What is in-plane X-ray diffraction (in-plane XRD)
In-plane diffraction refers to a diffraction technique in which both the incident and diffracted beams are nearly parallel to the sample surface. With standard diffraction geometries, such as the Bragg-Brentano geometry, lattice planes that are parallel to the sample surface are measured. X-rays penetrate deeply into the sample, where they are diffracted. However, when the sample layer is too thin, the X-rays are almost completely transmitted by the sample and a diffraction signal is difficult to measure. In these situations, that require sensitivity for studies of structural properties close to the sample’s surface, in-plane diffraction is used.
In-plane diffraction has two major features
- Because the beam is incident at a grazing angle, the penetration depth of the beam can be as low as 5 nm of the surface. Changing the incident angle offers the opportunity for depth resolution.
- The in-plane diffraction technique measures diffracted beams, which are scattered nearly parallel to the sample surface and hence measures lattice planes that are (nearly) perpendicular to the sample surface. These planes are not directly accessible by other techniques.
Applications of in-plane diffraction with PANalytical
In-plane diffraction is mainly used in the thin film industries for the phase analysis and microstructural characterization of semiconductor structures, hard disk coatings and other advanced material compositions.
Many different experiments are possible on PANalytical's X'Pert³ MRD (XL) and Empyrean diffraction system equipped with the in-plane option, incorporating different scan geometries and using different PreFIX modules.