Lithography in UV photoresist using NSOM

Abstract

The increasing demand for smaller devices as well as research into novel structures for high density data storage has necessitated the use of advanced nanolithography techniques for fabrication in the sub-100 nm regime. In this paper, nanoscale lines with a minimum full width at half maximum of 20 nm have been achieved, demonstrating resolution of λ/20. Lithography was made by near field scanning microscope (NSOM) in UV photoresist with 120 nm thickness. Second harmonic generation of femtosecond laser was used as light source of NSOM. The lithography results were measured and analyzed by the same tip of NSOM and scanning electron microscopy (SEM). The size of tip aperture used was about 50 nm. The effects of laser energy and writing speed on the size and depth of lines drawn were studied. By controlling these parameters properly, high quality nano-patterning in photoresist would be achieved. The nano-patterning techenique will have potential applications in nanodevice fabrication and data storage.