R&D: Ultrafast Flash Memory with Large Self-Rectifying Ratio Based on Atomically Thin MoS2-Channel Transistor

Materials Futures has published an article written by Liwei Liu, Frontier Institute of Chip and System, Fudan University, Shanghai 200433, People’s Republic of China, Yibo Sun, Xiaohe Huang, State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, People’s Republic of China, Chunsen Liu, State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, People’s Republic of China, Zhaowu Tang, Senfeng Zeng, David Wei Zhang, State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, People’s Republic of China, Shaozhi Deng, State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, People’s Republic of China, and Peng Zhou, State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, People’s Republic of China.

Abstract: “Flash memory with high operation speed and stable retention performance is in great demand to meet the requirements of big data. In addition, the realisation of ultrafast flash memory with novel functions offers a means of combining heterogeneous components into a homogeneous device without considering impedance matching. This report proposes a 20 ns programme flash memory with 10⁸ self-rectifying ratios based on a 0.65-nm-thick MoS₂-channel transistor. A high-quality van der Waals heterojunction with a sharp interface is formed between the Cr/Au metal floating layer and h-BN tunnelling layer. In addition, the large rectification ratio and low ideality factor (n = 1.13) facilitate the application of the MoS₂-channel flash memory as a bit-line select transistor. Finally, owing to the ultralow MoS₂/h-BN heterojunction capacitance (50 fF), the memory device exhibits superior performance as a high-frequency (up to 1MHz) sine signal rectifier. These results pave the way toward the potential utilisation of multifunctional memory devices in ultrafast two-dimensional NAND-flash applications.“