Nanostencil lithography

Stencil lithography is a method for fabricating nanometer scale patterns using nanostencils, shadow masks with nanometer size apertures. It is a resist-less, simple, parallel nanolithography process, and it does not involve any heat or chemical treatment of the substrates (unlike resist-based techniques).Nanostencil patterning has been applied in thin film sub-micron patterning of metals successfully for decades since it has several advantages over lithography techniques. It is a single processing step technique which can be applied to many different types of surfaces. The nanostencil patterning process does not utilize any solvents which makes it a favored technique for patterning metals on fragile and/or organic materials. However, for successful nanostencil patterning and unlimited (re)use of stencils, several issues need to be solved. The main issues that limit the re-usability of stencils are clogging of the apertures and deformation of the stencil caused by stress induced by the deposited material. Gradual clogging of the apertures of nanostencils used as miniature shadow masks in metal evaporations can be reduced by coating the stencil with self-assembled monolayers (SAM). An increase in material deposition through the apertures by more than 100% can be achieved with SAM-coated stencils, which increases their lifetime.