E-Beam evaporation is a physical vapor deposition (PVD) technique whereby an intense electron beam is generated from a filament and steered via electric and magnetic fields to strike the source material (e.g. pellets of Au) and vaporize it within a vacuum environment. At some point as the source material is heated via this energy transfer its surface atoms will have sufficient energy to leave the surface, traverse the vacuum chamber and coat a substrate positioned above the evaporating material.
The advantage of this method over thermal evaporation is the possibility to use higher energies into the material to be evaporated, which leads to the formation of thin films with a higher density and consequently with an increased adhesion to the substrate. This method is also good for posterior lift-off processes, and is the way to obtain thin films with the highest purity. By using a multiple crucible E-beam gun, several different materials can be deposited without breaking the vacuum and thus avoiding interlayer contamination.