety of dispersion models for the refractive index and extinction coefficient that are available within the NKD programs as well as the different kinds of experimental spectra that can be analyzed by NKDMatl and NKDStack.


          
    • NKDMatl: single layer material characterization

      This program has been developed for the analysis of materials deposited as a single thin film. Many dispersion models for the refractive index and absorption coefficient are implemented (for transparent materials, semiconductors, metals...).

      In-depth inhomogeneity, surface roughness, interface layers and bare substrate characterization are included as well. All these characteristics are fitted from the ellipsometric and/or spectrophotometric data, together with the thickness, refractive index and absorption coefficient.


          
    • NKDStack: multilayer coating characterization

      This is a program for analysis of spectrophotometric and ellipsometric spectra of samples with multilayer coatings. Thicknesses and dispersive complex refractive indices can be fitted from the data.

      For coatings with many layers, the characteristics of the component materials can be linked between the layers, in order to reduce the number of parameters and to obtain more meaningful results.

      Several dispersive and EMA models can be used for the layer materials. Besides, the program allows the simultaneous fitting of several spectra from the same sample, as well as the fitting of several samples from the same coating run.

    These programs can manage unconventional characterization needs in the research and manufacture of thin film products (fitting several spectra from a single sample, fitting together the data of several samples...).