Role of tip structure in scanning tunneling microscopy

Abstract
An ultrahigh vacuum scanning tunneling microscope (STM) equipped with a field ion microscope (FIM) has been built. By using the FIM image, a tungsten tip was tailored for high STM resolution in a scan of the Au(001) surface. The measured corrugation depth of the (1×5) rows was found to be a function of the size of the atomic cluster on the first plane of the tungsten tip.