Saturation behavior of ultrathin gate oxides after soft breakdown

The physical origin of post soft breakdown (SBD) current saturation behavior of ultrathin gate oxides is discussed on the basis of electron velocity saturation concept. The post soft breakdown current-voltage (I-V) characteristic is studied with the proportional difference operator (PDO) method. It is shown that the proportional difference of the soft breakdown I-V curve is a peak function. Its peak position and height are related to the saturation velocity of electron in SBD path and the saturation current density through the SBD path, respectively. In addition a simple and useful method of defining and characterizing the SBD path cross-section in SiO2 based on the defect scattering mechanism is also presented.EI0SUPPL.193-1952