Evidence for tip imaging in scanning tunneling microscopy

Abstract
It is demonstrated that scanning tunneling microscopy (STM) images often contain three-dimensional ghost images of the tunneling tip. These ghost images directly reflect the shape of the tip, as is proven by comparing them with tip indentations made in Si. Tip images appear as a set of identical protrusions, and have been observed regularly on Si surfaces annealed at 1200 K in ultrahigh vacuum. Imaging of rough surfaces may be fully dominated by this effect which can lead to incorrect image interpretations in STM and AFM.