Fabrication of Silicon Nanowire for Biosensor Applications

Single crystalline silicon nanowire (SiNW) array was fabricated by lithography and oxidation based technology. Uniform and well-defined single crystalline silicon nanowires were obtained, which have sub-100 nm and 5 to 200 mum in diameter and length, respectively, just using conventional micro-machining process such as stepper photolithography, anisotropic etching and thermal oxidation. Our approach to nanowire fabrication simply provides large-scale and well-controlled silicon nanowire array required for nanowire based electronics and biosensor applications without complex and expensive facilities and trivial nanowire assembly process. The contact electrodes for silicon nanowire device were fabricated using sputtered Ti/Au with 50 nm/200 nm thickness and I-V characteristics were recorded. Several types of chemical or biological functional groups were introduced onto silicon nanowire surface. The feasibility for sensor applications of nanowire was investigated.