Atom Probe Tomography and field evaporation of insulators and semiconductors: Theoretical issues

• We review Atom Probe Tomography of metallic tips in high electric fields.
• We study the fields inside and on the surface of semiconductors and insulators.
• In high electric fields the band gap is drastically reduced for these materials.

After reviewing the physics and chemistry in high electrostatic fields and summarizing the theoretical results for Atom Probe Tomography of metallic tips, we turn to the new challenges associated with insulators and semiconductors with regard to local fields inside and on the surface of such materials. The recent (theoretical) discovery that in high fields the band gap in these materials is drastically reduced to the point where at the evaporation field strength it vanishes will be crucial in our discussion.