Modification of Mo/Si multilayer coating by processing with fs laser pulses

Summary form only given. Mo/Si multilayer (ML) coatings are widely used as reflective coatings of XUV optics, particularly - mirrors and photomasks in EUV (13.5 nm) lithography. Therefore, the problem of controllable change of optical properties of such coatings, first of all - reflectivity in EUV spectral field without coating surface damage is important for some applications in EUV lithography like black border formation [1] and critical dimensions control [2]. Here we present the results of experiments on controllable decrease of Mo/Si multilayer coatings EUV reflectivity by modification of Mo/Si structure with fs laser pulses and results of modelling of multilayer reflectivity change with IMD software [3].