A Model for Switching Traps in Amorphous Oxides

Negative Bias Temperature Instability (NBTI) is frequently suspected to arise from a delicate interplay between some sort of hole trapping and an interface generation mechanism. In a recently suggested model the E´ center along with its second form as an Si - Si dimer are supposed to play a key role. Despite of its successful application to a large amount of experimental data, this model relies on a classical determination of the bandedge energy diagram and the carrier concentrations. The occurrence of subbands in the inversion layer shifts the initial energy level for charge trapping and may thus strongly impact the trapping dynamics. We evaluate the new model against measurement data in order to investigate the impact of quantization effects on the model parameters.