Fabrication of silica nanostructures with a microwave assisted direct patterning process

Silica nanostructures were fabricated on glass substrate using a microwave assisted direct patterning (MADP) process, which is a variety of soft lithography. During the MADP process using polydimethylsiloxane (PDMS), mold and microwave heating are performed simultaneously. Blanket thin film and micro-to nano-sized structures, including moth-eye patterns of SiO which consisted of coalesced silica nanoparticles, were formed on glass substrates from SiO₂ nano-particle dispersed solutions with varied microwave heating time. Optical properties and surface morphologies of micro-sized hemisphere, nano-sized pillar, motheye and 50 nm sized line/space silica patterns were measured using UV-vis and a scanning electron microscope. X-ray diffraction analysis of SiO₂ thin films with and without microwave heating was also carried out.