A new extrapolation law for data-retention time-to-failure of nonvolatile memories

In this letter, we demonstrate that the commonly assumed Arrhenius law is inconsistent with extrapolation of data-retention time-to-failure of nonvolatile memories in highly accelerated life-tests. We argue that the retention time, namely log(t/sub H/), varies linearly with temperature T rather than with 1/T as commonly assumed, yielding an important reduction in the extrapolated time-to-failure. Extensive experimental results demonstrate the physical consistency of the new model. In particular, data-retention of EPROM devices and leakage current of interpoly dielectric and gate oxide have been investigated over a wide range of temperatures. Finally, it is shown that our model reconciles seemingly controversial activation energy data from the literature.