Thin films and nanostructured coatings for eco-efficient buildings - Nanotechnology in Eco-efficient Construction - page 161

Table 8.1 Survey of thin fi lm deposition technologies

Particulate
deposition

Surface
modifi cation Atomistic deposition Bulk coating

Vacuum environment
• Evaporation
• Molecular beam epitaxy
• Ion beam deposition
Plasma environment
• Sputter deposition
• Ion plating
• Plasma polymerization
• Glow discharge
deposition
Electrolytic environment
• Electroplating
• Electroless deposition
Chemical vapour
environment
• Chemical vapour
deposition
• Spray pyrolysis
Liquid phase epitaxy

Thermal spraying
• Plasma
spraying
• Flame spraying
• Detonation gun
Fusion coating
• Enameling
• Electrophoresis

Wetting
processes
• Printing
• Dip coating
• Spin
coating
Printing
Cladding
• Explosive
• Roll-binding
Weld coating

Chemical
conversion
• Anodic
oxidation
• Nitridation
Leaching
Thermal
surface
treatment
Ion
implantation
Laser glazing

produced by drawing current through a resistive coil or boat, often of tung-
sten, in contact with the substance to be evaporated or by thermionic emis-
sion from a wire and focusing of the electron beam onto the substance to
be evaporated from a water-cooled 'electron gun'. The latter technique is
referred to as electron-beam, or e-beam, evaporation.
Sputter deposition is very generally employed to make uniform coatings
on glass, polymers, metals, etc. In essence, a plasma is set up in a low pres-
sure of inert and/or reactive gases, and energetic ions in the plasma dislodge
material from a solid plate or cylinder of the raw material of the fi lm
(known as the 'target') and deposit these atoms as a uniform fi lm on an
adjacent surface (called the 'substrate'). The technology is discussed in
detail in topics by Chapman (1980), Cuomo et al. (1989), Konuma (1992),
Wasa and Hayakawa (1992) and Depla and Mahieu (2008). The sputter
plasma can be inert, typically consisting of argon ions, in which case the
target and the thin fi lm have the same composition. Alternatively the plasma
can be reactive and contain for example oxygen so that an oxide fi lm can
be formed by sputtering from a metallic target; an additional admixture of
water vapour can yield an entire cocktail of metastable and highly reactive
species in the plasma (Liu et al. , 2011). Analogously, nitrides can be made
by sputtering in the presence of nitrogen, etc. The great versatility of the
reactive sputtering technique should be obvious.

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