井冈山Preparation of CVD diamond

At present, synthetic diamond single crystal methods can be divided into two categories: high temperature and high pressure method (HTHP), chemical vapor deposition method (CVD). The single particle size obtained by HTHP method is relatively small, and the single crystal synthesized by HTHP method may contain impurities such as catalysts, and can not be doped effectively.

Chemical vapor deposition (CVD) is a common preparation method of thin film materials, which uses the vapor precursor to deposit the required thin film materials on a specific substrate under specific conditions. In the preparation of single crystal diamond materials, usually used as methane and hydrogen as precursors, under high temperature (about 1000℃), atmospheric pressure (1 atmospheric pressure) or low pressure conditions, with single crystal diamond substrate as the substrate, in the way of gas phase epitaxial growth of single crystal diamond, the single crystal diamond substrate used can be natural diamond, HPHT diamond or CVD diamond.

According to scientists, the process of cultivating diamond is like growing food, "First there must be a seed chip, but also need to use methane gas, methane under the action of energy, formed a carbon plasma, the plasma is like dust, slowly deposited in the air to the diamond seed chip, bit by bit deposited on."