How to make diamonds by chemical vapor deposition?
Chemical vapor deposition (CVD) produces pure, high-performance solid materials. A small diamond, which serves as the “core”, is placed in a vacuum environment to remove impurities and injected with high temperature gases – methane and hydrogen – at 3,000 degrees Celsius, which cracks to form electrically charged ions, and carbon atoms are released from the methane cracks. The carbon ions are deposited on the surface of the diamond and replicate the structure into which they were placed and continue to grow at a rate of 0.006 centimeters per hour, which can result in a 1-carat diamond in a matter of days. CVD can be used to create diamond discoveries, effectively increasing diamond production and applicability.
Process Gas
Most of the process gases used for CVD diamond films are a mixture of methane, hydrogen and argon in specific proportions. The most commonly used gas is a mixture of 1% methane and 99% hydrogen, while argon is often used to dilute the gas.
Common substrate
As a common substrate for the gas deposition method, such as silicon, metal, metal compounds; when the precursor vapors come into contact with the substrate, there may be different changes, such as deposition, decomposition, and other reactions resulting in the desire to synthesize the attached to the substrate, these molecules continue to accumulate, we can get the material we want.
Advantages of Chemical Vapor Deposition (CVD)
- Lower upfront equipment costs
- Cultivate diamonds with higher carat weights
- Cultivated diamonds with higher clarity
- Cultivated diamonds are free of metallic inclusions.
The biggest advantage of CVD is that it can be deposited on various substrates, and the growth conditions are not as severe as those of the high-temperature, high-pressure method, so it is a good choice for the application of finished diamonds. In addition, a wide variety of diamonds can be grown with different parameters, which can be categorized into micron diamonds, nano diamonds, and ultra-nano diamonds according to different sizes.
