Abstract
In this article, the fabrication of single crystal silicon (SCS) nanowire (NW) structures and their novel characteristics are described. We have produced in-plane and out-of-plane SCS NWs by means of two different types of fabrication processes including wet and dry etching. In-plane SCS NWs were fabricated using nano-lithography based on a local anodization technique with an atomic force microscope (AFM). 200-nm-wide SCS NW bridges were realized on an active layer in a silicon-on-insulator (SOI) wafer. The strength that was measured by AFM bending testing was larger by 40 times than that of bulk SCS. Even at temperatures ranging from 373 to 573 K, the NWs showed plastic deformation with dislocation slips. Out-of-plane SCS NWs were fabricated using the combination of deep reactive ion etching (DRIE) and thermal oxidation. By DRIE, SCS nano-pillars with scalloping sidewalls were produced on a SCS wafer. Thermal oxidation and wet etching were carried out as the post-process; consequently 100-nm-diameter out-of-plane SCS NWs array without scallops was realized. The NWs with the tremendous aspect ratio of 160 showed very large elastic deformation originating from their own weight and sticking. Novel size effect phenomena occurred in the SCS NWs produced were discussed.
