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

摘要

In this Letter,we report a back-end-of-line (BEOL),complementary metal-oxide-semiconductor (CMOS)-compatible Al_(0.64)Sc_(0.36)N-based ferroelectric diode that shows polarization-dependent hysteresis in its leakage currents. Our device comprises a metal/insulator/ferroelectric/ metal structure (Pt/native oxide/Al_(0.64)Sc_(0.36)N/Pt) that is compatible with BEOL temperatures (≤350°C) grown on top of a 4-in. silicon wafer. The device shows self-selective behavior as a diode with > 105 rectification ratio (for 5 V). 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 ～ 50000 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 300 K. These results demonstrate that this system has significant potential as a future high-performance post-CMOS compatible nonvolatile memory technology.