A new disturb free programming scheme in scaled NAND Flash memory

Author

Shirota, Riichiro ; Huang, Chen-Hao ; Arakawa, Hideki

Author_Institution

Dept. of Electr. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan

fYear

2011

fDate

5-7 Dec. 2011

Abstract

New programming scheme is proposed to improve the program disturb characteristics in NAND Flash memory named Program Disturb Free Scheme (PDFS), which is executed by removing excess electrons from the channel and source/drain into bit line or source line using drift-diffusion mechanism, and also by recombining electrons in the surface states with accumulated holes before programming. Thus, no excess electron exists in the program inhibit cell string during programming, thereby program disturb can be suppressed drastically. By measuring 8Gbit NAND Flash memory with 50nm technology node, almost no Vt shift was observed even applying 30 times over programming (partial programming) in 2bit/cell operation. This universally applicable innovation is independent from generation of design rule. Therefore, new operation has broken new ground for the cell device engineering, especially for sub-30nm NAND which has seriously narrowed program operation margin.

Keywords

NAND circuits; flash memories; surface states; bit line; cell device engineering; cell string; disturb free programming scheme; drift-diffusion mechanism; electron recombination; scaled NAND flash memory; source line; storage capacity 8 Gbit; surface states; Boosting; Charge carrier processes; Electric potential; Flash memory; Programming; Spontaneous emission; Stress;

fLanguage

English

Publisher

ieee

Conference_Titel

Electron Devices Meeting (IEDM), 2011 IEEE International

Conference_Location

Washington, DC

ISSN

0163-1918

Print_ISBN

978-1-4577-0506-9

Electronic_ISBN

0163-1918

Type

conf

DOI

10.1109/IEDM.2011.6131520

Filename

6131520