Development of Nanoimprint Lithography for Fabrication of Electrochemical Transducers

Sammanfattning: This thesis gives an overview about the current status of nanoimprint lithography, a relatively new nanofabrication tool. The technology is capable for parallel mass production of nm-structured features having a resolution below 10 nm and is usable with high throughput on full wafer scale. The thesis is mainly divided into two parts dealing with nanoimprint lithography and electrochemistry. The work concerns the development of reliable and reproducible imprint processes, e.g. for fabrication of nm-structured interdigitated array electrodes usable in (bio-) electrochemical sensor applications. Such electrodes can be used for measuring electrochemical processes such as redox cycling, which become addressable when the electrode distance becomes smaller than the diffusion layer thickness at the electrode/electrolyte interface. The process development addresses several issues such as: (i) Production of nanoimprint stamps/molds with electron beam and UV-lithography. (ii) Evaluation of new polymers especially developed for nanoimprint lithography. (iii) Anti-adhesion treatment of different imprint molds with molecular layers and (iv) their characterization with photoelectron spectroscopy. (v) Development of post-imprint processes for substrate etching or metal lift-off. (vi) Deposition of non-corroding alternative organic adhesion promoters for gold on silicon dioxide. (vii) Evaluation of fluorescence microscopy as a tool for quality control in industrial nanoimprint processes. The electrochemistry part deals mainly with theoretical electrochemistry as we teach it in the biophysics course given at the department and is supposed to be used as course literature. Parallel to the NIL process development electrochemical equipment was built and evaluated with some standard measurements presented in this thesis. The outcome of this development was used to build a more advanced instrument suitable for redox cycling with nm-structured electrodes. First results with nm-structured electrodes are compared with mm-structured ones.