Nanostructures, which have characteristic dimensions that are difficult to achieve by conventional optical lithography techniques, are finding ever-increasing applications in a variety of fields. High resolution, reliability and throughput fabrication of these nanostructures is essential if applications incorporating nanodevices are to gain widespread acceptance. Owing to the minimal thermal and mechanical damage, ultra-short pulsed laser radiation has been shown to be effective for precision material processing and surface micro-modification. In this work, nanostructuring based on local field enhancement in the near field of a Scanning Probe Microscope (SPM) probe tip irradiated with femtosecond laser pulses has been studied. High spatial resolution (~10–12nm), flexibility in the choice of the substrate material and possibility of massive integration of the tips make this method highly attractive for nanomodification. We report results of nanostructuring of gold thin film utilizing an 800nm femtosecond laser system in conjunction with a commercial SPM in ambient air. Further, Finite Difference Time Domain (FDTD) simulation results for the spatial distribution of the laser field intensity beneath the tip are presented. Potential applications of this method include nanolithography, nanodeposition, high-density data storage, as well as various biotechnology related applications.
The Design of a Novel Tip Enhanced Near-field Scanning Probe Microscope for Ultra-High Resolution Optical Imaging
