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Aluminising vacuum chamber at Mont Mégantic Observatory used for re-coating telescope mirrors. [1] Vacuum deposition is a group of processes used to deposit layers of material atom-by-atom or molecule-by-molecule on a solid surface. These processes operate at pressures well below atmospheric pressure (i.e., vacuum). The deposited layers can ...
Physical vapor deposition (PVD), sometimes called physical vapor transport (PVT), describes a variety of vacuum deposition methods which can be used to produce thin films and coatings on substrates including metals, ceramics, glass, and polymers. PVD is characterized by a process in which the material transitions from a condensed phase to a ...
Evaporation is a common method of thin-film deposition. The source material is evaporated in a vacuum. The vacuum allows vapor particles to travel directly to the target object (substrate), where they condense back to a solid state. Evaporation is used in microfabrication, and to make macro-scale products such as metallized plastic film.
The VLS process takes place as follows: A thin (~1–10 nm) Au film is deposited onto a silicon (Si) wafer substrate by sputter deposition or thermal evaporation. The wafer is annealed at temperatures higher than the Au-Si eutectic point, creating Au-Si alloy droplets on the wafer surface (the thicker the Au film, the larger the droplets).
In this method, a source material is heated to produce an evaporated beam of particles, which travel through a very high vacuum (10 −8 Pa; practically free space) to the substrate and start epitaxial growth. [14] [15] Chemical beam epitaxy, on the other hand, is an ultra-high vacuum process that uses gas phase precursors to generate the ...
Deposition is the phase transition in which gas transforms into solid without passing through the liquid phase. Deposition is a thermodynamic process . The reverse of deposition is sublimation and hence sometimes deposition is called desublimation .
This process is used industrially to make such food products as evaporated milk for milk chocolate and tomato paste for ketchup. Vacuum evaporation plant vacuum pans in a beet sugar factory. In the sugar industry vacuum evaporation is used in the crystallization of sucrose solutions. Traditionally this process was performed in batch mode, but ...
Vacuum engineering is the field of engineering that deals with the practical use of vacuum in industrial and scientific applications. Vacuum may improve the productivity and performance of processes otherwise carried out at normal air pressure, or may make possible processes that could not be done in the presence of air.