Three-Dimensional Crossbar Arrays of Self-rectifying Si/SiO2/Si Memristors

Memristors are promising building blocks for next-generation non-volatile memory, bio-inspired computing, and beyond. Currently, however, they are still suffering from several difficulties that prevent their mass production, including material compatibility and large array operation. In this chapter, we first survey research efforts on using silicon oxide as the switching material, and various ways to integrate selectors with silicon oxide based memristors for large array operation. A self-rectifying unipolar p-Si/SiO2/n-Si memristor is then introduced. The resistive switching is related to the formation and the rupture of a highly localized Si-rich conduction channel, as suggested by both electrical characterization and direct observation using transmission electron microscope (TEM). The self-rectifying behavior is attributed to a p-i-n diode at each junction at low resistance state, and negates the need for an external selector in a passive memristor array. Finally, we discuss three-dimensional crossbars of all-Si based memristors. The effectiveness of the built-in diodes in blocking both intra- and inter-layer sneak pathSneak path current is confirmed with both simulation and experiments.