Measurement of the relative strain ratios normal to the crystal planes in Cu thin films using grazing incidence X-ray diffraction

The relative strain normal to the crystal planes in Cu thin films has been experimentally measured using grazing incidence X-ray diffraction. This was performed by measuring the ratio of the strain exerted in the same specific (hkl) crystal plane parallel and perpendicular to the film surface. The strain ratios of the (1 1 1), (2 0 0), (2 2 0) and (3 0 0) planes were found to be –0.804, –1.324, –1.003, and –1.369, respectively. These values are within experimental error of those calculated theoretically under the assumptions of plane stress conditions.