Polymer Removal for Bosch Process
The etching of deep trenches in bulk silicon is a combination of subsequent etch and deposition steps. The sidewall of the trench that was already etched, will be protected by depositing a polymer on its side wall. After the etch has reached the desired depth, this side wall polymer has to be removed prior to the next step of filling the trench.
Using a simple plasma process, the radicals created by microwave excitation will easily remove this polymer even from very deep and narrow trenches. Process temperature is here the crucial process parameter.
The removal process from “Bosch-polymers” has been proven both in batch as well as in the single wafer process.
Bosch process is a processing technology covered by different patents from Robert Bosch GmbH