The present invention provides a memory device in which a lower electrode, a seed layer, synthetic antiferromagnetic (SyAF) layers, a separation layer, a magnetic tunnel junction, a capping layer, and an upper electrode are formed on a substrate in a laminated manner, wherein a diffusion barrier is formed between the magnetic tunnel junction and the capping layer. In addition, the present invention provides a memory device in which a lower electrode, a seed layer, SyAF layers, a separation layer, a magnetic tunnel junction, a capping layer, and an upper electrode are formed on a substrate in a laminated manner, wherein the seed layer is formed of a material that allows the SyAF layers to grow in the FCC ( 111 ) direction.
1. A memory device in which a seed layer, synthetic antiferromagnetic layers, a separation layer, a magnetic tunnel junction, and a capping layer are formed in a laminated manner between two electrodes,
wherein the magnetic tunnel junction comprises a pinned layer, a tunnel barrier, and free layers;
the free layers comprise a laminated structure formed of a first free layer, an insertion layer, and a second free layer; and
at least one of the separation layer, the insertion layer, and the capping layer is formed of a material having a BCC structure.
2. The memory device according to claim 1 , wherein the magnetic tunnel junction is formed on the synthetic antiferromagnetic layers.
3. The memory device according to claim 2 , further comprising an oxide layer formed between the magnetic tunnel junction and the capping layer.
4. The memory device according to claim 2 , wherein at least one of the separation layer, the insertion layer, and the capping layer is formed of a material having a lattice constant of less than 330 pm.
5. The memory device according to claim 4 , wherein at least one of the separation layer, the insertion layer, and the capping layer is formed of at least one of tungsten, vanadium, chromium, and molybdenum.
6. The memory device according to claim 5 , wherein the capping layer is formed thicker than the separation layer and the insertion layer, and the separation layer and the insertion layer are formed to have identical thicknesses or different thicknesses.
7. The memory device according to claim 6 , wherein the capping layer is formed to have a thickness of 1 nm to 6 nm, and the separation layer and the insertion layer are each formed to have a thickness of 0.2 nm to 0.5 nm.
8. A memory device in which a lower electrode, a seed layer, synthetic antiferromagnetic layers, a separation layer, a magnetic tunnel junction, a capping layer, and an upper electrode are formed on a substrate in a laminated manner,
wherein the magnetic tunnel junction comprises a pinned layer, a tunnel barrier, and free layers,
the free layers comprise a laminated structure formed of a first free layer, an insertion layer, and a second free layer, and
at least one of the separation layer, the insertion layer, and the capping layer is formed of a bcc-structured material having a lattice constant of less than 330 pm.
9. The memory device according to claim 8 , wherein at least one of the separation layer, the insertion layer, and the capping layer is formed of at least one of tungsten, vanadium, chromium, and molybdenum.