Spin-on-glass coatings for the generation of superpolished substrates for use in the extreme-ultraviolet region

Farhad Salmassi, Patrick P. Naulleau, Eric M. Gullikson
2006 Applied Optics  
Substrates intended for use as extreme ultraviolet (EUV) optics have extremely stringent requirements in terms of finish. These requirements can dramatically increase the cost and fabrication time, especially when non-conventional shapes, such as toroids, are required. Here we present a spin-on-glass resist process capable of generating super-polished parts from inexpensive substrates. The method has been used to render diamond-turned substrates compatible for use as EUV optics. Toroidal
more » ... -turned optics with starting rms roughness in the 3.3 to 3.7 nm range have been smoothed to the 0.4 to 0.6 nm range. EUV reflectometry characterization of these optics has demonstrated reflectivities of approximately 63%.
doi:10.1364/ao.45.002404 pmid:16623236 fatcat:hkctjqqz6rhphix7jzqpbi6lba