On the stochastic nature of resistive switching in Cu doped Ge0.3Se0.7 based memory devices

Currently, there is great interest in using solid electrolytes to develop resistive switching based nonvolatile memories (RRAM) and logic devices. Despite recent progress, our understanding of the microscopic origin of the switching process and its stochastic behavior is still limited. In order to understand this behavior, we present a statistical breakdown analysis performed on Cu doped Ge0.3Se0.7 based memory devices under elevated temperature and constant voltage stress conditions. Following the approach of electrochemical phase formation, the precursor of the ON resistance switching is considered to be nucleation - the emergence of small clusters of atoms carrying the basic properties of the new phase which forms the conducting filament. Within the framework of nucleation theory, the observed fluctuations in the time required for ON resistance switching are found to be consistent with the stochastic nature of critical nucleus formation. (C) 2011 American Institute of Physics. [doi:10.1063/1.3631013]