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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 ...
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).
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 ...
Vacuum pump and bell jar for vacuum experiments, used in science education during the early 20th century, on display in the Schulhistorische Sammlung ('School Historical Museum'), Bremerhaven, Germany. A vacuum (pl.: vacuums or vacua) is space devoid of matter. The word is derived from the Latin adjective vacuus (neuter vacuum) meaning "vacant ...
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 .
However, the processing time is typically very long and the deposition rate is slow, so new routes have been invented to develop more rapid infiltration techniques: Thermal-gradient CVI with forced flow – In this process, a forced flow of gases and matrix material is used to achieve less porous and more uniformly dense material.
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 ...