Fabricate And Research Of BiFeO₃-Based Resistive Memory With Mn And Zn Ion-Doping

With the development of semiconductor integration technology,new memory devices have successfully attracted the attention of researchers.Resistive memory?RRAM?is considered to be the most promising memory device due to its simple structure,compatibility with COMS process,low power consumption,stronger micro-capacitability and simpler process basis.The current research on resistive memory mainly includes its own multi-functional applications and integrated with other devices.Based on the background,this paper designs a self-driven pressure-memory integrated system that combines the resistive memory with the pressure power generation system to realize self-driving,detecting and memory functions.Firstly,this paper designs and manufactures a pressure power generation system.The system utilizes the positive piezoelectric effect of the PZT pressure generator,and based on this,an external circuit is designed to achieve current amplification.The maximum output voltage of the system is 9V,the maximum output current is 0.2mA,and the reverse voltage is-0.2V.Therefore,the system puts forward requirements for resistive memory:low operating voltage?sensitivity requirement?;reset voltage higher than-0.2V?correctness requirement?;longer endurance and retention?persistence requirement?.Secondly,according to the performance of the pressure power generation system,a Pt/SRO/BiFeO₃/Ag structure resistive memory with relatively low operating voltage is selected as the system memory function module.In order to meet the requirements of the pressure generation system,the BiFeO₃ dielectric layer is doped with Mn ions,Zn ions and Mn/Zn ions.Through a series of tests on different doped devices,it is concluded that the doping of Mn ions reduces the leakage current of the device and improved the endurance of the device,but the operating voltage of the device was not improved and did not meet the sensitivity requirements;The doping of Zn ions greatly reduces the operating voltage of the device,but the endurance of the device is poor,and the reset voltage is-0.2V,which does not meet the requirements of correctness and durability;Co-doping of Mn/Zn ions not only greatly reduces the operating voltage of the device,improves endurance,but also ensures proper operation of the integrated system.Therefore,Mn/Zn ion co-doped devices were selected for self-driven system integration.Then,the mechanism of the series of resistive memory is analyzed.It is found that the device meets the space charge limiting current mechanism in the high resistance state and the ohmic mechanism in the low resistance state.The test of the temperature performance in the low-resistance state confirmed that the conduction mechanism of the device is Ag conductive filament type,and the corresponding resistive model is proposed.Finally,the pressure power generation system and the resistive memory were integrated and the performance was tested.It is found that the integrated system can accurately realize the memory of pressure under the action of applied voltage and no applied voltage.This paper creatively designed a self-driven pressure memory integrated system and pushed the application of resistive memory to a new level.