Experimental transient analysis of the tunnel current in EEPROM cells

Since the cell is written with a ramp waveform pulse in order to minimize the maximum tunnel current in actual device operation, the measurements were performed with ramp waveform writing pulses at different ramp speeds. The kind of information obtained from the transient analysis greatly improves the understanding of the device physics. By measuring tunnel current, some expected results, such as the dependence of the maximum current value on the ramp speed, were observed. Some unexpected results, such as an anomalous peak during the erasing operation and the influence of the ramp speed on the conduction properties of the thin oxide, which is shown by the Fowler-Nordheim plot of the experimental tunnel current, were also observed