CDE (Chemical Dry Etching)
Chemical dry etching. CDE is a common acronym for the chemical plasma etching process, also called “chemical etching” or “plasma etching”. Chemical dry etching takes place in the plasma by means of the reaction of active species (excited atoms, radicals, ions) with the substrate molecules. The process gas must be adapted to the substrate (selective etching process), the etching process is non-directional (isotropic).
Explanation of the drawing:
The figures show how the etching front proceeds over time. This type of trenches is generated with chemical plasma etching only.
Starting point of isotropic etching
Resulting etching front
Component
Etching trench
Etching mask
Isotropic etching attack
Explanation of the drawing:
This is a simplified representation of chemical etching. The etching attack is effected via the free areas of the etching mask. An etching front
is generated by the removal of the component substance. The etching front not only moves vertically down into the component but also
moves down below the mask at the same etching rate.
