CHARIOT is a Monte Carlo simulator used to understand and predict the results of electron-to-solid interactions, such as image formation in scanning electron microscopy (SEM), deposition of electron energy, backscattering coefficients and emission properties, as well as the transmission of electrons through thin films. Advanced models are used in CHARIOT for simulations. This allows for a significant increase in accuracy, especially at electron energies less than 10 keV.

Simulation layout of an electron microscope

    CHARIOT Software Simulates

  • image formation in SEM
  • electron trajectories in targets
  • energy deposition in materials; for example, the proximity function in electron lithography
  • electron penetration through films and emission properties
  • electron spectra

  • CHARIOT Considers

  • An advanced Monte Carlo model of electron scattering in materials
  • 2D and 3D multilayered patterns
  • The geometry and energy transfer function of a detector
  • Electron trajectories in electrostatic fields
  • Low voltage secondary electrons, with an emphasis on 0...50 eV
  • E-beams of point, Gaussian, and rectangular shapes, as well as tilted and conical beams
SEM image of contact hole with and without defect

    Physical Models

    Physical models used in CHARIOT software involve
  • elastic scattering of electrons
  • inelastic energy loss by electrons
  • generation of fast secondary electrons
  • generation of plasmons
  • electron penetration between layers

  • 3D target

    Each layer of a target can be specified separately, including its chemical composition, physical properties, and the geometry of the pattern. The layers can be automatically combined to imitate such processes as etch, film deposition, and lift off. In this way, a complex 3D pattern like a microcurcuit can be specified.

    All input data can be specified via a user-friendly graphical user interface, and a library of constants for a variety of materials is provided.

    Cluster version

    Monte Carlo simulations in general take time. A cluster version of CHARIOT was developed, which reduces the simulation time drastically.