A new fabrication technique for silicon nanowires

A new method is proposed for fabricating silicon nanowires (SiNWs) on silicon substrates instead of on SOI wafers, providing a cheaper process; it also enables their electrical properties to be measured easily. Using scanning probe lithography, mask patterns for SiNWs were defined on a (110)-oriented bare silicon wafer. Subsequently silicon nitride spacers were produced and utilized to protect SiNWs during a dry-oxidation process, which was applied to isolate the SiNWs from the substrate. The field induced oxide mask patterns generated with a scanning probe microscope were around 50-60 nm in width, and SiNWs with 34 nm in width and 160 nm in height resulted after wet potassium hydroxide (KOH) orientation-dependent etching at 40° for 400 s. SiNWs with line width around 34 nm on the bare silicon wafer were achieved with the scanning probe lithography process and conventional IC processing.