Stenci Lithography: Status and Prospectives

Stencil lithography is a surface patterning technique that relies on the local deposition of material through miniaturized shadow mask membranes. This method has been used since many years in various implementations for the formation of patterns (mainly structured thin metal films) on surfaces without the need for photolithography steps. Since none of the harsh process steps typically involved in lithography is necessary (e.g. spin coating of photoresist, high temperature baking, development, wet or dry etching and resist stripping) this single pattern formation step is particularly interesting in cases where the surfaces are already functionalized or fragile. Since a few years it is possible to push the stencil method continuously into the sub-micrometer scale, and in some particular cases sub-50 nm surface patterns can be achieved. The high resolution capability of nanostencil makes them interesting as tools for (in-vacuum) rapid-prototyping of nanostructures without the risk of contamination, or for laboratories without access to high-end nanolithography equipment. We are systematically looking for ways to improve stencil lithography in view of a reliable nanopatterning method that can be scalable to wafer sizes, and which is complementary to other new emerging methods such as nanoimprint (polymer indentation) or soft-lithography (molecular ink deposition). The talk will present the current state-of-the-art of the nanostencil lithography, will highlight the strength of the methods, but will also discuss the current limits and challenges ahead to make it a truly reliable nanofabrication method.