Samsung Advanced Institute of Technology

The distribution of N in semiconductor devices plays a crucial role in tuning their physical and electrical properties. However, direct observation and precise quantification of N remain challenging because of analytical limitations, particularly at critical interfaces in Si-based semiconductors. Although atom probe tomography (APT) has emerged as a powerful tool, distinguishing N from Si without isotope doping has been persistently difficult. In this study, we employed advanced APT with an extended flight path under optimized conditions to characterize the three-dimensional (3D) N distribution in actual device structures, including 2- and 5-nm-thick SiO₂/SiON-based gate dielectrics and a fin-structured 3D device. Our analysis revealed that the N distribution determines the formation of the N profile in gate dielectrics, which in turn affects the diffusion of impurities, ultimately impacting the electrical properties and reliability. Our work provides unprecedented insights into atomic-scale N behavior, paving the way for advancing next-generation semiconductor devices.