Controlled Synthesis of Horizontal Silicon Nanowires for Biosensor Application

Abstract

Top-down silicon nanowire (SiNW) fabrication mechanisms for connecting electrodes are widely utilized because they provide good control of the diameter to length ratio. The representative mechanism for the synthesis of SiNWs, a top-down approach, has limitations on the control of their diameter following lithography technologies, requires a long manufacturing process and is not cost-e®ective. In this study, we have implemented the bottom-up growth of horizontal SiNWs (H-SiNWs) on Si/SiO 2 substrates directly by plasma enhanced chemical vapor deposition (PECVD) under about 400 C. The HAuCl4 solution as a catalyst and SiH 4 gas as a precursor are used for the synthesis of H-SiNWs. After optimization of synthesis conditions, we evaluated the photoelectric properties of the H-SiNWs under illumination with di®erent light intensities. Further, we demonstrated the feasibility of H-SiNW devices for the detection of biotinylated DNA nanostructures and streptavidin interaction.