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The fabrication of very narrow metal lines by the lift-off technique, especially below sub-10 nm, is challenging due to thinner resist requirements in order to achieve the lithographic resolution. At such small length scales, when the grain size becomes comparable with the line-width, the built-in stress in the metal film can cause a break to occur at a grain boundary. Moreover, the line-width roughness (LWR) from the patterned resist can result in deposited metal lines with a very high LWR, leading to an adverse change in device characteristics. Here a new approach that is not based on the lift-off technique but rather on low temperature hydrogen reduction ofelectron-beam patterned metal naphthenates is demonstrated. This not only enables the fabrication of sub-10 nm metal lines of good integrity, but also of low LWR, below the limit of 3.2 nm discussed in the International Technology Roadmap for Semiconductors. Using this method, sub-10 nm nickel wires are obtained by reducing patterned nickel naphthenate lines in a hydrogen-rich atmosphere at 500°C for 1 h. The LWR (i.e., 3 σ LWR ) of these nickel nanolines was found to be 2.9 nm. The technique is general and is likely to be suitable for fabrication of nanostructures of most commonly used metals (and their alloys), such as iron, cobalt, nickel, copper, tungsten, molybdenum, and so on, from their respective metal―organic compounds.

High temperature nanoimprinting of viscous polymers which are glassy at room temperature is usually performed using brittle and expensive molds made of inorganic materials. As a replacement, soft molds made of plastics or elastomers have been used because of their low cost and ease of fabrication. However, the deformation of polymer molds under pressure remains a major issue which limits their resolution in high temperature nanoimprinting. Moreover, the replicated structures are often broken or lack definition due to sticking of the embossed polymer to the mold. We report a method for imprinting fine, densely packed nanostructures down to 12 nm into a wide range of technologically important polymers using a flexible and robust mold made from ethylene(tetrafluoroethylene) (ETFE). The high resolution achieved is due to the mold's mechanical stability and resistance to distortion at high pressures and high temperatures. The flexibility and low surface energy of ETFE provide a clean mold release without fracture or deformation of the embossed structures. Multiple imprinting and patterning on large areas is also made possible because of the good conformal contact and low-adhesion of the ETFE mold. Finally, this simple and inexpensive method allows reproduction of the stamps from one single master, thus providing an economical alternative to expensive and brittle inorganic materials.