Silicon-nitride as a tunnel dielectric for improved SONOS-type flash memory

Abstract

High-quality silicon-nitride (Si/sub 3/N/sub 4/) formed by rapid thermal nitridation is investigated as the tunnel dielectric in a SONOS-type memory device for the first time. Compared to a conventional thermal SiO/sub 2/ tunnel dielectric, thermal Si/sub 3/N/sub 4/ provides 100/spl times/ better retention after 1e5 P/E cycles and better endurance characteristics with low programming voltages. Hence, the SONNS structure is promising for nonvolatile memory applications.