Electron-Beam Evaporation
Thermal evaporation is one of the oldest thin film deposition methods. In a vacuum chamber, the source material is heated above its melting point. This may be done by resistive heating for materials with low melting points or by electron beam heating. The material is then evaporated and deposited on a substrate located above the heated source.
Our electron-beam evaporation system contains four crucibles for four different source materials. The electron beam comes from the bottom and is directed by a magnetic field to the surface of the source materials. The beam heats the material above its melting point. The maximum temperature is about 2000°C. The material is evaporated and deposited on the surface of the substrate. The substrates may be cooled using liquid nitrogen. The film thickness can be monitored in-situ by an oscillating quartz crystal.
Electron beam evaporation has the advantage of being highly directional thus enabling shadow evaporation. We use electron-beam evaporation for depositing thin films of Co, Ni, Au, Al, and SiOx.
In addition, an UHV metal-MBE systems has been set up at the WMI. The system has a sample holder, which can be rotated and tilt and therefore allows large flexibility for shadow evaporation processes used. The system is presently equipped with a an electron beam evaporation system with 6 crucibles for 6 different materials. The system can be eventually be upgraded with up to 6 effusion cells. The sample holder can be cooled by liquid nitrogen.