Initial gate leakage in ultra thin SiO2 - the role of a brief stress

For ultra thin oxide, the preferred plasma charging damage detection method has been narrowed down to initial gate leakage. The initial gate leakage measurement can in principle distinguish stress-induced-leakage-current (SILC) from soft breakdown if the test device is small. In a previous report, we showed that the expected sharp distinction between broken devices and non-broken devices does not exist when several devices are measured for very thin oxide. Here, the explanation for the lack of sharp distinction between broken and non-broken devices is provided with the support of new data. It is clear that there is a basic difference between plasma charging stress and bench-top electrical stress of ultra thin oxide. The results indicate that, to obtain a better measure of plasma charging damage using gate leakage, a brief stress is necessary.