FLOATING GATE NONVOLATILE FIELD EFFECT MEMORY DEVICE

摘要

A floating gate type nonvolatile memory device includes a conductive substrate area (13) separated from a floating gate (17) by a dielectric which consists of a silicon nitride or silicon oxynitride layer (19, 22) adapted for Poole-Frenkel conduction therein. In a modification, a very thin silicon dioxide layer (21) is provided between the substrate and the silicon nitride or silicon oxynitride layer (19, 22). In another embodiment a second silicon dioxide or silicon oxynitride layer (118) is located between the floating gate (107) and the silicon nitride layer (117). Floating gate devices according to the invention can be written and erased with voltage pulses of relatively low amplitude and short duration, yet exhibit excellent endurance and retention characteristics.