Enhanced retention characteristic of NiSi2/SiNx compound nanocrystal memory

Abstract

The NiSi2/SiNx compound nanocrystals (CNCs) were fabricated to integrate the compound tunnel barrier into nanocrystal memory, with the inclusion of nitride traps. The analysis of high resolution transmission electron microscopy and x-ray photoelectron spectroscopy reveal that the nanocrystal is mainly composed of NiSi2 and silicon nitride with small size of 4–5 nm and high density of ∼1×1012 cm−2. The charge storage characteristics of the memory capacitor based on NiSi2/SiNx CNCs were investigated by capacitance-voltage measurement and the enhanced retention characteristics, which remain 71.7% (∼1.9 V) in 104 s, are clarified to be due to the compound tunnel barrier and traps in nitride.