HIGH-TEMPERATURE CHARGE LOSS MECHANISM IN A FLOATING-GATE EPROM WITH AN OXIDE-NITRIDE-OXIDE (ONO) INTERPOLY STACKED DIELECTRIC

The intrinsic charge loss rate of a floating-gate EPROM cell at temperatures above 300-degrees-C appears to be much higher than the prediction from our previous model developed at lower temperatures. A detailed study of intrinsic charge loss rate at temperatures ranging from 340 to 430-degrees-C reveals that it follows a Frenkel-Poole model with a barrier height of 1.9 eV. The physical origin of this high-temperature charge loss is proposed. The model suggests that electrons leak through the thin bottom poly oxide and nitride, and then thermally surmount the barrier at the nitride/top-oxide interface.