title: The steady flying of a plasmonic flying head over a photoresist-coated surface in a near-field photolithography system.
abstract: The near-field photolithography technique (NFPT) offers a new approach of nanolithography for a dramatic increase in the resolution with high throughput and low cost. The NFPT utilizes the same flight principle as that of the magnetic head of hard-disk drives but replacing the magnetic head with a plasmonic flying head. The plasmonic flying head, which can focus the incident laser beam to a spot size of sub-20 nm with an enhanced field intensity by exciting surface plasmon polaritons, takes off and then flies steadily above the revolving disk coated by a photoresist film to be patterned with a narrow gap of tens of nanometers. As a key foundation of the NFPT, the take off and flight stability of the plasmonic flying head affects the pattern density and the fabrication efficiency. This work proposed and investigated a molecular glass photoresist, named FPT-8Boc, for the large-scale consistent fabrication with the NFPT. To overcome the take-off problem of the head over the soft photoresist film, a transition zone is intentionally formed by washing off the coated photoresist in the outer area of the disk using a solvent. The simulation results by COMSOL Multiphysics software and quasi-Newton iteration method review that the matched transition zone height with spreading length can guarantee the flight stability of the plasmonic flying head on the soft photoresist. Using this method, a preliminary photolithography result with a 31 nm line width has been achieved.
authors.forename: Jiaxin
authors.initials: J
authors.lastname: Ji
authors.forename: Yueqiang
authors.initials: Y
authors.lastname: Hu
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Meng
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.forename: Shayu
authors.initials: S
authors.lastname: Li
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Yang