Silicon nanocrystals synthesized by electron-beam co-evaporation method and their application for nonvolatile memory

In this paper, the silicon nanocrystals (Si NCs)/SiO₂ hybrid films designed for nonvolatile memory applications are prepared by electron-beam co-evaporation of Si and SiO₂. Transmission electron microscopy images and Raman spectra verify the formation of Si NCs. Metal-oxide-semiconductor capacitor structure with Si NCs embedded in the gate oxide is fabricated to characterize the memory behaviors. High-frequency capacitance-voltage and capacitance-time measurements further demonstrate the memory effect of the structure resulting from the charging or discharging behaviors of Si NCs. It is found that the memory window can be changed by adjusting the Si/SiO₂ wt. ratio in source material. The memory devices with Si NCs/SiO₂ hybrid film as floating gate yield good retention characteristics with small charge loss.