Most chemical elements can be vaporized by combining them with chemical groups, e.g. Si reacts with H to form SiH4, and Al combines with CH3 to form Al(CH3). In the thermal CVD process, the above gases absorb a certain amount of thermal energy as they pass through the heated substrate and form reactive groups, such as CH3 and AL(CH3)2, etc. They then combine with each other to form the reactive groups, which are then deposited on the substrate. Subsequently, they combine with each other and are deposited as thin films. In the case of PECVD, the collision of electrons, energetic particles and gas-phase molecules in the plasma provides the activation energy needed to form these reactive chemical groups.
The advantages of PECVD are mainly in the following aspects:
(1) Lower process temperature compared to conventional chemical vapor deposition, which is mainly due to plasma activation of reactive particles instead of conventional heating activation;
(2) Same as conventional CVD, good wrap-around plating of the film layer;
(3) The composition of the film layer can be controlled arbitrarily to a large extent, making it easy to obtain multilayer films;
(4) Film stress can be controlled by high/low frequency mixing technology.
–This article is released by vacuum coating machine manufacturer Guangdong Zhenhua
Post time: Apr-18-2024