title: Conduction mechanism of a TaO(x)-based selector and its application in crossbar memory arrays.
abstract: The conduction mechanism of a Pd/TaOx/Ta/Pd selector device, which exhibits high non-linearity (∼10(4)) and excellent uniformity, has been systematically investigated by current-voltage-temperature characterization. The measurement and simulation results indicate two dominant processes of selector current at opposite biases: thermionic emission and tunnel emission. The current-voltage-temperature behaviors of the selector can be well explained using the Simmons' trapezoidal energy barrier model. The TaOx-based selective layer was further integrated with a HfO2-based resistive switching layer to form a selector-less resistive random access memory (RRAM) device structure. The integrated device showed a reliable resistive switching behavior with a high non-linearity (∼5 × 10(3)) in the low resistance state (LRS), which can effectively mitigate the sneak path current issue in RRAM crossbar arrays. Evaluations of a crossbar array based on these selector-less RRAM cells show less than 4% degradation in read margin for arrays up to 1 Mbit in size. These results highlight the different conduction mechanisms in selector device operation and will provide insight into continued design and optimization of RRAM arrays.
authors.affiliation: Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, USA. wluee@eecs.umich.edu.
authors.forename: Ming
authors.initials: M
authors.lastname: Wang
authors.forename: Jiantao
authors.initials: J
authors.lastname: Zhou
authors.forename: Yuchao
authors.initials: Y
authors.lastname: Yang
authors.forename: Siddharth
authors.initials: S
authors.lastname: Gaba
authors.forename: Ming
authors.initials: M
authors.lastname: Liu
authors.forename: Wei D
authors.initials: WD
authors.lastname: Lu