Site-Specific Sample Preparation and Analysis of FinFET structure in 14nm Technology Node Chip via Atom Probe Tomography

At present the atom probe tomography (APT) has shown its advantage to analyze dopant distributions in FinFET devices with sub-nm 3D-resolution and good dopant sensitivity. Preparing samples for APT analysis can carry significant challenges. The main limiting factor with respect to the type of problems that can be addressed is the small volume investigated and the randomness of common sample preparation methods. An improved method utilizing focused ion beam (FIB) is presented that can be used to site-specific produce atom probe samples with features of interest at any desired orientation with an accuracy of better than 10 nm from samples of 14 nm FinFET devices. The sample analysis provides three dimensional compositions of Fin channel, metal gate and high-k oxide of the FinFET structure. Finally, the reconstruction data is discussed and the measurement is also compared with high resolution STEM-EDS analysis.