July 11, 2022
4 MIN READ
Mention diamonds and most people will associate that with the jewelry sector. They will also have in mind that such gems are to be found in mines and sometimes won under severe conditions (“blood diamonds”). For such reasons, the industry already investigated in the 1950s how to produce synthetic diamonds.
Today, there are several processes available to create artificial diamonds. Not only for jewelry where even experts are challenged to differentiate a natural diamond from an artificial, but also for the much larger market for diamonds in the industrial sector.
The key properties of synthetic diamonds that make them so interesting for the industrial sector are:
Some typical industrial application examples are machining and cutting tools, window material for transmitting infrared and microwave radiation, and heat sinks for lasers and transistors. Synthetic diamonds are also the base material for semiconductor wafers and Qubits for quantum computing.
Traditionally diamonds were naturally formed billions of years ago in the earth’s crust by carbon atoms being exposed to intense heat and pressure. However, due to technical advances, a new source of synthetically grown diamonds was created. This market can be divided into 2 main manufacturing methods:
Due to its small footprint and excellent process controls, the MPCVD growing process has gained in popularity. One important part of the MPCVD process is the creation of and maintaining optimal vacuum conditions inside a growth chamber. A typical growth chamber setup looks as below:
Synthetic diamond-making process. Source: NNE, 2019
The typical process steps are the following:
Nowadays, oil-sealed , or 2-stage rotary vane pumps are typically used in the MPCVD process. This is because these pumps are very well suited to achieve low conditioning pressure but also because they are mainly designed for continuous operation at fine vacuum. Additionally, these pumps face poor lubrication, overheating, or high oil loss when operating for days in the rough pressure phase required by this process.
The oil lubrication of TRIVAC pumps is secured by a built-in oil pump, which also enables a uniform oil distribution at rough pressure operation, whereas standard pumps without such oil pumps could fail.
NEO D 2-stage rotary vane pump is designed for operation at rough pressure and provides a perfect solution for the diverse pressure requirements of this growing process:
For those customers who want to achieve a conditioning pressure in the high-vacuum range <10-3 mbar, Leybold can also offer a wide range of turbo pumps like the TURBOVAC series. Next to this, we offer the required gauges and hardware.
With 175+ years of experience and a broad product range, Leybold is a great partner for your CVD diamond growth. From roughing pumps to turbo pumps or accessories, we have a large variety of products. We also have a dedicated applications team ready to calculate the ideal pump configuration. With a global support organization, we can support your manufacturing operations wherever they may be located.
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