An Analytical Model For Conductive Bridge Random Access Memory

An analytical model for conductive-bridge resistive-switching random-accessmemory (CBRAM) has been developed in this work. CBRAM is a popularinternational research in recent years. Based on high performance CBRAM isconsidered to be one of the most promising candidates for the next-generation universalmemory. To figure out the physical mechanism of CBRAM both the metal-ionmigration in the solid-electrolyte layer of the memory cell and the chemical reactionon the metallic surface of the electrodes are considered. The work gives an analyticalmodel based on the filament growth in the CBRAM cell. The forming processconsists of ion migration from anode to cathode and backward filament growth fromcathode to anode. The filament growth has different physical mechanisms in differentgrowth stage. The expression of every growth stage is given based on physicalanalysis. The lateral growth of the filament is responsible for the inverse proportionrelationship between the resistance of low resistance state and the applied currentcompliance. And CBRAM can achieve multilevel storage based on this mechanism.The accuracy of the model has been verified by both numerical simulation andexperimental results through comparisons. The analytical model and the numericalresults are exactly the same. Also good agreement has been achieved between theanalytical model and the experimental data. The model can be used for predicting thetime needed for forming and switching of the memory cell based on the devicestructure and applied bias. And with a desired forming time and operation voltage wecan get an optimized cell structure.