ANTENNA CHARGING EFFECTS ON THE ELECTRICAL CHARACTERISTICS OF POLYSILICON GATE DURING ELECTRON-CYCLOTRON-RESONANCE ETCHING

The nonuniformity of the induced leakage current in metal oxide semico nductor (MOS) capacitors has been investigated in an electron cyclotro n resonance (ECR) system. For plasma-etched MOS capacitors with 5-nm-t hick oxides, it is found that the leakage currents induced by plasma e tching increase with increasing overetching time. However, additional E(bd) (breakdown held) degradation is not obvious as overetching perce ntage increases from 10% to 50%. A mechanism based on the antenna char ging effect has been proposed to explain the E(bd) electrical characte ristics. In accordance with the mechanism, the E(bd) degradation has b een significantly reduced by first etching off a narrow peripheral edg e around the gate pattern.