Total Reflection X-rays Fluorescence (TXRF) utilizes total reflection of incident primary X-Rays, to enhance the intensity of Secondary (Fluorescent) X-rays emitted from a thin sample, placed on a polished carrier. This enables trace and ultra-trace elemental surface analysis of thin sample layers.
Specular X-ray Reflectivity (XRR)
Specular X-Ray Reflectivity (XRR) is a surface sensitive analytical technique that utilizes monochromatic X-ray beam reflection at a specular angle, to study material surfaces, ultra-thin films and multilayered structures. The term specular reflection means that the reflected angle of the X-ray beam is equal to its incident angle. The intensity of the reflected X-ray wave is correlated with the angle of incidence of the X-ray beam, its wavelength and properties of the reflecting layer such as refractive index, roughness, thickness and density. The mathematical analysis involves matching measured X-Ray intensity data with computer simulations. The angle of incidence is maintained at grazing angle around the critical angle, to investigate thin layers. The reflecting layer may be a single thin layer at the surface or an in-depth interlayer in a multi-layer structure. XRR is used to characterize single and multi-layer structures, thin films, optical coatings and catalyst surfaces.
Common Uses of Specular X-ray Reflectivity (XRR)
- Determining thickness, density and roughness of ultra-thin films, single and multilayer stacks in semiconductors
- Quality control of reflectance and resolution of optical coatings
- Research and development of specialized coatings for optical devices
- High throughput quality control of semiconductor wafer manufacturing
Advantages of Specular X-ray Reflectivity (XRR)
- High resolution and precision covering thicknesses from Ångstroms to microns
- Crystalline or amorphous materials can be characterized
- Conductors or insulators can be analyzed
- Measurements at ambient conditions
Limitations of Specular X-ray Reflectivity (XRR)
- Interpretation is based upon mathematical analysis and simulation
- Film thickness upper limit is around 200 nm
Industrial Applications of Specular X-ray Reflectivity (XRR)
- Semiconductors
- Optical coatings
- Materials science research
