Background
A 25 nm nickel (Ni) thin film on a glass substrate was measured at two different incident angles: 0.02° and 0.40°. Incident angle 0.02° is under condition of TXRF and then only the surface information is obtained. On the other hand, angle 0.40° is higher than the critical angle then it is possible to measure deeper area beneath the surface. Only Ni was strongly excited at 0.02° GI (Grazing Incidence) excitation condition (blue spectrum). However, elements included in the glass substrate are strongly exited at the higher 0.40° angle (red spectrum) because X-rays penetrate more deeply into the substrate. It is possible to change incident angle arbitrarily, and then the characterization of the solid surface can be done by using this function.
TXRF products from Rigaku
The new, next generation benchtop total reflection X-ray fluorescence (TXRF) spectrometer
Ultra-trace elemental surface contamination metrology by TXRF with VPD capability; up to 300 mm wafers