HfOx-Based RRAM Device With Sandwich-Like Electrode for Thermal Budget Requirement

The thermal budget of the standard integrated circuits (ICs) manufacturing process is one of the key considerations in the development of resistive random access memory (RRAM). To investigate the thermal budget effect on device performance, three types of HfOx-based RRAM devices with different top electrodes are subjected to postmetalization annealing (PMA) at 400 degrees C for more than three hours. Electrical results show that the initial amount of oxygen vacancies in the HfOx dielectric layer is strongly dependent on the electrode configuration. A device with sandwich-like (TiN/Ti/TiN) top electrode exhibits better performance in thermal stability, forming, switching uniformity, and endurance as compared to other devices with a single layer (TiN) or bi-layer (TiN/Ti) top electrode. This is mainly due to the proper engineering of the oxidation reaction at the metal-metal oxide interface. We believe that this work provides a valuable guideline in the design and optimization of RRAM electrodes.