Loading patent…
AssigneeThe Regents of the University of California
InventorsClaude Montcalm, Paul B. Mirkarimi
Estimating the term…
A high reflectance-low stress Mo—Si multilayer reflective coating particularly useful for the extreme ultraviolet (EUV) wavelength region. While the multilayer reflective coating has particular application for EUV lithography, it has numerous other applications where high reflectance and low stress multilayer coatings are utilized. Multilayer coatings having high near-normal incidence reflectance (R≧65%) and low residual stress (≦100 MPa) have been produced using thermal and non-thermal approaches. The thermal approach involves heating the multilayer coating to a given temperature for a given time after deposition in order to induce structural changes in the multilayer coating that will have an overall “relaxation” effect without reducing the reflectance significantly.
In a process for producing Mo—Si multilayer reflective coatings having a reflectance of at least 65% in the extreme ultraviolet wavelength region and a magnitude of residual stress of no greater than 100 MPa, the improvement including:
A method for significantly reducing the magnitude of residual stress in Mo—Si multilayer coatings to less than 100 MPa while maintaining least a 65% reflectance of the multilayer coatings in the extreme ultraviolet wavelength region, comprising:
Dependencies are inferred from the claim text.