The present invention utilizes to wafer acceptance testing equipment to fast
monitor the quality of a tunnel oxide layer. First, a control gate and a floating
gate in a memory cell are electrically connected. Then a plurality of swing time-dependent
DC ramping voltages are applied and each corresponding gate leakage current is
measured to calculate each corresponding value. Finally a ratio of each
value is calculated and a -gate voltage curve is plotted to actually
simulate the device failure.
