Title :
A double-density dual-mode phase change memory using a novel background storage scheme
Author :
Wu, J.Y. ; Lee, Moon Ho ; Khwa, W.S. ; Lu, H.C. ; Li, H.P. ; Chen, Y.Y. ; BrightSky, M. ; Chen, T.S. ; Wang, T.Y. ; Cheek, R. ; Cheng, H.Y. ; Lai, E.K. ; Zhu, Yujia ; Lung, H.L. ; Lam, Chris
Author_Institution :
Emerging Central Lab., Macronix Int. Co., Ltd., Hsinchu, Taiwan
Abstract :
Conventional phase change memory (PCM) stores information in amorphous/crystalline states that can be read out as HRS/LRS. In this work we report a radically different mode of storage that can concurrently and independently work with the conventional storage mode. By stressing the memory cell with current we can shift the threshold for RESET switching, and the resulting R-I curve can be used to store logic states. These two modes of storage, HRS/LRS and R-I characteristics, are completely independent and do not interfere with each other, thus allow dual-mode storage. The background (R-I mode) and foreground (HRS/LRS) data can be independently written and read. Furthermore, the total number of bits stored is the multiplication of foreground and background storage. A 4-bit per cell storage scheme is illu strated.
Keywords :
phase change memories; background storage; double density phase change memory; dual mode phase change memory; dual mode storage; high resistance state; logic state storage; low resistance state; memory cell stressing; reset switching threshold; Phase change materials; Resistance; Sensors; Soldering; Stress; Thermal stability; Writing;
Conference_Titel :
VLSI Technology (VLSI-Technology): Digest of Technical Papers, 2014 Symposium on
Conference_Location :
Honolulu, HI
Print_ISBN :
978-1-4799-3331-0
DOI :
10.1109/VLSIT.2014.6894382
