Autonomous refresh of floating body cell (FBC)

Author

Ohsawa, Takashi ; Fukuda, Ryo ; Higashi, Tomoki ; Fujita, Katsuyuki ; Matsuoka, Fumiyoshi ; Shino, Tomoaki ; Furuhashi, Hironobu ; Minami, Yoshihiro ; Nakajima, Hiroomi ; Hamamoto, Takeshi ; Watanabe, Yohji ; Nitayama, Akihiro ; Furuyama, Tohru

Author_Institution

Center for Semicond. R&D, Toshiba Corp., Yokohama

fYear

2008

fDate

15-17 Dec. 2008

Firstpage

1

Lastpage

4

Abstract

Physics of autonomous refresh of FBC is presented. Current input to the floating body by impact ionization and output by charge pumping can balance to make FBC refresh by itself without sense amplifier operation. Thanks to this feature, multiple cells on a BL can be refreshed simultaneously, leading to a drastic reduction of BL charging current compared to the conventional refresh. 600 muA refresh current for 1 G-bit memory is achieved in 32 nm technology node with 4 ms retention time. If gate direct tunneling current is used as output, FBC can realize static RAM without periodical refresh when retaining data.

Keywords

impact ionisation; random-access storage; charge pumping; floating body cell; gate direct tunneling current; impact ionization; memory; static RAM; Charge pumps; Degradation; Design engineering; Impact ionization; Interface states; Intrusion detection; Operational amplifiers; Physics; Random access memory; Tunneling;

fLanguage

English

Publisher

ieee

Conference_Titel

Electron Devices Meeting, 2008. IEDM 2008. IEEE International

Conference_Location

San Francisco, CA

ISSN

8164-2284

Print_ISBN

978-1-4244-2377-4

Electronic_ISBN

8164-2284

Type

conf

DOI

10.1109/IEDM.2008.4796819

Filename

4796819