MAGNETIC FILM, MAGNETORESISTANCE EFFECT ELEMENT AND MAGNETIC MEMORY
20220052111 · 2022-02-17
Assignee
Inventors
Cpc classification
H10B61/20
ELECTRICITY
International classification
Abstract
Provided are a magnetic film, a magnetoresistance effect element and a magnetic memory which take advantages of atop-pinned structure and a bottom-pinned structure, maintain perpendicular magnetic anisotropy of magnetic layers in a fixing layer and allow strong pinning even in an annealing treatment after a protective film is formed.
A fixing layer of a magnetic film has a basic configuration in which a first magnetic layer (21), a first non-magnetic layer (31), a first Pt layer (41), a second magnetic layer (22) disposed adjacent to each other in this order.
The magnetization directions of the first magnetic layer (21) and the second magnetic layer (22) are both a direction perpendicular to the film surface, and an antiferromagnetic coupling is formed between the first magnetic layer (21) and the second magnetic layer (22).
Claims
1-19. (canceled)
20. A magnetic film comprising: a first magnetic layer; a first non-magnetic layer which is provided adjacent to the first magnetic layer; a first Pt layer which is provided adjacent to the first non-magnetic layer on the side opposite to the first magnetic layer; and a second magnetic layer which is provided adjacent to the first Pt layer on the side opposite to the first non-magnetic layer, wherein the magnetization directions of the first magnetic layer and the second magnetic layer are both a direction perpendicular to the film surface, and an antiferromagnetic coupling is formed between the first magnetic layer and the second magnetic layer.
21. The magnetic film according to claim 20, wherein the first magnetic layer and the second magnetic layer are Co.
22. The magnetic film according to claim 20, wherein the first non-magnetic layer is Ir or Ru.
23. The magnetic film according to claim 22, wherein the Ir film thickness of the first non-magnetic layer is 0.5±0.15 nm or 1.35±0.1 nm, and the Ru film thickness is 0.9±0.2 nm or 0.4±0.15 nm.
24. The magnetic film according to claim 20, wherein the film thickness of the second magnetic layer is thicker than the film thickness of the first Pt layer.
25. The magnetic film according to claim 20, wherein a first adjustment layer is disposed on the side of the first magnetic layer opposite to the first non-magnetic layer, and the first adjustment layer contains Pt.
26. The magnetic film according to claim 21, wherein a first adjustment layer is disposed on the side of the first magnetic layer opposite to the first non-magnetic layer, and the first adjustment layer contains Pt.
27. The magnetic film according to claim 22, wherein a first adjustment layer is disposed on the side of the first magnetic layer opposite to the first non-magnetic layer, and the first adjustment layer contains Pt.
28. The magnetic film according to claim 23, wherein a first adjustment layer is disposed on the side of the first magnetic layer opposite to the first non-magnetic layer, and the first adjustment layer contains Pt.
29. The magnetic film according to claim 20, further comprising a second non-magnetic layer which is provided adjacent to the second magnetic layer on the side opposite to the first Pt layer; a second Pt layer which is provided adjacent to the second non-magnetic layer on the side opposite to the second magnetic layer, and a third magnetic layer which is provided adjacent to the second Pt layer on the side opposite to the second non-magnetic layer, wherein the magnetization direction of the third magnetic layer is a direction perpendicular to the film surface, and an antiferromagnetic coupling is formed between the second magnetic layer and the third magnetic layer.
30. The magnetic film according to claim 29, further comprising a third non-magnetic layer which is provided adjacent to the third magnetic layer on the side opposite to the second Pt layer, a third Pt layer which is provided adjacent to the third non-magnetic layer on the side opposite to the third magnetic layer, and a fourth magnetic layer which is provided adjacent to the third Pt layer on the side opposite to the third non-magnetic layer, wherein the magnetization direction of the fourth magnetic layer is a direction perpendicular to the film surface, and an antiferromagnetic coupling is formed between the third magnetic layer and the fourth magnetic layer.
31. The magnetic film according to claim 30, further comprising a fourth non-magnetic layer which is provided adjacent to the fourth magnetic layer on the side opposite to the third Pt layer, a fourth Pt layer which is provided adjacent to the fourth non-magnetic layer on the side opposite to the fourth magnetic layer, and a fifth magnetic layer which is provided adjacent to the fourth Pt layer on the side opposite to the fourth non-magnetic layer, wherein the magnetization direction of the fifth magnetic layer is a direction perpendicular to the film surface, and an antiferromagnetic coupling is formed between the fourth magnetic layer and the fifth magnetic layer.
32. The magnetic film according to claim 25, wherein the order of the first non-magnetic layer and the first Pt layer laminated is reversed.
33. The magnetic film according to claim 29, wherein the order of the first non-magnetic layer and the first Pt layer laminated, and/or, the order of the second non-magnetic layer and the second Pt layer laminated are reversed.
34. The magnetic film according to claim 30, wherein the order of the first non-magnetic layer and the first Pt layer laminated, and/or, the order of the second non-magnetic layer and the second Pt layer laminated, and/or, the order of the third non-magnetic layer and the third Pt layer laminated are reversed.
35. The magnetic film according to claim 31, wherein the order of the first non-magnetic layer and the first Pt layer laminated, and/or, the order of the second non-magnetic layer and the second Pt layer laminated, and/or, the order of the third non-magnetic layer and the third Pt layer laminated, and/or, the order of the fourth non-magnetic layer and the fourth Pt layer laminated are reversed.
36. A magnetoresistance effect element comprising: a first fixing layer including the magnetic film according to claim 25; and a first barrier layer, wherein the first barrier layer is disposed on the side of the first adjustment layer of the first fixing layer, and the first adjustment layer is a Co/Pt multilayer film.
37. The magnetoresistance effect element according to claim 36, wherein the first magnetic layer and the second magnetic layer are Co, the first non-magnetic layer is Ir or Ru, and the Ir film thickness of the first non-magnetic layer is 0.5±0.15 nm or 1.35±0.1 nm, and the Ru film thickness is 0.9±0.2 nm or 0.4±0.15 nm.
38. A magnetoresistance effect element comprising: a second fixing layer including the magnetic film according to claim 25; and a second barrier layer, wherein the second barrier layer is disposed on the side opposite to the first adjustment layer of the second fixing layer, and the first adjustment layer is a layer containing Pt as a main element.
39. A magnetoresistance effect element comprising: a first fixing layer including the magnetic film according to claim 32; and a first barrier layer, wherein the first barrier layer is disposed on the side of the first adjustment layer of the first fixing layer, and the first adjustment layer is Co/Pt multilayer film.
40. A magnetic memory comprising the magnetoresistance effect element according to claim 36.
41. A magnetic memory comprising the magnetoresistance effect element according to claim 39.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0090] Hereinafter, a magnetic film, a magnetoresistance effect element and a magnetic memory of the present invention will be described in detail with reference to the drawings.
[0091] Here, the drawings are only an example, and will be described with reference numerals, and do not limit the present invention.
Embodiment 1
[0092]
[0093] Since the first fixing layer (P1) is disposed on the lower electrode (E1), the recording layer (F1), and the first barrier layer (B1), the configuration of Embodiment 1 is a part or all of the magnetoresistance effect element having a top-pinned structure.
[0094] The magnetization directions of the first magnetic layer (21) and the second magnetic layer (22) are both a direction perpendicular to a film surface, and an antiferromagnetic coupling is formed between the first magnetic layer (21) and the second magnetic layer (22).
[0095] The first magnetic layer (21) and the second magnetic layer (22) contain any of Co, Fe, and Ni.
[0096] In addition, the first magnetic layer (21) and the second magnetic layer (22) may further contain non-magnetic elements such as W, Ta, Hf, Zr, Nb, Mo, Ti, V, Cr, Si, Al, B, Pd, and Pt.
[0097] Specific examples include Co, Fe, Ni, CoFe, FeNi, CoNi, and CoB, and Co is more preferable because in this case an antiferromagnetic coupling is formed between two magnetic layers with the first non-magnetic layer (31) and the first Pt layer (41) to be described below therebetween, and the magnetization directions of the two magnetic layers tend to be a direction perpendicular to the film surface.
[0098] The film thicknesses of the first magnetic layer (21) and the second magnetic layer (22) each are preferably in a range of 0.3 nm to 3.0 nm and more preferably in a range of 0.5 nm to 1.1 nm. This is because stable ferromagnetism cannot be obtained when the film thickness is thinner, but an antiferromagnetic coupling is significantly weaker when the film thickness is thicker than 3 nm.
[0099] In addition, the first magnetic layer (21) and the second magnetic layer (22) may be composed of a plurality of layers. For example, multilayer films such as Co/Pt/Co or Co/Pt/Co/Pt/Co may be used.
[0100] In addition, the film thickness of the second magnetic layer (22) is preferably thicker than the film thickness of the first Pt layer (41) to be described below.
[0101] The crystal structure of the first magnetic layer (21) and the second magnetic layer (22) preferably has an fcc (111) structure (face-centered cubic). This is because the perpendicular magnetic anisotropy is easily maintained when the crystal orientation is higher.
[0102] In addition, when the main element of the first magnetic layer (21) and/or the second magnetic layer (22) is Co, in an X-ray diffraction spectrum, it is desirable to have a main peak of an X-ray diffraction intensity when an angle 2θ, which is twice an angle of X-ray incidence, is 42° or more and 43° or less. When the peak of the spectrum appears when 2θ is 42° or more and 43° or less, the lattice constant of Co is almost the same as that of bulk Co(111). The inventors have found that perpendicular magnetic anisotropy becomes stronger when there is not much Co strain.
[0103] In the first non-magnetic layer (31), the magnetic layers are antiferromagnetically coupled by the element film constituting the non-magnetic layer, and the interlayer exchange coupling energy between the magnetic layers, that is, the antiferromagnetic coupling force, is adjusted by the constituent elements and their film thickness. Examples of materials whose interlayer exchange coupling energy changes depending on the film thickness include such as Ir, Ru, Rh, and Os.
[0104] The first non-magnetic layer (31) may also contain other elements using these alloys as long as the crystal structure does not change. For example, Ta, B, Nb, and V and the like may be exemplified.
[0105] The film thickness of the first non-magnetic layer (31) is desirably adjusted to 0.5±0.15 nm or 1.35±0.1 nm, which shows peak positions of the antiferromagnetic coupling strength, when Ir is contained as the main element.
[0106] The film thickness of the first non-magnetic layer (31) is desirably adjusted to 0.9±0.2 nm or 0.4±0.15 nm, which shows peak positions of antiferromagnetic coupling strength, when Ru is contained as the main element.
[0107] The first Pt layer (41) contains Pt as the main element and is inserted adjacently between the first non-magnetic layer (31) and the second magnetic layer (22).
[0108] The film thickness of the first Pt layer (41) is preferably in a range of 0.1 nm to 0.9 nm and more preferably in a range of 0.25 nm to 0.7 nm. Here, the film thickness of the first Pt layer (41) is preferably thinner than the film thickness of the second magnetic layer (22).
[0109] The first adjustment layer (A1) of the first fixing layer (P1) is more desirably a multilayer film which contains Pt and in which a plurality of Co/Pt are laminated. As shown in
[0110] The film thickness of Co among the Co/Pt multilayer films of the first adjustment layer (A1) is preferably in a range of 0.2 nm to 0.7 nm and more preferably in a range of 0.2 nm to 0.4 nm. The film thickness of Pt is preferably in a range of 0.4 nm to 1.1 nm and more preferably in a range of 0.6 nm to 0.9 nm. In addition, among the Co/Pt multilayer films of the first adjustment layer (A1), the film thickness of Pt is preferably thicker than the film thickness of Co.
[0111] Here, among the Co layers in the first adjustment layer (A1), the film thickness of the Co layer adjacent to the first barrier layer (B1) is preferably in a range of 0.3 nm to 1.6 nm and more preferably in a range of 0.5 nm to 1.4 nm, regardless of the above range.
[0112] The cap layer (C1) is a layer which is provided on the side opposite to the first barrier layer (B1) of the first fixing layer (P1) and includes an upper electrode, and electrically connects the first fixing layer (P1) of the magnetoresistance effect element to a bit line of a select transistor.
[0113] In addition, in the cap layer (C1), in addition to the upper electrode, a non-magnetic layer or the like required for improving characteristics of the magnetoresistance effect element can be appropriately formed between the upper electrode and the first fixing layer (P1).
[0114] The first barrier layer (B1) is a tunnel barrier layer which is disposed on the side of the first adjustment layer (A1) of the first fixing layer (P1) and composed of an insulation layer, and forms a magnetic tunnel junction between the first fixing layer (P1) and the recording layer (F1) to be described below. An insulator such as MgO, Al.sub.2O.sub.3, SiO.sub.2, TiO, Hf.sub.2O, or ScC is used, and MgO or ScC is preferably used so that a large magnetoresistance change rate is exhibited by combining materials of two end surfaces.
[0115] In order to increase the TMR ratio, the film thickness of the first barrier layer (B1) is preferably 0.5 nm or more and more preferably 0.8 nm or more. In addition, in order to reverse the magnetization with a small write current I.sub.C, the film thickness is preferably 2.0 nm or less and more preferably 1.2 nm or less. Therefore, the film thickness is adjusted to be within a range of 0.5 to 2.0 nm and more preferably in a range of 0.8 to 1.2 nm.
[0116] The recording layer (F1) is disposed adjacent to the first barrier layer (B1) on the side opposite to the first fixing layer (P1) and the magnetization direction is a direction perpendicular to a film surface.
[0117] The recording layer (F1) contains at least one of Co, Fe, and Ni.
[0118] In addition, the recording layer (F1) may further contain non-magnetic elements such as W, Ta, Hf, Zr, Nb, Mo, Ti, V, Cr, Si, Al, B, Pd, and Pt.
[0119] Specific examples include such as Co, Fe, Ni, CoFe, FeNi, CoNi, CoB, FeB, NiB, and CoFeB, and CoFeB and FeB are more preferable. In addition, the recording layer (F1) may be a Co/Pt multilayer film.
[0120] Here, the recording layer (F1) desirably has perpendicular magnetic anisotropy due to interface magnetic anisotropy with the first barrier layer (B1). In addition, for the recording layer (F1), one or more non-magnetic insertion layers such as W, Ta, and Mo may be inserted, a layer such as MgO may be inserted to increase the interface, and the perpendicular magnetic anisotropy may be further improved.
[0121] The lower electrode (E1) is disposed on the side of the recording layer (F1) opposite to the first barrier layer (B1). The lower electrode (E1) is electrically connected to a select transistor (not shown) and the magnetoresistance effect element receives a current supply from the select transistor to write and read.
[0122] Here, in Embodiment 1, as shown in
[0123] The first reference layer (R1) is inserted in order to improve characteristics of the magnetoresistance effect element, particularly, the TMR ratio.
[0124] The first reference layer (R1) contains a magnetic layer and a non-magnetic layer, the magnetic layer is adjacent to the first barrier layer (B1), and the non-magnetic layer is adjacent to the first adjustment layer (A1).
[0125] The magnetic layer contains at least one of Co, Ni, and Fe.
[0126] In addition, the magnetic layer of the first reference layer (R1) may further contain non-magnetic elements such as W, Ta, Hf, Zr, Nb, Mo, Ti, V, Cr, Si, Al, B, Pd, and Pt.
[0127] Specific examples include such as Co, Fe, Ni, CoFe, FeNi, CoNi, CoB, FeB, NiB, and CoFeB, and CoFeB and FeB are more preferable.
[0128] The film thickness of the magnetic layer of the first reference layer (R1) is preferably in a range of 0.3 nm to 3.0 nm and more preferably in a range of 1.0 nm to 1.4 nm.
[0129] In order to improve the crystal orientation of the magnetic layer of the first adjustment layer (Al) and the like, the non-magnetic layer of the first reference layer (R1) is inserted between the magnetic layer of the first reference layer (R1) and the first adjustment layer (A1).
[0130] The non-magnetic layer of the first reference layer (R1) contains, for example, Ta, W, or Mo, and the film thickness thereof is about 0.3 nm. The magnetic layer of the first reference layer (R1) and the magnetic layer adjacent to the first reference layer (R1) of the first adjustment layer (A1) are magnetically coupled.
[0131] In addition, in Embodiment 1, as shown in
[0132] Features of Embodiment 1 will be described.
[0133] First, as described in the background art, in order to generate an antiferromagnetic coupling between magnetic layers, generally, the magnetic layer and the non-magnetic layer are disposed adjacent to each other (refer to
[0134] In the present invention, the crystal orientation of the magnetic layer is improved by inserting the Pt layer between the magnetic layer and the non-magnetic layer, which is between the magnetic layers forming an antiferromagnetic coupling, and even after the annealing treatment at 300° C. to 400° C., the perpendicular magnetic anisotropy and the antiferromagnetic coupling are maintained (the same applies to other embodiments).
[0135] In addition, in order to perform sufficient pinning with the conventional layer configuration, a multilayer film with an increased number of laminated magnetic layers forming an antiferromagnetic coupling such as Co/Pt/Co/Pt/Co as in
[0136] Here, as will be described below, even in the conventional example in
[0137] Hereinafter, the evaluation results of Embodiment 1 will be described.
Evaluation Test 1
[0138] The perpendicular magnetic anisotropy of the magnetoresistance effect element of Embodiment 1 was evaluated.
[0139]
[0140] An evaluation element in
[0141] Magnetization curves (magnetization versus field curves) obtained from the evaluation films are shown in
[0142] In addition, although not shown here, the M-H loop when a magnetic field was applied in the plane, a substantially vertical loop was not obtained in the zero magnetic field, and a curve as shown in
[0143] In
Evaluation Test 2
[0144] The perpendicular magnetic anisotropy of the magnetoresistance effect element having a layer configuration as a comparative example of Embodiment 1 was evaluated.
[0145]
[0146] An evaluation element in
[0147] Magnetization curves obtained from the evaluation films are shown in
[0148] In
[0149] That is, unlike Embodiment 1, in the configuration in
[0150] In addition, as in this comparative example, generally, it was necessary to prepare a multilayer structure of Co/Pt in order to prepare a perpendicular magnetic film. When the multilayer structure was prepared in this manner, in a production device, in order to secure throughput, cathodes corresponding to the number of layers of Co and Pt were prepared. Therefore, as the number of layers increased, the production cost increased. On the other hand, the present invention was also advantageous in terms of production cost because a stronger antiferromagnetic coupling could be formed in a vertical film even if the number of layers was small.
Evaluation Test 3
[0151] The crystal orientation of the magnetoresistance effect element of Embodiment 1 was evaluated.
[0152] An evaluation element of
[0153]
[0154] In
[0155] Here, although not shown, it was understood that, when analyzed together with the results of evaluation elements having other configurations, if the film thickness of the second magnetic layer (22) was thicker than the film thickness of the first Pt layer (41), the crystal orientation of the second magnetic layer (22) could be further improved, and since a main X-ray diffraction peak was shown at an angle of X-ray incidence 20 of 42° or more and 43° or less, the crystal structure of Co was mainly the fcc (111) structure.
[0156] In this manner, it was understood that the element having the configuration of Embodiment 1 could improve the crystal orientation of the magnetic layer, and thus it easily maintained the perpendicular magnetic anisotropy and easily became a perpendicular magnetic film.
Evaluation Test 4
[0157] As a comparative example of Embodiment 1, the X-ray diffraction spectrum in the case of a layer configuration having a low crystal orientation was confirmed.
[0158]
[0159] In
[0160] That is, it was clearly understood that, unlike the element whose magnetization direction was a direction perpendicular to a film surface as in Evaluation Test 3, when the magnetization easy axis of the magnetic layer was the in-plane direction, there was no main X-ray diffraction peak at an angle of X-ray incidence 2θ of 42° or more and 43° or less, and the magnetization direction of Co was unlikely to be vertical.
Embodiment 2
[0161]
[0162] Since the second fixing layer (P2), the second barrier layer (B2), and the recording layer (F1) are disposed on the lower electrode (E1) in this order, the configuration of Embodiment 2 is a part or all of the magnetoresistance effect element having a bottom-pinned structure.
[0163] The magnetization directions of the first magnetic layer (21) and the second magnetic layer (22) are both a direction perpendicular to a film surface, and an antiferromagnetic coupling is formed between the first magnetic layer (21) and the second magnetic layer (22).
[0164] Desirably, the first adjustment layer (A1) included in the bottom-pinned structure contains Pt and is a Pt layer. In this case, the film thickness of the first adjustment layer (A1) is preferably 3 nm or more, and more preferably 5 nm or more. Here, the first adjustment layer (A1) may be referred to as an underlayer.
[0165] In the first non-magnetic layer (31) of the second fixing layer (P2), the magnetic layers are antiferromagnetically coupled by the element film constituting the non-magnetic layer, and the interlayer exchange coupling energy between the magnetic layers, that is, the antiferromagnetic coupling force, is adjusted by the constituent elements and their film thickness. Examples of materials whose interlayer exchange coupling energy changes depending on the film thickness include Ir, Ru, Rh, and Os and the like.
[0166] The first non-magnetic layer (31) may also contain other elements using these alloys as long as the crystal structure does not change. For example, such as Ta, B, Nb, and V may be exemplified.
[0167] The film thickness of the first non-magnetic layer (31) is desirably adjusted to 0.5±0.15 nm or 1.35±0.1 nm, which shows peak positions of antiferromagnetic coupling strength, when Ir is contained as the main element.
[0168] The film thickness of the first non-magnetic layer (31) is desirably adjusted to 0.9±0.2 nm or 0.4±0.15 nm, which shows peak positions of antiferromagnetic coupling strength, when Ru is contained as the main element.
[0169] Details of the first magnetic layer (21) of the second fixing layer (P2), the first Pt layer (41), and the second magnetic layer (22) are the same as those in Embodiment 1.
[0170] The second barrier layer (B2) is a tunnel barrier layer which is disposed on the side opposite to the first adjustment layer (A1) of the second fixing layer (P2) and composed of an insulation layer, and forms a magnetic tunnel junction together with the second fixing layer (P2) and the first recording layer (F1) to be described below. An insulator such as MgO, Al.sub.2O.sub.3, SiO.sub.2, TiO, Hf.sub.2O, or ScC is used and MgO or ScC is preferably used so that a large magnetoresistance change rate is exhibited by combining materials on two end surfaces.
[0171] In order to increase the TMR ratio, the film thickness of the second barrier layer (B2) is preferably 0.5 nm or more and more preferably 0.8 nm or more. In addition, in order to reverse the magnetization with a small write current I.sub.C, the film thickness is preferably 2.0 nm or less and more preferably 1.2 nm or less. Therefore, the film thickness is adjusted to be within a range of 0.5 nm to 2.0 nm and more preferably within a range of 0.8 nm to 1.2 nm.
[0172] The recording layer (F1) is disposed adjacent to the second barrier layer (B2) on the side opposite to the second fixing layer (P2), and the magnetization direction is a direction perpendicular to a film surface.
[0173] The recording layer (F1) contains at least one of Co, Fe, and Ni.
[0174] In addition, the recording layer (F1) may further contain non-magnetic elements such as W, Ta, Hf, Zr, Nb, Mo, Ti, V, Cr, Si, Al, B, Pd, and Pt.
[0175] Specific examples include such as Co, Fe, Ni, CoFe, FeNi, CoNi, CoB, FeB, NiB, and CoFeB, and CoFeB and FeB are more preferable. In addition, the recording layer (F1) may be a Co/Pt multilayer film.
[0176] Here, the recording layer (F1) desirably has perpendicular magnetic anisotropy due to interface magnetic anisotropy with the second barrier layer (B2). In addition, for the first recording layer (F1), one or more non-magnetic insertion layers such as W, Ta, and Mo may be inserted, a layer such as MgO may be inserted to increase the interface, and the perpendicular magnetic anisotropy may be further improved.
[0177] The cap layer (C1) is a layer which is provided on the side opposite to the second barrier layer (B2) of the second fixing layer (P2) and includes an upper electrode, and electrically connects the second fixing layer (P2) of the magnetoresistance effect element to a bit line of a select transistor.
[0178] In addition, in the cap layer (C1), in addition to the upper electrode, a non-magnetic layer or the like required for improving characteristics of the magnetoresistance effect element can be appropriately formed between the upper electrode and the second fixing layer (P2).
[0179] The lower electrode (E1) is disposed on the side opposite to the second barrier layer (B2) of the second fixing layer (P2). The lower electrode (E1) is electrically connected to a select transistor (not shown), and the magnetoresistance effect element receives a current supply from the select transistor to write and read.
[0180] Here, in Embodiment 2, as shown in
[0181] In addition, in Embodiment 2, as shown in
[0182] Features of Embodiment 2 will be described.
[0183] Also, in Embodiment 2, the crystal orientation of the magnetic layer is improved by inserting the Pt layer under the magnetic layer, which is between the magnetic layers forming an antiferromagnetic coupling, and even after the annealing treatment at 300° C. to 400° C., the perpendicular magnetic anisotropy and the antiferromagnetic coupling are maintained
[0184] Hereinafter, the evaluation results of Embodiment 2 will be described.
Evaluation Test 5
[0185] The perpendicular magnetic anisotropy of the magnetoresistance effect element of Embodiment 2 was evaluated.
[0186]
[0187] Since the Ir film has a film thickness of 0.53 nm and allows upper and lower magnetic layers to be effectively antiferromagnetically coupling, an evaluation film having an Ir film thickness t.sub.Ir of 0.5 nm and 0.55 nm was prepared and annealed at 300° C. and 400° C. for 1 hour.
[0188]
Embodiment 3
[0189]
[0190] That is, with the first barrier layer (B1), the recording layer (F1) and the second barrier layer (B2) therebetween, the first fixing layer (P1) is disposed on the side of the first barrier layer (B1), and two fixing layers of the second fixing layer (P2) are disposed on the side of the second barrier layer (B2).
[0191] Here, in Embodiment 3, a case in which two fixing layers having an antiferromagnetic coupling configuration in which a non-magnetic layer/Pt layer/magnetic layer is repeated twice are disposed is shown, but a configuration in which one, three, four, or five or more non-magnetic layers are inserted may be used. In addition, the numbers of non-magnetic layers in the first fixing layer (P1) and the second fixing layer (P2) may be different, and only one of the fixing layers between the first fixing layer (P1) and the second fixing layer (P2) may have a configuration of the non-magnetic layer/Pt layer/magnetic layer.
Embodiment 4
[0192] Embodiment 4 has a configuration of a magnetic film included in Embodiments 1 and 2. As shown in
[0193] The magnetization directions of the first magnetic layer (21) and the second magnetic layer (22) are both a direction perpendicular to a film surface, and an antiferromagnetic coupling is formed between the first magnetic layer (21) and the second magnetic layer (22).
[0194] In the first non-magnetic layer (31), the magnetic layers are antiferromagnetically coupled by the element film constituting the non-magnetic layer, and the interlayer exchange coupling energy between the magnetic layers, that is, the magnitude of antiferromagnetic coupling, is adjusted by the constituent elements and their film thickness. Examples of materials whose interlayer exchange coupling energy changes depending on the film thickness include Ir, Ru, Rh, and Os and the like.
[0195] The first non-magnetic layer (31) may also contain other elements using these alloys as long as the crystal structure does not change. For example, Ta, B, Nb, and V and the like may be exemplified.
[0196] The film thickness of the first non-magnetic layer (31) is desirably adjusted to 0.5±0.15 nm or 1.35±0.1 nm, which shows peak positions of antiferromagnetic coupling strength, when Ir is contained as the main element.
[0197] The film thickness of the first non-magnetic layer (31) is desirably adjusted to 0.9±0.2 nm or 0.4±0.15 nm, which shows peak positions of antiferromagnetic coupling strength, when Ru is contained as the main element.
[0198] Details of the first magnetic layer (21), the first Pt layer (41), and the second magnetic layer (22) are the same as those in Embodiment 1.
[0199] In addition, in Embodiment 4, as shown in
[0200] As described above, Embodiment 4 has features of the invention shown in Embodiment 1 and Embodiment 2, and due to the layer configuration of the first magnetic layer (21)/the first non-magnetic layer (31)/the first Pt layer (41)/the second magnetic layer (22), since crystal orientation of the second magnetic layer (22) can be improved, the perpendicular magnetic anisotropy and antiferromagnetic coupling between the first magnetic layer (21) and the second magnetic layer (22) can be maintained even in the annealing treatment at 400° C.
Embodiment 5
[0201] Embodiment 5 has a configuration of the magnetic layer included in Embodiments 1 and 2, and in Embodiment 4, the first adjustment layer (A1) is additionally disposed. As shown in
[0202] The magnetization directions of the first magnetic layer (21) and the second magnetic layer (22) are both a direction perpendicular to a film surface, and an antiferromagnetic coupling is formed between the first magnetic layer (21) and the second magnetic layer (22).
[0203] In the first non-magnetic layer (31), the magnetic layers are antiferromagnetically coupled by the element film constituting the non-magnetic layer, and the interlayer exchange coupling energy between the magnetic layers, that is, the magnitude of antiferromagnetic coupling, is adjusted by the constituent elements and their film thickness. Examples of materials whose interlayer exchange coupling energy changes depending on the film thickness include Ir, Ru, Rh, and Os and the like.
[0204] The first non-magnetic layer (31) may also contain other elements using these alloys as long as the crystal structure does not change. For example, Ta, B, Nb, and V and the like may be exemplified.
[0205] The film thickness of the first non-magnetic layer (31) is desirably adjusted to 0.5±0.15 nm or 1.35±0.1 nm, which shows peak positions of antiferromagnetic coupling strength, when Ir is contained as the main element.
[0206] The film thickness of the first non-magnetic layer (31) is desirably adjusted to 0.9±0.2 nm or 0.4±0.15 nm, which shows peak positions of antiferromagnetic coupling strength, when Ru is contained as the main element.
[0207] Details of the first magnetic layer (21), the first Pt layer (41), and the second magnetic layer (22) are the same as those in Embodiment 1.
[0208] The first adjustment layer (A1) contains Pt, and a Pt layer, and a Co/Pt multilayer film containing Pt as a main element may be exemplified. In addition, it may contain other elements as long as properties of the crystal structure and/or layers do not change.
[0209] Here, in Embodiment 5, as shown in
[0210] In Embodiment 5, since the first adjustment layer (A1) is additionally provided in Embodiment 4, in addition to the effects shown in Embodiment 4, the crystal orientation of the magnetic layer (particularly, the first magnetic layer) in the fixing layer can be additionally improved and the magnetic characteristics are improved.
[0211] In the following Embodiments 6-10, more specific examples will be described.
Embodiment 6
[0212]
[0213] Here, 21, 22, 23, and 24 correspond to the first magnetic layer, the second magnetic layer, the third magnetic layer, and the fourth magnetic layer. In addition, 31, 32, and 33 correspond to the first non-magnetic layer, the second non-magnetic layer, and the third non-magnetic layer. In addition, 41, 42, and 43 correspond to the first Pt layer, the second Pt layer, and the third Pt layer.
[0214] Here, in the layer configuration of Embodiment 6, the fact that the crystal orientation and perpendicular magnetic anisotropy of the magnetic layer in the fixing layer are maintained can be evaluated in the evaluation test described above. That is, the crystal orientation was confirmed by the fact that, in the X-ray diffraction spectrum, a main peak of an X-ray diffraction intensity was shown when the angle 2θ, which is twice an angle of X-ray incidence, was 42° or more and 43° or less, and the states of the perpendicular magnetic anisotropy and antiferromagnetic coupling were confirmed by the fact that, in the magnetization curve of the evaluation film, a substantially vertical loop was obtained when μ.sub.0H was near zero.
[0215] The inventors have found that, in the examination of the layer configuration, in order to particularly maintain the crystal orientation, focusing on, for example, a ratio of Co and Pt, a peak in the X-ray diffraction spectrum was shown between 42° or more and 43° or less.
[0216] In addition, in the layer configuration of Embodiment 6, some or all of the magnetic layers (the first magnetic layer, the second magnetic layer, the third magnetic layer, and the fourth magnetic layer) to be antiferromagnetically coupled are made into multiple layers, and the film thickness of each layer including the Pt layer inserted under the magnetic layer can be made thin. As in the following examples, the first Pt layer, the second Pt layer, and the third Pt layer (Pt(0.25-0.6)) in
Co(0.5-1.4)/MgO(0.8-1.2)/Co(0.5-1.4)/Pt(0.6-0.9)/Co(0.2-0.4)/Pt(0.6-0.9)/Co(0.2-0.4)/Pt(0.6-0.9)/Co(0.5-1.1)/Ir(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/Ir(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/Ir(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)
Embodiment 7
[0217]
[0218] Here, 21, 22, 23, and 24 correspond to the first magnetic layer, the second magnetic layer, the third magnetic layer, and the fourth magnetic layer. In addition, 31, 32, and 33 correspond to the first non-magnetic layer, the second non-magnetic layer, and the third non-magnetic layer. In addition, 41, 42, and 43 correspond to the first Pt layer, the second Pt layer, and the third Pt layer.
[0219] In the configuration of Embodiment 7, the first reference layer (R1) is disposed on the side of the first barrier layer (B1) of the first fixing layer (P1).
[0220] Here, as in Embodiment 6, in the configuration of Embodiment 7, some or all of the magnetic layers (the first magnetic layer, the second magnetic layer, the third magnetic layer, and the fourth magnetic layer) to be antiferromagnetically coupled are made into multiple layers, and the film thickness of each layer including the Pt layer inserted under the magnetic layer can be made thin. As in the following examples, the first Pt layer, the second Pt layer, and the third Pt layer (Pt(0.25-0.6)) in
CoFeB(1.0-1.4)/MgO(0.8-1.2)/CoFeB(1.0-1.4)/Ta or W or Mo(0.3)/Co(0.2-0.4)/Pt(0.6-0.9)/Co(0.2-0.4)/Pt(0.6-0.9)/Co(0.2-0.4)/Pt(0.6-0.9)/Co(0.5-1.1)/Ir(0.53)/Pt(0.2-0.4)/Co(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/Ir(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/Ir(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)
Embodiment 8
[0221]
[0222] Here, 21, 22, and 23 correspond to the first magnetic layer, the second magnetic layer, and the third magnetic layer. In addition, 31 and 32 correspond to the first non-magnetic layer and the second non-magnetic layer. In addition, 41 and 42 correspond to the first Pt layer and the second Pt layer.
[0223] In Embodiment 8, in addition to the configuration of the non-magnetic layer/Pt layer/magnetic layer, the first reference layer (R1) is disposed on the side of the second barrier layer (B2) of the second fixing layer (P2), and the second barrier layer (B2) is MgO.
[0224] As in Embodiment 6, in the layer configuration of Embodiment 8, some or all of the magnetic layers (the first magnetic layer, the second magnetic layer, and the third magnetic layer) to be antiferromagnetically coupled are made into multiple layers, the film thickness of each layer including the Pt layer inserted under the magnetic layer can be made thin. As in the following examples, the first Pt layer and the second Pt layer (Pt(0.25-0.6)) in
Pt(>3)/Co(0.4-0.6)/Ir(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/Ir(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/Ta or W or Mo(0.3)/CoFeB(1.0-1.4)/MgO(0.8-1.2)/CoFeB(1.0-1.4)/Ta or W or Mo(0.3)/CoFeB(1.0-1.4)/MgO(0.8-1.2)
[0225] Here, as will be described below, the first Pt layer and the second Pt layer (Pt(0.25-0.6)) in
Pt(>3)/Co(0.4-0.6)/Ir(0.4-0.6)/Pt(0.1-0.2)/Co(0.2-0.3)/Pt(0.1-0.2)/Co(0.2-0.3)/Ir(0.4-0.6)/Pt(0.1-0.2)/Co(0.2-0.3)/Pt(0.1-0.2)/Co(0.2-0.3)/Ta or W or Mo(0.3)/CoFeB(1.0-1.4)/MgO(0.8-1.2)/CoFeB(1.0-1.4)/Ta or W or Mo(0.3)/CoFeB(1.0-1.4)/MgO(0.8-1.2)
Embodiment 9
[0226]
[0227] Here, 21, 22, and 23 correspond to the first magnetic layer, the second magnetic layer, and the third magnetic layer. In addition, 31 and 32 correspond to the first non-magnetic layer and the second non-magnetic layer. In addition, 41 and 42 correspond to the first Pt layer and the second Pt layer.
[0228] As in Embodiment 6, in the layer configuration of Embodiment 9, some or all of the magnetic layers (the first magnetic layer, the second magnetic layer, and the third magnetic layer) to be antiferromagnetically coupled are made into multiple layers, the film thickness of each layer including the Pt layer inserted under the magnetic layer can be made thin. As in the following examples, the first Pt layer and the second Pt layer (Pt(0.25-0.6)) in
Pt(>3)/Co(0.4-0.6)/Ir(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/Ir(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/MgO(0.8-1.2)/Co(0.7-1.1)/Pt(0.5-0.8)/Co(0.7-1.1)/Pt(0.5-0.8)
[0229] In addition, as will be described below, the first Pt layer and the second Pt layer (Pt(0.25-0.6)) in
Pt(>3)/Co(0.4-0.6)/Ir(0.4-0.6)/Pt(0.1-0.2)/Co(0.2-0.3)/Pt(0.1-0.2)/Co(0.2-0.3)/Ir(0.4-0.6)/Pt(0.1-0.2)/Co(0.2-0.3)/Pt(0.1-0.2)/Co(0.2-0.3)/MgO(0.8-1.2)/Co(0.7-1.1)/Pt(0.5-0.8)/Co(0.7-1.1)/Pt(0.5-0.8)
Embodiment 10
[0230]
[0231] Here, 21, 22, and 23 correspond to the first magnetic layer, the second magnetic layer, and the third magnetic layer. In addition, 31 and 32 correspond to the first non-magnetic layer and the second non-magnetic layer. In addition, 41 and 42 correspond to the first Pt layer and the second Pt layer.
[0232] In Embodiment 8, in addition to the configuration of the non-magnetic layer/Pt layer/magnetic layer, the first reference layer (R1) is disposed on the side of the second barrier layer (B2) of the second fixing layer (P2), and the second barrier layer (B2) is ScC.
[0233] As in Embodiment 6, in the layer configuration of Embodiment 10, some or all of the magnetic layers (the first magnetic layer, the second magnetic layer, and the third magnetic layer) to be antiferromagnetically coupled are made into multiple layers, the film thickness of each layer including the Pt layer inserted under the magnetic layer can be made thin. As in the following examples, the first Pt layer and the second Pt layer (Pt(0.25-0.6)) in
Pt(>3)/Co(0.4-0.6)/Ir(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/Ir(0.4-0.6)/Pt(0.2-0.4)/Co(0.4-0.6)/Ta or W or Mo(0.3)/FeB(1.0-1.4)/ScC(0.8-1.2)/FeB(1.0-1.4)/Ta or W or Mo(0.3)/CoFeB(1.0-1.4)/MgO(0.8-1.2)
[0234] In addition, as will be described below, the first Pt layer and the second Pt layer (Pt(0.25-0.6)) in
Pt(>3)/Co(0.4-0.6)/Ir(0.4-0.6)/Pt(0.1-0.2)/Co(0.2-0.3)/Pt(0.1-0.2)/Co(0.2-0.3)/Ir(0.4-0.6)/Pt(0.1-0.2)/Co(0.2-0.3)Pt(0.1-0.2)/Co(0.2-0.3)/Ta or W or Mo(0.3)/FeB(1.0-1.4)/ScC(0.8-1.2)/FeB(1.0-1.4)/Ta or W or Mo(0.3)/CoFeB(1.0-1.4)/MgO(0.8-1.2)
Embodiment 11
[0235]
[0236] The magnetic memory includes a memory cell array, an X driver, a Y driver, and a controller. The memory cell array has magnetic memory cells disposed in an array. The X driver is connected to a plurality of word lines WL, and the Y driver is connected to a plurality of bit lines BL, and functions as a reading unit and a writing unit.
Embodiment 12
[0237]
[0238] In the configuration of
[0239] On the other hand, in the configuration of
Evaluation Test 1 of Embodiment 12
[0240] First, in
[0241] The magnetization curves obtained from the evaluation elements are shown in
[0242] In both the evaluation elements of
[0243] In both the evaluation elements of
[0244] Here, it could be understood that, even if annealing was performed at 400° C., Co in the magnetic layers was favorably antiferromagnetically coupled.
[0245] Based on the results of Evaluation Test 1 of Embodiment 12, it could be understood that, even if the order of the non-magnetic layer and the Pt layer laminated was reversed, perpendicular magnetic anisotropy was confirmed, and the magnetic layers were favorably antiferromagnetically coupled.
Evaluation Test 2 of Embodiment 12
[0246] Next, in the evaluation elements of
[0247] The result obtained by measuring the external magnetic field Hex obtained in the evaluation element is shown in
[0248] In
[0249] Here, it could be understood that, even if annealing was performed at 400° C., Co in the magnetic layers was favorably antiferromagnetically coupled.
[0250] Based on the results of Evaluation Test 2 of Embodiment 12, it could be understood that, even if Pt was inserted into antiferromagnetically coupled Co—Ir—Co, it was possible to maintain a strong external magnetic field.
[0251] From Embodiment 12, an example of the present invention is additionally summarized as shown in
[0252]
[0253]
[0254] In
[0255] Although not shown, similar to
[0256] Here, in the above configuration, except that the lamination order of the non-magnetic layers and Pt layer laminated adjacent to each other was reversed, a configuration, film thicknesses, materials, and the like are the same as those when the lamination order is not revered.
[0257] In addition, although not shown, the following examples can also be used as modifications.
[0258] In Embodiment 1 shown in
[0259] Similarly, in
[0260] Here, in the above configuration, except that the Pt insertion layer is inserted between the magnetic layer and the non-magnetic layer, a configuration, film thicknesses, materials, and the like are the same as those when the Pt insertion layer is not inserted.
[0261] In addition, in
[0262] Here, in the above configuration, except that the Pt insertion layer is inserted between the non-magnetic layer and the magnetic layer, a configuration, film thicknesses, materials, and the like are the same as those when the Pt insertion layer is not inserted.
REFERENCE SIGNS LIST
[0263] 21 First magnetic layer [0264] 22 Second magnetic layer [0265] 23 Third magnetic layer [0266] 24 Fourth magnetic layer [0267] 25 Fifth magnetic layer [0268] 26 Sixth magnetic layer [0269] 31 First non-magnetic layer [0270] 32 Second non-magnetic layer [0271] 33 Third non-magnetic layer [0272] 34 Fourth non-magnetic layer [0273] 35 Fifth non-magnetic layer [0274] 41 First Pt layer [0275] 42 Second Pt layer [0276] 43 Third Pt layer [0277] 44 Fourth Pt layer [0278] 45 Fifth Pt layer [0279] A1 First adjustment layer [0280] A2 Second adjustment layer [0281] B1 First barrier layer [0282] B2 Second barrier layer [0283] P1 First fixing layer [0284] P2 Second fixing layer [0285] R1 First reference layer [0286] F1 Recording layer [0287] E1 Lower electrode [0288] C1 Cap layer [0289] H1 Heavy metal layer [0290] BL1 First bit line [0291] BL2 Second bit line [0292] GND Ground line [0293] WL Word line