Plasma-induced roughness and chemical modifications of TiN bottom electrode and their impact on HfO2-MIM properties

Metal-insulator-metal (MIM) stacks, though simple in design, are the backbone device for resistive random access memories (ReRAM) and, as such, play a vital role in emerging memory technologies. In this work, we characterize the impact of Ar, Ar/N2, and BCl3/Cl2 plasma processes on the physical properties of the TiN bottom electrode (BE) surface. The BCl3/Cl2 process increases roughness by 40%. Ar and Ar/N2 processes both decrease PVD TiN roughness by 50%. This reduction propagates through the entire MIM stack. X-ray photoelectron spectroscopy (XPS) indicates that both plasma processes alter the Ti-ON concentration on the TiN surface. The impact of BE surface roughness and composition on MIM electrical properties is currently under investigation.