film and coating deposition on a substrate (rus. осаждение пленок и покрытий на подложку) — a technique for producing continuous layers of materials represented by films or coatings on a cold or heated surface of a substrate by their deposition from vapour (gas phase), plasma or a colloid solution.

Description

Chemical vapour deposition (CVD) of films is based on high-temperature vapour reactions of metal chlorides in an atmosphere of hydrogen and nitrogen or hydrogen and hydrocarbons. CVD of films occurs in temperatures ranging between 1200K and 1400K. Using lasers, this temperature may be reduced to 600-900 K, which helps to produce nanostructured films. The chemical vapour deposition process involves metal-organic precursors like tetradimethyl(ethyl)amides M[N(CH3)2]4 and M[N(C2H5)2]4 with high vapour pressure; precursor decomposition and activation of a reagent gas (N2, NH3) is achieved by the use of electron cyclotron resonance.

Physical vapour deposition (PVD) occurs in vacuum chambers under a pressure of 10–2 to 10–3 Pa by condensation on a substrate of material vapours produced by heating, vapourisation or sputtering of a target. Vapours of an evaporated material may have a pressure of approx. 1 Pa. The target may be subject to different types of exposure, such as cathode or magnetron sputtering and induction, laser or electron beam evaporation. The key parameters of physical vapour deposition include substrate temperature (condensation temperature), rate of condensation, vacuum intensity and method of evaporation (sputtering).

In the plasma-enhanced deposition process involving metal cathodes, reactive actuating media (argon mixed with nitrogen or hydrocarbons under pressure of ~0.1 Pa) are used to maintain the arc discharge; films are deposited on a substrate heated to 500-800 K; continuity and thickness of the film, as well as the size of crystallites in the film, are controlled by adjusting the gas pressure and arc discharge parameters. The deposition of films from colloid solutions on a substrate includes the preparation of a solution, the deposition process, drying and annealing.

The deposition of nanoparticles of oxides and chalcogenides is used to produce semiconductor films of ZnO, SnO2, TiO2, CdS, PbS. Nanostructured films containing nanoparticles of different semiconducting materials are produced by co-deposition.

Pulsed electrode position of coatings and films from metals is achieved by the electrolysis of a solution containing ions of a deposited element. Time-varying (pulsing) potential drop is created between the layer of deposited metal on a substrate and an electrode submerged in the solution. The size of grains and chemical composition of films can be controlled by changing the parameters of the pulse mode, adding organic dopants to the solution or adjusting the temperature of the solution and the substrate.

Author

  • Gusev Alexander I.

Source

  1. Gusev A. I. Nanomaterials, Nanostructures, and Nanotechnologies (in Russian) // Fizmatlit, Moscow (2007) - 416 pp.

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