Basic feasibility constraints for multilevel CHE-programmed flash memories

This paper discusses the basic constraints for the feasibility of multileve l (NM) Flash memories, with specific reference to devices programmed by cha nnel hot electron injection. Issues such as programming algorithm, program and read disturb immunity, data retention, and sense circuitry sensitivity are considered. Experimental data concerning the most suited programming al gorithm and reliability aspects are given. A guideline for the evaluation o f NIL storage feasibility is provided, and a simple set of equations for ba sic constraint estimation is derived.