Memory Window Enhancement in Antiferroelectric RAM by Hf Doping in ZrO2

Antiferroelectric random access memory (AFERAM) is one of the newest alternative non-volatile memory technologies to emerge in recent years. ZrO2-based antiferroelectric films are exceptionally well-suited for memory applications with very high cycling endurance (>10(10)) and low operating voltages (< 2 V). Lightly alloying ZrO2 with HfO2 is performed to assess AFERAM device performance with back-end-of-line compatible thin film Zr1-xHfxO2 (x <= 0.13) capacitors. The transition fields associated with antiferroelectric behavior are reduced with more Hf incorporation, yielding a larger magnitude switching polarization and memory window. Cycling endurance beyond 10(10) cycles is conducted on thin film capacitors where wake-up in AFERAM first leads to an increase, then a decrease in the memory window at a cumulative cycle number found to be dependent on the amount of Hf-incorporation. Hf-incorporation into ZrO2 is demonstrated to be a feasible way to improve the memory window in ZrO2-based AFERAM.

Automated summary

Antiferroelectric random access memory (AFERAM), a new alternative non-volatile memory technology, has high cycling endurance and low operating voltages. By alloying ZrO2 with HfO2, the transition fields associated with antiferroelectric behavior are reduced, resulting in increased switching polarization and memory window. Cycling endurance tests show that the number of cycles is dependent on the amount of Hf-incorporation. Therefore, incorporating Hf into ZrO2 is a feasible method to improve the memory window in ZrO2-based AFERAM.