Nanometer precision metrology of submicron Cu/SiO₂ interconnects using fluorescence and transmission x-ray microscopy

The x-ray fluorescence and soft x-ray transmission microscopy was used to quantitatively measure in situ Cu/SiO2 interconnect dimensions down to 0.3 μm. The methods and analysis techniques for measuring submicron linewidths, thicknesses and lengths with accuracies of 30-60 mm precisions, were also discussed. A simplifying 1D approximation was made that all Cu structures were very long in the longitudinal direction.