A Novel Ion-Bombarded and Plasma-Passivated Charge Storage Layer for SONOS-Type Nonvolatile Memory

A novel technique combination of ion bombardment (IB) and NH₃ plasma treatment (PT) has been presented to yield a highly effective charge storage layer for Si/SiO2/Si3N4/SiO2/Si (SONOS)-type nonvolatile memory applications. The IB technique creates additional trap sites within the charge storage layer strikingly to enhance the charge trapping/detrapping efficiency of the storage layer, and the NH₃ PT passivates shallow trap sites significantly to improve reliability characteristics. The distribution of trap sites corresponding with various energy levels is clearly described by discharge-based multipulse analysis. As compared with the control sample (without IB and NH₃ PT), the ion-bombarded and NH₃-plasma-passivated memory device has faster program/erase speeds and larger memory window. In addition, the competent reliability properties of the ion-bombarded and NH₃-plasma-passivated memory, such as good endurance, long data retention, and acceptable disturbance, were also demonstrated in this letter.