Memory Properties of Nickel Silicide Nanocrystal Layer for Possible Application to Nonvolatile Memory Devices

The memory properties of nickel silicide (NiSi) nanocrystal (NC) layers, which were directly grown in silicon dioxide by thermal annealing of a simple sandwich structure composed of an ultrathin Ni film sandwiched between two silicon-rich oxide (SiO_x) layers, have been investigated for possible nonvolatile memory (NVM) applications. Capacitance-voltage (C-V) measurements on MOS capacitors with a floating gate based on a NiSi NC layer of average diameter of 2.9 nm and areal density of 1.3 times 10¹² cm^-2 are shown to have a memory window of ~10 V, a retention time > 10⁸ s, and an endurance > 10⁶ program/erase cycles. These C-V characteristics demonstrate that the NiSi NC layer has high potential for NVM applications.