Reducing floating gate to floating gate coupling effect
AssigneeSanDisk Corporation
InventorsYupin Fong, Daniel Guterman
Life of this patent
Estimating the term…
Abstract
For a non-volatile memory system, compressing the erase threshold voltage distribution into the lowest threshold voltage state will decrease the valid data threshold voltage window. Decreasing the valid data threshold voltage window reduces the floating gate to floating gate coupling effect. The compression can be performed as part of the erase process or part of the programming operation.
Claims28
A method for operating non-volatile memory, comprising:
- erasing a set of non-volatile storage elements by moving threshold voltages for said non-volatile storage elements to a first range, said first range is below zero volts;
- compressing said threshold voltages and moving said threshold voltages to a second range, said second range is above zero volts;
- and
- programming at least a subset of said non-volatile storage elements from said second range to one or more of additional ranges above zero volts.
A non-volatile memory system, comprising:
- a plurality of non-volatile storage elements;
- and
- one or more control circuits in communication with said non-volatile storage elements, said one or more control circuits erase said non-volatile storage elements by lowering threshold voltages for said non-volatile storage elements to levels below zero volts, compress said threshold voltages and raise said threshold voltages to levels above zero volts, and program at least a subset of said non-volatile storage elements from said levels above zero volts to one or more valid data states.
A method for operating non-volatile memory, comprising:
- erasing a set of non-volatile storage elements by moving threshold voltages for said non-volatile storage elements to a first range, said first range is associated with non-valid data;
- moving said threshold voltages for said non-volatile storage elements to a second range different than said first range;
- and
- programming at least a subset of said non-volatile storage elements from said second range to one or more of other ranges associated with valid data states.
A non-volatile memory system, comprising:
- a plurality of non-volatile storage elements;
- and
- one or more control circuits in communication with said non-volatile storage elements, said one or more control circuits erase a set of non-volatile storage elements by moving threshold voltages for said non-volatile storage elements from valid data ranges to a non-valid data range, compress said threshold voltages and move said threshold voltages to a first range of said valid data ranges and program at least a subset of said non-volatile storage elements from said first range of said valid ranges to one or more of additional ranges of said valid ranges.
A method for erasing non-volatile memory, comprising:
- erasing a set of non-volatile storage elements by intentionally moving threshold voltages for said non-volatile storage elements to a range outside of valid data ranges;
- and
- compressing said threshold voltages and moving said threshold voltages to a valid data range.
Dependencies are inferred from the claim text.