Fabrication of silicon-based multilevel nanostructures via scanning probe oxidation andanisotropic wet etching

Abstract

A rational approach is described for fabricating multilevel silicon-based nanostructures viascanning probe oxidation (SPO) and anisotropic wet etching. Using silicon oxidenanopatterns on Si(100) and Si(110) surfaces created by SPO as masks, two-dimensional(2D) nanostructures with high aspect ratio and a variety of patterns can be formed byanisotropic wet etching with KOH. By employing a mixture of KOH solutions andisopropyl alcohol (IPA) as an alternative to KOH alone, control of the morphology of theetched silicon surfaces, crucial for further fabrication, was greatly improved. The SPOand etching processes can be continually repeated on the 2D nanostructures,permitting the formation of various multilevel silicon-based nanostructures, includinga T-gate structure useful for electronic circuitry. In addition, these multilevelsilicon structures can be used as nanoimprint moulds for their rapid replication.