Method for improving read margin in a flash memory device
AssigneeAdvanced Micro Devices, Inc.
InventorsBinh Quang Le, Pau-Ling Chen
Life of this patent
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Abstract
A method for providing a modified threshold voltage distribution for a dynamic reference array in a flash memory cell array. The dynamic reference array and an associated core memory cell array are programmed using two different programming processes to produce different Vt distributions for the dynamic reference array and the core memory cell array. The dynamic reference array is programmed using a finer program pulse to achieve a smaller distribution width, thus enhancing the read margin for the memory cell array. The finer pulse may be of shorter duration or of smaller amplitude. The finer programming process may be applied to one or more threshold voltage distributions (states) in the memory cell array.
Claims20
A method for improving read margin in a flash memory device comprising a dynamic reference memory array and a core memory array, said method comprising:
- programming said core memory array to produce a first threshold voltage (Vt) distribution with a first distribution width;
- programming said dynamic reference memory array to produce a second Vt distribution having a second distribution width;
- and
- wherein said second distribution width is less than said first distribution width.
A method for programming a flash memory device comprising a core memory cell array and a dynamic reference memory cell array, said method comprising:
- applying a first programming pulse to said core memory cell array using a first write/verify cycle;
- applying a second programming pulse to said reference memory cell array using a second write/verify cycle;
- and
- wherein said second pulse is finer than said first pulse.
A method for programming a flash memory device comprising a core memory cell array and a dynamic reference memory cell array, said method comprising:
- programming a first portion of said core memory cell array to a first state using a first programming process;
- and
- programming a first portion of said reference memory cell array to a first state using a second programming process that is finer than said first programming process.
Dependencies are inferred from the claim text.