Subwavelength structures induced by laser direct writing and applications for data storage devices

Abstract

Two kinds of laser direct writing techniques were developed for the fabrication of nanostructures, and their applications in high density data storage were explored. The first technique is laser-induced nanostructure self-organization, which is based on the intrinsic laser-material interactions. Although this technique is suitable for the formation of large scale nanostructures, its lack of precise position registration and alignment capability makes it unsuitable for device fabrication. The second a mix-and-match technique which combines the conventional photolithography with the laser direct writing using a femtosecond laser and near-field optics. The developed technology was applied to the nanocell fabrication of non-volatile phase change random access memory, with a feature size far below the optical diffraction limit. The functionality of nanocell was demonstrated successfully, and the scalability of programming current and fast switching were evaluated. A theoretical model was proposed to explain the fast switching phenomenon, which will be of great importance for developing fast-response phase change memories.