Lateral Confinement of Cylindrical Domain Thin Polymer Films

The current method to produce masks with nanofeatures at the nano-level involves expensive processes using photolithography and with the ever increasing demand for smaller feature densities, one must take production costs into account. Block copolymers offer a cheaper alternative to create masks with nanofeatures, and depending on the ratio of their components, the minority block self assembles into different shapes, including spheres, cylinders, and gyroids. We focus on the block copolymer Poly (styrene-b-2-vinyl pyridine), which self assembles into a cylindrical array when the 2-vinyl pyridine fraction (fpvp) is .25. However, when spun coat on a plain silicon wafer, the cylinders assume random and disordered patterns. By depositing the polymer into channels of different widths and looking at the transitional order, we aim to improve the orientational and translational order of these cylinders. We looked at the effect of different annealing temperatures and different channel widths to understand the phenomena of defect suppression by the channels and defect generation at higher temperatures. The aim is to produce aligned, relatively defect free cylinders of nanoscale dimensions, which can be used as a template for nanowires and for making masks with nanofeatures.