Oxide Semiconductors with Non-Volatile Resistance Switching

摘要

Metal-oxide-metal hetero-structures have been deposited by Pulsed Laser Deposition and sputtering and their I-V and switching characteristics investigated as a function of active oxide layer, top metal electrode type and structure, and oxide thickness. Non-volatile switching has been observed for structures containing (Pr,Ca)Mn03, (La,Ca)Mn03, (La,Sr)Mn03, Sr(Zr,Cr)03 and SrTi03 as the active layer and Mg, Cr, Cu, Ag, and Pt as the top metal. The electrical transport was due to space charge limited current with I + aV + bV(exp 2) and was a function of metal work function (parameter a) and heat of oxide formation (b). The switching was interpreted as due to electric field activated motion of mobile donors in the oxide layers. The I-V characteristics were modeled as using self-consistent approach allowing for donor redistribution as a function of field and chemical potential of the metal electrodes.