Simulations of RF wave-induced modulation of filament growth and bipolar resistive switching in conductive bridging RAM

We have simulated Ag–Ge–Te-based conductive bridge RAM (CBRAM) under RF electromagnetic wave input to investigate the RF effects on heat transfer and electrochemical reaction. The RF simulations agreed with the experimental transmission coefficient S₂₁ between 0.4 and 1 GHz, indicating an effective, uniform electric field applied in the RF-applicable CBRAMs. The heat transfer simulations showed a minimal temperature increase of about 1 K under the RF wave at 10 MHz and 10 dBm, indicating negligible thermal effects. The electrochemical simulations were based on the Nernst–Planck equation, taking into account the Ag ion transport in the Ag–GeTe electrolyte by diffusion and migration. Electrode kinetics were calculated for charge transfer reactions using the Butler–Volmer equation. The cathode electrode moved at a velocity equal to the rate of Ag electrodeposition on the cathode. The electrode movement represented filament growth. The electrochemical simulations successfully reproduced filament growth, bipolar resistive switching, experimental currents, and SET/RESET voltages. In addition, the electrochemical simulations under RF waves showed a decrease in the magnitude of SET and RESET voltages, consistent with experimental observations. The RF-induced SET/RESET voltage modulation was attributed to redox reactions that changed the average ion concentration during RF cycles, accelerating filament growth and dissolution.