MOSFET Nonvolatile Memory with High-Density Cobalt-Nanodots Floating Gate and $\hbox {HfO}_{\bf 2}$ High-k Blocking Dielectric

We report high-performance MOSFET nonvolatile memory with high-density cobalt-nanodots (Co-NDs) floating gate (the density is as high as 4-5 × 10¹² /cm ² and the size is ~2 nm) and HfO₂ high-k blocking dielectric. The device is fabricated using a gate-last process. A large memory window, high-speed program/erase (P/E), long retention time, and excellent endurance till 10⁶ P/E cycles are obtained. In addition, the discrete Co-NDs make dual-bit operation successful. The high performance suggests that high work-function Co-NDs combined with high-k blocking dielectric have a potential as a next-generation nonvolatile-memory candidate.