Negative charge injection to a positively charged SiO₂ hole exposed to plasma etching in a pulsed two-frequency capacitively coupled plasma in CF₄/Ar

In a pulsed 2f-CCP in CF₄/Ar, the correlation between a reduction of the charging voltage at the bottom of a SiO₂ hole under etching and negative charge injection to the hole was examined. A comparison of the bottom potentials of the SiO₂ holes between those with exposure plasmas in pure Ar and those in CF₄ made it possible to identify, as the injected charge, light electrons and massive negative ions in an electronegative plasma.