General introduction of vacuum coating technology

The thickness is from several nanometers to tens of microns, so the thickness and width of film is very small, especially for nm-thick film. It can be considered as a two-dimensional material. And comparing with three-dimensional bulk materials, thin film materials have special properties, especially those with special optical, electrical, and magnetic effects. Because most of the materials that play a role in the application are the parts near the surface, or surface plays a special role, so the bulk material surface preparation to meet the requirements of the film, the surface processing of materials that can give the surface a special performance or to be protective of surface materials nickel oxide to greatly improve the performance. Meanwhile, thin film materials with bulk materials, alternative energy can be saved, and preparation of bulk materials to avoid technical difficulties, so the thin-film technology in the new materials research has been widely appreciated.

Thin film preparation methods can be divided into gas generation, oxidation, ion implantation, diffusion, electroplating method, coating method, liquid phase growth method. Vapor generation method which can be divided into physical vapor deposition (referred to as PVD method) and chemical vapor deposition (referred to as CVD method), because they are basically in a vacuum environments, and therefore refer to them as vacuum coating membrane technology.

Now widely used and emerging vacuum coating technology categories, PVD methods include vacuum evaporation, sputtering and ion plating, is the basic thin film preparation techniques. Vacuum evaporation in a vacuum chamber, heating the container to be evaporated to form thin films of materials, atoms or molecules to escape from the surface of the gasification, the formation of vapor flow, sputtering to a solid (called the substrate) surface condensation to form solid films. Evaporation source is a key component of the evaporation plant, according to the different evaporation sources can be divided into resistive evaporation source evaporation coating deposition method, electron beam evaporation source evaporation, high-frequency induction evaporation sources and laser-beam evaporation evaporation source steam plating method. Sputtering many ways, more representative of the method are: DC two, three pole or four-pole sputtering, magnetron sputtering, the target for sputtering, RF sputtering, reactive sputtering, bias splash shot, asymmetric exchange sputtering, ion beam sputtering. Ion plating known as ion plating (referred to as IP), which is in a vacuum evaporation and sputtering techniques developed on the basis of a new coating technology, which makes the vacuum evaporation of material ionized gas or in gas ion or ion bombardment of evaporated material, while the evaporation material or reaction products deposited on the substrate. In recent years, physical vapor deposition technology continues to expand the object, processing the substrate temperature further reduced, the new coating, composite coating, large numbers of multi-layer coating. With high-power laser technology has become more sophisticated, microwave technology and performance requirements for the continuous improvement of film, many new physical technologies in reference to the films to, such as pulsed laser deposition (PLD), molecular beam epitaxy (MBE) [, liquid phase epitaxy (LPE), hot-wall epitaxy (HWE) [1]. Among them, pulsed laser deposition (PLD) is produced by excimer laser pulses of high power pulsed laser beam focusing effect on the target surface, the target surface temperature and ablation, and further high temperature high pressure plasma, which kinds of plasma emission and directed local expansion in the matrix on the formation of thin film deposition. PLD technology in refractory materials and multi-component materials (such as compound semiconductor, electronic ceramics, superconducting materials) precision epitaxial single crystal thin film, especially nano-film and multilayer structures prepared by a broad outlook on the show. Molecular beam epitaxy method (MBE) in 1969 by Bell Labs JRArthur named. It is mainly used to develop a new b - d semiconductor epitaxial growth method, this method is the required extension of the membrane material on the jet furnace, in the 10-8Pa order of magnitude under conditions of ultra-high vacuum The heating evaporation, and these components of the membrane material atoms (or molecules) by a certain percentage of injection to heat the substrate under the epitaxial deposition of the film. At present, prepared by MBE thin-film semiconductor laser, HgCdTe infrared detector, InGaAs / InGaAsP quantum well material in such practical applications show a significant prospect.

In general, chemical vapor deposition (CVD) coating technologies include thermal decomposition, reduction, oxidation, stimulate the reaction, adding water solution, the ammonia reaction, chemical transport reaction method neodymium fluorideand so on. In recent years, CVD technology has been greatly developed, many new technologies, such as metal organic chemical vapor deposition (MOCVD) method, plasma enhanced chemical vapor deposition (PECVD), laser-induced chemical vapor deposition (LCVD) method, ultra-high vacuum / chemical vapor deposition (UHV / CVD) method, the RF heating chemical vapor deposition (RF / CVD) method and the UV energy-assisted chemical vapor deposition (UV / CVD) method and other new technologies. Source:http://www.mhcocm.com