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

fYear

2014

fDate

9-12 June 2014

Firstpage

1

Lastpage

2

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;

fLanguage

English

Publisher

ieee

Conference_Titel

VLSI Technology (VLSI-Technology): Digest of Technical Papers, 2014 Symposium on

Conference_Location

Honolulu, HI

ISSN

0743-1562

Print_ISBN

978-1-4799-3331-0

Type

conf

DOI

10.1109/VLSIT.2014.6894382

Filename

6894382