High-resolution laser direct writing with a plasmonic contact probe

We developed a contact-probe-based laser direct writing technique with nanometer scale resolution. The probe uses a solid-immersion-lens (SIL) or a bowtie nano-aperture to enhance the resolution in laser direct writing method and scans sample surface in contact mode for high scan speed. The bowtie shaped nano-aperture is fabricated by focused ion beam (FIB) milling on the metal film coated on cantilever type probe tip and dielectric material (Diamond-like carbon) is covered the probe for surface protection. Using a plasmonic contact probe, we obtained an optical spot beyond the diffraction limit and the size of spot was less than 30 nm at 405 nm wavelength. The proposed probe is integrated with a conventional laser direct writing system and by getting rid of external gap control unit for near-field writing, we achieved high scan speed (similar to 10 mm/s). The raster scan mode for the arbitrary patterning was developed for practical applications. Furthermore, we designed developing a parallel maskless writing system for high throughput with an array of contact probes.