具有低功耗和多值存储性能的双层WO_X/AlON阻变存储器的研究

A WO_X/AlON Dual-layer Resistive RAM with Low Power and Multi-level Storage Characteristic

针对当前阻变存储器(RRAM)面临的功耗和高密度存储的问题,介绍了一种降低功耗和形成多值存储能力的器件结构.相比单层结构的AlON RRAM,双层结构的WOX/AlON RRAM具有低至10μA的复位(reset)电流,1 000次以上的转换特性(endurance),较低的操作电压,以及多值存储等性能.针对WOX/AlONRRAM,提出了WOX介质层的等效电路模型为固定电阻与二极管串联模型.在直流置位(DC set)过程中,电路中存在一个较大的过冲电流,使得无法通过控制限流来获得不同大小的低阻态.在增加WOX介质层后,在WOX层和AlON层间形成了界面肖特基势垒,因此有效地抵抗了过冲电流,提高了低阻态的可控性.

A low power and multilevel resistive switching memory device was proposed to solve the power consumption and high density storage problem.Compared with the AlON single-layer,the AlON/WOX bilayer structure displayed better performances,such as： lower reset current of 10μA,better endurance of 1000 cycles,lower operation voltage,and multilevle storage ability.An equivalent circuit model including a constant resistance in series with a diode was proposed for the WOX/AlON RRAM.During the set process,a large overshoot current flowed through the AlON single layer device,thus the compliance current failed to control the resistance.However,in the AlON/WOX bilayer device,there is a Schottky barrier formed in the WOX interface,which can effectively restrain the overshoot current.Therefore,the LRS can be controlled successfully,and multilevel storage was realized.