Research On Key Technology Of Resistive Memory Based On Al Interconnection

Modern Floating-Gate nonvolatile memories, represented by Flash memory, have achieved great success. However, Flash memory is expected to face physical limit with the decrease of the technology node, especially below the32nm node. A lot of novel nonvolatile memory technologies sprang up like mushrooms for the next generation nonvolatile memory substituting Flash. Among them, Resistance random access memory(RRAM) attracts much attention of memory industry for its quick growing and bright future.A large amount of materials has resistive switching behaviors, including transition metal oxides, the perovskite structure ternary or quaternary oxides, and organic materials. When Choosing materials as functional materials, compatibility with standard CMOS logic technology is an important factor to consider. At present, the major bottleneck for resistance change memory are large power consumption, which erase current in the Milliampere order of magnitude, low resistance state lower than lkohm, and the erase voltage of3volts or more, the uniformity of electrical parameters of the device, reliability and other issues. Aimed at issues encountered in RRAM development process, we proposed a solution based on the Al interconnect system.Firstly based on Al interconnect back-end process, we studied the resistive switching properties of TiOx based RRAM devices, then the impact of different electrodes and the oxidation time on the device performance was researched. Eventually found that the higher work function of the electrode, the more stable resistance properties. And increasing oxidation time can help reduce the power consumption of the device; followed by the proposed N-doped AlOx-based RRAM memory research, and found that the device with low power consumption advantage has erasing voltages which lower than0.5V, good endurance performance of more than1000times, and N content impact on the device performance. Then, for the A1ON device, we studied the impact of the current set process on the reset current, finally found that the current set algorithm can significantly reduce the reset current lower than50uA, and the underlying mechanisms were analyzed. We then characterized the data retention performance of the AlON device by constant current operation, and the complex impedance spectroscopy was researched to study its electrical conductivity. Finally, we proposed WOx/AION dual layer structure and found that the reset current can be as low as lOuA.Compared with the single-layer structure, the high and low resistance state was improved by two orders of magnitude, achieving multi-level storage ability. And then the conductivity was characterized by AC conductance and AC capacitance. Eventually, we analyzed the noise immunity and the stability performance of different resistance state through random telegraph noise results for the WOx/AlON device.