Scanning tunneling microscopy in surface science

Abstract

This chapter discusses the use of scanning tunneling microscopy (STM) in surface science. Basic principles of STM imaging are introduced, and the imaging methodology is discussed, along with practical and instrumentation requirements. The approach taken in surface imaging by STM is illustrated by the example of silicon surfaces. An application of STM that has gained ever-increasing importance is discussed in detail: atomic-scale spectroscopy. A survey of the spectroscopic capabilities of STM is provided, and a variety of techniques for local spectroscopy and spectroscopic imaging are introduced. In addition, pathways toward obtaining chemical and element specificity at the atomic scale—traditionally a weakness of STM—are discussed. The extension of the operating conditions of STM to high and low temperatures has opened up new avenues of investigation. Here, variable-temperature STM of dynamic surface processes is discussed, as well as manipulation of atoms and molecules at cryogenic temperatures. Examples of STM imaging and spectroscopy on subsurface structures include the use of ballistic electrons to probe buried interfaces, and cross-sectional STM on cleavage faces of III/V semiconductors to image embedded nanostructures. The chapter concludes with a brief discussion of STM image simulation techniques.