Three-dimensional nanofabrication by electron-beam lithography and directed self-assembly

Abstract

In this thesis, we investigated three-dimensional (3D) nanofabrication using electron-beam lithography (EBL), block copolymer (BCP) self-assembly, and capillary force-induced self-assembly. We first developed new processes for fabricating 3D nanostructures using a hydrogen silsesquioxane (HSQ) and poly(methylmeth-acrylate) (PMMA) bilayer resist stack. We demonstrated self-aligned mushroom-shaped posts and freestanding supported structures. Next, we used the 3D nanostructures as topographical templates guiding the self-assembly of polystyrene-b-polydimethylsiloxane (PS-b-PDMS) block copolymer thin films. We observed parallel cylinders, mesh-shaped structures, and bar-shaped structures in PDMS. Finally, we studied capillary force-induced self-assembly of linear nanostructures using a spin drying process. We developed a computation schema based on the pairwise collapse of nanostructures. We achieved propagation of information and built a proof of concept logic gate.