What is Oxygen Plasma?

Oxygen plasma refers to any plasma treatment performed while introducing oxygen to the plasma chamber. Oxygen is often used to clean surfaces prior to bonding. It may also be combined with other gases to etch a variety of materials such as plastic and rubber.

Oxygen plasma in a PE-50
Oxygen plasma in a PE-50 plasma cleaner.
Oxygen(O2) is the most common gas used in plasma cleaning technology due to its low cost and wide availability. Oxygen plasma is created by utilizing an oxygen source on a plasma system.

All systems available from Plasma Etch will work with oxygen gas. An oxygen generator can be purchased and set up right in your lab.

Oxygen gas is commonly used to clean non-metal materials such as glass, plastics, and Teflon. Like other forms of plasma, oxygen cleans organics and is capable of surface modification.

O2 plasma will clean the surface of a plastic sample and increase its wettability. Oxygen plasma can also be used to clean metal surfaces if it's mixed with Argon. Argon gas strips the oxygen molecule away from the metal to prevent oxidation.

Plasma Ashing with Oxygen

Plasma ashing is the process of removing carbon from products during the manufacturing process. Plasma ashing is always performed with oxygen plasma treatment in a high frequency plasma system.

Generally, the goal of plasma ashing is to completely remove organic matter, including volatile carbon oxides and water vapor. All removed contaminants are pumped out of the chamber by the vacuum system.

Oxygen plasma removes all traces of organic matter and leaves no residues unless there were excessive inorganic contaminants on the sample.

Argon Plasma Treatment

Another gas commonly used for plasma treatment is argon. The most notable difference between oxygen and argon is that oxygen plasma is capable of surface modification, while argon is not. Additionally, oxygen will etch while argon will only clean.

If left in the plasma for too long, oxygen may modify the surface of some plastics rendering them unbondable; however, argon is safe to use for longer periods of time.

Oxygen plasma needs an additional oxidation preventing gas for materials that oxidize easily (e.g. silver, copper); argon is typically used with oxygen.

Oxygen and CF4

O2 may also be mixed with CF4 for reactive ion etching applications in larger plasma treatment systems. Plasma Etch currently offers three systems capable of reactive ion etching: PE-100, PE-200, and BT-1.

Next: Argon Plasma