The failure of the vacuum system of semiconductor equipment is generally divided into two categories: one is the failure of the DVE vacuum pump unit and measurement system, and the other is the leakage of the vacuum system.

For the first type of failure, check the ultimate vacuum of the DVE vacuum pump or replace the vacuum gauge to confirm. For the second type of failure, leak detection is required. Two methods are often used in leak detection of semiconductor equipment: static pressure leak detection and He mass spectrometry leak detection.

The static pressure leak detection method is to separate the vacuum chamber from the DVE vacuum pump group with a valve, and measure the change of its internal pressure. Mass spectrometry leak detection is more complicated. The He mass spectrometer leak detector generally needs to be taken to the site. There is a molecular pump in the leak detector, so handle it with care. The high-sensitivity method of leak detectors is often used to detect leaks, which is beneficial to protect the molecular pump. Leak detectors have limited air extraction capabilities, so it is often necessary to vacuum the equipment itself. Vacuum to 0.5~10Pa will do. Wait until the leak rate is stable or change from stable to decreasing before starting leak detection.

In the process of leak detection, if you need to operate the gate valve, rough valve, bleed valve, etc., you must first stop the leak detector from leak detection and select the leak detection port not to vent, so as to prevent the vacuum chamber from suddenly entering a large amount of gas and damaging the inspection Leak meter.

After the vacuum is pumped, the gate valve and the rough pumping valve should be closed to avoid diversion causing the vacuum leak rate measurement value to be less than the actual value. It is best to stop the molecular pump and mechanical pump on the equipment to avoid their interference; the equipment with cold pump should stop the cold pump completely if you want to detect leaks.

When using the vacuum method to detect the leakage rate of the double-sealed structure product, the leakage rate often rises slowly, so pay attention to this point in the leak detection process. In addition, the He bag is required to not leak, and the He flow rate is generally required. This is helpful for confirming the location of the leaking point, but there are special cases where more He needs to be sprayed in some places where He is not easy to reach to avoid missed detection. The bellows installed during leak detection cannot be leak-tested. After the leak is found, a second confirmation must be performed, and the leak must be confirmed again after the leak is repaired.

There are many parts in the vacuum part of semiconductor equipment. If a part has a large leakage rate, it is easy to cause the high vacuum to fail to be pumped up. Difficult vacuum failures of semiconductor equipment are mostly caused by micro-leakage, which causes the high vacuum to fail. The difficulty of vacuum leak detection is to pay attention to the details of the operation and be patient. In addition, there must be room for choosing domestically produced high-vacuum timepieces, otherwise the desired high-vacuum degree will not be displayed.
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