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 ZrO2 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 ZrO2 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 not were embedded in the ZrO2 layer with densities of Zr-NC up to 1.22 x 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 inter-face between Zr-NCs and the ZrO2 capping layer.