Zn-doped Zr oxynitride as charge-trapping layer for flash memory applications

In this work, we proposed Zn-doped Zr oxynitride (ZrZnON) as a new charge-trapping layer for flash memory applications and investigated its memory characteristics based on the capacitor structure of Al/Al₂O₃/ZrZnON/SiO₂/Si. The high-K dielectric film, ZrON, was used as the control group. The effects of incorporating ZnO in ZrON were studied by comparing the differences of memory properties between the two charge-trapping layers. Measured data showed that the memory device containing ZrZnON had much larger C-V hysteresis window, higher programming/erasing speeds and much better charge retention properties than the one containing ZrON. These improvements should result from charge traps created by ZnO incorporation and deeper quantum wells built by the band-gap alignment of ZrZnON to the SiO₂ tunnel layer and Al₂O₃ blocking layer.