Electrical Width Determination of Silicon Nanowires Prepared by Using the Top-Down Method

Abstract

High-aspect-ratio nanowires of various widths and lengths (105 nm similar to 20 mu m and 2 similar to 20 mu m, respectively), but of fixed thickness (40 nm), were prepared by using the top-down method, and their resistances were measured in the two-terminal configuration. By taking into account the series resistance corresponding to the trapezoidal section of the channel connecting a nanowire to a wider electrode region, we obtained a sheet resistance and a source/drain resistance of 16.81 and 11.17 k Omega, respectively, in a consistent manner. We also determined the effective electrical widths, which are different from the physical widths by as much as 40 nm for a 105-nm-wide nanowire, and found a linear dependence of the surface depletion layer's thickness at the side walls on their physical width, which was attributed to structural damage that occurred during the plasma etch process.