Nanostructuring of Polymers in Liquid by the Use of Polymer Crazing
The development of nanostructures is usually based on UV- or DUV-lithography. Using these techniques, a new set of lithographic masks has to be generated for each step in development. Other methods to create nanostructures are the direct writing techniques like ebeam, but this techniques suffer from very high installation and operation costs. To overcome these cost and time intensive procedures we have developed an in-situ technique which allows to write lateral structures with a resolution of 80 nm over an area of up to 100 µm in square with simultaneous characterization. This method is based on a conventional scanning force microscope modified for the use in a development liquid onto a commercial available PMMA/MA e-beam resist and is independent of the substrate material. Specific variations of the tip force which define the depth of structuring allow even structures with oblique faces. Furthermore it has to be emphasized that negative structures can be processed on the in fact positive resist. The created patterns could act as templates for the deposition of e.g. metals or alloys. This can be followed by further lithographic processes of the presented method. For the structuring a completely new mechanism is used. The polymer chains are not cracked as in e-beam lithography, but the crazing of the polymer is used. With new experiments we can prove the fundamentals of the presented technique. In this presentation we will illustrate the feasibilities of this method with respect to electrochemical applications on several examples.