CVD can be used to produce synthetic diamond by creating the circumstances necessary for carbon atoms in a gas to settle on a substrate in crystalline form.

CVD of diamond has received a great deal of attention in the materials sciences because it allows many new applications of diamond that had previously been considered too difficult to make economical.

The advantages to CVD diamond growth include the ability to grow diamond over large areas, the ability to grow diamond on a substrate, and the control over the properties of the diamond produced.

With CVD diamond growth areas of greater than fifteen centimeters ( six inches ) diameter have been achieved and much larger areas are likely to be successfully coated with diamond in the future.

The most important attribute of CVD diamond growth is the ability to control the properties of the diamond produced.

* T. Liu, D. Raabe and S. Zaefferer " A 3D tomographic EBSD analysis of a CVD diamond thin film " Sci.

* A black synthetic diamond, specifically CVD polycrystalline diamonds or HPHT polycrystalline compact diamonds

Synthetic diamond is also widely known as HPHT diamond or CVD diamond after the two common production methods ( referring to the high-pressure high-temperature and chemical vapor deposition crystal formation methods, respectively ).

The properties of synthetic diamond depend on the details of the manufacturing processes ; however, some synthetic diamonds ( whether formed by HPHT or CVD ) have properties such as hardness, thermal conductivity and electron mobility that are superior to those of most naturally-formed diamonds.

The second method, using chemical vapor deposition ( CVD ), creates a carbon plasma over a substrate onto which the carbon atoms deposit to form diamond.

Whereas the mass-production of high-quality diamond crystals make the HPHT process the more suitable choice for industrial applications, the flexibility and simplicity of CVD setups explain the popularity of CVD growth in laboratory research.

The advantages of CVD diamond growth include the ability to grow diamond over large areas and on various substrates, and the fine control over the chemical impurities and thus properties of the diamond produced.

An alternative, and completely different growth technique is chemical vapor deposition ( CVD ).

Unlike HPHT, CVD process does not require high pressures, as the growth typically occurs at pressures under 27 kPa.

The CVD growth involves substrate preparation, feeding varying amounts of gases into a chamber and energizing them.

In particular, CVD diamond is often contaminated by silicon originating from the silica windows of the growth chamber or from the silicon substrate.

* Thin film growth and preparation techniques with stringent requirements for purity, such as molecular beam epitaxy ( MBE ), UHV chemical vapor deposition ( CVD ) and UHV pulsed laser deposition ( PLD )

** Ultrahigh vacuum CVD ( UHVCVD ) – CVD process at very low pressure, typically below 10 < sup >− 6 </ sup > Pa (~ 10 < sup >− 8 </ sup > torr ).

In response to this argument, Wolfgang Kopp states that " we have to take into account that death from atherosclerosis and cardiovascular disease ( CVD ) occurs later during life, as a rule after the reproduction phase.

Unlike the statins, where cholesterol lowering has been proven to reduce CVD risk and overall mortality under well-defined circumstances, no such effect has ever been documented with phytosterol-enriched foods or phytosterol OTC medications.

Those films are produced by various chemical vapor deposition ( CVD ) techniques in an atmosphere rich in hydrogen ( typical hydrogen / carbon ratio > 100 ), under strong bombardment of growing diamond by the plasma ions.

Although it currently cannot attain the mobility that poly-Si can, it has the advantage over poly-Si that it is easier to fabricate, as it can be deposited using conventional low temperature a-Si deposition techniques, such as PECVD, as opposed to laser annealing or high temperature CVD processes, in the case of poly-Si.

As a result of the stepwise, the process is slower than CVD, however it can be run at low temperatures, unlike CVD.

* Coatings deposited on the SMF work tool, such as chemical vapor deposition ( CVD ) or physical vapor deposition ( PVD ) and titanium nitride ( TiN ) or diamond-like carbon coatings exhibit low chemical reactivity even in high energy frictional contact, where the subject material's protective oxide layer is breached, and the frictional contact is distinguished by continuous plastic deformation and plastic flow.

Around the year 2000, there was a wave of attempts to dope synthetic CVD diamond films by sulfur aiming at n-type conductivity with low activation energy.

** Atmospheric pressure CVD ( APCVD ) – CVD process at atmospheric pressure.

Even a high mortality from CVD after the reproduction phase will create little selection pressure.

Gemesis has the world's largest facilities for both the high pressure – high temperature ( HPHT ) and chemical vapor deposition ( CVD ) diamond production methods.

** Low-pressure CVD ( LPCVD ) – CVD process at sub-atmospheric pressures.

** Aerosol assisted CVD ( AACVD ) – A CVD process in which the precursors are transported to the substrate by means of a liquid / gas aerosol, which can be generated ultrasonically.

** Direct liquid injection CVD ( DLICVD ) – A CVD process in which the precursors are in liquid form ( liquid or solid dissolved in a convenient solvent ).

** Plasma-Enhanced CVD ( PECVD ) – CVD process that utilizes plasma to enhance chemical reaction rates of the precursors.

** Remote plasma-enhanced CVD ( RPECVD ) – Similar to PECVD except that the wafer substrate is not directly in the plasma discharge region.

* Atomic layer CVD ( ALCVD ) – Deposits successive layers of different substances to produce layered, crystalline films.

* Hot wire CVD ( HWCVD ) – also known as catalytic CVD ( Cat-CVD ) or hot filament CVD ( HFCVD ), this process uses a hot filament to chemically decompose the source gases.

* Metalorganic chemical vapor deposition ( MOCVD ) – This CVD process is based on metalorganic precursors.

* Rapid thermal CVD ( RTCVD ) – This CVD process uses heating lamps or other methods to rapidly heat the wafer substrate.

On April 25, 2002, the United States Department of Commerce announced it had determined subsidy and anti-dumping rates, with a final subsidy rate of 18. 79 % and an average dumping rate of 8. 43 %, to give a combined CVD / AD rate of 27. 22 %.

IBM and others use UHV CVD for SiGe ; other techniques used include MOVPE for III-V systems.

Phosphorus could be intentionally introduced into diamond grown by chemical vapor deposition ( CVD ) at concentrations up to ~ 0. 01 %.

Chemical vapor deposition ( CVD ) is a chemical process used to produce high-purity, high-performance solid materials.

In a typical CVD process, the wafer ( substrate ) is exposed to one or more volatile precursors, which react and / or decompose on the substrate surface to produce the desired deposit.

Microfabrication processes widely use CVD to deposit materials in various forms, including: monocrystalline, polycrystalline, amorphous, and epitaxial.

The CVD process is also used to produce synthetic diamonds.

A number of forms of CVD are in wide use and are frequently referenced in the literature.

Most modern CVD processes are either LPCVD or UHVCVD.

The precursor vapors are then transported to the substrate as in classical CVD process.

Polysilicon may be grown directly with doping, if gases such as phosphine, arsine or diborane are added to the CVD chamber.

CVD oxide invariably has lower quality than thermal oxide, but thermal oxidation can only be used in the earliest stages of IC manufacturing.