High density self assembled nanoparticle film with temperature-controllable interparticle spacing for deep sub-wavelength nanolithography using localized surface plasmon modes on planar silver nanoparticle tunable grating

A novel photolithographic technique using a periodic hexagonal close packed silver nanoparticle 2D array photo mask has been demonstrated to transfer a nano-pattern into a photoresist using G-I line proximity photolithography. This method can be made to precisely control the spacing between nanoparticles by using temperature. The high-density nanoparticle thin film is accomplished by self assembly through the Langmuir-Schaefer (LS) technique on a water surface and then transferring the particle monolayer to a temperature sensitive polymer membrane. A 30 nm hexagonal close packed silver nanoparticle 2D array pattern with a 50 nm period has been successfully transferred into S1813 photoresist using I-line exposure wavelength. The resultant feature sizes were 34 nm with a period of 46 nm, due to the surface plasmon resonance where the S1813 photoresist feature is approximately 11 times smaller than I-line exposure wavelength. © 2007 Elsevier B.V. All rights reserved.