Experimental Study of Charge Displacement in Nitride Layer and its Effect on Threshold Voltage Instability of Advanced Flash Memory Devices

Abstract

The effect of charge displacement in nitride layer of ONO stack in scaled flash cells are experimentally studied by using gate stress measurements. The redistribution of charge is found to follow Poole-Frenkel conduction mechanisms. However, the measurements on scaled devices show significant random telegraph noise. The noise will be even more pronounced in future scaled devices.