Formation of NiSi2/SiNX compound nanocrystal for nonvolatile memory application

Abstract In this paper, the NiSi 2 /SiN X compound NCs (CNCs) structure is studied to further improve the retention. To introduce the nitride based traps, NiSi 2 was also sputtered in the mixture gas of Ar (50 sccm) and NH 3 (10 sccm) at room temperature, and the NiSi 2 /SiN X CNCs can be easily formed after rapid thermal annealing. In addition, standard memory devices with single and double NiSi 2 nanocrystal were also prepared for comparison. By XPS analyses, the nanocrystals fabricated in the ambiance of NH 3 can be confirmed to be composited of NiSi 2 and SiN X compound. According to memory characteristics results, better retention characteristic of device with single-layer NiSi 2 /SiN X compound nanocrystal NVMs can be observed after 10 4  s, raises from 50% to 72% in comparison with the control sample, even better than the double-layer NiSi 2 nanocrystal, 58%. Indeed, the formation of NiSi 2 /SiN X CNCs can improve the retention characteristics remarkably due to the additional tunnel barrier and deep traps in the nitride.