Scratch induced nano-wires acting as a macro-pattern for formation of well-ordered step structures on H-terminated Si(1 1 1) by chemical etching

Scratching of H-terminated Si(1 1 1) surfaces with Teflon tweezers produced surface damage in the form of nano-wires. Successive etching of the scratched H–Si(1 1 1) surface with 40% NH4F led to formation of well-ordered patterns of surface crystal steps, in contrast to the case of no scratching.The results were explained on the basis of a reported mechanism for NH4F etching at the Si(1 1 1) surface, by assuming that step etching stopped at the scratch-induced nano-wires. Auger electron microprobe inspection showed that the nano-wires contained carbon and fluorine as the main elements. It is suggested that a combination of controlled macro-sized patterning and chemical etching provides a new promising approach to nanostructuring at the Si surface.