Hard-tip, soft-spring lithography

Lithographic tips Scanning probe techniques such as atomic-force microscopy can be readily harnessed to prepare nanoscale structures with exquisite resolution, but are not generally suitable for high-throughput patterning. Techniques based on contact printing, by contrast, offer high throughput over large areas, but cannot compete on resolution. Now, Wooyoung Shim and colleagues describe an approach that offers the best of both worlds. By attaching an array of hard, scanning-probe-like silicon tips to a flexible elastomeric substrate (similar to those used in contact printing), they are able to rapidly create arbitrary patterns with sub-50-nanometre resolution over centimetre-scale areas. This new nanolithography strategy should be suitable for a range of rapid prototyping applications in both industrial and research applications. Scanning probe techniques such as atomic force microscopy can be readily harnessed to prepare nanoscale structures with exquisite resolution, but are not in general suited for high-throughput patterning. Techniques based on contact printing, on the other hand, offer high throughput over large areas, but can't compete on resolution. Now, an approach is described that offers the best of both worlds: by attaching an array of hard, scanning-probe-like silicon tips to a flexible elastomeric substrate (similar to those used in contact printing), it is possible to rapidly create arbitrary patterns with sub-50-nm resolution over centimetre-scale areas. Nanofabrication strategies are becoming increasingly expensive and equipment-intensive, and consequently less accessible to researchers. As an alternative, scanning probe lithography has become a popular means of preparing nanoscale structures, in part owing to its relatively low cost and high resolution, and a registration accuracy that exceeds most existing technologies 1 , 2 , 3 , 4 , 5 , 6 . However, increasing the throughput of cantilever-based scanning probe systems while maintaining their resolution and registration advantages has from the outset been a significant challenge 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 . Even with impressive recent advances in cantilever array design, such arrays tend to be highly specialized for a given application, expensive, and often difficult to implement. It is therefore difficult to imagine commercially viable production methods based on scanning probe systems that rely on conventional cantilevers. Here we describe a low-cost and scalabl