Self-Rectifying Effect in Resistive Switching Memory Using Amorphous InGaZnO

Resistance random access memory (ReRAM) has received attention as next-generation memory because of its excellent operating properties and high density integration capability as a crossbar array. However, the application of the existing ReRAM as a crossbar array may lead to crosstalk between adjacent cells due to its symmetric I–V characteristics. In this study, the self-rectifying effect of contact between amorphous In-Ga-Zn-O (a-IGZO) and TaO _x was examined in a Pt/a-IGZO/TaO _x /Al₂O₃/W structure. The experimental results show not only self-rectifying behavior but also forming-free characteristics. During the deposition of a-IGZO on the TaO _x , an oxygen-rich TaO _x interfacial layer was formed. The rectifying effect was observed regardless of the interface formation and is believed to be associated with Schottky contact formation between a-IGZO and TaO _x . The current level remained unchanged despite repeated DC sweep cycles. The low resistance state/high resistance state ratio was about 10¹ at a read voltage of ?0.5 V, and the rectifying ratio was about 10³ at ±2 V.