A Robust Data Retention Characteristic of Sol–Gel-Derived Nanocrystal Memory by Hot-Hole Trapping

A new sol-gel-derived Ti_xZr_ySi_zO nanocrystal (NC) memory with a high-performance data retention characteristic is demonstrated by the hot-hole-trapping method. Prior to rapid thermal annealing, the high-density NC layer is formed by depositing a well-mixed solution of titanium tetrachloride, silicon tetrachloride, and zirconium tetrachloride. The electrical properties of the sol-gel-derived NC memory are demonstrated in terms of memory window, charge retention, program speed, and endurance. The memory window of the NC memory from the novel hot-hole-trapping mechanism can be achieved up to 4.18 ± 0.21 V, and long retention times obtained from extrapolation up to 10⁶ s are observed as 8%, 13%, and 21% window narrowing under respective temperatures of 25 °C, 85 °C, and 125 °C. The good electrical performance is attributed to the contribution of the high density of isolated NCs and hole-trapped into the deep-trap energy level, so no significant lateral and vertical charge leakage occurs.