Damage of silicon induced in low-energy CF₄ discharges

The damage of silicon induced by low-energy (30 eV) CF₄ discharges in a rf hollow oval magnetron system has been studied. The damage level was evaluated by the surface trap density measured by the high-low frequency capacitance-voltage method. By comparison with the results obtained using low-energy Ar discharges and other high-energy (450 eV) CF₄ and Ar discharges, the involatile reaction residue was inferred as the major cause of damage in the low-energy CF₄ discharges.