Development of high-quality graphene nano-ribbon fabrication process for high sensitivity strain sensor

A strain sensor having large deformability and high sensitivity is strongly demanded. In order to fabricate a sensing part of a next generation strain sensor, graphene nanoribbon (GNR) fabrication process was developed. It was predicted that GNR has high strain sensitivity based on piezoresistivitve effect when its width is less than 70 nm. In this study, top-down approach was applied to fabricate the GNR. At first, in order to synthesize a high-quality graphene sheet, acetylene-based LPCVD (low pressure chemical vapor deposition) using Cu foil was developed. After the synthesis, a graphene sheet was transferred onto a Si/SiO₂ substrate and the quality of the transferred graphene sheet was evaluated by using Raman spectroscopy. Finally, GNR and metallic electrodes were fabricated by applying MEMS techniques such as electron beam evaporation using stencil mask and electron beam lithography.