X-Ray Diffracto-meter

X-ray analysis is an important feedback for sample growers and designers, and useful complement to local scanning methods. In comparison to local probe imaging methods, x-ray techniques are non-local, non-destructive, local in reciprocal space, provides statistically averaged structural parameters due to relatively large irradiated volume of layered semiconductor samples. Typical penetration depth of x-rays of few micrometers provides structural information of the whole stack of semiconductor layers within a sample. The modern X'Pert PRO x-ray diffraction system (fy. PANalytical) at ZMNS supports wide variety of analytical techniques. The modular configuration with special accessories was ordered especially for the study of perfect semiconductor epitaxial layers as well as for investigation of lattice-mismatched heterostructures, nanostructures, and deformed multilayers (of certain defects density). In standard high resolution x-ray diffraction mode for rocking curve measurements on perfect epitaxial layers, the thickness and composition of layers can be obtained. Adding the analyzer crystal this mode turnes to triple axis configuration where it is possible to separate lattice strain effects by recording reciprocal space maps. The sophisticated system is also able of newer methods of in-plane scattering geometries. Grazing incidence setups allow better intensity contrast due to suppressing of scattering from the substrate. In comparison to standard reflectivity setup, grazing incidence scattering has larger accesible region, which is useful especially  in case of lateral structures of the order of 10 - 200  nm (such as InAs quantum dots). In grazing incidence diffraction or reflectometry we can study layer thickness, interface quality, density and morphological corelations such as from the ordered self-organized nanostructures. Interchangable point to line focus optics with collimating mirror and automatic absorber  provide  very high dynamic range useful especially for reflectivity measurements. For samples not requiring the highest resolution, the new X'Celerator detector makes the measurements even more efficient. In addition to single crystal layers, the compact system offers also applications for analysis of amorphous, polycrystalline, textured or other highly defect samples. Pre-aligned, fast-interchangable PreFIF x-ray optical modules make the reconfiguration between measurement setups rapid and very simple. All components and shielding with double independent safety loops meet the highest German Röntgenverordnung classification Vollschutz standard. With the new control and data collection software together with the simulation and fitting package the analysis became very fast and effective.