U.S. patent application number 14/499510 was filed with the patent office on 2015-01-15 for perpendicular write head with laminated side shields.
The applicant listed for this patent is SEAGATE TECHNOLOGY LLC. Invention is credited to Christina Laura Hutchinson, David Christopher Seets.
Application Number | 20150014174 14/499510 |
Document ID | / |
Family ID | 45870425 |
Filed Date | 2015-01-15 |
United States Patent
Application |
20150014174 |
Kind Code |
A1 |
Hutchinson; Christina Laura ;
et al. |
January 15, 2015 |
PERPENDICULAR WRITE HEAD WITH LAMINATED SIDE SHIELDS
Abstract
A perpendicular write head, the write head having an air bearing
surface, the write head including a magnetic write pole, wherein at
the air bearing surface, the write pole has a trailing side, a
leading side that is opposite the trailing side, and first and
second sides; side gaps, wherein the side gaps are proximate the
write pole along the first and second side edges; and side shields
proximate the side gaps, wherein the side shields have gap facing
surfaces and include at least one set of alternating layers of
magnetic and non-magnetic materials, wherein only one kind of
material makes up the gap facing surfaces at the air bearing
surfaces.
Inventors: |
Hutchinson; Christina Laura;
(Eden Prairie, MN) ; Seets; David Christopher;
(Excelsior, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SEAGATE TECHNOLOGY LLC |
Cupertino |
CA |
US |
|
|
Family ID: |
45870425 |
Appl. No.: |
14/499510 |
Filed: |
September 29, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12892083 |
Sep 28, 2010 |
8848316 |
|
|
14499510 |
|
|
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|
Current U.S.
Class: |
205/136 ;
205/170 |
Current CPC
Class: |
C25D 7/00 20130101; G11B
5/1278 20130101; C25D 5/02 20130101; G11B 5/3116 20130101; C25D
5/12 20130101; G11B 5/858 20130101 |
Class at
Publication: |
205/136 ;
205/170 |
International
Class: |
G11B 5/858 20060101
G11B005/858; C25D 5/02 20060101 C25D005/02; C25D 7/00 20060101
C25D007/00 |
Claims
1-20. (canceled)
21. A method of forming laminated side shields comprising the steps
of: forming a conductive seedlayer; forming a block that
encapsulates the conductive seedlayer, the block having vertical
side walls and a top; forming a layer of magnetic material on at
least one of the vertical side walls of the block by
electroplating; and forming a layer of non-magnetic material on the
layer of magnetic material by electroplating.
22. The method according to claim 21, wherein the conductive
seedlayer is formed on or within a substrate.
23. The method according to claim 22, wherein the substrate is
configured to allow electrical connection to the conductive
seedlayer.
24. The method according to claim 23, wherein the conductive
seedlayer is grounded to the substrate.
25. The method according to claim 23, wherein the conductive
seedlayer is formed in electrical contact with a conductive
non-plating trace.
26. The method according to claim 21, wherein the conductive
seedlayer comprises Ru, NiFe, NiP, or combinations thereof.
27. The method according to claim 25, wherein the conductive
non-plating trace comprises chromium or tantalum.
28. The method according to claim 21, wherein the block comprises a
conductive material.
29. The method according to claim 28, wherein the conductive
material comprises NIP, NIFe, Cu, or combinations thereof.
30. The method according to claim 21, wherein the block is formed
by depositing photoresist material; etching at least part of the
photoresist material to leave an area clear of photoresist
material; electroplating the block in the area clear of photoresist
material.
31. The method according to claim 21, wherein the block is formed
by depositing block material and etching some of the block material
away to form the block.
32. The method according to claim 21, wherein the layers of
magnetic material and non-magnetic material independently have
thicknesses, and each of the thicknesses can be controlled by
controlling a time in a plating bath, a plating current of a
plating bath, components of the plating baths, or combinations
thereof.
33. The method according to claim 21 further comprising forming
subsequent layers of magnetic and non-magnetic materials by
subsequent electroplating steps.
34. The method according to claim 21 further comprising patterning
the block before plating the layer of mangiest material.
35. A method of forming laminated side shields comprising the steps
of: forming a conductive seedlayer within or on a substrate,
wherein the substrate is configured to allow electrical connection
to the conductive seedlayer; forming a block that encapsulates the
conductive seedlayer, the block having vertical side walls and a
top; forming a layer of magnetic material on at least one of the
vertical side walls of the block by electroplating; and forming a
layer of non-magnetic material on the layer of magnetic material by
electroplating.
36. The method according to claim 35, wherein the block is formed
by depositing photoresist material; etching at least part of the
photoresist material to leave an area clear of photoresist
material; electroplating the block in the area clear of photoresist
material.
37. The method according to claim 35, wherein the block is formed
by depositing block material and etching some of the block material
away to form the block.
38. The method according to claim 35, wherein the layers of
magnetic material and non-magnetic material independently have
thicknesses, and each of the thicknesses can be controlled by
controlling a time in a plating bath, a plating current of a
plating bath, components of the plating baths, or combinations
thereof.
39. The method according to claim 35 further comprising forming
subsequent layers of magnetic and non-magnetic materials by
subsequent electroplating steps.
40. A method of forming laminated side shields comprising the steps
of: forming a conductive seedlayer within or on a substrate,
wherein the substrate is configured to allow electrical connection
to the conductive seedlayer; forming a block that encapsulates the
conductive seedlayer, the block having vertical side walls and a
top; delivering a current to the conductive seedlayer; forming a
layer of magnetic material on at least one of the vertical side
walls of the block by electroplating; and forming a layer of
non-magnetic material on the layer of magnetic material by
electroplating.
Description
BACKGROUND
[0001] Perpendicular magnetic recording, where the recorded data
(or bits) are stored in an out of plane, or perpendicular
orientation in the recording layer is one possible path towards
reaching ultra high recording densities in hard disk drives. In
order to reach the high recording densities, different methods of
shielding the perpendicular writer paddle and pole may likely have
to be uncovered. Side shields, may cause erasure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] FIGS. 1A and 1B are schematic views of a portion of
perpendicular write heads according to an embodiment;
[0003] FIG. 1C is a plan view of a perpendicular write head
according to an embodiment that depicts only a single kind of
material in contact with the side gap at the ABS;
[0004] FIG. 1D is a view of a portion of a write head from the ABS
that does not have only a single kind of material in contact with
the side gap at the ABS;
[0005] FIGS. 2A-2C are a plan view of a perpendicular write head
according to an embodiment before the air bearing surface (ABS) has
been defined (FIG. 2A), a view of a perpendicular write head
according to an embodiment from the ABS (FIG. 2B), and a cross
section view of a perpendicular write head according to an
embodiment (FIG. 2C);
[0006] FIGS. 3A-3D are a plan view of a perpendicular write head
according to an embodiment before the air bearing surface (ABS) has
been defined (FIG. 3A), a view of a perpendicular write head
according to an embodiment from the ABS (FIG. 3B), a cross section
view of a perpendicular write head according to an embodiment (FIG.
3C), and a plan view of a perpendicular write head according to an
embodiment before the air bearing surface has been defined (FIG.
3D);
[0007] FIGS. 4A-4D are a plan view of a perpendicular write head
according to an embodiment before the air bearing surface (ABS) has
been defined (FIG. 4A), a view of a perpendicular write head
according to an embodiment from the ABS (FIG. 4B), a cross section
view of a perpendicular write head according to an embodiment (FIG.
4C); and a plan view of a perpendicular write head according to an
embodiment that includes a leading and trailing shield (FIG.
4D);
[0008] FIGS. 5A-5C are a plan view of a perpendicular write head
according to an embodiment before the air bearing surface (ABS) has
been defined (FIG. 5A), a view of a perpendicular write head
according to an embodiment from the ABS (FIG. 5B), and a cross
section view of a perpendicular write head according to an
embodiment (FIG. 5C);
[0009] FIGS. 6A-6D depict a method of forming side shields
according to an embodiment;
[0010] FIGS.7A-7C depict a method of forming a block with
electroplating according to an embodiment;
[0011] FIGS. 8A-8D depict a method of forming a block with
deposition of block material according to an embodiment;
[0012] FIG. 9 is a tunneling electron microscope (TEM) image of
alternating magnetic and non-magnetic layers formed using a method
according to an embodiment; and
[0013] FIGS. 10A-10B are scanning electron microscope (SEM) images
of a top down view of a write pole (FIG. 10A), and a top down view
of a write pole with patterned laminated shields (FIG. 10B)
according to an embodiment.
[0014] The figures are not necessarily to scale. Like numbers used
in the figures refer to like components. However, it will be
understood that the use of a number to refer to a component in a
given figure is not intended to limit the component in another
figure labeled with the same number.
DETAILED DESCRIPTION
[0015] In the following description, reference is made to the
accompanying set of drawings that form a part hereof and in which
are shown by way of illustration several specific embodiments. It
is to be understood that other embodiments are contemplated and may
be made without departing from the scope or spirit of the present
disclosure. The following detailed description, therefore, is not
to be taken in a limiting sense.
[0016] Unless otherwise indicated, all numbers expressing feature
sizes, amounts, and physical properties used in the specification
and claims are to be understood as being modified in all instances
by the term "about." Accordingly, unless indicated to the contrary,
the numerical parameters set forth in the foregoing specification
and attached claims are approximations that can vary depending upon
the properties sought to be obtained by those skilled in the art
utilizing the teachings disclosed herein.
[0017] The recitation of numerical ranges by endpoints includes all
numbers subsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2,
2.75, 3, 3.80, 4, and 5) and any range within that range.
[0018] As used in this specification and the appended claims, the
singular forms "a", "an", and "the" encompass embodiments having
plural referents, unless the content clearly dictates otherwise. As
used in this specification and the appended claims, the term "or"
is generally employed in its sense including "and/or" unless the
content clearly dictates otherwise.
[0019] "Include," "including," or like terms means encompassing but
not limited to, that is, including and not exclusive.
[0020] Disclosed herein are apparatuses and devices, for example
perpendicular write heads. Generally, perpendicular write heads may
be utilized to write data, or bits (or bytes) to magnetic recording
media. Disclosed perpendicular write heads can also be part of a
larger device that can include other components, for example a
reader for reading the magnetic recording media. In embodiments,
the larger device can be referred to as a slider.
[0021] FIG. 1A schematically depicts a disclosed perpendicular
write head 100. The perpendicular write head 100, which may also be
referred to herein as simply a write head, is shown from the air
bearing surface (ABS). This view can also be described as the view
as seen from the magnetic recording media. This write head 100 may
include a magnetic write pole 110. The write pole 110, along with
other components (such as a write coil and a return pole which are
not shown herein) may function to induce a magnetic field from the
write pole that passes through at least a portion of the magnetic
recording media and back to the return pole. Although not required,
the write pole 110 may have a trapezoidal shape as depicted in FIG.
1A.
[0022] The write pole 110 has four sides. The four sides of the
write pole 110 can generally be identified based on the direction
which the magnetic recording media moves past the write pole when
in use. The usual direction of movement of the magnetic recording
media with respect to the write head is shown by the arrow in FIG.
1A. Based on this direction of movement, the write pole has a
leading edge 104, which is the first to reach the magnetic
recording media and a trailing edge 102, which is directly opposed
to the leading edge 104. The write pole 110 also has a first side
106 and a second side 108 which are generally the third and fourth
sides of the write pole 110.
[0023] Proximate (or adjacent or directly adjacent) to the write
pole 110 on the first and second sides 106 and 108 are first and
second side gaps 120a and 120b. The first and second side gaps 120a
and 120b are generally made of non-magnetic material. Proximate (or
adjacent or directly adjacent) to the first and second side gaps
120a and 120b are first and second side shields 130a and 130b.
[0024] The side shields in a write head may comprise both magnetic
and non-magnetic material. In embodiments, the side shields may
comprise alternating layers of magnetic and non-magnetic materials.
A side shield may comprise at least one set of alternating layers
of magnetic and non-magnetic materials. One set of alternating
layers, as that phrase is utilized herein, generally refers to one
magnetic layer and one non-magnetic layer. A side shield may
comprise a plurality of alternating layers, two or more sets of
alternating layers, more than five sets of alternating layers, or
from five to fifty sets of alternating layers.
[0025] The layers of the side shield may be laminated in different
directions. For example, the alternating layers of the side shields
may be laminated parallel to the ABS (which is shown in FIG. 1C),
at a skewed angle to the ABS, or along the write pole
(perpendicular to the ABS). Some of these types of side shields are
depicted in the more specific figures that follow. These
differently laminated side shields are similar in that only a
single kind of material is in contact with the side gaps at the
ABS. This can be seen in FIG. 1C, where it can be seen that only a
magnetic layer 135a of the first side shield 130a is in contact
with the side gap 120a at the ABS. This may be contrasted with the
case where more than one kind of material is in contact with the
side gaps at the ABS. This is depicted in FIG. 1D, where it can be
seen that material from three magnetic layers (stippled layers) and
four non-magnetic layers (non-stippled layers) of the side shield
193a are in contact with the side gap 192a at the ABS.
[0026] It should be noted that "a single kind of material being in
contact with the side gaps at the ABS" may be considered met in the
instance where one kind of material was meant to be in contact with
the side gaps at the ABS, and except for manufacturing variation,
only one kind of material would be in contact with the side gaps at
the ABS. Each of the side shields 130a and 130b have gap facing
surfaces 131a and 131b, which are identified in FIG. 1A. Side
shields have gap facing surfaces 131a and 131b that are made of a
single kind of material. In embodiments, side shields have gap
facing surfaces 131a and 131b that are made of a single kind of
material, either magnetic or non-magnetic. In embodiments, side
shields have gap facing surfaces 131a and 131b that are made of
magnetic material.
[0027] Generally, the magnetic and non-magnetic layers have
thicknesses on the nanometer scale. Generally, the layers may be as
thin as possible. Generally, the layers may have thicknesses from 1
nanometers (nm) to 100 nm, from 1 nm to 50 nm, from 1 nm to 15 nm,
from 1 nm to 10 nm, or from 3 nm to 8 nm.
[0028] Layers of materials in side shields may, but need not have
the same thicknesses throughout the side shields. Magnetic layers
may have different thicknesses than non-magnetic layers, a first
magnetic layer may have a different thickness than a second (or
subsequent) magnetic layer, a first non-magnetic layer may have a
different thickness than a second (or subsequent) non-magnetic
layer, or some combination thereof. In embodiments, a layer or
layers more proximate the side gap may have a different thickness
than other layer or layers in the side shield. In embodiments, a
layer at the gap facing surface may be thicker than other layers in
the side shields. In embodiments, layers closer to the ABS may be
thicker than layers farther away from the ABS. In embodiments, a
magnetic layer at the gap facing surface may be thicker than other
magnetic layers in the side shields.
[0029] In embodiments, at least one of the magnetic layers may be
at least as thick as or thicker than at least one of the
non-magnetic layers (or at least one of the non-magnetic layers may
be thinner than or as thin as at least one of the magnetic layers).
In embodiments, each individual magnetic layer may be at least as
thick as or thicker than each individual non-magnetic layer (or
each individual non-magnetic layer may be thinner or as thin as
each individual magnetic layers). In embodiments, the ratio of the
thickness of each individual magnetic layer to the thickness of
each individual non-magnetic layer is from 1:1 to 20:1. In
embodiments, the ratio of the thickness of each individual magnetic
layer to the thickness of each individual non-magnetic layer is
from 1:1 to 10:1. In embodiments, the ratio of the thickness of
each individual magnetic layer to the thickness of each individual
non-magnetic layer is from 3:1 to 10:1.
[0030] Generally, the magnetic material may be a material that has
soft magnetic properties. Types of materials that can be used may
include, for example, FeCo, CoNiFe, NiFe, FeCoX, CoNiFeX, NiFeX
where X is a transition metal, and similar materials. In
embodiments, the magnetic layers can be made of FeCo. Types of
non-magnetic materials may include, for example, NiP, NiCu, NiRh,
NiPd, NiV, and similar materials. In embodiments, the non-magnetic
layers can be made of NiP. In embodiments, the magnetic layers can
be made of FeCo and the non-magnetic layers can be made of NiP. The
materials utilized may also be engineered via the addition of other
materials to enhance various properties, including for example
saturation induction (Bs), magnetic anisotropy (Hk), and
resistivity.
[0031] All of the non-magnetic layers in disclosed side shields
may, but need not be made of the same non-magnetic material.
Similarly, the magnetic layers in disclosed side shields may, but
need not be made of the same magnetic material. In embodiments, a
side shield may include magnetic layers of more than one type of
materials. For example, a non-magnetic layer could be between a
magnetic layer of FeCo and a magnetic layer of NiFe. Alternatively,
a laminated structure having a periodic structure could be
utilized, an example of such a structure could include: high
magnetic saturation material/non-magnetic material/low magnetic
saturation material/non-magnetic material/high magnetic saturation
material/non-magnetic material/low magnetic saturation material,
etc. Such an embodiment could look similar to other embodiments
except that every other magnetic layer would be made of a less
magnetic material.
[0032] Disclosed write heads may also include other shields besides
the first and second side shields. FIG. 1B depicts a disclosed
write head 101 that includes the components discussed above (which
are numbered similarly) as well as a trailing shield 150 proximate
the gap at the trailing edge 102 of the write pole 110; and a
leading shield 140 proximate the gap at the leading edge 104 of the
write pole 110. Embodiments of write poles disclosed herein can
include a trailing shield, or a leading shield, or both trailing
and leading shields. In embodiments, disclosed write heads can
include a trailing shield. In embodiments, disclosed write heads
may include a trailing shield and a leading shield.
[0033] Laminated shields (for example side shields 130a and 130b)
can generally function to minimize or eliminate proximal and distal
erasure from the side shields. This is thought to be caused by
magnetic charges adjacent to the write pole and the side shield
acting as a lower reluctance short for the writer flux to the
media. The disclosed laminated side shields can alleviate or
completely mitigate these issues. Because the magnetic layers are
thin (on the nm scale), the material grain size can be reduced,
which can thereby optimize the magnetic properties of the
materials.
[0034] FIGS. 2A-2C depict an embodiment of a write head. FIG. 2A is
a plan view of a write head before the ABS has been defined. FIG.
2B is a view from the ABS. FIG. 2C is a cross section view taken at
C-C in FIG. 2A. In this embodiment, the magnetic and non-magnetic
materials of the side shields are generally laminated parallel to
the ABS. Stated another way, going away from the ABS through the
side shield the side shield is made of alternating layers of
magnetic and non-magnetic material; or the magnetic and
non-magnetic layers are stacked on each other traveling away from
the ABS. This can be seen in FIG. 2A, where the first side shield
230a is made of alternating magnetic layers 231a, 233a, 235a, and
237a; and non-magnetic layers 232a, 234a, 236a, and 238a. The
second side shield 230b, although not numbered similarly, has the
same alternating layers.
[0035] The non-magnetic layers can generally function to close the
flux paths from the edges or corners of the magnetic layers. The
laminated layers of non-magnetic layers can provide edge curling
domains that mitigate the edge charges of the magnetic layers. The
reluctance of a thin film can be much larger perpendicular to the
film than it is in the plane of the film. Therefore, a high
reluctance for the side shield flux leakage to the media can be
obtained through the lamination of the magnetic and non-magnetic
layers. The effect of the magnetic and non-magnetic layers is
illustrated in the second side shield 230b, where the location of
the non-magnetic layers function to cap the leakage from one
magnetic layer to another by one having a positive magnetic field
at the write gap and the subsequent layer having a negative
magnetic field at the write gap, thereby decreasing or eliminating
the overall leakage.
[0036] FIG. 2B shows the disclosed write head from the ABS. The
view in FIG. 2B makes it appear as if the side shields 230a and
230b are made of a single kind of material. Proceeding into the
side shield shown in FIG. 2B (i.e., proceeding into the paper),
would eventually allow contact of a second layer, which would be
the first non-magnetic layer seen in FIG. 2A. FIG. 2B shows that
only one kind of material, a magnetic material is present proximate
the gaps 220a and 220b, or more specifically at the gap facing
surfaces of the side shields 230a and 230b. FIG. 2C shows a cross
sectional view of the write head seen in FIG. 2A taken at line C-C
in FIG. 2A.
[0037] FIGS. 3A-3C depict another embodiment of a disclosed write
head. FIG. 3A is a plan view of a write head before the ABS has
been defined. FIG. 3B is a view from the ABS. FIG. 3C is a cross
section view taken at C-C in FIG. 3A. The components in FIGS. 3A-3C
are numbered similarly to FIGS. 2A- 2C.
[0038] In this embodiment, the magnetic and non-magnetic materials
of the side shields are laminated at an angle with respect to the
ABS. The side shields in this embodiment may also be described as
having an axis upon which the magnetic and non-magnetic layers are
stacked, and that axis (which can be referred to as a layer axis)
intersects the ABS at an angle that is not 90.degree. (i.e, they
are not stacked perpendicularly to the ABS as they were in the
FIGS. 2A-2C embodiment). This angle is shown in FIG. 3A, as
.alpha.. In embodiments, the layer axis of the first and second
side shields .alpha. may be equal. In embodiments, the layer axis
of the first and second side shields .alpha. may be from 0.degree.
to 180.degree.. In embodiments, the layer axis of the first and
second side shields .alpha. may be less than 90.degree.. In
embodiments, the layer axis of the first and second side shields
.alpha. may be equal and be from 0.degree. to 45.degree.. In
embodiments, the layer axis of the first and second side shields
.alpha. may be equal and be from 10.degree. to 20.degree.. The
layer axis may be skewed towards or away from the block. The
embodiment depicted in FIG. 3D has the laminated layers skewed
towards the block 305 instead of away from the block (as they were
in FIG. 3A).
[0039] An embodiment such as that depicted in FIGS. 3A-3C can
further increase the reluctance of the flux leakage to the media.
As can be seen in FIG. 3B, this particular configuration of side
shields also has only one kind of material, a magnetic material
present proximate the gaps 320a and 320b, or more specifically at
the gap facing surfaces of the side shields 330a and 330b.
[0040] FIGS. 4A-4C depict another embodiment of a disclosed write
head. FIG. 4A is a plan view of a write head before the ABS has
been defined. FIG. 4B is a view from the ABS. FIG. 4C is a cross
section view taken at C-C in FIG. 4A. The components in FIGS. 4A-4C
are numbered similarly to FIGS. 2A-2C.
[0041] In this embodiment, the magnetic and non-magnetic layers are
laminated perpendicular to the ABS and parallel to the write pole
surface, but still have only a single kind of material proximate
the gaps 420a and 420b, or more specifically at the gap facing
surfaces of the side shields 430a and 430b. The configuration of
the magnetic and non-magnetic layers in this embodiment can be
described as being stacked away from the surface of the write
pole.
[0042] An embodiment such as that depicted in FIGS. 4A-4C may
provide shielding of the writer flux and also provide a high
reluctance of the write pole flux to minimize write field loss. An
embodiment that includes trailing and lead shields that are a
single body 450 can be seen in FIG. 4D. In such an embodiment,
inclusion of optional trailing and leading shields 450, located
beyond the trailing gap 451 and leading gap 452 may provide a flux
return path away from the side shields.
[0043] FIGS. 5A-5C depict another embodiment of a disclosed write
head. FIG. 5A is a plan view of a write head before the ABS has
been defined. FIG. 5B is a view from the ABS. FIG. 5C is a cross
section view taken at C-C in FIG. 5A. The components in FIGS. 5A-5C
are numbered similarly to FIGS. 2A-2C.
[0044] In this embodiment, the magnetic and non-magnetic layers are
non-planar, at least partially follow the periphery of the write
pole, and are nested. The layers can be described as nested because
one layer fits entirely within the subsequent layer. More
specifically, the layer that contacts the gap facing surfaces, in
embodiments, a magnetic layer can completely house the subsequent
layer, in embodiments a non-magnetic layer.
[0045] Disclosed side shields may be fabricated using commonly
utilized techniques. Alternatively, disclosed side shields can be
fabricated using disclosed methods that include electroplating.
Such methods may include forming a conductive seedlayer; forming a
block that encapsulates the conductive seedlayer; forming a layer
of magnetic material on at least one vertical side wall of the
block by electroplating and forming a layer of non-magnetic
material on the layer of magnetic material by electroplating.
[0046] First, form a conductive seedlayer. The conductive seedlayer
is a material that is electrically conductive and will allow
material to plate out of an electrochemical plating bath. Materials
that can be utilized for the conductive seedlayer may include, for
example, Ru, NiFe, NiP, or similar materials. In embodiments, the
conductive seedlayer can be made from Ru. The conductive seedlayer
is configured within a substrate (for example a wafer) to allow
electrical connection to deliver a current to the conductive
seedlayer. In embodiments, the conductive seedlayer can simply be
grounded to the substrate (not shown). FIG. 6A illustrates another
method of configuring the conductive seedlayer within a substrate.
The conductive seedlayer 605 may be in contact with a conductive
non-plating trace 610 that affords electrical connection 608. In
this particular example, the conductive seedlayer 605 and the
conductive non-plating trace 610 may be formed on a wafer 615. The
conductive non-plating trace 610 may be made of chromium (Cr) or
tantalum (Ta), for example.
[0047] The next step includes forming a block that encapsulates the
conductive seedlayer. By encapsulating the conductive seedlayer,
the block can be used to form vertical laminations of magnetic and
non-magnetic material by electroplating. The block generally has
vertical sidewalls and a top. The block can generally be made of
conductive materials. Materials that may be utilized for the block
may include, for example, NiP, NiFe, Cu. In embodiments, the block
can be made from NiFe. The block 620 is depicted in FIG. 6B along
with the other components depicted in FIG. 6A. Because the
conductive seedlayer is encapsulated and the electroplated metal
will grow isotropically from the edge of the conductive seedlayer,
the material will electroplate horizontally the same distance that
it will plate vertically.
[0048] The block can be formed in numerous ways. One disclosed
process of forming the block is schematically depicted in FIGS.
7A-7C. It generally includes utilizing photoresist material and
electroplating the block. The photoresist material can be deposited
on the substrate 715 and etched forming a photoresist negative 760,
having an area above the conductive seed layer 705 clear of
photoresist material (see FIG. 7A). This article can then be placed
in an electroplating bath from which the block will plate. The
block material will be electrodeposited in the area that is clear
of photoresist material, thereby forming the block 720 (see FIG.
7B). Assuming that the photoresist material was not in contact with
the conductive seedlayer, the block will then encapsulate the
conductive seedlayer. The photoresist material can then be removed
leaving only the block (see FIG. 7C).
[0049] Another process of forming the block is schematically
depicted in FIGS. 8A-8D. It generally includes depositing the block
material (a conductive material) and etching away the unwanted
portions using a photoresist mask. The block material 821 may be
deposited on the substrate 815 to completely encapsulate the
conductive seedlayer 805 (seen in FIG. 8A). Photoresist mask 822 is
then deposited on a portion of the block material 821 that is to
remain to form the final block. The photoresist mask 822 may cover
enough of the block material 821 so that the block may ultimately
extend beyond the conductive seedlayer 805 (seen in FIG. 8B). The
excess block material is then etched away using the photoresist
mask 822 to protect the covered portion of the block material 821
(seen in FIG. 8C). The photoresist mask 822 is then removed leaving
the block 820 that covers the conductive seedlayer 805 (seen in
FIG. 8D). This method of forming a block may be more useful in
situations where the block is to be less than 500 nm thick.
[0050] Next, in disclosed methods, a layer of magnetic material may
be formed on at least one of the vertical side walls of the block
by electroplating. This can be accomplished by placing the block
(along with the other components on the substrate that are depicted
in FIG. 6B) in an electroplating bath. The components in the
plating bath can depend in part on the material being plated and
the particular parameters of plating. Once the pre-determined
thickness of the layer has been reached, the block can be removed
from the plating bath. The pre-determined thickness of the layers
can be controlled by the time in the plating bath, the plating
current, the components of the electroplating bath, or a
combination thereof. FIG. 6C depicts the article after a first
magnetic layer 625 has been plated on the block.
[0051] Next, in disclosed methods a non-magnetic layer of material
may be formed on at least a portion of the magnetic layer by
electroplating. This can be accomplished by placing the block
(along with the other components on the substrate that are depicted
in FIG. 6C) in a second electroplating bath. It should be noted
that the second plating bath can be a different bath or the same
bath with a different plating solution. The components in the
second plating bath can depend in part on the material being plated
and the particular parameters of plating. Once the pre-determined
thickness of the layer has been reached, the block can be removed
from the second plating bath. The pre-determined thickness of the
layers can be controlled by time in the second plating bath, the
plating current, the components of the second electroplating bath,
or a combination thereof. FIG. 6D depicts the article after a first
non-magnetic layer 630 has been plated on the magnetic layer
625.
[0052] The method may also include placing the block in
electroplating baths in order to form subsequent magnetic and
non-magnetic layers. Forming layers of magnetic and non-magnetic
materials may be repeated a plurality of times until the
pre-determined number of alternating layers are obtained. Disclosed
methods may also optionally include patterning the block before
plating if the lamination plated width is important to the design
or to prevent some features from plating. Disclosed methods may
also optionally include removing laminations along the top surface
of the block. Etching methods, such as chemical mechanical
polishing (CMP) may be used to retain only vertical laminations.
Disclosed methods may also be followed, preceded, or both by
further processing that may be desired to fabricate a perpendicular
write head.
[0053] FIG. 9 is a tunneling electron microscopy (TEM) image of
four magnetic layers 921a, 923a, 925a, and 927a (more specifically
CoFe layers) and three non-magnetic layers 922a, 924a, and 926a
(more specifically NiP) that were formed using a disclosed
method.
[0054] FIG. 10A shows a scanning electron microscopy (SEM) image of
a top down view of a write pole with vertically laminated side
shields as disclosed herein. The image in FIG. 10A shows the write
pole 1010, the ABS, and the layers 1020 in the side shields. FIGS.
10B and 10C show scanning electron microscopy (SEM) images of a top
down view (FIG. 10B) of a write pole with patterned vertically
laminated side shields as disclosed herein.
[0055] Thus, embodiments of PERPENDICULAR WRITE HEAD WITH LAMINATED
SIDE SHIELDS are disclosed. The implementations described above and
other implementations are within the scope of the following claims.
One skilled in the art will appreciate that the present disclosure
can be practiced with embodiments other than those disclosed. The
disclosed embodiments are presented for purposes of illustration
and not limitation.
* * * * *