Characterization of polycrystalline gradient thin film by X-ray diffraction method

A direct method is proposed to quantitatively characterise the structural d epth profiles emerged in the polycrystalline thin films based on the inform ation obtained by X-ray diffraction (XRD) with various incident angles and treated by a numerical procedure known as the constrained linear inversion. It should be noted that the proposed method was neither sensitive to the r andom noise appearing in experiment nor to the error originated from the me asured thickness of the specimen. To testify the validity of the method, XR D measurements were carried out on a specially designed Pd/Ag bilayer sampl e, which was annealed at 490 degrees C for 20 min, and the depth profiles w ere accordingly calculated through resolving the obtained XRD patterns. The elemental concentration depth profile of the Pd/Ag bilayer sample was in t urn calculated from the resolved patterns, which was in good agreement with those obtained by Auger electron analysis on the annealed sample.