Principles and Advantages of Plasma Enhanced Chemical Vapor Deposition (PE-CVD)

There are many kinds of plasma-enhanced chemical vapor deposition technology (PECVD for short), such as DC PECVD, pulsed DC PECVD, metal-organic compound PECVD, RF PECVD, microwave PECVD, arc light PECVD, etc. In recent years, with the cross-fertilization of various coating technologies, PVD and PECVD integrated composite deposition, particle nitriding and PECVD integrated composite deposition in the same furnace have been continuously developed. Of course, in recent years, with the cross-fertilization of various coating technologies, PVD and PECVD integrated composite deposition, particle nitriding and PECVD integrated composite deposition in the same furnace devices and technologies are constantly being developed. At present, most of the industrialized deposition of hard coating materials apply DC and pulsed DC PECVD technology.

The earliest application of PECVD is accompanied by the development of the semiconductor industry and appeared for the processing of semiconductor materials, i.e., the use of silicone in the semiconductor material substrate deposition of Si02. later based on the characteristics of the PECVD process is particularly suitable for industrial production, the process began to be used in a large number of microelectronics industry (such as integrated circuit process, etc.), is mainly used in the deposition of large-area parts of the protective film and various insulating layers and DLC films. PECVD technology is the use of high-voltage electric field applied in the deposition chamber, so that the reaction gas in a certain pressure and excitation source (eg: DC high voltage, pulsed power supply, radio frequency or laser, etc.), electrons in the accelerating effect of the electric field to obtain energy, and the neutral particles in the gas (atoms or molecules occurring inelastic collision, and then the ionization of secondary electrons, which in turn further and the atoms in the gas, the secondary electrons, and the atoms in the gas. They are further and gas atoms and molecules in the collision ionization and produce electrons, so repeatedly collision and ionization, it will produce a large number of electrons and ions. Because of which the number of positive and negative particles are equal, it is called plasma. Charged particles in the collision process will also be due to the composite and transformed into neutral particles, and in the form of glow discharge to release excess energy. Reaction gas is excited into a very active molecular yard, ions and atomic groups composed of plasma, greatly reducing the deposition reaction temperature, accelerate the chemical reaction process to improve the deposition rate.

The reaction gas is excited into very active molecules, atoms, ions and atomic groups composed of plasma, which greatly reduces the deposition reaction temperature, accelerates the chemical reaction process and improves the deposition rate. Therefore, the general PECVD technology deposition temperature <600 ℃, broadening the scope of application of the substrate material, with simple equipment, small deformation of the workpiece, good performance around the plating, coating uniformity, modulation of the composition of the advantages of convenience. It overcomes the disadvantages of high deposition temperature of CVD technology and strict requirements on the substrate material, and avoids the problems of poor winding plating and complex equipment of PVD technology, which is very suitable for industrialized production. At present, PECVD is mainly used in MEMS industry (such as integrated circuit process) and the preparation of fine films. At the same time, PECVD technology is also used in binary optics, solar films, gradient refractive index optical films and anti-laser damage films with its good uniformity and step coverage, dense deposited films, high bonding of the film layer with the substrate, and fast deposition speed.