Ultrathin Oxide on Polysilicon by ECR(Electron Cyclotron Resonance) N2O Plasma

We have developed a process of growing ultrathin oxide on polysilicon layer by using Electron Cyclotron Resonance (ECR) N2O plasma. Sub-4 nm thick polyoxide on n+ and p+ polysilicon layer were grown and characterized. The oxides have relatively large breakdown voltage, small electron trapping and QBD up to 7 C/ for polyoxide on p+ cm2 polysilicon and up to 5 C/ for polyoxide on n+ polysilicon under negative constant cm2 current density of 1 / . Small but slightly larger charge trapping characteristics of mA cm2 polyoxide on n+ polysilicon than that on p+ polysilicon resulted from the roughness between polyoxide and polysilicon at positive bias. These ultrathin plasma polyoxides are good candidates for futuer interpoly dielectrics and the gate oxides for thin film transistors.