Project

Optical film characterization

ellipsometry-fig1.jpg

PlanOpSim has used a number of optical techniques for characterization and parameter extraction from thin film materials. The most important optical parameters extracted are:

  • Refractive index and absorption coefficient
  • Haze and transmission
  • Optical retardation of birefringent materials
  • Film thickness
  • Transmission and reflection

Thin film characterization techniques very recquire parameter fitting to extract material parameters from measured transmitted and reflected signals. We build a parametrized model of the wavelength-dependendent refractive index, extra-ordinairy axis, layers and their thickness. The parameters are then varied to find the best fit to measured data. The fit can be performed on multiple measurements and/or multiple samples. The more data, the more reliable the extracted parameters will be.

PlanOpSim can help you with these techniques:

  • Spectroscopic Ellipsometry: is the reference method for dsetermining the refractive index of thin films.
  • Optical retardation measurements using a Babinet compensator: the most accurate method to determine the retardation factor of a birefringent film.
  • Transmission and reflection spectrometry: is an alternative method to determine the refractive index and asbsorption coefficient. Generally thicker films are needed than in ellipsometric measurements
  • Haze & Transmission: Haze is an important experimental parameter for scattering and structured films. The measurement must be carefully conducted with an integrating sphere.