Plasma coating refers to a coating that has been deposited on a substrate surface using a plasma system. This plasma technology is used in a number of applications where a very thin and uniform film thickness is required. Common coating materials include chemicals such as silicon dioxide or silicon nitride as well as a variety of organic polymer forming species. Deposition of a polymer surface coating using plasma is referred to as plasma polymerization.
Plasma coating applications include coating objects with antiglare, dielectric, water repellent (hydrophobic), heat and chemical resistance coatings. A coating may be deposited on a variety of materials including metals, polymers and ceramics.
PECVD, or Plasma-Enhanced Chemical Vapor Deposition is a plasma treatment process that involves placing the parts to be coated into a vacuum chamber. The chamber is sealed and the pressure is reduced to approximately 0.1-0.5 mbar. Next, a process gas and chemical are allowed to flow into the chamber at a very slow rate. A voltage is then applied to form the plasma. The process is continued until the desired film thickness is achieved. This plasma process has a huge advantage over regular Chemical Vapor Deposition (CVD) in that PECVD can be conducted at a far lower temperature.
PECVD technology applications are found in many industries. For example, in optics it is used to apply antireflective, scratch resistant and bypass filter coatings to lenses and shields. In micro-electronics plasma systems are used to prepare photosensitive and electronically active layers, thin film transistors, passivation layers, dielectric layers, isolating layers and diffusion barrier layers. This plasma technology is also used to prepare light detectors, solar cells, sensors and etch stop layers. It is further used for encapsulation. In packaging, PECVD is used to prepare chemical and humidity barriers.