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 Delta 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. (C) 2008 Elsevier B.V. All rights reserved.