Defect-Free nanoscale printing using the Talbot effect*

An Extreme Ultraviolet (EUV) lithography technique that utilizes a compact EUV laser to print nanoscale features on a photoresist is presented. The lithographic method uses the Talbot effect and is based on the self-imaging produced when a periodic transmission mask is illuminated with a coherent light beam. A periodic mask composed of an array of tiles with an arbitrary design produces self images that are used to replicate the mask in the surface of a photoresist. When illuminated with coherent light, the tiled diffractive mask produces images which are 1$\times$ replicas at certain locations (Talbot planes). The self-images are generated by the diffraction of the thousands of cells in the mask. Thus, any defect in any of the unitary cells is averaged over a very large numbers of tiles consequently rendering a virtually defect-free image. This is a unique characteristic of this photolithographic approach.