Failure Analysis of Single and Dual nc-ITO Embedded ZrHfO High-k Nonvolatile Memories

Abstract

The nanocrystaline indium tin oxide (nc-ITO) embedded Zr-doped HfO2 (ZrHfO) high-k dielectric has been fabricated into nonvolatile memories with a low leakage currents, a large charge-storage capacity, and a long charge retention time. Recently, it has demonstrated that the dual-layer nc-ITO embedded capacitor has a charge trapping density more than double that of the single-layer nc-ITO embedded capacitor with a faster charging rate. In this paper, authors investigated the charge transport and the breakdown mechanisms of the single- and dual-layer nc-ITO embedded ZrHfO thin films. The charges transport followed the F-N tunneling mechanism. In addition, the dual-layer nc-ITO embedded capacitor has smaller breakdown strength and a larger leakage current than the single-layer nc-ITO embedded capacitor.