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

Abstract

A rational approach is described for fabricating multilevel silicon-based nanostructures via scanning probe oxidation (SPO) and anisotropic wet etching. Using silicon oxide nanopatterns 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 by anisotropic wet etching with KOH. By employing a mixture of KOH solutions and isopropyl alcohol (IPA) as an alternative to KOH alone, control of the morphology of the etched silicon surfaces, crucial for further fabrication, was greatly improved. The SPO and etching processes can be continually repeated on the 2D nanostructures, permitting the formation of various multilevel silicon-based nanostructures, including a T-gate structure useful for electronic circuitry. In addition, these multilevel silicon structures can be used as nanoimprint moulds for their rapid replication.