Nanosensor Fabrication with Silicon Nanowires

Abstract

Silicon nanowires (SiNW) are a promising platform for the highly sensitive electrical detection of biological and chemical analytes. Compared to thin metal film-based sensors, nanowires have extremely high sensitivity to molecules of chemical analytes. Our paper discusses the progress we have made on the synthesis and functionalization of silicon nanowires on a silicon-on-insulator substrate. A fully automated chemical vapor deposition (CVD) system from FirstNano in New York was used to synthesize SiNW on a 4-inch silicon substrate. We adjusted a doping concentration of boron gas to synthesize a longer SiNW. The average length of a silicon nanowire was approximately 16？m, with an approximate width of 50nm. Figure 1 illustrates an SEM image of magnified nanowires on a silicon substrate. After a high quality SiNW was synthesized, we developed nanosensors by utilizing optical lithography and e-beam evaporation. This paper discusses mask designs, elimination of silicon substrate contamination, metal etching and IV curves for a packaged sensor chip. We present results of the UV-Vis measurements after the surface modifications of the nanosensor. The paper presents a highly labor intensive drop-cast method for nano-wires that caused some contamination issues on the nanosensors. We present different chemical agents for surface modifications on SiNWs. These different chemical modifications could be used on SiNWs to attact specific analytes of interest to nanosensors