06522580 is referenced by 759 patents.

A non-volatile memory system having an array of memory cells with at least one storage element each is operated with a plurality of storage level ranges per storage element. A flash electrically erasable and programmable read only memory (EEPROM) is an example, wherein the storage elements are electrically floating gates. The memory is operated to minimize the effect of charge coupled between adjacent floating gates, by programming some cells a second time after adjacent cells have been programmed. The second programming step also compacts a distribution of charge levels within at least some of the programming states. This increases the separation between states and/or allows more states to be included within a given storage window. An implementation that is described is for a NAND type of flash EEPROM.

Title
Operating techniques for reducing effects of coupling between storage elements of a non-volatile memory operated in multiple data states
Application Number
9/893277
Publication Number
6522580 (B2)
Application Date
June 27, 2001
Publication Date
February 18, 2003
Inventor
Khandker N Quader
Sunnyvale
CA, US
Yupin Fong
Fremont
CA, US
Tomoharu Tanaka
Yokohama
US
Jian Chen
San Jose
CA, US
Agent
Skjerven Morrill
US
Assignee
SanDisk Corporation
CA, US
IPC
G11C 16/34
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