The present invention provides 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 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, 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 seed layer is formed of a material that allows the synthetic antiferromagnetic layers to grow in the FCC (111) direction.
1. A memory device, comprising:
a substrate; and
a lower electrode, seed layer, synthetic antiferromagnetic layer, separation layer, magnetic tunnel junction, capping layer, and upper electrode laminated on the substrate,
wherein a diffusion barrier is formed between the magnetic tunnel junction and the capping layer,
wherein the diffusion barrier serves to prevent a material forming the capping layer from diffusing from the capping layer into the magnetic tunnel junction.
2. The memory device according to claim 1 , further comprising an oxide layer formed between the magnetic tunnel junction and the diffusion barrier.
3. The memory device according to claim 1 , wherein the magnetic tunnel junction is formed by laminating a pinned layer, a tunnel barrier, and a free layer,
wherein the free layer comprises a first magnetization layer, an insertion layer having no magnetization, and a second magnetization layer.
4. The memory device according to claim 3 , wherein the free layer has perpendicular magnetic anisotropy.
5. The memory device according to claim 3 , wherein the capping layer is formed of a material having a body-centered cubic (BCC) structure.
6. The memory device according to claim 5 , wherein the capping layer is formed of a material comprising tungsten (W).
7. The memory device according to claim 6 , wherein the diffusion barrier is formed of a material having a smaller atomic radius than the material forming the capping layer.
8. The memory device according to claim 7 , wherein the diffusion barrier is formed of at least one of iron (Fe), chromium (Cr), molybdenum (Mo), and vanadium (V).
9. The memory device according to claim 8 , wherein the diffusion barrier is formed to have a thickness of 0.1 nm to 0.7 nm.
10. A memory device, comprising:
a substrate; and
a lower electrode, seed layer, synthetic antiferromagnetic layer, separation layer, magnetic tunnel junction, and upper electrode laminated on the substrate,
wherein the magnetic tunnel junction comprises a free layer forming a double layer;
an oxide layer, a diffusion barrier, and a capping layer are laminated between the magnetic tunnel junction and the upper electrode; and
the diffusion barrier serves to prevent a material forming the capping layer from diffusing from the capping layer into the oxide layer.
11. The memory device according to claim 10 , wherein the oxide layer comprises magnesium oxide (MgO), the diffusion barrier comprises iron (Fe), and the capping layer comprises tungsten (W).
12. The memory device according to claim 11 , wherein the diffusion barrier is formed of iron (Fe) to have a thickness of 0.1 nm to 0.7 nm.