Small target compatible dimensional and analytical metrology for semiconductor nanostructures using x-ray fluorescence techniques

Abstract

X-ray fluorescence techniques in special operation modes can provide valuable quantitative insights for semiconductor related applications and can be made compatible to typical sizes of homogeneously structured metrology pads. As their dimensions are usually in the order of several 10 μm per direction, it must be ensured that no adjacent regions are irradiated or that no x-ray fluorescence radiation from adjacent areas reaches the detector. As this can be realized by using small excitation beams, a multitude of information can be retrieved from such XRF data. In addition to elemental composition, including sensitivity to sub-surface features, one can derive quantitative amounts of material and even dimensional properties of the nanostructures under study. Here, we show three different approaches for studies related to semiconductor applications that are capable to be performed on real world dies with commonly sized metrology pads.

Reference-free x-ray fluorescence analysis with a micrometer-sized incident beam

“…-free XRF is now applicable at multiple spatial resolutions ranging from the mm to the nm range. With this metrological toolset, quantitative composition analysis can be performed at medium to high spatial resolution for a wide range of potential sample systems [39].…”