Chemical Vapor Deposition (CVD) is a type of coating technology that converts gaseous precursors into solid materials through chemical reactions and deposits them on the surface of the substrate. The basic principle of CVD is to generate a thin film on the surface of the substrate through chemical reactions such as pyrolysis, reduction, and oxidation. CVD technology has the advantages of a wide range of material selection, high film quality, and flexible process.

The development of CVD technology began in the early 20th century, but its application in industry was mainly concentrated in the mid-to-late 20th century. With the development of the semiconductor industry, CVD technology has been widely used and developed rapidly.

There are many methods of chemical vapor deposition, such as atmospheric pressure chemical vapor deposition (APCVD), low pressure chemical vapor deposition (LPCVD), ultrahigh vacuum chemical vapor deposition (UHVCVD), laser chemical vapor deposition (LCVD), metal-organic chemical vapor deposition (MOCVD), plasma enhanced chemical vapor deposition (PECVD), etc.

The development of chemical vapor deposition is inseparable from its own characteristics, which are as follows.

I) There are many types of deposits: metal films, non-metallic films can be deposited, and multi-component alloy films, as well as ceramic or compound layers can be prepared as required.

2) The CVD reaction is carried out at atmospheric pressure or low vacuum, and the diffraction of the coating is good. It can evenly coat complex surfaces or deep holes and fine holes in workpieces.

3) It can obtain a thin film coating with high purity, good density, low residual stress and good crystallization. Due to the mutual diffusion of reaction gas, reaction product and substrate, a film layer with good adhesion can be obtained, which is very important for surface passivation, corrosion resistance and wear resistance.

4) Since the temperature of thin film growth is much lower than the melting point of the film material, a film layer with high purity and complete crystallization can be obtained, which is necessary for some semiconductor films.

5) By adjusting the deposition parameters, the chemical composition, morphology, crystal structure and grain size of the coating can be effectively controlled.

6) The equipment is simple and easy to operate and maintain.

7) The reaction temperature is too high, generally 850~1100℃, and many substrate materials cannot withstand the high temperature of CVD. Plasma or laser assisted technology can be used to reduce the deposition temperature.