Characterization of uniformity and reproducibility of photoresist nanomasks fabricated by near-field scanning optical nanolithography.

The uniformity and reproducibility of the photoresist nanopatterns fabricated using near-field scanning optical nanolithography (NSOL) are investigated. The nanopatterns could be used as nanomasks for pattern transfer on a silicon wafer. In the NSOL process, uniform patterning with high reproducibility is essential for reliable transfer of the mask patterns on a silicon substrate. Using an aperture type cantilever nanoprobe operated at contact mode and a positive photoresist, various nanopatterns are produced on thin photoresist layer coated on the silicon substrate. The size and shape variations of thereby produced patterns are investigated using atomic force microscope to determine their uniformity and reproducibility. It is demonstrated that the NSOL-produced photo-resist nanomasks can be successfully applied for silicon pattern transfer by fabricating a silicon nanochannel array.