How does the semiconductor vacuum chamber achieve and maintain a vacuum environment?
Publish Time: 2025-03-03
In the semiconductor manufacturing process, the vacuum environment is crucial to ensure the quality and performance of the device. As a key device to achieve this environment, the mechanism of achieving and maintaining the vacuum environment of the semiconductor vacuum chamber is particularly critical.
1. Realization of the vacuum environment
The semiconductor vacuum chamber achieves a vacuum environment through a vacuum pump system. The vacuum pump system is usually composed of a combination of multiple types of pumps to meet different vacuum requirements. In the initial stage, a mechanical pump is usually used as a fore pump, which extracts the gas molecules in the container through rotating mechanical parts (such as pistons or turbines) to quickly drop the gas pressure to a lower level. Subsequently, a higher-performance pump, such as a diffusion pump, molecular pump or ion pump, will take over the work of the mechanical pump and further reduce the gas pressure to the required vacuum degree.
The diffusion pump uses heated liquid metal or oil vapor as the working medium, and carries and discharges gas molecules through the high-speed movement of steam molecules. The molecular pump generates a strong shear force through the high-speed rotating blades to directly extract the gas molecules from the container. The ion pump ionizes the gas molecules through electric and magnetic fields and adsorbs them on the negative electrode, thus achieving an ultra-high vacuum environment.
2. Maintenance of the vacuum environment
Once the required vacuum degree is reached, the semiconductor vacuum chamber needs to take measures to maintain this environment. First, the design of the vacuum chamber needs to use materials with low outgassing rates, such as stainless steel and aluminum, to reduce the release of internal gas molecules. At the same time, the structure of the vacuum chamber also needs to be carefully designed to ensure that there are no dead corners inside and reduce gas residue.
Secondly, the vacuum pump system will continue to operate to extract any gas molecules that enter the vacuum chamber. In addition, the vacuum chamber is also equipped with monitoring equipment such as vacuum gauges to monitor the vacuum degree in real time and adjust it when necessary.
In order to further improve the stability and durability of the vacuum degree, the semiconductor vacuum chamber also uses baking and degassing technology. By heating the vacuum chamber and its internal components, the release of gas adsorbed on the surface can be accelerated and the vacuum degree can be improved. At the same time, the use of degassing agents or high-frequency discharge treatment can also effectively remove gas molecules.
The semiconductor vacuum chamber achieves and maintains a vacuum environment through a vacuum pump system and a series of carefully designed measures. This environment is crucial for many key steps in the semiconductor manufacturing process, such as crystal growth, thin film deposition, ion implantation and etching. By continuously optimizing the design and manufacturing technology of vacuum chambers, the semiconductor industry can continuously improve the quality and performance of devices and promote the continuous advancement of semiconductor technology.
