Probing of Surfaces by Scanning Tunneling Microscope

Principle of the method

In the Scanning Tunneling Microscope (STM) the specimen surface is scanned by a very fine tip. The probe tip is brought very close to the surface by a piezo actuator until an electric tunneling current is established. To keep the tunneling current constant during the scan the tip surface distance must be continuously controlled which provides topographic information on atomic level.