Operation Characterization of Flash Memory with Silicon Nitride/Silicon Dioxide Stack Tunnel Dielectric

The operating characteristics of flash memory devices with tunnel dielectrics comprising a silicon nitride layer or a silicon nitride/silicon dioxide (N/O) stack and annealed at various temperatures are studied. The present work indicates that flash memory devices with an N/O stack tunnel dielectric have a higher program/erase speed and reliability than those with a single Si 3 N 4 layer. The stack tunnel dielectric composed of a thick Si 3 N 4 layer and a thin SiO 2 layer exhibits even better performance for flash memory operation. Flash memory devices having N/O stack tunnel dielectrics annealed at low temperatures show better performance in terms of erase speed and charge retention but poor robustness under read disturbance.