Fourier ptychography is a computational imaging techniques that combines various full-field coherent images acquired under varied illumination angles and combined to yield a angular spectrum with a large synthetic numerical aperture and non-interferometric phase information. We present here the implementation of this technique in a full-field soft x-ray microscope designed to emulate modern EUV lithography tools imaging conditions, and we show that this technique can be used for the study of EUV photomasks. The technique allows us to quantitatively characterize phase defects (predominant in EUV lithography), to study new mask designs made of phase structures, to study sub-resolution assist features and extend the resolution of the microscope down to 26-nm, correspond to the N1 technology node.

Selective patterning of chemical functional groups on polymer surfaces is utilized for controlled placement of monodisperse noble metal nanoparticles. Self-assembled diblock copolymer films deposited on Hydrophobic silicon substrates are used as a template for metal nanoparticle organization. By varying the processing conditions of polymer templates, micelle and cylindrical polystyrene-b-poly(methyl methacrylate) diblock copolymer templates were fabricated. Functional groups on the surface of poly(methyl methacrylate) domains in the diblock copolymer films were chemically modified from an ester group to a carboxylate using a base catalyzed hydrolysis step. Gold and silver nanoparticles were fabricated in solution in order to achieve size and shape control. After gold nanoparticle synthesis, a ligand exchange reaction was performed to produce nanoparticles with amine functional groups for chemical attachment on chemically modified poly(methyl methacrylate) surfaces. Atomic force microscopy and scanning electron microscopy images demonstrate that this fabrication route results in preferential attachment of metal nanoparticles on poly(methyl methacrylate) thin films and on poly(methyl methacrylate) domains in polystyrene-b-poly(methyl methacrylate) diblock copolymer thin films.