Three-Dimensional Elemental Analysis of Commercial 45 nm Node Device with High-$k$/Metal Gate Stack by Atom Probe Tomography

Laser-assisted atom probe tomography (APT) was successfully applied to analyze the elemental distributions in a high-k/metal gate stack of a commercially available 45 nm node real device. APT revealed the multilayer structure of the high-k/metal gate stack with nearly atomic-scale resolution, and successfully detected small amounts of Zr in the thin layer of high-k HfO2 dielectrics and H in the Ti layer of the metal gate. The present results demonstrate the usefulness of APT as a tool of elemental analysis in nanoscale multilayer device structures.