CVD Encyclopedia
2022-06-23 10:47:33Author:wattsine
We all know that there are two methods of synthetic diamonds, one is the HPHT high temperature and high pressure method and the other is the CVD method. Today, as a senior CVD cultivation diamond growth equipment manufacturer, Wattsine Microwave Source will take you to focus on the CVD method of diamond synthesis.
According to the different growth principles, the cvd method of synthesizing single crystal diamond is mainly divided into three kinds: hot wire cvd method (HFCVD), DC plasma arc jet cvd method (DC-PJ CVD) and microwave plasma cvd method (MPCVD), of which MPCVD method is the most important.
Compared to the HFCVD method, MPCVD has the advantage of a non-polar discharge and avoids contamination of the diamond by hot wires (tantalum, tungsten, etc.) at high temperatures. In addition, hot wires are often sensitive to certain gases (e.g. high concentrations of oxygen etc.) and their service life is affected during the growth process due to prolonged exposure to reaction gases, thus indirectly increasing the cost of synthesis. Therefore, the MPCVD synthesis method is not only effective in avoiding diamond contamination, but also allows the use of multiple gases in the reaction system to meet different industrial needs.
Compared to the DC-PJ CVD method, the MPCVD method enables smooth and continuous adjustment of microwave power and stable control of the reaction temperature, thus avoiding the problem of crystal seeds falling off the substrate due to arcing and flame failure in the DC-PJ CVD method. By adjusting the structure of the reaction chamber of the MPCVD equipment and by reasonably controlling the microwave power and pressure, a large area of stable discharge plasma can be obtained, which is necessary for the production of high quality, large size single crystal diamonds. Therefore, compared to other cvd methods, the MPCVD method is considered to be the most promising diamond/diamond synthesis method for industrial applications.