In-plane diffraction

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 are measured that are parallel to the sample surface. X-rays penetrate to a certain depth into the sample, where they are diffracted. However, when the sample layer is too thin, the X-rays are completely transmitted by the sample and no diffraction signal can be measured. In these circumstances, 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 is limited to within about 100 nm of the surface.
• 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 inaccessible 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'Pert PRO MRD for in-plane diffraction system, incorporating different scan geometries and using different PreFIX modules.