RF source care – discharge chamber

We do a lot of cleaning and repair service at Plasma Process Group and we get a good chance to see your hardware throughout its life cycle. For the same reason, we also get to see what causes that life cycle to shorten. Here are a few quick things you can do or keep in mind to get the most out of your hardware:

The discharge chamber inside your RF ion source is made of quartz and can crack easily. We’ve all damaged a discharge chamber at one time or another, usually when the boss is standing right next to us. But if you don’t break it, can you just pretend nothing happened? Unfortunately, the answer is no. Tiny cracks are huge holes to process gas and plasma.

When process gas or plasma leak behind the discharge chamber, it increases the risk that a secondary discharge ignites. An uncontrolled discharge near the RF antenna and beaded leads may cause the source to extinguish and sputter coat the ceramic insulators with copper. Sputter coating damage can occur to the gas isolator and RF feedthru. A significant discharge may require a complete source refurbishment to recover insulator performance.

Quartz discharge chambers can be cleaned using the same process to clean molybdenum grids. Media blast pressure should be 30 psi or less. Just in case, we recommend keeping a spare discharge chamber on hand and change them out between process when necessary.