Influence of substrates on resistive switching behaviors of V-doped SrTiO_3 thin films

摘要

V-doped SrTiO_3 (V:STO) thin films on Si and Pt/Ti/SiO_2/Si substrates are synthesized by sol-gel method to form metal-insulator-metal (MIM) structures. Bipolar resistive switching (RS) characteristics were investigated in Pt/V:STO/Si and Pt/V:STO/Pt structures respectively. The enhancement of resistive switching behavior in Pt/V:STO/Pt/Ti/SiO_2/Si structures were demonstrated in terms of the maximum operation voltage reduced from 20 to 2 V and the improved R_(OFF)/R_(ON) ratio increased from 10~2 to 10~3. The electrochemical migration of oxygen vacancies resulted from the metal-oxide interfaces was applied to explain the resistive switching behaviors. On the basis of current-voltage characteristics, the switching mechanisms for the low resistance state (LRS) and high resistance state (HRS) currents of V:STO films are considered as Ohmic and trap-controlled space charge-limited current (SCLC) behavior, respectively.