Spectroscopic Ellipsometry Software – SpectraRay/4

The proprietary SpectraRay/4 SENTECH Spectroscopic Ellipsometry Software, includes data acquisition, modeling, fitting, and extended reporting of ellipsometric, reflection, and transmission data.

Key features & benefits

About SpectraRay/4

SpectraRay/4, the SENTECH proprietary spectroscopic ellipsometry software, includes data acquisition, modelling, fitting, and extended reporting of ellipsometric, reflection, and transmission data. It supports variable angles, multi-experiment, and combined photometric measurements. SpectraRay/4 includes a large and comprehensive library of materials data based on SENTECH thickness measurements and literature data as well. The large number of dispersion models allows the modelling of nearly any type of material.


The mapping option of our spectroscopic ellipsometry features predefined or user-defined patterns, extensive statistics, and graphical display of data as 2D colour, grey, contour, +/- deviation from the mean value, and 3D plot.


Measurement parameters may be simulated as a function of wavelength, photon energy, reciprocal centimetre, angle of incidence, time, temperature, thin film thickness measurement, and other parameters.


Multilayer analysis by SpectraRay/4 – thickness of Si3N4/Si02/Si3N4 (nm).


Interactive mode

  • Setting measurement parameters and starting thin film thickness measurement
  • Building a model by drag and drop from a materials library or from already existing dispersion models
  • Defining and varying parameters to fit the calculated spectra to the measured spectra
  • Interactively improving the model for best figure of merit
  • Reporting the results as a word document by selecting from predefined or customized templates
  • Saving all experimental data, the protocol, and comments in one experiment file

Recipe mode

The advantage of SpectraRay/4 recipe mode is a two step action:
  1. Selection and
  2. Execution of predefined recipes from a library.
The recipes comprise thickness measurement parameters, models, fitting parameters, and reporting templates.

First step:

Second step:

Third step:

Fourth step:

SpectraRay/4 provides a user-friendly workflow-oriented interface to operate SENTECH Spectroscopic Ellipsometry tools and a comprehensive set of tools to model, fit, and represent ellipsometric data. The user interface incorporates a recipe-oriented operation for operators and an advanced mode for interactive measurement and modelling.

Flexibility and modularity

SpectraRay/4 features uniaxial and biaxial anisotropic material measurements, thin film thickness measurement, and the measurement of layers. The software treats sample effects like depolarisation, non-uniformity, scattering (Mueller-matrix), and backside reflection.

The software includes all utilities of the general spectroscopic ellipsometry software package for data import and export (ASCII included), file management, arithmetic manipulations of spectra, display, printing, and reporting (in Word file format *.doc). The scripting capability makes it very flexible to automate routine measurements, tailor them for demanding applications, and control third-party hardware like sensors, heating stage, sample cell or cryostat.


  • Ellipsometric parameter ψ, Δ, tan (ψ), cos (Δ)
  • Fourier coefficients
  • Reflectance R, Rp, Rs
  • Transmittance T
  • Optical properties n, k, ne, no, ke, ko
  • Material properties ε1, ε2
  • MSE value
  • Colour values
  • Brendel oscillator
  • Cauchy
  • Cody-Lorentz
  • Drude-Lorentz oscillator
  • Effective medium and index gradient
  • Extended Drude
  • Formula
  • Forouhi-Bloomer
  • Hamberg
  • Harmonic oscillator
  • Sellmeier
  • Sernelius
  • Spectrum combination
  • Tanguy
  • Tauc-Lorentz
  • Uniaxial & biaxial anisotropic and others
  • Sample information
  • Angle of incidence: multiple or single angle measurement
  • Wavelength range
  • Measurement mode: (ψ,Δ), (S1, S2), T, Rp, Rs
  • Mapping options
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