Thermal Stability of Metal-Silicide Nanocrystal Nonvolatile Memory with Barrier Engineered Tunnel Layers

Abstract

WSi(2) nanocrystal nonvolatile, memory devices were fabricated with a silicon oxide-nitride-oxide (SiO(2): 2 nm/Si(3)N(4):2 nm/SiO(2): 3 nm) tunnel layer. WSi(2) nanocrystals of 2.5 nm diameters and a density of 3.6 x 10(12) cm(-2) were formed using radio frequency magnetron sputtering and annealing processes. The WSi(2) nanocrystal nonvolatile memory device exhibited strong thermal stability during writing/erasing operations at temperatures up to 125 degrees C. When the writing/erasing voltages were applied at +10 V/-10 V for 500 ms, the memory window of the initial similar to 2.6 V decreased by approximately 1.1 V at 25 degrees C and 0.4 V at 125 degrees C after 10(4) sec, respectively. These results show that WSi(2) nanocrystals with barrier-engineered tunnel layers are possible for application in nonvolatile memory devices.