Two-bit effect of trigate nanowires polycrystalline silicon thin-film-transistor nonvolatile memory with oxide/nitride/oxide gate dielectrics

Abstract

This work studies the two-bit effect of trigate nanowires polycrystalline silicon thin-film transistors with silicon-oxide-nitride-oxide-silicon nonvolatile memory. The two-bit effect is clearly demonstrated by the localized charge trapping in a nitride layer. The programing operation is performed by channel hot electrons injection, and erasing is performed by channel hot holes injection. The threshold voltage shifts between forward read and reverse read schemes is 2.2V. At a large gate length of 5μm, the programing is dominated by Fowler–Nordheim tunneling, resulting in the absence of two-bit storage capacity. Regarding the two-bit programing and erasing speed characteristics, one-bit programing or erasing does not affect the other bit.