The shrinking of semiconductor devices means smaller and smaller architectures are used in their design process, requiring higher resolution characterization. Atom probe tomography (APT) is increasingly used in advanced semiconductor analysis, as it enables detection, visualization, and analysis of these structures, along with elemental composition, at very low concentrations.
However, APT requires the preparation of high-quality, high-yield, and site-specific atom probe tips. This can be a daunting challenge due to the strict criteria applied to these tips. For example, the needle-shaped specimen needs a tip radius of less than 50 nm, a uniform circular cross-section to produce a radially symmetric electric field, correct taper angle for evaporation events to occur, and minimal damage introduced to the tip during preparation.
Focused ion beam (FIB) milling using DualBeam (combined FIB and scanning electron microscopy) technology is ideally suited for this particular type of preparation, as milling allows for highly precise quantities of material to be removed while being monitored in real time. Thermo Fisher Scientific has introduced Thermo Scientific Atom Probe LX Software and the Thermo Scientific Helios 5 FX DualBeam, brand new sample preparation technology that automates the atom probe tip milling process, making it reliable, precise, and repeatable.
These high-quality tips allow you to detect phenomena such as etch-related impurities (e.g. fluorides, chlorides) at interfaces, hydrogen distribution within features, heavy metal diffusion into the gate oxide, and lateral diffusion of dopants in epi-layers. See the Helios 5 FX DualBeam product page for more information.
