Field and temperature dependence of TDDB of ultrathin gate oxide

The results of an investigation of time-dependent breakdown (TDDB) of intrinsic ultrathin gate oxide are presented for a wide range of oxide fields 4.6<E/sub ox/<10.4 MV/cm at elevated temperatures. It was found that TDDB of ultrathin oxide follows the E model down to 4.6 MV/cm. The data show that TDDB t/sub 50/ starts deviating from the 1/E model for fields below 7.2 MV/cm. The data also show that the TDDB activation energy for this type of gate oxide is linearly dependent on oxide field. In addition, we show that the field acceleration parameter /spl gamma/ decreases as temperature increases.