Magnetic memory devices
A magnetic memory device includes a first magnetic pattern and a second magnetic pattern that are sequentially stacked on a substrate, a tunnel barrier pattern between the first magnetic pattern and the second magnetic pattern, a lower electrode between the substrate and the first magnetic pattern, a blocking pattern between the lower electrode and the first magnetic pattern, a metal oxide pattern between the blocking pattern and the first magnetic pattern, and a buffer pattern between the metal oxide pattern and the first magnetic pattern. The lower electrode, the blocking pattern, the metal oxide pattern, and the buffer pattern include first, second, third, and fourth non-magnetic metals, respectively. The metal oxide pattern has an amorphous phase.
1. A magnetic memory device comprising:
a first magnetic pattern and a second magnetic pattern that are sequentially stacked on a substrate;
a tunnel barrier pattern between the first magnetic pattern and the second magnetic pattern;
a lower electrode between the substrate and the first magnetic pattern;
a blocking pattern between the lower electrode and the first magnetic pattern;
a metal oxide pattern between the blocking pattern and the first magnetic pattern;
a buffer pattern between the metal oxide pattern and the first magnetic pattern; and
a seed pattern between the buffer pattern and the first magnetic pattern,
wherein the lower electrode, the blocking pattern, the metal oxide pattern, the buffer pattern, and the seed pattern include first, second, third, fourth, and fifth non-magnetic metals, respectively,
wherein at least a portion of the blocking pattern and the metal oxide pattern has an amorphous phase,
wherein the buffer pattern has a crystalline phase, and
wherein the blocking pattern, the metal oxide pattern, and the buffer pattern are sequentially stacked between the lower electrode and the seed pattern.
2. The magnetic memory device of claim 1 ,
wherein the lower electrode includes a nitride of the first non-magnetic metal,
wherein the blocking pattern includes a boride of the second non-magnetic metal, and
wherein the third non-magnetic metal of the metal oxide pattern is different from the first non-magnetic metal and the second non-magnetic metal.
3. The magnetic memory device of claim 2 , wherein an oxide formation energy of the third non-magnetic metal is lower than an oxide formation energy of the first non-magnetic metal and an oxide formation energy of the second non-magnetic metal.
4. The magnetic memory device of claim 2 , wherein the third non-magnetic metal is different from the fourth non-magnetic metal of the buffer pattern.
5. The magnetic memory device of claim 4 , wherein an oxide formation energy of the third non-magnetic metal is lower than an oxide formation energy of the fourth non-magnetic metal.
6. The magnetic memory device of claim 2 , wherein the metal oxide pattern includes an oxide of the third non-magnetic metal.
7. The magnetic memory device of claim 2 ,
wherein the third non-magnetic metal is different from the fourth non-magnetic metal of the buffer pattern, and
wherein the fourth non-magnetic metal comprises at least one of tantalum (Ta), tungsten (W), niobium (Nb), chromium (Cr), molybdenum (Mo), aluminum (Al), ruthenium (Ru), or vanadium (V).
8. The magnetic memory device of claim 1 , further comprising:
an interfacial oxide pattern between the blocking pattern and the metal oxide pattern,
wherein the interfacial oxide pattern includes the same element as the blocking pattern and further includes oxygen.
9. The magnetic memory device of claim 1 ,
wherein the fifth non-magnetic metal of the seed pattern includes at least one of chromium (Cr), ruthenium (Ru), or iridium (Ir).
10. The magnetic memory device of claim 1 , further comprising:
an upper electrode on the second magnetic pattern;
a capping pattern between the second magnetic pattern and the upper electrode; and
a non-magnetic pattern between the second magnetic pattern and the capping pattern,
wherein the capping pattern includes a non-magnetic metal.
11. A magnetic memory device comprising:
a first magnetic pattern and a second magnetic pattern that are sequentially stacked on a substrate in a first direction perpendicular to an upper surface of the substrate;
a tunnel barrier pattern between the first magnetic pattern and the second magnetic pattern;
a lower electrode between the substrate and the first magnetic pattern;
a metal oxide pattern between the lower electrode and the first magnetic pattern;
a buffer pattern between the metal oxide pattern and the first magnetic pattern; and
a seed pattern between the buffer pattern and the first magnetic pattern,
wherein the metal oxide pattern, the buffer pattern, and the seed pattern each include a respective non-magnetic metal,
wherein the metal oxide pattern has an amorphous phase,
wherein the buffer pattern has a crystalline phase, and
wherein the metal oxide pattern, the buffer pattern, and the seed pattern are sequentially stacked in the first direction between the lower electrode and the first magnetic pattern.
12. The magnetic memory device of claim 11 , further comprising:
a blocking pattern between the lower electrode and the metal oxide pattern,
wherein the lower electrode includes a nitride of a first non-magnetic metal, and
wherein the blocking pattern includes a boride of a second non-magnetic metal.
13. The magnetic memory device of claim 12 ,
wherein the non-magnetic metal of the metal oxide pattern is a third non-magnetic metal,
wherein the metal oxide pattern includes an oxide of the third non-magnetic metal, and
wherein an oxide formation energy of the third non-magnetic metal is lower than an oxide formation energy of the first non-magnetic metal and an oxide formation energy of the second non-magnetic metal.
14. The magnetic memory device of claim 13 ,
wherein the non-magnetic metal of the buffer pattern is a fourth non-magnetic metal, and
wherein the oxide formation energy of the third non-magnetic metal is lower than an oxide formation energy of the fourth non-magnetic metal.
15. The magnetic memory device of claim 12 , further comprising:
an interfacial oxide pattern between the blocking pattern and the metal oxide pattern,
wherein the interfacial oxide pattern includes at least one of the second non-magnetic metal or boron.
16. A magnetic memory device comprising:
a substrate;
lower and upper electrodes on the substrate, wherein the lower electrode is between the upper electrode and the substrate;
first and second magnetic layers on the substrate, wherein the first magnetic layer is between the lower electrode and the second magnetic layer;
a tunnel barrier layer between the first and second magnetic layers;
a non-crystalline metal oxide layer between the lower electrode and the first magnetic layer;
a blocking layer between the lower electrode and the non-crystalline metal oxide layer, at least a portion of the blocking layer having an amorphous phase; and
a buffer layer between the non-crystalline metal oxide layer and the first magnetic layer, the buffer layer having a crystalline phase.
17. The magnetic memory device of claim 16 ,
wherein the non-crystalline metal oxide layer comprises a metal that has a lower oxide formation energy than a metal of the blocking layer.
18. The magnetic memory device of claim 16 ,
wherein the non-crystalline metal oxide layer comprises a metal that has a lower oxide formation energy than a metal of the buffer layer.
19. The magnetic memory device of claim 16 , further comprising a seed layer between the buffer layer and the first magnetic layer,
wherein the buffer layer comprises a crystalline layer between the non-crystalline metal oxide layer and the seed layer.