Random circuit breaker network model for unipolar resistance switching

The resistance switching (RS) behavior in polycrystalline TiO₂ film is described by proposing a new percolation model based on a network of circuit breakers with two switchable metastable states. A series of I-V curves from repeated Set and Reset operations for a single TiO₂ capacitor shows current flow path through the anatase film with high lateral resolution. High resistance state (HRS) is obtained by applying the Reset voltage of 1.0 V, while repeating the Reset and Set operations shows the conductive spots in the low resistance state (LRS). Computer simulations of on-state circuit breakers indicate that a switching in one circuit breaker trigger an avalanche of switching in other circuit breakers. It is also found that the formation of percolating clusters during the forming and the Set operations occur in self-organized avalanche processes.