High-Reliability Dynamic-Threshold Source-Side Injection for 2-Bit/Cell With MLC Operation of Wrapped Select-Gate SONOS in NOR-Type Flash Memory

Abstract

For the first time, a high-performance (tau(PGM) = 200 ns/tau(ERS) = 5 ms) cell with superior reliability characteristics is demonstrated in a NOR-type architecture, using dynamic-threshold source-side injection (DTSSI) in a wrapped select-gate silicon-oxide-nitride-oxide-silicon memory device, with multilevel and 2-bit/cell operation. Using DTSSI enables easy extraction of the multilevel states with a tight V(TH) distribution, a nearly negligible second-bit effect, superior endurance characteristics, and good data retention.