Magnetoresistive random-access memory (MRAM)
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsYu-Der Chih, Chia-Fu Lee
Life of this patent
Estimating the term…
Abstract
A method for identifying an IM state of MRAM cell writes includes providing a plurality of MRAM cells and partitioning the plurality of MRAM cells into a plurality of groups including a first group and a second group. A first MRAM cell of the first group is written from a first state to a second state and a second MRAM cell of the second group is written from the first state to the second state. The writing of the first MRAM cell is verified, including comparing a first read current of the first MRAM cell to a first reference value. The writing of the second MRAM cell is verified, including comparing a second read current of the second MRAM cell to a second reference value.
Claims20
A method, comprising:
- providing a plurality of magnetoresistive random-access memory (MRAM) cells;
- partitioning the plurality of MRAM cells into a plurality of groups including a first group and a second group;
- writing a first MRAM cell of the first group from a first state to a second state;
- writing a second MRAM cell of the second group from the first state to the second state;
- verifying the writing of the first MRAM cell, including comparing a first read current of the first MRAM cell to a first reference value;
- and
- verifying the writing of the second MRAM cell, including comparing a second read current of the second MRAM cell to a second reference value.
A memory device, comprising:
- a first group of magnetoresistive random-access memory (MRAM) cells including a first MRAM cell;
- a second group of MRAM cells including a second MRAM cell;
- and
- a sense amplifier configured to compare a first read current of the first MRAM cell to a first reference value, and to compare a second read current of the second MRAM cell to a second reference value that is different from the first reference value;
- wherein the first and second MRAM cells are configured to be selectively written from a first state to a second state, and wherein the sense amplifier is configured to:
- verify a writing of the first MRAM cell from the first state to the second state by the comparing the first read current of the first MRAM cell to the first reference value;
- and
- verify a writing of the second MRAM cell from the first state to the second state by the comparing the second read current of the second MRAM cell to the second reference value.
A method, comprising:
- providing a plurality of magnetoresistive random-access memory (MRAM) cells;
- partitioning the plurality of MRAM cells into a plurality of groups including a first group having a first plurality of MRAM cells and a second group having a second plurality of MRAM cells;
- comparing a base read current of each of the first plurality of MRAM cells and of each of the second plurality of MRAM cells to a base reference value;
- based on the comparing, writing selected ones of the first plurality of MRAM cells from a first state to a second state;
- based on the comparing, writing selected ones of the second group of MRAM cells from the first state to the second state;
- comparing a first read current of each of the first plurality of MRAM cells to a first reference value different than the base reference value;
- and
- comparing a second read current of each of the second plurality of MRAM cells to a second reference value different than the base reference value and the first reference value.
Dependencies are inferred from the claim text.