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

Abstract

In this letter, HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -based RRAM with varying device sizes is discussed with an analysis of the device-size dependence on reset current ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">reset</sub> ). 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 HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> dielectric as the resistance switching layer. Uniform bipolar switching characteristics with a very low <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">reset</sub> of about 100 μA are achieved in 60-nm contact size devices. Self-compliance effect is also observed in the scaled devices.