Design and fabrication of robust broadband extreme ultraviolet multilayers

The robust designs of broadband extreme ultraviolet multilayers based on the multiobjective genetic algorithm are validated experimentally. In order to reduce the influence of random layer thickness fluctuations on the great deformation of the experimental reflection of extreme ultraviolet multilayer with a wide angular band, the multiobjective genetic algorithm has been improved to optimize the multilayer system composed by the layer thicknesses which can be controlled precisely. The robust designs of broadband Mo/Si multilayers were fabricated, and the experimental results were presented and analyzed, and then the advantage of robust multilayer designs was demonstrated.