In the vernacular, what is the role of nitrogen in semiconductor production?
Nitrogen is used in semiconductor factories, and to put it bluntly, there are four things to do.
The first thing is to be a bodyguard. When the chip is processed at high temperature, it is particularly easy to be oxidized by oxygen, and it is wasted once oxidized. Nitrogen is an inert gas with a stable character and does not like to react with other things. Therefore, filling nitrogen is equivalent to putting a protective coat on the chip. If oxygen cannot enter, the chip will not be burned out.
The second thing is to be a cleaner. The semiconductor workshop is full of dust and water vapor invisible to the naked eye. It is a disaster for these things to fall on the chip. Nitrogen is blown from the pipeline to take away all the dirt in the cavity and pipeline, ensuring that the chip is produced in a clean environment.
The third thing is to be a porter. When the chip is transported between different processes, it cannot be directly exposed to the air. It should be wrapped with nitrogen and sent to the past, just like an air bag for the chip, which is both anti-collision and anti-dirty.
The fourth thing is air conditioning. Some processes generate a lot of heat, and nitrogen blowing in the past helps to take the tropics away and keep the temperature stable.
Where does the nitrogen come from. The semiconductor factory is usually equipped with a nitrogen making machine to separate the nitrogen in the air. The raw material of the nitrogen making machine is compressed air, so an air compressor must be connected to supply air to it.
This air compressor is very particular. Because the nitrogen making machine has extremely high requirements on the quality of the air intake, even a little oil in the air will be blocked in the molecular sieve of the nitrogen making machine, resulting in a decrease in the purity of nitrogen and directly affecting the yield of the chip. So this air compressor must be oil-free.
Many semiconductor factories now choose water-lubricated oil-free screw air compressors to do this job. Its working method is very simple. The single screw and star wheel inside the machine rotate to compress air. Instead of using oil to reduce friction, it uses water. The water inside lubricates the screw while taking away the heat generated by compression, and the air coming out is completely oil-free. Because there is no oil, there is no need to change oil and no need to deal with waste oil. The condensed water discharged is clean water, and sludge will not accumulate in the pipeline. In this way, the air fed into the nitrogen making machine is really clean, and the purity of the nitrogen coming out is guaranteed.
To put it simply, nitrogen in the semiconductor factory is bodyguards, cleaners, porters and air conditioners, while the water-lubricated oil-free screw air compressor is the source that provides clean raw materials for the nitrogen making machine. The source is not clean, and the back is completely useless.