Ion dynamics in laser-produced plasma for EUV generation in nanolithography devices

Increasing EUV photon power in laser-produced plasma (LPP) sources is critically needed for efficient nanolithography devices. Improving debris mitigation methods is another important subject in the development of EUV sources for high volume manufacture tools. We investigated different mechanisms affecting ions acceleration in LPP to predict the maximum ion energies and flux arriving at the mirror surface. We studied in details plasma evolution produced by Nd:YAG laser from Sn target to predict EUV producing ions dynamics and their contributions to EUV source. The 3D multi-physics fully integrated HEIGHTS package was used in this analysis. We continue to develop, enhance, and benchmark the models implemented in our package to include various physics involved in LPP systems. HEIGHTS simulation of detail ion kinetic energies were compared with experimental data and showed great confidence in our advanced self-integrated models that can then be used for the explanation of the experimental data as well as for various predictions. Spatial and charge distributions were predicted for EUV producing ions and debris. We studied various target configurations and laser parameters to enhance the power of EUV sources as well as to reduce and mitigate ions and debris effects on the collecting mirror system. The comprehensive integrated full 3D models allowed accurate simulation of all processes of plasma formation, dynamics, and EUV photons emission and collection.