Dielectric Breakdown in Silicon Dioxide Films on Silicon

The breakdown characteristics of thermally grown films on Si are shown to depend on oxide thickness, substrate doping concentration, sample preparation, presence of passivating layers, and testing temperatures. The maximum breakdown strength varies as thickness−0.21 below 800Aå, is essentially constant from 1000 to 2000Aå, and increases slightly (8%) with increasing testing temperature in the range −196° to +300°C. The breakdown strength is only moderately affected by the dopant‐type level in the starting silicon wafer: 1020 phosphorus atoms/cm3 in the silicon reduced the breakdown strength in 200Aå thick oxides by only 20%. The initial condition of the silicon wafer, cleaning procedure, oxidation temperature, passivation layer, and postmetalization anneal are important parameters in the control of defect‐related, low‐field breakdowns, while the oxidation ambient, substrate doping, oxide thickness, metalization, and measuring temperature have little or no influence on this process.