Evaporation and Sputtering

Evaporation/condensation and sputtering/condensation are quite different methods of producing thin films. A comparison of their characteristics is given in Table 13. 

THIN FILMS PRODUCED BY EVAPORATION AND SPUTTERING EVAPORATION SPUTTERING 

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The fonnation of clusters in the gas phase involves condensation of the vapour of the constituents, with the exception of the electrospray source [6], where ion-solvent clusters are produced directly from a liquid solution. For rare gas or molecular clusters, supersonic beams are used to initiate cluster fonnation. For nonvolatile materials, the vapours can be produced in one of several ways including laser vaporization, thennal evaporation and sputtering. 

Mainly Co—Pt and Co—Pd have been studied by evaporation and sputtering. Although both processes show different physical processes the MO properties of the films do not vary much. Studies have also been carried out for materials with a lower Curie temperature (109). 

Alloy coating of turbine components by electron-beam evaporation and sputtering. 

Coatings of refractory compounds can be deposited reactively in a manner similar to reactive evaporation and sputtering by spraying the pure metal in an atmosphere of either a hydrocarbon or nitrogen. 

In order to achieve the enhanced strength, atomically sharp A IB interfaces are needed for the mechanism proposed by Koehler. The multilayer hlms should be deposited under a relative low temperature in order to avoid the interdiffusion between the layers. Thus, PVD techniques such as evaporation and sputtering deposition are the reasonable methods to fabricate multilayer hlms. There are several ways to achieve the alternate deposition of the composing layers A and hxed substrate position mode, repeated substrate po-... 

The other platform is dielectrics, for example, silicon dioxide, silicon nitride, silicon oxynitride, tantalum pentoxide, and titanium dioxide. They can be deposited by various methods, such as plasma-enhanced chemical vapor deposition, thermal evaporation, electron-beam evaporation, and sputtering. There are a number of dielectrics with refractive indices ranging from 1.45 to 2.4, facilitating diverse waveguide designs to satisfy different specification. Dielectrics have two other... 

In all vacuum coating methods layers are formed by deposition of material from the gas phase. The coating material may be formed by physical processes such as evaporation and sputtering, or by chemical reaction. Therefore, a distinction is made between physical and chemical vapor deposition ... 

In many cases, particularly with evaporation and sputtering methods, adhesion of the deposited film to the substrate may be inherently poor. It is extremely desirable in such cases to deposit a thin layer of an intermediate material that has better adhesion to the substrate. Examples of appropriate adhesion layers are discussed after presentation of evaporation and sputtering techniques. 

The most widely used vacuum deposition techniques are evaporation and sputtering, often employed for smaller substrates. In the evaporation process, heating the metal by an electron beam or by direct resistance produces the vapours. The system is operated at a very high vacuum (between 10-5 and 10 6 Torr) to allow a free path for the evaporant to reach the substrate. The rate of metal deposition by evaporation processes varies from 100 to 250,000 A min h These processes can be operated on a batch or a continuous scale. On the other hand, in the case of the sputtering technique, the reaction chamber is first evacuated to a pressure of about 10-5 Torr and then back-filled with an inert gas up to a pressure of 100 mTorr. A strong electric field in the chamber renders ionisation of the inert gas. These inert gas ions... 

What methods are used for evaporation and sputtering of substances to obtain nanocomposite films by PVD method ... 

The technique may be said to combine the advantages of vacuum evaporation and sputtering, so that excellent qualities of adhesion are obtained without a limitation of maximum thickness of the coating—while at the same time the rate of deposition can be comparatively high. Many metals, alloys, and compounds may be deposited, on both metallic and non-metallic articles. However, its use at present is mainly for functional and protective applications, particularly where high resistance to corrosion is required. Thus, as examples, aluminium may be deposited on various types of steel and on titanium for uses in the aerospace and defence industries—and can be regarded as a less hazardous replacement for cadmium electroplating. 

Chemical Bonding and Morphology of Interfaces in Aluminized Silicones from Evaporation and Sputtering... 

FM. D Heurle and J.M.E. Harper, Note on the Origin of Intrinsic Stresses in Films Deposited Via Evaporation and Sputtering, Thin Solid Films, Vol.171, 1989, p. 81. 

Vapor deposition. Both physical and chemical vapor deposition methods can be used to prq)are dense inorganic membranes. In either process, vaporization of the membrane material to be deposited is effected by physical means (such as thermal evaporation and sputtering) or chemical reactions. 

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