Near-field photo-patterning of ultra-thin polymer films

Abstract

Photo-patterning of pyrene-labeled ultra-thin polymer films was investigated by scanning near-field optical microscopy and the well-defined Langmuir–Blodgett films. Pyrene was bleached by ultra-violet near-field illumination, and the recorded mark was read out as a dark region in contrast with the bright area due to fluorescence from unbleached areas. The line width for the patterned structure was much smaller than the wavelength of the excitation light. The high spatial resolution was not dependent on the scanning rate but was lowered with the increase in film thickness. For a high-resolution patterning, the recording medium is required to be thinner than the near-field region (≈100 nm). The best performance for the spatial resolution, signal intensity and contrast could be obtained with a film thickness of 10–20 nm.