Thickness measurement of complex sample with synchronous radiation

Film samples, especially the complex sample, require thickness measurement in very high precision, which can not be achieved by weighing method due to the samples’ small mass. The beamlines of median energy(4B7A) and low energy(4B7B) in Beijing Synchronous Radiation Facility have energies of 0.1 keV to 6.0 keV and energy resolution of over 1 000. This paper presents a thickness measurement method for complex samples by measuring single-energy photon filtering from the samples with the two beamlines, and analyzes the measurement uncertainty at different energy points to improve the measurement precision. The thickness obtained for a complex sample with CH substrate has a measurement uncertainty of less than 1%.