<p>This
article represents a new method for Data Retention failure (DR) in NAND Flash
memories by analyzing the <b>charge leakage</b> phenomena. Retention failure
accrue when stored data changes its level. This usually happens at and because
of a high temperature environment that accelerate leakage.</p>
<p>The
amount of electron charge in the cell is rather hard to calculate. However, we
know that a verification process done at the end of the programming with
respect to the amount of charge, is apparently enough to indicate the proper
logical level. Moreover, when the cell is exposed to high temperature the
charge leaks out but the manufacturer`s guarantee that the memory storage will
withstand the JEDS218 standard, this mean that this amount of charge should be enough
for 10 years at temperature ambient range of 25÷55°C. Hence, after 10 years, in
the worst-case scenario, the amount of charge might be so low that its results
can adversely affect its logical level.</p>
<p>In
our previous work, we found that the programed cell array affected by
temperature as shown in figure 1, begin with the average voltage is equal to V<sub>t1</sub>
and later, when the leakage occurs, the average voltage decreases while the
variation increases.</p>
Reliability prediction for Flash memories Retention failure by charge loss