Row structure in metal‐induced Si(111) surface reconstructions

Abstract

We demonstrate that quantum size effects play a crucial role in the row structure of metal-induced Si KEYWORDS: models of surface kinetics; quantum effects; surface relaxation and reconstruction; metalsemiconductor interfacesThe reconstruction of the Si(111) surface is a well-known process that has been the subject of numerous experimental and theoretical studies. However, metal-induced reconstruction of Si(111) continues to present theoretical challenges, particularly concerning the coverage-dependent structural arrangements. In such systems a submonolayer of metal atoms is deposited onto the Si(111) surface, resulting in a reconstruction of the Si(111) surface and arrangement of the metal adsorbate into rows of monolayer height.1 -17 Using scanning tunnelling microscopy, these rows are visible and both the height and width of the rows are evident. We introduce here a theoretical model that demonstrates that the quantum size effect plays a crucial role in determining the widths of these rows, and we show that our model provides complete agreement with all recent metal-induced M/Si(111)-3 ð 1 reconstructions (where M D Li, Na, K, Rb, Ag) and Si(111)-4 ð 1-In reconstructions. The quantum size effect has proved to be a crucial element in understanding and modelling the work function, 18 resistivity 19 and stability 20 of metallic thin films, and in the pattern formation of metal-on-metal surfaces. 21 The quantum size effect has proved to be a valuable tool for studying small, confined free-electron systems, and our application to metal-induced reconstruction of Si(111) surfaces represents another success of this approach.