SpectraRay II - Anisotropy

SpectraRay Anisotropic Sample Analysis Software for Spectroscopic Ellipsometry

• Advanced optical modeling of anisotropic layer stacks
• Covers the entire spectral range of the SENTECH ellipsometer product family
• Uniaxial and biaxial layer types with up to 3 direction dependent dielectric functions n_x(λ), n_y(λ), n_z(λ) or ε_x, ε_y, ε_z
• Application of ‘isotropic’ dispersion relations (including oscillators, effective medium approximation and others)
• Fit of 3 Euler angles α, β, γ provides crystal coordinate system orientation 
• Isotropic and anisotropic layers can be stacked
• Comfortable operation due to complete integration in SpectraRay II software package

Unlike isotropic materials, anisotropic materials show optical properties that depend on the direction of the propagation of light with respect to the material axes. This means, an anisotropic material is characterized by more than one refractive index at a given wavelength. Anisotropic behavior of a sample can be verified by taking ellipsometric data at multiple angles of incidence or by different rotation angles of the sample on the plane of the sample surface (z-axis).

The SpectraRay anisotropic sample analysis software allows the characterization of anisotropic samples for any set of angles of incidence, sample rotation or polarizer azimuth.

The SpectraRay anisotropic sample analysis software supports the analysis of ellipsometric data at any orientation of the sample (often called generalized ellipsometry).

The following complex dispersion relations are added to the SpectraRay II software package:

• Uniaxial material type n_xy, n_z (ε_xy, ε_z)
• Biaxial material type n_x, n_y, n_z (ε_x, ε_y, ε_z) with 3 Euler angles α, β, γ

The harmonic integration of the anisotropy capability in SpectraRay II is almost seamless regarding the software concept. It ensures comfortable operation and modeling as known from SpectraRay II.

The uniaxial material type supports 2 complex dispersion relations n_xy(λ), n_z(λ). The biaxial material type supports up to 3 complex dispersion relations n_x(λ), n_y(λ), n_z(λ). All ‘isotropic’ dispersion relation types can be chosen for n_i(λ) (Cauchy, Sellmeier, Oscillators, Effective Medium Approximation EMA and many others). The fit of the 3 Euler angles α, β, γ is possible as well and provides the orientation of the optical coordinate system of any layer with respect to the sample surface and the ellipsometer plane. Both, isotropic and anisotropic layers can be stacked.

Please contact us for more information.