When coating, metal target is seriously poisoned. Why? How to avoid and how to deal with the target

Causes of poisoning:

Vacuum chamber leaks air or water, there are volatile components in the vacuum chamber, not filled with argon, filled with air or other, which may cause poisoning. These components react with the target and become black to cover the surface of the target, affecting the film forming speed.

Terms of settlement:

The target can be restored by beating it with IF or RF source for one or two hours.

Targets can also be removed and polished with sandpaper.

To prevent target poisoning, first of all, ensure that the vacuum chamber does not leak, clean up the interior, remove volatile components and so on.