$\hbox {HfO}_{2}$ -Based RRAM Devices With Varying Contact Sizes and Their Electrical Behavior

In this letter, HfO₂-based RRAM with varying device sizes is discussed with an analysis of the device-size dependence on reset current (I_reset). Device sizes down to 60 nm were achieved by using different thicknesses of nitride spacer after 200-nm contact hole is formed. Platinum (Pt) bottom electrode and titanium nitride (TiN) top electrode were used with HfO₂ dielectric as the resistance switching layer. Uniform bipolar switching characteristics with a very low I_reset of about 100 μA are achieved in 60-nm contact size devices. Self-compliance effect is also observed in the scaled devices.