One of the common methods of physical vapor deposition (PVD) is thermal evaporation. This is a form of thin film deposition. It is a vacuum technology used to apply evaporation coating materialsto the surface of various objects. The coating, also called a thin film, usually ranges from angstroms to micrometers in thickness and can be a single material or multiple materials in a layered structure.
Method for thermally evaporating heating source material
The method of filament evaporation is a simple resistance heating element or filament. These resistive evaporation filaments come in many different physical configurations, including many materials called "boats"-basically thin metal sheets of suitable high-temperature metals (such as tungsten) with shaped dents or grooves, materials Placed in it. The filament power supply provides low-voltage safety and requires very high currents, usually several hundred amperes.
Thermal evaporation process
The evaporation material applied using thermal evaporation technology can be pure atomic elements, including metals and non-metals, and can also be molecules such as oxides and nitrides. The object to be coated is called the substrate, and it can be any of a variety of objects, such as semiconductor wafers, solar cells, optical components, or many other possibilities.
Thermal evaporation refers to heating a solid evaporating material in a high vacuum chamber to reach a temperature that produces a certain vapor pressure. Inside the vacuum, even a relatively low vapor pressure is sufficient to generate a vapor cloud in the chamber. This evaporating material constitutes a vapor stream, which passes through the chamber and hits the substrate, as a coating or film adheres to the substrate. In most thermal evaporation processes, the material is placed in a crucible and heated to its melting point to turn it into a liquid, and then continues to be heated to become vapor. The vapor flow rises, and the substrate that is inverted on the top of the chamber is wounded with a thin film. This thermal evaporation system design and method can adjust many parameters, allowing engineers to obtain desired results for variables such as thickness, uniformity, bond strength, stress, grain structure, optical or electrical properties.
We also provide accessories such as residual gas analyzer (RGA) and other custom functions and custom automation functions to help you perfect thermal evaporation techniques and methods. Cryogenic pumps are the most popular type of high vacuum pump used for evaporation, but other options can be used if required. No matter which option you choose, the thin-film evaporation system can provide relatively high deposition rate, real-time rate and thickness control, and (with appropriate physical configuration) good evaporation flow direction control for the purpose of improving processing to achieve direct patterning coating. If you have any questions about evaporation materials or evaporation coatings, please contact us