United States Patent 6,141,248

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United States Patent	6,141,248
Forbes, et. al.	Oct. 31, 2000

DRAM and SRAM memory cells with repressed memory

Abstract

The transfer device of a typical DRAM cell is replaced with a transistor having an additional gate. The unique cell can be accessed as a typical DRAM cell by reading from or writing to a storage capacitor or as a nonvolatile memory by storing charges on the additional gate. Thus, a DRAM cell having a nonvolatile memory component within its cell is formed in a simple and cost effective manner. Transistors in a typical SRAM cell are also replaced by the transistors with the additional gate to form a SRAM cell having a nonvolatile component built within its cell.

Inventors:	*Forbes; Leonard (Corvallis, OR); Reinberg; Alan R.* (Westport, CT).
Assignee:	*Micron* Technology, Inc. (Boise, ID).
Appl. No.:	362,909
Filed:	Jul. 29, 1999

Intl. Cl. :	G11C 14/00
Current U.S. Cl.:	365/185.08; 365/149; 365/154
Field of Search:	365/185.08, 149, 154

References Cited | [Referenced By]

U.S. Patent Documents

4,271,487	Jun., 1981	Craycraft et al.	365/185.08
4,333,166	Jun., 1982	Edwards	365/185.08
4,760,556	Jul., 1988	Deguchi et al.	365/149
5,042,011	Aug., 1991	Casper et al.
5,111,427	May, 1992	Kobayashi et al.	365/154
5,153,853	Oct., 1992	Eby et al.
5,280,205	Jan., 1994	Green et al.
5,399,516	Mar., 1995	Bergendahl et al.
5,418,739	May, 1995	Takasugi
5,424,569	Jun., 1995	Prall
5,488,587	Jan., 1996	Fukumoto
5,497,494	Mar., 1996	Combs et al.
5,619,642	Apr., 1997	Nielson et al.
5,627,785	May, 1997	Gilliam et al.
5,796,670	Aug., 1998	Liu
5,801,401	Sept., 1998	*Forbes*
5,852,306	Dec., 1998	*Forbes*
5,870,327	Feb., 1999	Gitlin et al.
5,880,991	Mar., 1999	Hsu et al.
5,986,932	Nov., 1999	Ratnakumar et al.	365/185.08 X
6,009,011	Dec., 1999	Yamauchi	365/185.08 X

Other References

Dipert et al., "Flash Memory Goes Mainstream," IEEE SPECTRUM, Oct. 1993/vol. 30/Nov. 10, pp. 48-52.

Primary Examiner: Hoang; Huan
Attorney, Agent or Firm: Dickstein, Shapiro, Morin & Oshinsky LLP
83 Claims, 14 Drawing Figures


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