Simple Experimental Determination of the Spread of Trapped Hot Holes Injected in Silicon-Oxide-Nitride-Oxide-Silicon (SONOS) Cells: Optimized Erase and Cell Shrinkage

Abstract

In this paper, we present a simple experimental method to extract the effective length of trapped holes in the nitride resulting front the hot hole injection (HHI) in Silicon-Oxide-Nitride-Oxide-Silicon (SONOS) memory cells. The method utilizes the correlation between the threshold voltage (V-TH) lowering and dispersion by HHI and the V-TH roll-off in virgin samples. We also interpret the observed program/erase endurance cycling in light of HHI results, and find the minimum erasing time for maintaining the endurance margin for given device. Finally, we discuss the channel length scaling issues in SONOS cells, using HHI erase, cycling and off current data.