Multidimensional Simulation and Optimization of Hybrid Laser and Discharge Plasma Devices for EUV Lithography

Current devices for EUV lithography combine both laser and discharge physics to achieve sufficient brightness with minimum debris generation to support the throughput requirements of High-Volume Manufacturing (HVM) lithography exposure tools with long lifetime. Source performance, Debris mitigation, and reflector system are critical to efficient EUV collection and component lifetime. Integrated models are developed to simulate EUV emission at high power and debris generation and transport in hybrid EUV devices. The models being developed include, for example, new ideas and parameters of laser beams in discharge devices. In addition, optimization of source parameters, combination magnetic fields and gas jet parameters to significantly reduce the debris, and mirror surface conditions to enhance the reflectivity of EUV. Source optimization studies include full 3-D simulation of laser interaction with tin targets followed by discharge simulation to produce the optimum EUV photons. Initial simulations show that for HVM devices a combination of source optimization, innovative debris mitigation system, and understanding debris/mirror interaction is required to achieve the lifetime needed.