The use of Scanning Tunneling Microscopy in combination with Scanning Electron Microscopy in the fabrication and imaging of microstructures

Abstract

In the last few years, Scanning Tunneling Microscopy (STM), has proven to be a powerful and versatile technique to investigate the topographic and electronic structure of metals and semiconductors with an unprecedent vertical (0.01 nm) and lateral (0.2 nm) resolution. In this paper we are interested in the use of STM to study surfaces having microfabricated structures in the nanometer range, particularly those produced by the STM tip itself.In order to study these samples we have used an STM integrated into a commercial Scanning Electron Microscope (SEM). This allows to address two problems which limit the operation of STM: (i) the limited STM scanning range (1-10 μm) which makes difficult the localization of microstructures on the sample; (ii) the undetermined size and shape of the STM probing tip.Our STM/SEM combination has been described in detail earlier. In short, it consists of an STM placed on the sample stage of a commercial SEM allowing the simultaneous operation of both microscopes.