Studies on nonvolatile resistance memory switching in ZnO thin films

[摘要] Six decades of research on ZnO has recently sprouted a new branch in the domain of resistive random access memories. Highly resistive and c-axis oriented ZnO thin films were grown by us using d.c. discharge assisted pulsed laser deposition on Pt/Ti/SiO₂/Si substrates at room temperature. The resistive switching characteristics of these films were studied in the top-bottom configuration using currentâ€�?�voltage measurements at room temperature. Reliable and repeated switching of the resistance of ZnO thin films was obtained between two well defined states of high and low resistance with a narrow dispersion and small switching voltages. Resistance ratios of the high resistance state to low resistance state were found to be in the range of 2â€�??5 orders of magnitude up to 20 test cycles. The conduction mechanism was found to be dominated by the Ohmic behaviour in low resistance states, while Pooleâ€�?�Frenkel emission was found to dominate in high resistance state. The achieved characteristics of the resistive switching in ZnO thin films seem to be promising for nonvolatile memory applications.

[学科分类] 材料工程

[关键词] ZnO thin film;pulsed laser deposition;resistive switching;nonvolatile memories.