Aluminum scandium nitride-based metal-ferroelectric-metal diode memory devices with high on/off ratios

In this Letter, we report a back-end-of-line (BEOL), complementary metal-oxide-semiconductor (CMOS)-compatible Al0.64Sc0.36N-based ferroelectric diode that shows polarization-dependent hysteresis in its leakage currents. Our device comprises a metal/insulator/ferroelectric/metal structure (Pt/native oxide/Al0.64Sc0.36N/Pt) that is compatible with BEOL temperatures (<= 350 degrees C) grown on top of a 4-in. silicon wafer. The device shows self-selective behavior as a diode with > 10(5) rectification ratio (for 5V). It can suppress sneak currents without the need for additional access transistors or selectors. Furthermore, given the polarization-dependent leakage, the diode current-voltage sweeps are analogous to that of a memristor with an on/off ratio of similar to 50 000 between low and high resistance states. Our devices also exhibit stable programed resistance states during DC cycling and a retention time longer than 1000 s at 300K. These results demonstrate that this system has significant potential as a future high-performance post-CMOS compatible nonvolatile memory technology. Published under an exclusive license by AIP Publishing.

Automated summary

The researchers reported a BEOL, CMOS-compatible Al0.64Sc0.36N-based ferroelectric diode with polarization-dependent hysteresis in leakage currents. The device shows promising rectification ratio and self-selective behavior, making it a potential high-performance post-CMOS compatible nonvolatile memory technology in the future.