Arsenic dopant mapping in state-of-the-art semiconductor devices using electron energy-loss spectroscopy

Knowledge of the dopant distribution in nanodevices is critical for optimising their electrical performances. We demonstrate with a scanning transmission electron microscope the direct detection and two-dimensional distribution maps of arsenic dopant in semiconductor silicon devices using electron energy-loss spectroscopy. The technique has been applied to 40–45 nm high density static random access memory and to n–p–n BiCMOS transistors. The quantitative maps have been compared with secondary ion mass spectrometry analysis and show a good agreement. The sensitivity using this approach is in the low 1019 cm−3 range with a spatial resolution of about 2 nm.