A combination of measurements of crystal truncation roda and X-ray standing waves has been used for a detailed characterization of buried Ge δ layers on Si(001). Measurements of crystal truncation rods reveal the interface roughness, the δ layer lattice constant and the δ layer concentration. From measurements with X-ray standing waves the dopant lattice position and crystallinity of the δ layer are determined. We find a linear dependence of the local tetragonal distortion of the Ge bonding in the δ layer on the Ge concentration in the layer.
AbstractGrazing-incidence X-ray analysis techniques which are commonly used for the nondestructive characterization of surfaces and thin films are reviewed. The X-ray reflectivity technicue is used to study surface uniformity and oxidation, layer thickness and density, interface roughness and diffusion, etc. The grazing-incidence in-plane diffraction technique is used to determine in-plane crystallography of epitaxial films. The grazing-incidence asymmetric-Bragg diffraction is used for surface phase identification and structural depth profiling determination of polycrystalline films. Typical examples to illustrate the types of information that can be obtained by the techniques are presented.
AbstractSpectroscopic Ellipsometry (SE) and Grazing X-ray Reflectance (GXR) techniques are applied on different III-V epitaxial structures in order to extract accurately their structural information. Thickness information are obtained directly from Fourier transformation of the GXR spectra and confirmed by simulation of the reflectance curve. Compositions are deduced from SE regression using GXR thickness as input values. Examples on monolayer and bilayer structures are first remembered. Then the potentiality of the method is demonstrated to more complex systems (multilayer mirrors and HEMT structures).
The Characterization of Interface Roughness and Other Defects in Multilayers by X-Ray Scattering