A Self Rectifying Resistive Switching Device Based on HfO2/TaO $_{{x} Bilayer Structure
To effectively solve the crosstalk issue in high density crossbar array (CBA) high rectifying characteristics should be introduced in the resistance random access memory (ReRAM) device, and in depth understanding of the affecting factors on rectifying properties is essential for the large scale application of ReRAM. In this paper, a high performance self rectifying device with CMOS compatible Pd/HfO<sub>2</sub>/TaO<sub><italic>x</italic>/sub>/Ta structure was demonstrated in a 1 kb CBA. Forming free, self compliance, and high uniformity characteristics were successfully achieved. By modulating the thickness of the HfO<sub>2</sub> rectifying layer, the rectifying ratio of device could be achieved as high as <inline formula> <tex math notation="LaTeX"\sim 2\times 10^\textsf {3} /tex math>/inline formula> under 3 V at low resistance state (LRS) It was also experimentally confirmed that the selected unit cell in high resistance state (logically the " OFF" state) was stably readable when it was surrounded by unselected LRS (logically the " ON" state) cells, in an array of up to <inline formula> <tex math notation="LaTeX"$32 \times 32$ /tex math>/inline formula> cells. Furthermore, a model based on interfacial barrier modulation and defects trapping/detrapping was proposed to elucidate the impact of the dielectric thickness on the self rectifying characteristics of the device. The results presented in this paper provide a great potential for selector free high density memory applications.
IEEE Transactions on Electron Devices