Thermal Evaporation is one of Physical Vapour Deposition (PVD). Thermal Evaporation uses heating of solid materials in high vacuum. These materials can be both metals and non-metals such as oxides or nitrides. The heating temperature must be high enough to produces the sufficient vapour pressure into vacuum chamber. The thickness range of films produced by thermal evaporation can be from angstroms to microns and can have single or multi-layered structure.
There are two basic methods to heat a source material. First one is a simple electrical resistive heat element, or filament. Usually the filament power sources are low voltage and high current devices.
The second method is known as
E-beam Evaporation (Electron Beam Evaporation). Electrons injected from source are concentrated to beam, accelerated by the high voltage, and directed to material. At the standard 10 kV and 0.1 amp current the beam will deliver 1 kilowatt of concentrated power to heat the material up. E-beam units usually have multiple crucibles and thus are capable to multi-layer processing.