Correlation between two time-dependent dielectric breakdown measurements for the gate oxides damaged by plasma processing

The relationship between two time-dependent dielectric breakdown (TDDB), the charge-to-breakdown under constant-current injection (Q/sub bd/), and the time-to-breakdown under constant-voltage stress (t/sub bd/) is derived from a defect generation model and investigated for the gate oxide damaged by plasma processing such as the antenna effect. It is found that although the Q/sub bd/ of the damaged oxide monotonously decreases with antenna ratio (r=exposed antenna surface area/gate area), the t/sub bd/ does not apparently decrease in a certain antenna ratio region. The difference between the degradation rate of Q/sub bd/ and t/sub bd/ along r is explained by taking into account the r- and time dependence of gate current density under constant-voltage stress J and the rand J-dependence of Q/sub bd/.