PECVD
PECVD (Plasma Enhanced Chemical Vapor Deposition) is a technology used to deposit thin films on the surface of substrates.
The principle mainly includes the following steps:
1. Introduction of gas precursors: through specific gas precursors (such as silane, ammonia, etc.) into the reaction chamber. These gases, under the right conditions, will decompose and form a solid film.
2. Plasma generation: Plasma is generated in the reaction chamber by applying a high-frequency electric field or a direct current electric field. This process excites gas molecules, ionizing them and generating charged particles (electrons, ions, etc.) and neutral particles.
3. Chemical reaction: Under the action of plasma, the gas precursor decomposes into active species (such as atoms, molecules, etc.), which react on the surface of the substrate to form a thin film. Due to the presence of plasma, the reaction rate is usually high and can be deposited at lower temperatures, making it suitable for heat-sensitive materials.
4. Deposition of thin films: Active species aggregate on the surface of the substrate and undergo chemical reactions to form solid films. During the deposition process, the adjustment of parameters such as temperature, pressure, and gas flow can affect the quality and properties of the film.
5. Thin film characteristics control: By changing the type, flow rate, reaction pressure and plasma power of the precursor, the deposition of different types of thin films, such as silicon nitride, silicon oxide, etc., can be realized to regulate their electrical, optical and mechanical properties.
PECVD is widely used in semiconductors, optoelectronic devices, solar cells, and other fields, and is valued for its advantages in thin film quality and deposition conditions.