退火温度对TiO_2基电阻开关器件性能的影响

Effects of Annealing Temperatures on Resistive Switching Characteristics of TiO_2 Based ReRAM

采用直流磁控溅射法在n+-Si上制备了TiO2薄膜,采用电子束蒸发镀膜仪在TiO2薄膜上沉积Au电极,获得了Au/TiO2/n+-Si结构的器件.研究了退火温度对薄膜结晶性能及器件电阻开关特性的影响.Au/TiO2/n+-Si结构的器件具有单极性电阻开关特性,置位(set)电压,复位(reset)电压、reset电流及功率的大小随退火温度的不同而不同,并基于灯丝理论对器件的电阻开关效应的工作机理进行了探讨.研究结果表明,500℃退火的器件具有良好的非易失性.器件高低阻态的阻值比大于103,其信息保持特性可达10年之久.在读写次数为100次时,器件仍具有电阻开关效应.

TiO2 thin films were deposited on heavily doped silicon wafer by DC magnetron sputtering and the Au electrodes were evaporated on TiO2/n＋-Si by electric beam evaporation to get Au/TiO2/n＋-Si structured resistive random access memory（ReRAM）.The effects of annealing temperatures on the crystalline structure of the TiO2 thin films and the resistive switching characteristics of the fabricated device were investigated.Au/TiO2/n＋-Si structured device exhibits reversible and steady unipolar resistive switching behaviors.The values of set voltage,reset voltage,reset current and reset power vary with the annealing temperatures.The resistive switching mechanism is discussed based on the filamentary model.The results reveal that the fabricated device annealed at 500℃ has good nonvolatile property. The average ratio of resistances between high resistance state（HRS） and low resistance state（LRS） is larger than 103 and the devices could maintain a sufficient margin of memory for more than 10 years.The resistive switching characteristic is remained after 100 switching cycling tests.