Electrically Driven Insulator–Metal Transition-Based Devices—Part II: Transient Characteristics

Part II of this paper discusses the transient characteristics of the electrically driven insulator-metal transition (E-IMT) material-based device. To model the full transient characteristics, we modify the electrothermal model developed in Part I to capture extrinsic capacitance and 2-D heat transport effects. In order to test the model against the experiment, we fabricated and tested scaled E-IMT devices with a necked-down design to minimize nonhomogeneity. We show excellent agreement of the predictions of the model with the experimental data, and we find that the IMT device goes through three stages before a steady state is established. These three stages are identified as the times required for the incubation of the IMT transition, positive feedback, and width expansion of the IMT zone within the device. The impact of capacitance and 2-D heat transport is discussed. Furthermore, we show an inverse relation arises between the incubation time and the applied voltage. This paper satisfactorily explains the turn-on transient in a nanoscale E-IMT device within the framework of our electrothermal (Joule heating) model.