Thermal Evaporator System |
Thermal evaporation is one of the common techniques of
Physical Vapor Deposition (PVD) for thin film deposition on the surface of
various objects. It is the simplest of the PVD techniques. A thermal evaporation
system uses vacuum technology for applying coatings or thin films of pure
materials on the object surface for different purposes. A resistive heat source
is used for evaporating a solid material in a vacuum chamber to form thin
films.
Thermal
Evaporator
In a Thermal Evaporator System, the material is heated until vapor pressure is produced and its
surface atoms have sufficient energy to leave the surface. At this point, the
free atoms in the form of evaporated material, or vapor stream traverse the
vacuum chamber at thermal energy (less than 1 eV). This vapor stream hits the
substrate material positioned above the evaporating material to deposits a
coating or thin film.
Thermal Evaporator |
Using the thermal
evaporation technique, an operator can adjust the system on different
parameters to achieve desired results for thickness, uniformity, adhesion
strength, stress, grain structure, optical or electrical properties, etc. Some
common custom adjustments that a thermal evaporator offers: the ability to hold
any shape and size substrate, the capability of multiple evaporation sources,
thin-film thickness monitor, pressure adjustment, and cross-contamination
shield.
Materials
used for Thin Film Deposition in Thermal Evaporator System
The thermal evaporation system can be used for single layer or
multi-layer thin films of metals, oxides & nitrides of non-metals, and
organic OLEDs. The material to be applied can be in the pure atomic form or can
be in the molecular form such as oxides and nitrides. Some common materials
used for thin-film depositions are aluminum, chromium, gold, silver, copper,
indium, and many more. The substrate on which the thin film is deposited can be
semiconductor wafers, solar cells, optical components, or any other material
depending on the industrial requirement.
Some common uses of Thermal Evaporation
- Applying electrical contacts on a substrate by depositing metal thin films such as silver or aluminum.
- Deposit metallic contact layers for thin film devices such as solar cells, thin-film transistors, and OLEDs
- Depositing thick indium layers for wafer bonding