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The Development of New Coating Materials

Decent Essays

PECVD
Summary :
Recent advances in science and technology have stimulated the development of new coating materials, surface and interface engineering processes, and thin film systems, that provide ever-improving performance in numerous areas, ranging from optics and optoelectronics to aerospace, automotive, biomedical, microelectronics, and other applications.
PECVD Process :

In PECVD processing, glow discharge plasmas are sustained within chambers where simultaneous CVD reactions occur. Generally, the radio frequencies employed range from about 100 kHz to 40 MHz at gas pressures between 50 mtorr to 5 torr. Under these conditions, electron and positive-ion densities number between lo9 and 101*/cm3, and average electron energies range from 1 to 10 eV. This energetic discharge environment is sufficient to decompose gas molecules into a variety of component species, such as electrons, ions, atoms, and molecules in ground and excited states, free radicals, etc. The net effect of the interactions among these reactive molecular fragments is to cause chemical reactions to occur at much lower temperatures than in conventional CVD reactors without benefit of plasmas. Therefore, previously unfeasible high-temperature reactions can be made to occur on temperature-sensitive substrates.

Typical cylindrical, radial flow, silicon nitride deposition reactor

The tube or tunnel reactors employed can be coupled inductively with a coil or capacitively with electrode plates. In both cases,

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