Filamentary bipolar electric pulse induced resistance switching in amorphous silicon resistive random access memory

Abstract

Metal/amorphous silicon/metal resistive random access memory structures fabricated with sets of tungsten and copper electrodes have exhibited electric pulse induced resistance switching with unique dependence on electrode material. Electrical forming, which is required to initiate bipolar resistance switching, was found to depend on the electrode material and was found to be enough to produce Joule heating, which may result in diffusion of the metal electrode ions into the α-Si to form a metallic filament. The Joule heating and heat transfer during the electrical forming process have been simulated using comsol multiphysics 4.3b software. The results showed that the produced heat is enough to cause electrode diffusion into α-Si. Tungsten and copper electrode materials were use with the W/α-Si/W samples showing much better switching characteristics compared to the Cu/α-Si/Cu samples. A model for filament formation, and bipolar resistance switching based on electrode material diffusion into α-Si, has been suggested.