CVD DIAMONDS

CVD DIAMONDS – SYNTHETIC MAN MADE

Produced using microwaves and gasses in vacuum plasma reactors CVD Diamonds “Chemical Vapour Deposition” are synthetic diamonds. Due to a heated exchange hydrocarbon gasses break down, and carbon atoms begin to precipitate in thin layers onto a flat substrate or wafer. The deposits occur a in similar way that layers of ice or snow may build up whilst freezing.CVD DIAMOND MANUFACTURING PROCESSEffective substrates include diamond, silicon, tungsten, molybdenum, silicon carbide, silicon nitride, quartz glass or cemented carbide. Growth rates of around 0.10 millimetres (mm), or 100 microns of diamond hour are commonplace. While growth has its limits in terms of depth, CVD stones over 3 mm in thickness are very difficult and expensive to grow.

(Image: a microwave plasma reactor for producing CVD diamond).

CVD DIAMOND PLASMA REACTOR

 

Initially the  process was successfully developed by Houston, Texas based chemical manufacturer Union Carbide Corporation in the 1950s, the CVD process is less costly and simpler than the HPHT process. Hence the equipment is less expensive, and  the process is conducted a moderate temperatures and lower pressures.

Like HPHT, the CVD method has recently become economically viable. CVD synthesis capability has advanced noticeably in recent years. Especially relevant is the emergence of several startup companies attempting to commercialise the production of CVD gem quality synthetics.

CHARACTERISTICS OF CVD DIAMONDS

(Image: CVD diamonds )

Due to tFully Grown CVD Diamondshe unique growth processes, CVD stones are similar to type IIa rough, contain minimal amounts of nitrogen, have a high thermal conductivity. Consequently CVD diamond has unique shape, the CVD method, produces flat, tabular synthetic diamond crystals, which are different to natural diamond crystals in structure. As a result it has been extremely difficult to grow CVD stones deeper than 3 mm, most CVD diamonds are smaller than 1 carat.

USES FOR CVD DIAMONDS.

  • Optical uses (e.g. infrared windows, lenses, ATR units, X-ray windows)
  • Thermal uses (heatspreaders, laser submounts, X-ray targets)
  • Mechanical uses (cutting tools, scalpels, knives, length gauge tips, wear resistant components e.g. for textile machines, insert for dresser tools)
  • Electrochemical uses (electrodes, electro-chemical detectors, bio-chemical sensors)
  • Radiation sensors (ionizing radiation detectors/dosimeters, fluorescence beam monitors)

CVD DIAMOND MONITORCVD DIamond Window

cvd_heat_spreaders

 

4 Comments

  1. […] as natural diamonds, particularly since these challenges have become prevalent with regards to Chemical Vapour Deposition (CVD) synthetic diamonds in the past two […]

  2. […] by chemical vapour deposition (CVD) Synthetic CVD diamonds, have rapidly improved in recent years due to advances in growth techniques and post growth […]

  3. […] Quality CVD Diamonds: Grown by chemical vapour deposition (CVD) Synthetic CVD diamonds, have rapidly improved in recent years due to advances in growth techniques and post growth […]

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