Novel sol-gel derived SONOS-type nanocrystal memory

A nanocrystal (NC) memory by sol-gel spin-coating method was demonstrated. The high-density and isolated NC was formed by depositing a mixed solution of nickel tetrachloride, zirconium tetrachloride, silicon tetrachloride, and germanium tetrachloride with a post-rapid thermal annealing process. The electrical properties in terms of memory window, charge retention, program/erase speed, and endurance were demonstrated. The memory window of the NC memory can be up to 2.8 V; the retention times were extrapolated up to 10⁶ sec for about 5% and 10% charge loss at 25 and 85°C measurement, respectively. The voltage shift after 10⁴ program/erase cycles is less than 1 V. The good electrical performance was attributed to the effects of the high-density isolated NCs.