MRAM cell and MRAM
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsPerng-Fei Yuh, Yih Wang
Life of this patent
Estimating the term…
Abstract
Magnetic random access memory (MRAM) cells are provided. MRAM cell includes a plurality of stacked magnetic tunnel junction (MTJ) devices coupled in serial, and a transistor. The transistor has a gate coupled to a word line, a first terminal coupled to a bit line through the stacked MTJ devices, and a second terminal coupled to a source line. The stacked MTJ devices have different sizes. Each of the stacked MTJ devices includes a free layer, a pinned layer and a barrier layer between the free layer and the pinned layer. The free layers of two adjacent stacked MTJ devices are in direct contact with each other.
Claims20
A magnetic random access memory (MRAM) cell, comprising:
- a plurality of stacked magnetic tunnel junction (MTJ) devices coupled in serial;
- and
- a transistor having a gate coupled to a word line, a first terminal coupled to a bit line through the stacked MTJ devices, and a second terminal coupled to a source line,
- wherein the stacked MTJ devices have different sizes,
- wherein each of the stacked MTJ devices comprises a free layer, a pinned layer and a barrier layer between the free layer and the pinned layer,
- wherein the free layers of two adjacent stacked MTJ devices are in direct contact with each other.
A magnetic random access memory (MRAM) cell, comprising:
- a plurality of stacked magnetic tunnel junction (MTJ) devices coupled in serial;
- and
- a transistor having a gate coupled to a word line, a first terminal coupled to a bit line through the stacked MTJ devices, and a second terminal coupled to a source line,
- wherein each of the stacked MTJ devices comprises a free layer, a pinned layer and a barrier layer between the free layer and the pinned layer,
- wherein a first stacked MTJ device of the stacked MTJ devices is directly coupled to the transistor,
- wherein the free layers of two adjacent stacked MTJ devices between the first stacked MTJ device and the bit line are in direct contact with each other,
- wherein size of the first stacked MTJ device is greater than that of the two adjacent stacked MTJ devices.
A magnetic random access memory (MRAM), comprising:
- a plurality of memory cells arranged in a memory array, wherein each of the memory cells comprises a plurality of magnetic tunnel junction (MTJ) devices coupled in series for storing multiple-bit data,
- wherein in each of the memory cells, the MTJ devices are stacked and coupled between a respective bit line and a respective source line, and the MTJ devices have different sizes,
- wherein in each of the memory cells, each of the MTJ devices comprises a free layer, a pinned layer and a barrier layer between the free layer and the pinned layer,
- wherein in each of the memory cells, the free layers of two adjacent MTJ devices are in direct contact with each other.
Dependencies are inferred from the claim text.