CVD refers to a gas phase reaction at high temperature, such as the thermal decomposition of metal halides, organic metals, hydrocarbons, etc., hydrogen reduction or a method of causing its mixed gas to react chemically at high temperature to precipitate inorganic materials such as metals, oxides, and carbides. This technology was originally developed as a coating method, but it is not only used for coatings of heat-resistant materials, but also for the refining of high-purity metals, powder synthesis, semiconductor films, etc. It is a very characteristic technical field.

PECVD: It is to ionize the gas containing the atoms that make up the film with the help of microwaves or radio frequencies, and form plasma locally. The plasma is very chemically active and easily reacts to deposit the desired film on the substrate. In order to enable the chemical reaction to proceed at a lower temperature, the activity of the plasma is used to promote the reaction, so this CVD is called plasma enhanced chemical vapor deposition (PECVD).