Patent ID: 6173037
Filing Date: 2001-01-09
Classification: G01N

Abstract:
A method of examining a sample by means of X-ray fluorescent analysis, which sample comprises a substrate which is provided with a thin layer, the substrate containing a first chemical element, the thin layer containing the same chemical element and a second chemical element which does not form part of the substrate, said method including the steps of:irradiating the sample by means of primary X-rays;measuring an intensity of comparatively hard X-ray fluorescent radiation and of comparatively soft X-ray fluorescent radiation, both types of radiation being generated in the sample in response to the irradiation by means of the primary X-rays;measuring an intensity of X-ray fluorescent radiation whose wavelength deviates from the comparatively hard and comparatively soft X-rays, generated in the sample in response to the irradiation by means of the primary X-rays,determining a thickness of the thin layer or the concentration of the first or the second chemical element on the basis of the measured intensities of the three types of X-ray fluorescent radiation,determining a reliability or an accuracy of the the thickness or the concentration determined in said determining stop on the basis of the measured intensities of the three wavelengths of the X-ray fluorescent radiation.