Apparatus for reducing the impact of program disturb
AssigneeSanDisk Technologies LLC
InventorGerrit Jan Hemink
Life of this patent
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Abstract
The unintentional programming of an unselected (or inhibited) non-volatile storage element during a program operation that intends to program another non-volatile storage element is referred to as “program disturb.” A system is proposed for programming and/or reading non-volatile storage that reduces the effect of program disturb. In one embodiment, different verify levels are used for a particular word line (or other grouping of storage elements) during a programming process. In another embodiment, different compare levels are used for a particular word (or other grouping of storage elements) during a read process.
Claims24
A non-volatile storage system, comprising:
- non-volatile storage elements, said non-volatile storage elements include a first set of non-volatile storage elements connected to a particular word line, a second set of non-volatile storage elements connected to said particular word line, and a third set of non-volatile storage elements connected to a group of word lines different than said particular word line;
- and
- a managing circuit in communication with said non-volatile storage elements, said managing circuit programs said first set of non-volatile storage elements using a first set of target levels, said managing circuit programs said second set of non-volatile storage elements using a different set of target levels;
- said managing circuit programs said third set of non-volatile storage elements using a second set of target levels, at least one of said first set of target levels is different than a corresponding target level of said second set of target levels, at least one of said different set of target levels is different than a corresponding target level of said second set of target levels, said different set of target levels is different than said first set of target levels.
A non-volatile storage system, comprising:
- non-volatile storage elements, said non-volatile storage elements include a first set of non-volatile storage elements connected to a particular word line, a second set of non-volatile storage elements connected to said particular word line, and a third set of non-volatile storage elements connected to a second set of word lines different from said particular word line;
- and
- one or more managing circuits in communication with said non-volatile storage elements, said one or more managing circuits cause sensing of said first set of non-volatile storage elements using a first target level, said one or more managing circuits cause sensing of said second set of non-volatile storage elements using a second target level, said one or more managing circuits cause sensing of said third set of non-volatile storage elements using a different target level, said first target level is different from said second target level, said different target level is different from said second target level, said different target level is different from said first target level.
A method for operating a non-volatile storage system, comprising:
- sensing a first set of non-volatile storage elements using a first set of compare voltages, said first set of non-volatile storage elements is connected to a particular word line;
- sensing a second set of non-volatile storage elements using a second set of compare voltages different from said first set of compare voltages, said second set of non-volatile storage elements is connected to said particular word line;
- and
- sensing a third set of non-volatile storage elements using a third set of compare voltages different from said first set of compare voltages and said second set of compare voltages, said third set of non-volatile storage elements is connected to a second set of word lines different from said particular word line.
Dependencies are inferred from the claim text.