Stackable All-Oxide-Based Nonvolatile Memory With $ \hbox{Al}_{2}\hbox{O}_{3}$ Antifuse and $\hbox{p-CuO}_{x}/ \hbox{n-InZnO}_{x}$ Diode

We developed all-oxide-based nonvolatile memory for low-cost, high-density, and high-performance one-time field-programmable (OTP) memories compared with Si-based antifuse memory using antifuse technologies over a glass substrate. The oxide OTP memory employed the p-CuO/InZnO_x diode as the switching element of the memory cell and Al₂O₃ for the antifuse as the storage node of the memory cell. The memory cell is programmed from the breakdown of Al₂O₃ by applying a program voltage bias that is about 4.5 V. The OTP memory cells show large on/off ratio of about 10⁶ and small current distributions at programmed and unprogrammed states resulting from the perfect uniformity of Al₂O₃ thin film before and after breakdown. It also showed a fast programming speed of about 20 ns.