Investigation of Channel Hot Electron Injection by Localized Charge-Trapping Nonvolatile Memory Devices

A novel measurement method to extract the spatial distribution of channel hot electron injection is described. The method is based on characterization of localized trapped-charge in the nitride read-only memory (NROM) device. The charge distribution is determined by iteratively fitting simulated subthreshold and gate induced drain leakage (GIDL) currents to measurements. It is shown that the subthreshold and the GIDL measurements are sensitive to charge trapped over the n+junction edge. Their characteristics are determined by the trapped charge width, densitiy and location and the associated fringing field. Extremely high sensitivity of the GIDL measurement to localized charge over the n+ junction is demonstrated. The extracted charge distribution width is shown to be ∼ 40 nm, located over the junction edge.