Electrical Characteristics of TiSi2 Nanocrystal Nonvolatile Memory with Barrier-Engineered Tunnel Layer

Abstract

In this study, we fabricated TiSi2 nanocrystal nonvolatile memory devices with silicon nitride-oxide-nitride (NON) and SiO2 tunnel barriers. The TiSi2 nanocrystals with diameters of 2-5nm and a density of 1.5 x 10(12) cm(-2) were formed using radio frequency magnetron sputtering in argon and a postannealing process. The memory effect of the TiSi2 nanocrystal memory device with the NON tunnel barrier was observed at about 0.7 V at 100 ms when the applied program/erase voltages were + 7V/-7V. Also, the memory window of the NON tunnel barrier device was maintained up to 1.3 V after 10(3)s. These results indicate that the NON tunnel barrier provides an effective tunneling thickness for the fast program/erase speeds and an adequate physical thickness for long charge retention characteristics in nonvolatile memory devices.