EP0427171A2
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EP
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Magnetic thin film structures
Assignee: International Business Machines Corp
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Filing: 1990-11-05
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Granted: —
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Expires: 2010-11-05
Abstract
Abstract Magnetic thin film structures are disclosed including a laminate (10) of a layer (16) of nonmagnetic material sandwiched between first and second layers (12, 14) of magnetic material and at least one edge closure layer (18, 20) of magnetic material disposed on a side edge of the laminate with the edge closure layer being in magnetic contact with the first and second layers of magnetic material. The edge closure layer (18, 20) eliminates magnetic edge closure domains and magnetic edge-curling walls in the yoke (28) and poletip regions (30), or in a fluxguide (33) of a magnetic recording head (26) to substantially eliminate Barkhausen noise and wall network instabilities. Multiple layer laminates are also disclosed having a plurality of nonmagnetic layers each of which are sandwiched between layers of magnetic material and wherein the laminate (10) includes edge closure layers that contact all the magnetic layers. Several methods are disclosed for fabricating the laminate. In one class of technique, the side edges are deposited together with a top layer (134) in a single plating operation. In an another embodiment, the side edge closure layers are separately plated. Another embodiment provides for a layer (92) of antiferromagnetic material deposited between the nonmagnetic layer (16) and one of the magnetic layers (12, 14) to provide additional anisotropy.
Inventors
- 👤 Bernell Edwin Argyle
- 👤 Thomas Claude Arnoldussen
- 👤 Thomas Joseph Beaulieu
- 👤 Dean A. Herman, Jr.
- 👤 Sol Krongelb
- 👤 Hin Pong Edward Lee
- 👤 Daniel Andrew Nepela
- 👤 Bojan Petek
- 👤 Lubomyr Taras Romankiw
- 👤 John Casimir Slonczewski
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 19:31
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/32; H01F41/34; B; B82; B82Y; B82Y25/00; H01F10/00; H01F10/32; H01F10/324; H01F10/3268; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49034
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
68 words
A magnetic thin film structure (10) comprising: a laminate (10) of at least one nonmagnetic spacer layers (16), each of said spacer layers being sandwiched between a respective pair of magnetic layers (12, 14) a first edge closure layer of magnetic material disposed on a first side edge of said laminate, said first edge closure layer being in magnetic contact with each of said magnetic layers (12, 14).
Claim 2
Dependent Claim
68 words
A magnetic thin film structure (10) comprising: a laminate (10) of at least one nonmagnetic spacer layers (16), each of said spacer layers being sandwiched between a respective pair of magnetic layers (12, 14) a first edge closure layer of magnetic material disposed on a first side edge of said laminate, said first edge closure layer being in magnetic contact with each of said magnetic layers (12, 14).
Claim 3
Dependent Claim
50 words
The structure of claim 1 further including a second edge closure layer of magnetic material disposed on a second side edge of said laminate opposed to said first side edge, said second edge closure layer of magnetic material being in magnetic contact with each of said magnetic layers (12, 14).
Claim 4
Dependent Claim
31 words
The structure of claim 1 or 2 wherein each of said magnetic layers (12, 14) and edge closure layers (18, 20) carry a substantially identical amount of magnetic flux in saturation.
Claim 5
Dependent Claim
52 words
The structure of claims 1, 2 or 3 wherein each of said magnetic layers (12, 14) and said edge-closure (18, 20) layer(s) comprise a ferromagnetic material or especially a ferrimagnetic material wherein the ferromagnetic material is NiFe especially permolly wherein the ferrimagnetic material is a ferrite especially one of MnZn and NiZn.
Claim 6
Dependent Claim
41 words
The structure of claim 1 wherein each of said spacer layers (16) comprises an insulator or an conductor wherein the insulator is especially one of SiO₂ and Al₂O₃ wherein the conductor is especially one of NiP, Cu and a Cu alloy.
Claim 7
Dependent Claim
26 words
The structure of any one of claim 1 to 5 further including an antiferromagnetic layer (92) sandwiched between said magnetic layers separating said spacer layers (82).
Claim 8
Dependent Claim
78 words
The structure of claim 6 wherein each of said antiferromagnetic layers (92; 107) comprises an alloy of Mn and an element selected from the group consisting of Fe, Co, Cu, Ge, Ni, Pt and Rh wherein each of said magnetic layers (84, 86; 98, 100, 102, 104) and said edge-closure layer(s) (106, 108) comprise especially NiFe, each of said spacer layers (82; 94, 96) comprises especially NiP and each of said antiferromagnetic layers (92; 107) comprises especially FeMn.
Claim 9
Dependent Claim
33 words
The structure of claim 6 or 7 wherein said laminate includes opposed third and fourth side edges, said antiferromagnetic layer being spaced from at least one of said third and fourth side edges.
Claim 10
Dependent Claim
29 words
The structure of claim 6, 7, or 8 wherein said antiferromagnetic layer is spaced from at least one of said third and fourth side edges by about 1 µm.
Claim 11
Dependent Claim
22 words
The structure of any one of claim 1 to 9 wherein said structure comprises a portion of a magnetic recording head (26).
Claim 12
Dependent Claim
34 words
The structure of claim 10 wherein said structure comprises a yoke portion (28) of a magnetic recording head (26) and at least one pole tip region (30) in contact with said yoke portion (28).
Claim 13
Dependent Claim
14 words
The structure of claim 10 or 11 wherein said structure comprises a fluxguide (33).
Claim 14
Dependent Claim
32 words
The structure of claims 1, 2, 10, 11 or 12 wherein said laminate (10) comprises alternate layers of magnetic and nonmagnetic material with the number of magnetic layers being an even number.
Claim 15
Dependent Claim
49 words
The structure of claims 1, 2, 10, 11 or 12 wherein said laminate includes a top and bottom magnetic layer of a first thickness and at least one intermediate magnetic layer, each of said at least one intermediate magnetic layers being about double the thickness of said first thickness.
Claim 16
Dependent Claim
15 words
The structure of claim 14 wherein said edge closure layer is of said first thickness.
Claim 17
Independent Claim
171 words
A method of fabricating a magnetic thin film structure comprising the steps of: depositing a first layer (112) of magnetic material on a substrate (110); depositing a barrier layer (114) on said first layer (112) of magnetic material; forming a frame on said barrier layer (114) and removing exposed regions of said barrier layer thereby exposing said first layer of magnetic material; forming a laminate of alternate layers of at least one intermediate layer (120) of magnetic material and at least one layer of nonmagnetic material on said first layer of magnetic material, one layer of said at least one layer of nonmagnetic material being an upper layer of said laminate; removing said frame; and depositing a top layer (134) of magnetic material on said upper layer and at least a first edge closure layer of magnetic material on a first side edge of said laminate, said first edge closure layer being in magnetic contact with each of said at least one intermediate layer and said top layer of magnetic material.
Claim 18
Independent Claim
171 words
A method of fabricating a magnetic thin film structure comprising the steps of: depositing a first layer (112) of magnetic material on a substrate (110); depositing a barrier layer (114) on said first layer (112) of magnetic material; forming a frame on said barrier layer (114) and removing exposed regions of said barrier layer thereby exposing said first layer of magnetic material; forming a laminate of alternate layers of at least one intermediate layer (120) of magnetic material and at least one layer of nonmagnetic material on said first layer of magnetic material, one layer of said at least one layer of nonmagnetic material being an upper layer of said laminate; removing said frame; and depositing a top layer (134) of magnetic material on said upper layer and at least a first edge closure layer of magnetic material on a first side edge of said laminate, said first edge closure layer being in magnetic contact with each of said at least one intermediate layer and said top layer of magnetic material.
Claim 19
Dependent Claim
28 words
The method of claim 16 further including the steps of depositing a protective cap (140) surrounding said laminate and removing all material on said substrate outside said cap.
Claim 20
Dependent Claim
38 words
The method of claim 16 wherein said barrier layer (114) comprises an insulator or a conductor or a semiconductor wherein said insulator is especially SiO₂ wherein said conductor is especially Ti and wherein said semiconductor is especially Si.
Claim 21
Independent Claim
147 words
A method of fabricating a magnetic thin film structure comprising the steps of: depositing a first layer (144) of magnetic material on a substrate (142); forming a frame on said first layer of magnetic material; forming a laminate of alternate layers (150) of magnetic material and nonmagnetic material, said laminate including at least one layer of nonmagnetic material (158) and at least two layers of magnetic material, one layer of said at least two layers of magnetic material being an upper layer of said laminate; removing said frame; and depositing a top layer (150) of magnetic material on said upper layer and at least a first edge closure layer of magnetic material on a first side edge of said laminate, said first edge closure layer being in magnetic contact with each of said at least two layers of magnetic material and said top layer of magnetic material.
Claim 22
Independent Claim
147 words
A method of fabricating a magnetic thin film structure comprising the steps of: depositing a first layer (144) of magnetic material on a substrate (142); forming a frame on said first layer of magnetic material; forming a laminate of alternate layers (150) of magnetic material and nonmagnetic material, said laminate including at least one layer of nonmagnetic material (158) and at least two layers of magnetic material, one layer of said at least two layers of magnetic material being an upper layer of said laminate; removing said frame; and depositing a top layer (150) of magnetic material on said upper layer and at least a first edge closure layer of magnetic material on a first side edge of said laminate, said first edge closure layer being in magnetic contact with each of said at least two layers of magnetic material and said top layer of magnetic material.
Claim 23
Dependent Claim
58 words
The method of claim 16 or 19 wherein first and second edge closure layers (168, 170) of magnetic material are deposited on opposed side edges of said laminate, both of said first and second edge closure layers being in magnetic contact with said at least two layers of magnetic material and said top layer (134) of magnetic material.
Claim 24
Dependent Claim
49 words
The method of claim 19 or 20 further including the steps of: depositing a protective cap (172) surrounding said laminate (110); removing all material on said substrate (142) outside said cap; removing said cap (172); and simultaneously removing magnetic material oustide said laminate and said top magnetic layer (134).
Claim 25
Dependent Claim
31 words
The method of claim 16, 17, 19 or 20 wherein said laminate is formed by alternately plating said magnetic and nonmagnetic layers out of the same bath or of separate baths.
Claim 26
Dependent Claim
35 words
The method of claim 22 wherein said plating of said magnetic and nonmagnetic layers out of the same bath includes modulating the current density of the bath to selectively deposit said magnetic and nonmagnetic material.
Claim 27
Dependent Claim
37 words
The method of claim 22 or 23 wherein said plating of said magnetic and nonmagnetic layers out of the same bath includes modulating the current density of the bath to selectively deposit said magnetic and nonmagnetic material.
Claim 28
Independent Claim
105 words
A method of fabricating a magnetic thin film structure comprising the steps of: forming a laminate of alternate layers of magnetic material (178) and nonmagnetic material (182) on a substrate (180), said laminate including at least one layer of nonmagnetic material and at least two layers of magnetic material, one layer of said at least two layers of magnetic material being a top layer (134) of said laminate; depositing a first edge closure layer of magnetic material on a first side edge of said laminate, said first edge closure layer being in magnetic contact with each of said at least two layers of magnetic material.
Claim 29
Independent Claim
105 words
A method of fabricating a magnetic thin film structure comprising the steps of: forming a laminate of alternate layers of magnetic material (178) and nonmagnetic material (182) on a substrate (180), said laminate including at least one layer of nonmagnetic material and at least two layers of magnetic material, one layer of said at least two layers of magnetic material being a top layer (134) of said laminate; depositing a first edge closure layer of magnetic material on a first side edge of said laminate, said first edge closure layer being in magnetic contact with each of said at least two layers of magnetic material.
Claim 30
Dependent Claim
50 words
The method of claim 25 further including depositing a second edge closure layer of magnetic material on a second side edge of said laminate opposed to said first side edge, said second edge closure layer being in magnetic contact with each of said at least two layers of magnetic material.
Claim 31
Dependent Claim
44 words
The method of claim 25 or 26 wherein the step of forming a laminate further includes trimming opposed side edges of said laminate to reduce the width of said laminate to a predetermined value, said trimmed edges forming said first and second side edges.
Claim 32
Dependent Claim
43 words
The method of claim 25,26 or 27 wherein the step of depositing the first and second edge closure layers includes exposing said first and second side edges to an activating solution and subsequently plating the first and second side edges with magnetic material.
Claim 33
Dependent Claim
27 words
The method of claim 28 wherein the plating step includes immersing the laminate in an electroless bath system wherein said electroless bath contains especially Ni and Fe.
Claim 34
Independent Claim
149 words
A method of fabricating a magnetic thin film structure comprising the steps of: depositing a first layer (196) of magnetic material on a substrate (198); depositing a first masking layer having a window (202) on said first layer of magnetic material; depositing a layer (204) of nonmagnetic material on said first layer (196) through said window (202); widening the window of said first masking layer (200); depositing a second layer (210) of magnetic material on said layer (204) of nonmagnetic material through said widened window (202), said second layer extending over opposed side edges of said layer of nonmagnetic material and magnetically contacting said first layer of magnetic material; depositing a second masking layer (212) on said second layer (210) of magnetic material; and removing said first masking layer (200), said first layer (196) of magnetic material surrounding said second masking layer (212) and said second masking (212) layer.
Claim 35
Independent Claim
149 words
A method of fabricating a magnetic thin film structure comprising the steps of: depositing a first layer (196) of magnetic material on a substrate (198); depositing a first masking layer having a window (202) on said first layer of magnetic material; depositing a layer (204) of nonmagnetic material on said first layer (196) through said window (202); widening the window of said first masking layer (200); depositing a second layer (210) of magnetic material on said layer (204) of nonmagnetic material through said widened window (202), said second layer extending over opposed side edges of said layer of nonmagnetic material and magnetically contacting said first layer of magnetic material; depositing a second masking layer (212) on said second layer (210) of magnetic material; and removing said first masking layer (200), said first layer (196) of magnetic material surrounding said second masking layer (212) and said second masking (212) layer.
Claim 36
Independent Claim
175 words
A method of fabricating a magnetic thin film structure comprising the steps of: depositing a first layer (196) of magnetic material on a substrate (198); depositing a first masking layer (218) having a window (202) of a first width on said first layer of magnetic material; depositing a layer (204) of nonmagnetic material on said first layer through said window; removing the first masking layer (200) and depositing a second masking layer having a window (202) of a second width greater than said first width on said first layer; depositing a second layer (210) of magnetic material on said layer of nonmagnetic material through the window (202) in said second masking layer (212), said second magnetic layer (210) extending over opposed side edges of said layer (204) of nonmagnetic material and magnetically contacting said first layer of magnetic material; depositing a third masking layer on said second layer of magnetic material; and removing said second masking layer, removing said first layer of magnetic material surrounding said second masking layer and removing said second masking layer.
Claim 37
Independent Claim
175 words
A method of fabricating a magnetic thin film structure comprising the steps of: depositing a first layer (196) of magnetic material on a substrate (198); depositing a first masking layer (218) having a window (202) of a first width on said first layer of magnetic material; depositing a layer (204) of nonmagnetic material on said first layer through said window; removing the first masking layer (200) and depositing a second masking layer having a window (202) of a second width greater than said first width on said first layer; depositing a second layer (210) of magnetic material on said layer of nonmagnetic material through the window (202) in said second masking layer (212), said second magnetic layer (210) extending over opposed side edges of said layer (204) of nonmagnetic material and magnetically contacting said first layer of magnetic material; depositing a third masking layer on said second layer of magnetic material; and removing said second masking layer, removing said first layer of magnetic material surrounding said second masking layer and removing said second masking layer.
Claim 38
Independent Claim
133 words
A method of fabricating a magnetic thin film structure comprising the steps of: depositing a first layer (216) of magnetic material on a substrate (214); depositing a first masking layer (218) having a window (220) on said first layer of magnetic material; depositing a layer of nonmagnetic material on said first layer through said window; depositing a second layer (228) of magnetic material on said layer of nonmagnetic material through said window (220), said second magnetic layer extending over one side edge of said layer of nonmagnetic material and magnetically contacting said first layer of magnetic material; depositing a second masking layer on said second layer of magnetic material; and removing said first masking layer, removing said first layer of magnetic material surrounding said second masking layer and removing said second masking layer.
Claim 39
Independent Claim
133 words
A method of fabricating a magnetic thin film structure comprising the steps of: depositing a first layer (216) of magnetic material on a substrate (214); depositing a first masking layer (218) having a window (220) on said first layer of magnetic material; depositing a layer of nonmagnetic material on said first layer through said window; depositing a second layer (228) of magnetic material on said layer of nonmagnetic material through said window (220), said second magnetic layer extending over one side edge of said layer of nonmagnetic material and magnetically contacting said first layer of magnetic material; depositing a second masking layer on said second layer of magnetic material; and removing said first masking layer, removing said first layer of magnetic material surrounding said second masking layer and removing said second masking layer.
Claim 40
Dependent Claim
42 words
The method of claim 32 wherein the step of depositing the layer of nonmagnetic material includes placing the substrate assembly in a deposition system wherein the direction of deposition is at an angle with respect to an axis normal to the substrate.
Claim 41
Dependent Claim
25 words
The method of claim 30, 31, 32 or 33 wherein the step of depositing a first or/and second masking layer includes depositing a photoresist (200).
Claim 42
Dependent Claim
45 words
The method of claim 30, 31, 32, 33 or 34 wherein the step of depositing a second masking layer includes depositing a thin film of a refractory metal wherein said refractory metal is especially selected from the group consisting of Ti, Mo, Ta and W.
References Cited (Backward Citations)
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