Solving the issue of increasing forming voltage during device miniaturization in hafnium oxide-based resistive access memory using high-k sidewall material

Abstract

An electrothermal coupling model of resistive random access memory (RRAM) was established based on the oxygen vacancy conduction mechanism. By resolving the partial differential equation for the coefficients, the variation process of the device resistance was simulated. In our studies, a device model was proposed which can accurately simulate the whole process of RRAM forming, reset, and set. Based on the established model, a new high dielectric constant (high-k) material (La2O3) is introduced as the sidewall material. The La2O3 sidewall material can concentrate the electric field and helps to speed up the formation of conductive filaments. The La2O3 sidewall can effectively reduce the forming voltage increase during the miniaturization process. Then, the influence of sidewall thermal conductivity on forming voltage is studied, and it is discovered that low thermal conductivity helps to reduce the model’s forming voltage and increase the temperature concentration. These findings serve as a foundation for more studies on the choice of sidewall materials.