A nano-imprint device including at least: a substrate, having a surface, on the substrate, a plurality of nano-trenches parallel two by two, each nano-trench extending in a longitudinal direction and being delimited laterally by side walls, the nano-trenches and the side walls being directed substantially perpendicular to the surface of the substrate, each nano-trench comprising a bottom surface with at least one first and one second level in a direction perpendicular to the substrate, respectively of depth h1 and h2>h1, measured relative to the top of the side walls, and the bottom surfaces of the nano-trenches, of the least deep level (h1) being in a first type of material, the side walls being in a second type of material.