Plasma etching is a form of surface treatment in which larger quantities of material are impacted and removed. Plasma etching leads to a deep structuring of the surface.
Reactive ions that are created within the plasma react with surface atoms. The resultant volatile side products are removed from the chamber with the plasma gas. The plasma etching process can be modified further by adding activated neutral (uncharged) molecules to the process.
There are two main options for plasma etching:
While plasma etching with masks, it is important to control the direction of material removal. Isotropic plasma etching will lead to a “ballooning” of cavities under the mask, while anisotropic plasma etching will result in pits with almost vertical walls. Control is mostly achieved by adjusting the chemistry (different gases used in chamber) of the plasma etching procedure. With a Thierry plasma system, all these options are available.