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United States Patent 6,141,256
Forbes Oct. 31, 2000

Differential flash memory cell and method for programming same


A flash memory cell. The flash memory cell includes first and second transistors. The first transistor has a control gate coupled to a word line, a drain coupled to a data line and a floating gate. The second transistor, similarly, includes a control gate coupled to the word line, a drain coupled to a second data line and a second floating gate. The first floating gate stores a state of the second transistor prior to programming of the flash memory cell. Further, the second floating gate stores a programmed state of the second transistor. A difference between the states of the first and second transistors represents the value of the data stored in the flash memory cell.

Inventors: Forbes; Leonard (Corvallis, OR).
Assignee: Micron Technology, Inc. (Boise, ID).
Appl. No.: 470,079
Filed: Dec. 22, 1999

Related U.S. Application Data
Continuation of (including streamline cont.) Ser. No. 31,616, Feb. 27, 1998, Pat. No. 6,009,018, which is a continuation of Ser. No. 790,902, Jan. 29, 1997, Pat. No. 5,754,477.
Intl. Cl. : G11C 7/00
Current U.S. Cl.: 365/185.33; 365/202; 365/207
Field of Search: 365/185.01, 230.01, 185.33, 202, 207

References Cited | [Referenced By]

U.S. Patent Documents
5,021,999Jun., 1991Kohda et al. 365/168
5,027,171Jun., 1991Reedy et al. 357/23.5
5,111,430May, 1992Morie 365/185
5,253,196Oct., 1993Shimabukuro 365/45
5,293,560Mar., 1994Harari 365/185
5,317,535May, 1994Talreja et al. 365/185
5,357,134Oct., 1994Shimoji 257/325
5,388,069Feb., 1995Kokubo 365/185
5,418,743May, 1995Tomioka et al. 365/189.01
5,424,993Jun., 1995Lee et al. 365/218
5,430,670Jul., 1995Rosenthal 365/45
5,434,815Jul., 1995Smarandoiu et al. 365/189.01
5,438,544Aug., 1995Makino 365/185
5,467,306Nov., 1995Kaya et al. 365/185.2
5,477,485Dec., 1995Bergemont et al. 365/185.24
5,485,422Jan., 1996Bauer et al. 365/168
5,627,781May, 1997Hayashi et al. 365/185.2
5,714,766Feb., 1998Chen et al. 257/20
5,754,477May, 1998Forbes 365/185.33
6,009,018Dec., 1999Forbes 365/185.33

Foreign Patent Documents
0139185May, 1985EP
0448118Sept., 1991EP
0750353Dec., 1996EP
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Primary Examiner: Fears; Terrell W.
Attorney, Agent or Firm: Schwegman, Lundberg, Woessner & Kluth, P.A.
35 Claims, 7 Drawing Figures

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