GIXRF combined with XRR for characterization of near surface layers

GIXRF and XRR are powerful non-destructive techniques for characterization of thin layers in depths up to a few hundred nanometers.

Both techniques use a similar measurement procedure, i.e. increasing the incidence angle and collecting data at various angles. Typically the angular range for GIXRF is smaller than for XRR, but can be extended easily.

The techniques on their own have limitations (i.e. ambiguity of the depth-profile for GIXRF, no information on elemental composition for XRR) and in both cases part of the produced radiation and thus information is left unused. By combining them the additional information can be used to eliminate the uncertainties of the individual methods.

The requirements on the primary beam are similar for both setups: low angular and energy divergence. Typically multilayers or crystals are used in combination with several slits to create a monochromatic and almost parallel beam.


Figure 1: The use of data from both detectors combines the benefits of both techniques
and thus reduces the ambiguities of the fitting-procedure,
increasing the confidence in the found solution.
The following parameters were used for the calculation:
thickness d=4.4nm, density ρ=9.7g/cm3, roughness σ=0.7nm