Plasma Processing

Plasma is a highly ionized gas that is composed of electrons, ions, and neutral particles yet is roughly electrically neutral overall. Composed of charged particles, plasma is electrically conductive. The charged particles collide with other molecules, exciting them into higher energy states. As the molecules quickly relax back to lower energy states, they give off photons, which causes the plasma to glow.

 

Plasma processing is often done inside of a plasma chamber at extremely low pressures (that is, under high vacuum), though some kinds of plasma processing do not require a vacuum chamber and are done at atmospheric pressure.

 

Typically, a radio frequency (RF) generator uses two electrodes to excite gases that are introduced into the vacuum chamber at precisely controlled flow rates. This basic setup can be used to accomplish various types of processing based on the gases used and the amount of power applied. Common types of plasma processing include plasma cleaning, plasma activation, and PECVD plasma coating.