Nanopatterning with a high repetition rate λ= 46.9 nm capillary discharge table-top laser M. G. Capeluto a , G. Vaschenko b , M. Grisham b , M. C. Marconi a,b , S. Ludueña c , L. Pietrasanta c , Y. Lu d , B. Parkinson d , C. S. Menoni b , and J. J. Rocca b a Departamento de Física, c Centro de Microscopias Avanzadas, Facultad de Ciencias Exactas, Universidad de Buenos Aires, Argentina b NSF ERC for Extreme Ultraviolet Science & Technology and Department of Electrical and Computing Engineering, Colorado State University, USA d Department of Chemistry, Colorado State University, USA Abstract. We have exploited the high average power and high spatial coherence of a compact high repetition rate λ = 46.9 nm capillary discharge laser to demonstrate nanometer-scale patterning in poly-methyl methacrylate. Interference patterns were generated through wave-front division interferometry using a Lloyd’s mirror. Gratings with periods as small as 55 nm were imprinted on PMMA. These results, that constitute the first demonstration of nanopatterning with a soft x-ray laser, illustrate the potential of high repetition soft x-ray lasers in nanotechnology applications. 1. Introduction The miniaturization of devices has pushed the limits of feature size fabrication to the nanometer scale. Light sources with increasingly short wavelength, down to the 157 nm corresponding to the F 2 laser, have been used to print progressively smaller features. In this path, compact high repetition rate soft x-ray lasers could provide a way to achieve the recording of nanoscale features, in particular when the pattern can be created by interference effects that take advantage of the coherence of this type of compact soft x- ray source. In these proceedings we report the imprinting of nanometer patterns in poly- methyl methacrylate (PMMA) using the combination of a 46.9 nm table-top discharge pumped laser and a Lloyd’s mirror interferometer. 2. Experimental set up and procedure To generate nanometer gratings by interferometric lithography we employed the same type of Lloyd’s mirror interferometer used previously for PMMA patterning with synchrotron radiation at 13 nm [1] and for plasma diagnostics with 46.9 nm radiation