Dependence of gate oxide breakdown frequency on ion current density distributions during electron cyclotronresonance 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. Thegate oxide degradation and the breakdown are brought about due to the nonuniform plasma radiation by the unevenmagnetic field profile. Therefore, the flat equi-magnetic field profile suppresses the gate oxide degradation during electron cyclotron resonance (ECR) plasma etching.