Insertion of Ag Layer in TiN/SiN_x/TiN RRAM and Its Effect on Filament Formation Modeled by Monte Carlo Simulation

Abstract

In this study, the electrical characteristics of TiN/SiNx/TiN and TiN/Ag/SiNx/TiN RRAMs were thoroughly investigated through I-V measurements. Our novel Ag-inserted silicon nitride-based resistive switching memory (RRAM) achieved switching operation at lower voltages and lower current levels compared to the conventional silicon nitride RRAM that does not have an Ag insertion layer. These enhanced characteristics enable low power operation, one of the main goals of RRAM research. Gradual conductance modulation is also possible in this device with constant voltage pulses being 50% lower than that seen in conventional devices, this property fulfills an important requirement that makes our device suitable for use as a neuromorphic synapse device. The conduction mechanism of our Ag-inserted device was further analyzed through I-V measurements and compared with a control group. Based on these data, a 2D Monte Carlo simulation was implemented to investigate the mechanism behind the new behavior displayed by our Ag-inserted silicon nitride RRAM. A resistive network model was used to calculate the voltage and electric field distribution, and then the motion of the particles was simulated by taking into account its relation to the heat generated inside the device.

Keywords

• Memristors
• Monte Carlo simulation
• resistive RAM (RRAM)
• silver
• silicon nitride
• synapse device