Lastly, we discuss how to round the tapered holes.
This step involves removing the photoresist covering the surface of the wafer, exposing the entire bare wafer to the plasma. This step uses SF6 and O2, differing from before by not including Ar gas, thus the physical bombardment effect is weaker, and it is primarily a chemical action, achieving isotropic etching to smooth sharp corners and rough sidewalls.
2024-12-10