Charge trapping and stress-induced dielectric breakdown characteristics of HfO/sub 2/ films

The reliability and integrity of HfO/sub 2/ prepared by sputtering were studied. By monitoring the current-voltage and current-stressing duration characteristics, we found that a significant charge trapping effect is found for very short stressing time (<30 s) but stress-induced trap generation is insignificant. Area and stress-voltage effects on the time-dependent dielectric breakdown (TDDB) were also studied. It was found that the Weibull shape factors for soft and hard breakdown are different and their values are 1.43 and 1.95, respectively. It suggests that the soft breakdown should have different precursor defects from those of the hard breakdown.