Formation of Well-Ordered Step Structures on Si(111) by a Combination of Chemical Etching and Surface Scratching for Producing Macrosized Patterns

Abstract

Scratching of H-terminated Si(111) surfaces with Teflon tweezers, followed by etching with 40% NH4F, led to formation of well-ordered patterns of surface crystal steps, in contrast to the case of no scratching. The scratching produced surface damage in the form of nanowires, and the step patterns changed in shape by altering the direction of scratching. The results were explained on the basis of a reported mechanism for NH4F etching at the Si(111) surface by assuming that step etching stopped at the scratch-induced nanowires of damage. It is suggested that a combination of controlled macrosized patterning and chemical etching provides a new promising approach to well-regulated nanostructuring at the Si surface.