Dependence of Gate Oxide Breakdown Frequency on Ion Current Density Distributions during Electron Cyclotron Resonance Plasma Etching

According to the reduction of gate oxide thickness in Metal-Oxide-Semiconductor (MOS) devices, the gate oxide degradation caused by the stored charge during magnetized high-density plasma etching becomes a serious problem. The gate oxide degradation and the breakdown are brought about due to the nonuniform plasma radiation by the uneven magnetic field profile. Therefore, the flat equi-magnetic field profile suppresses the gate oxide degradation during electron cyclotron resonance (ECR) plasma etching.