We have carried out emission selected computerized tomography time and space measurements of the absolute net production rate of Ar(2P1) in a pulsed capacitively coupled plasma for SiO2 etching pulsively sustained at 100 MHz and continuously biased at 500 kHz between electrodes in CF4/Ar and pure Ar at 25 mTorr. Double-layer formation by excessive negatively charged particles in the interface close to the wafer is experimentally estimated only at the wafer's anodic phases during the off-period of the plasma source as seen by the probed net excitation rate. The successive space and time configuration of the net excitation rate will support a sufficient capability to inject energetic negative ions to the biased wafer having microstructures and to neutralize the inner wall to be etched.
ASJC Scopus subject areas
- Condensed Matter Physics