Large-area micro/nanostructures fabrication in quartz by laser interference lithography and dry etching

Laser interference lithography (LIL) has the capability to fabricate large-area microstructures on the photoresist with only a couple of minutes’ exposure and development. In this study, LIL was adopted to fabricate micro/nanostructures in quartz by combining the following dry-etching process either reactive ion etching (RIE) or inductively coupled plasma (ICP). A layer of gold film was coated on the quartz to act as a hard mask during the dry-etching process. A microhole array in quartz with a thin gold film covered on the surface was fabricated when choosing RIE. Each hole in the microhole array was surrounded with gold nanoparticle capped silica (Au/SiO₂) cones when using ICP instead of RIE. This is due to the thin gold film that serves as the mask for creating the surface roughness required for creating the silica cone structure.