Physical mechanism of HfO<inf>2</inf>-based bipolar resistive random access memory

Abstract

The (anode) TiN/Ti/HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /TiN (cathode) resistive random access memory (RRAM) has shown yield ~100%. Its simple metal-insulator-metal (MIM) structure exhibits great potential for an embedded BEOL memory compatible with the high-k/metal gate CMOS process. There have been many theories of RRAM physical mechanism in the literature. This paper focuses on HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -based RRAM and describes a complete physical mechanism from forming, SET/RESET, current conduction, to explanations of various observed phenomena including multilevel, cell size scaling, resistance fluctuation, soft error, and non-abrupt RESRT process. Finally, suggestions for device optimization are given based on the physical model.