A study on Nonvolatile Conductive Bridging Random-access-memory cell with InGaZnO solid electrolyte

Abstract

Recently, the market of NAND Flash memory has continuously grown on the strength of expansion of big data industries and demands for mobile appliances. With this trend, 3D NAND Flash memory and next generation non-volatile memory are constantly being studied for high-performance, highly integrated memory development. One of the next generation non-volatile memories, Conductive Bridge Random-access-memory (CBRAM) is a resistance-change memory that has bipolar switching characteristics and advantages for simple structure, low power consumption, high speed and CMOS compatibility. In this paper, we studied the bipolar switching behavior of CBRAM cell with InGaZnO (IGZO). The IGZO-based CBRAM has the advantage of implementing IGZO-based transistors and system-on-panel applications in future flat panel displays. Prior to experiments, indium-gallium-zinc oxide (IGZO) was deposited by RF magnetron sputtering system at 2-sccm O2 flow. An X-ray diffraction analysis was performed on the sample after deposition. The thickness of the various IGZO film thicknesses was evaluated to have the proper bipolar switching memory characteristics. As a result, optimum conditions were obtained when the CuTe upper electrode and the IGZO thin film having a thickness of 5 nm were annealed at 400 ° C. Through the experiments, the characteristics of the conductive bridge memory cell according to the annealing temperature increase(room-temperature, 200 and 400 ° C ) and the IGZO thin film thickness (5, 10, and 20 nm) were measured by I-V measurement. The AC endurance cycles and the DC retention time were evaluated under optimal conditions determined by I-V measurement. After that, we observed the difference in the repetitive driving in the same cell as the difference between the cell and the cell through the cumulative distribution. Finally, Read Disturb (RD) measurements and Read Telegraph Noise (RTN) measurements of the high resistance state (HRS) and the low resistance state (LRS) were made.