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United States Patent 6,140,181
Forbes, et. al. Oct. 31, 2000

Memory using insulator traps

Abstract

A memory cell provides point defect trap sites in an insulator for storing data charges. Single electrons are stored on respective point defect trap sites and a resulting parameter, such as transistor drain current, is detected. By adjusting the density of the point defect trap sites, more uniform step changes in drain current are obtained as single electrons are stored on or removed from respective trap sites. By also adjusting the trapping energy of the point defect trap sites, the memory cell provides either volatile data storage, similar to a dynamic random access memory (DRAM), or nonvolatile data storage, similar to an electrically erasable and programmable read only memory (EEPROM). The memory cell is used for storing binary or multi-state data.


Inventors: Forbes; Leonard (Corvallis, OR); Geusic; Joseph E. (Berkeley Heights, NJ).
Assignee: Micron Technology, Inc. (Boise, ID).
Appl. No.: 394,109
Filed: Sept. 10, 1999

Related U.S. Application Data
Division of Ser No. 969,099, Nov. 13, 1997.
Intl. Cl. : H01L 21/336
Current U.S. Cl.: 438/257; 257/314; 257/315; 257/321; 257/324; 438/197; 438/211; 438/264; 438/488
Field of Search: 438/299, 197, 144, 158, 167, 257, 211, 264, 488; 437/43; 257/321, 324; 365/185.9, 168, 185.03, 185.33

References Cited | [Referenced By]

U.S. Patent Documents
4,507,673Mar., 1985Aoyama et al. 357/23.R
4,939,559Jul., 1990DiMaria et al. 357/23.5
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
5,298,447Mar., 1994Hong 437/43
5,317,535May, 1994Talreja et al. 365/185
5,388,069Feb., 1995Kokubo 365/185
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
5,449,941Sept., 1995Yamazaki et al. 257/411
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
5,493,140Feb., 1996Iguchi 257/316
5,508,543Apr., 1996Hartstein et al. 257/314
5,627,781May, 1997Hayashi et al. 365/185.2
5,670,790Sept., 1997Katoh et al. 257/14
5,714,766Feb., 1998Chen et al. 257/20
5,740,104Apr., 1998Forbes 365/185.03
5,754,477May, 1998Forbes 365/185.33
5,959,896Sept., 1999Forbes 365/185.33

Foreign Patent Documents
3-222367Oct., 1991JP
6-224431Aug., 1994JP
6-302828Oct., 1994JP
8-255878Oct., 1996JP
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Primary Examiner: Smith; Matthew
Assistant Examiner: Keshaven; B.V.
Attorney, Agent or Firm: Schwegman, Lundberg, Woessner & Kluth, P.A.
21 Claims, 5 Drawing Figures

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