Thickness Estimation of the Si Thin Films: a Simulation Study
  We propose a theoretical study for Si thin film thickness measurement that is based on incident low energy electron beam on the film and counting the transmitted/incident electron fraction. It estimates the thin film thickness distribution from a exponential relation which obtained from counting the fraction of transmitted/incident electron at different thicknesses. By using this obtained equation, it is possible to estimate unknown thickness of the Si thin film. In order to calculate the Si thin film thickness estimation, the energy of the incident electron beams is varied from 6-12 keV, while the thickness of the Si film is varied between 100-400 nm. The most significant feature of this method is that no expensive instruments are required. As anticipated, the proposed method shows that there is a relationship between film thickness and incident beam energy, which by using this relationship, we can find unknown film thickness in 1-D and 2-D conditions. Other advantages include wide measurement range, no calibration need and simple method. Additionally, an investigation by different beam energies helps to avoid artefact from this method. All calculations were done by CASINO numerical simulation package. 
Mohammad Babazadeh, Abdollah Rahmat Nezamabad, Hossein Movla, Farzad   Ghafari Jouneghani
cond-mat.mtrl-sci