Time evolution of capture cross sections of radiation-induced Si/SiO2 interface traps studied by single-frequency ac conductance technique

We report the time-dependent evolution of the capture cross sections of interface traps in metal/SiO2/Si capacitors after they are created by x-ray irradiation. A single-frequency ac conductance technique was used in this study. The capture cross section decreases significantly right after irradiation, and gradually recovers over a time scale similar to that of the interface-trap transformation process reported previously [T. P. Ma, Semicond. Sci. Technol. 4, 1061 (1989)]. The x-ray dose dependence and the effect of PMA (post-metal anneal) will also be presented.