Memory properties of oxide–nitride–oxynitride stack structure using ultra-thin oxynitrided film as tunneling layer for nonvolatile memory device on glass

Abstract

In this work, metal–oxide–nitride–oxynitride–silicon (MONOS) devices with silicon oxynitride film as tunneling layer of nonvolatile memory have been fabricated. General chemical vapor deposition cannot generate uniform thickness of ultra-thin tunneling layer for fabrication of the nonvolatile memory device on glass because of rough poly-silicon surface due to melting/crystallization of substrate during irradiation of laser beam. plasma-assisted oxynitridation is applied to form uniform and ultra-thin tunneling layer instead of conventional deposition and nonvolatile memory devices were fabricated with oxide–nitride–oxynitride stack structure. The charge storage effect of MONOS devices with different oxide–nitride–oxynitride thickness was investigated by high frequency capacitance–voltage measurement. The results demonstrate that the MONOS device using oxide–nitride–oxynitride stack structure with a ultra-thin tunneling oxynitride of 2.3 nm thickness, a charge trapping layer of silicon nitride of 10 nm thickness, and a blocking layer of 8.5 nm thickness have the relative large Δ V FB of 9.13 V in the large range voltage sweeps ranging from the large range capacitance–voltage characteristic curves. The difference of flatband voltage between the programming and erasing states was initially 4.92 V and decreased to 3.22 V after 1000 s.