Charge loss in EPROM due to ion generation and transport in interlevel dielectric

A new charge loss mechanism in EPROMs implying generation of mobile ions in the bulk of the interlevel dielectric is proposed. Mobile ions generated in the intermediate dielectric screen the negative charge stored into the floating gate. Charge release is a field-assisted thermally activated mechanism. The phosphorus content of the interlevel dielectric seems to increase the activation energy of the phenomenon. Experiments designed to directly evaluate interlevel dielectric ion generation have been performed. Finally, the impact of this new data loss effect on the scaling down of the EPROM cell has been evaluated.<>