STEM Energy-Dispersive X-ray Spectroscopy for Quantitative Compositional Metrology in ULSI Technology

For metrology in the semiconductor industry, the application of energy dispersive x-ray spectroscopy (EDS) in a scanning transmission electron microscope (STEM) is often limited to qualitative characterization of devices. Compositional quantification is limited by count statistics of x-ray photons within the allotted measurement time and by the standardless Cliff-Lorimer method. Quantitative metrology here means compositional mapping, at nanometre scale lateral spatial resolution, of microelectronic devices in Ultra Large-Scale Integration (ULSI) technology by an electron probe under non-channelling conditions.