Ballistic electron emission microscopy

BEEM is a three terminal scanning tunneling microscopy (STM) technique that was invented in 1988 at the Jet Propulsion Laboratory in Pasadena, California by L. Douglas Bell, Michael H. Hecht, and William J.

When performing BEEM, electrons are injected from a STM tip into a grounded metal base of a Schottky diode.

A small fraction of these electrons will travel ballistically through the metal to the metal– semiconductor interface where they will encounter a Schottky barrier.

The atomic scale positioning capability of the STM tip gives BEEM nanometer spatial resolution.

In addition, the narrow energy distribution of electrons tunneling from the STM tip gives BEEM a high energetic resolution (about 0.02 eV).