A High-Speed 7.2-ns Read-Write Random Access 4-Mb Embedded Resistive RAM (ReRAM) Macro Using Process-Variation-Tolerant Current-Mode Read Schemes

作者：Chang Meng Fan^*; Sheu Shyh Shyuan; Lin Ku Feng; Wu Che Wei; Kuo Chia Chen; Chiu Pi Feng; Yang Yih Shan; Chen Yu Sheng; Lee Heng Yuan; Lien Chen Hsin; Chen Frederick T; Su Keng Li; Ku Tzu Kun; Kao Ming Jer; Tsai Ming Jinn

来源：IEEE Journal of Solid-State Circuits, 2013, 48(3): 878-891.

DOI：10.1109/JSSC.2012.2230515

• Multilevel cell (MLC)
• read disturbance
• resistive RAM (ReRAM)
• single-level cell (SLC)

ReRAM is a promising next-generation nonvolatile memory (NVM) with fast write speed and low-power operation. However, ReRAM faces two major challenges in read operations: 1) low read yield due to wide resistance distribution and 2) the requirement of accurate bitline (BL) bias voltage control to prevent read disturbance. This study proposes two process-variation-tolerant schemes for current-mode read operation of ReRAM: parallel-series reference-cell (PSRC) and process-temperature-aware dynamic BL-bias (PTADB) schemes. These schemes are meant to improve the read speed and yield of ReRAM, while taking read disturbance into consideration. PSRC narrows the reference current distribution to achieve high read yield against resistance variation. PTADB achieves small fluctuations in BL bias voltage to prevent read disturbance, while providing rapid BL precharge speeds. This study fabricated a 4-Mb ReRAM macro to confirm the effectiveness of the proposed schemes for both SLC and MLC operations. The fastest sub-8-ns (7.2 ns) read-write random access time among megabit scaled embedded NVM macros has been demonstrated.

• 出版日期2013-3
• 单位清华大学