Fabrication and Memory Effect of Zr Nanocrystals Embedded in ZrO2 Dielectric Layer

A floating gate (FG) memory structure employing Zr nanocrystals (NCs) embedded in a ZrO 2 dielectric layer was fabricated for the first time through a one-step process using dc-magnetron sputtering deposition. The unique FG memory stacked only with an NC-capping ZrO 2 control oxide layer, without a tunneling oxide layer, was obtained under oxygen-deficient conditions during the sputtering process. Transmission electron microscopy (TEM) revealed that crystalline Zr-NCs with sizes ranging from 3 to 8 nm were embedded in the ZrO 2 layer with densities of Zr-NC up to 1.22 × 10 12 cm -2 . Capacitance versus voltage ( C – V ) curves of a Zr-NC-based metal–oxide–semiconductor (MOS) capacitor were also obtained. The clockwise C – V hysteresis loops on the basis of the Zr-NC-based MOS structure fabricated in this work were understood by the electron trapping of Zr–O dangling bonds at the interface between Zr-NCs and the ZrO 2 capping layer.