Yinglong Huang

A New Dynamic Selector Based on the Bipolar RRAM for the Crossbar Array Application

Crossbar array architecture is usually used for the high-density integration of the RRAM device. However, the large sneak current in the passive crossbar array limits the increase in the integration density. In this brief, the bipolar TiN/TaOx/Pt RRAM device is proposed as the dynamic selector for the unipolar Pt/TaOx/Pt RRAM device to suppress the sneak current in the crossbar array. The testing results show that the bipolar RRAM can act as a good selector, and the sneak current is reduced by about two orders estimated by the 1/2 Vread voltage scheme. With the suppressed sneak current, the maximum size of the crossbar array with the bipolar RRAM selector can be increased to more than 1 Mb according to the simulation results, indicating that the bipolar RRAM selector has great potential for the high-density memory applications.

Material engineering technique for SiO X -based embedded RRAM with CMOS compatible process

The resistive switching behavior recently observed in silicon oxide (SiOX) makes this material attractive to embedded resistive random access memory (RRAM) fabrication due to process compatibility. In SiOX-based RRAM devices, switching mechanism is closely correlated with defects in the oxides. Therefore developing a method to control the defects is necessary for performance enhancement. In this paper, a new material engineering technique for SiOX-based embedded RRAM fabrication is proposed and experimentally demonstrated. Metal-Insulator-Metal (MIM) Al/SiO2/TiN capacitor can be converted into RRAM device with nitrogen ion implantation, which is fully compatible with CMOS process. The doped MIM device exhibits stable bipolar resistive switching behavior with large OFF/ON ratio. Compared with PECVD SiOXNY resistive switching device, this material engineering technique with better control of defects density is shown to improve the low resistance uniformity of the fabricated device.

A TaO x based threshold switching selector for the RRAM crossbar array memory

Suppressing the sneak current in the crossbar array is a great challenge for the high-density integration of RRAM. In this paper, a novel threshold switching selector device with the simple structure of Pt/TaOx/Pt is proposed for RRAM application. The measured data shows that this device exhibits good selector characteristics, such as tight cycle to cycle distribution of switching voltage, good resistance uniformity and abrupt switching properties with no hysteresis phenomenon. The conductive current of the selector is induced mainly by the Schottky emission mechanism. And the threshold switching phenomenon may be caused by the electrical breakdown of the defective TaOx film. The threshold switching selector shows a great potential for the high-density RRAM application.