U.S. patent application number 15/361166 was filed with the patent office on 2017-08-17 for cmp pad conditioners with mosaic abrasive segments and associated methods.
The applicant listed for this patent is Chien-Min Sung. Invention is credited to Chien-Min Sung.
Application Number | 20170232576 15/361166 |
Document ID | / |
Family ID | 59560049 |
Filed Date | 2017-08-17 |
United States Patent
Application |
20170232576 |
Kind Code |
A1 |
Sung; Chien-Min |
August 17, 2017 |
CMP PAD CONDITIONERS WITH MOSAIC ABRASIVE SEGMENTS AND ASSOCIATED
METHODS
Abstract
A CMP pad conditioner comprises a plurality of abrasive
segments. Each abrasive segment includes a segment blank and an
abrasive layer attached to the segment blank, the abrasive layer
including a superhard abrasive material. A pad conditioner
substrate is also provided. Each of the plurality of abrasive
segments is permanently affixed to the pad conditioner substrate in
an orientation that enables removal of material from a CMP pad by
the abrasive layer as the pad conditioner and the CMP pad are moved
relative to one another.
Inventors: |
Sung; Chien-Min; (Tansui,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sung; Chien-Min |
Tansui |
|
TW |
|
|
Family ID: |
59560049 |
Appl. No.: |
15/361166 |
Filed: |
November 25, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13846740 |
Mar 18, 2013 |
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15361166 |
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12168110 |
Jul 5, 2008 |
8398466 |
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13846740 |
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11560817 |
Nov 16, 2006 |
7762872 |
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12168110 |
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60976198 |
Sep 28, 2007 |
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Current U.S.
Class: |
451/56 |
Current CPC
Class: |
B24B 53/017 20130101;
B24B 37/34 20130101; B24B 37/20 20130101 |
International
Class: |
B24B 53/017 20060101
B24B053/017; B24B 37/34 20060101 B24B037/34; B24B 37/20 20060101
B24B037/20 |
Claims
1. A CMP pad conditioner, comprising: a plurality of abrasive
segments, each abrasive segment including: a segment blank; and an
abrasive layer attached to the segment blank, the abrasive layer
including a superhard abrasive material; and a pad conditioner
substrate; each of the plurality of abrasive segments being
permanently affixed to the pad conditioner substrate in an
orientation that enables removal of material from a CMP pad by the
abrasive layer as the pad conditioner and the CMP pad are moved
relative to one another.
2. The pad conditioner of claim 1, wherein at least some of the
plurality of abrasive segments are radially distributed about a
face of the pad conditioner substrate.
3. The pad conditioner of claim 1, wherein at least two of the
plurality of abrasive segments differ in at least one of: a
geometric configuration; an abrasive layer material; and an
abrasive profile.
4. The pad conditioner of claim 1, wherein arrangement of the
abrasive segments on the face of the pad conditioner substrate
uniformly distributes drag forces across substantially each
abrasive segment.
5. The pad conditioner of claim 1, wherein a longitudinal axis of
each of the plurality of abrasive segments is aligned along a
radius of the pad conditioner substrate.
6. The pad conditioner of claim 1, wherein each of the abrasive
layers includes an abrading surface or point, and wherein the
abrading surfaces or points are leveled relative to one another
such that no abrading surface or point protrudes above another
abrading surface or point by more than about 30 microns.
7. The pad conditioner of claim 1, wherein each of the abrasive
layers includes an abrading surface or point, and wherein at least
one abrading surface or point is oriented at a greater elevation
than is an abrading surface or point of an immediately adjacent
abrasive layer.
8. The pad conditioner of claim 1, wherein the plurality of
abrasive layers are attached to the segment blanks with an organic
material layer including one or more of: amino resins, acrylate
resins, alkyd resins, polyester resins, polyamide resins, polyimide
resins, polyurethane resins, phenolic resins, phenolic/latex
resins, epoxy resins, isocyanate resins, isocyanurate resins,
polysiloxane resins, reactive vinyl resins, polyethylene resins,
polypropylene resins, polystyrene resins, phenoxy resins, perylene
resins, polysulfone resins, acrylonitrile-butadiene-styrene resins,
acrylic resins, polycarbonate resins, polyimide resins, and
mixtures thereof.
9. The pad conditioner of claim 1, wherein the abrasive layers are
attached to the segments blanks by a brazing alloy.
10. The pad conditioner of claim 1, wherein the abrasive layers
comprise PCD blades.
11. The pad conditioner of claim 1, wherein the abrasive layers
include individual abrasive grits.
12. The pad conditioner of claim 1, wherein each of the abrasive
layers includes a cutting face, and wherein each cutting face is
angled at 90 degrees or less relative to a finished surface of the
CMP pad.
13. A CMP pad conditioner, comprising: a plurality of abrasive
segments, each abrasive segment including: <a segment blank; and
an abrasive layer attached to the segment blank by a brazing alloy,
the abrasive layer including a superhard abrasive material; and a
pad conditioner substrate; each of the plurality of abrasive
segments being permanently affixed to the pad conditioner substrate
in an orientation that enables removal of material from a CMP pad
by the abrasive layer as the pad conditioner and the CMP pad are
moved relative to one another.
14. The pad conditioner of claim 13, wherein at least some of the
plurality of abrasive segments are radially distributed about a
face of the pad conditioner substrate.
15. The pad conditioner of claim 13, wherein at least two of the
plurality of abrasive segments differ in at least one of: a
geometric configuration; an abrasive layer material; and an
abrasive profile.
16. The pad conditioner of claim 13, wherein arrangement of the
abrasive segments on the face of the pad conditioner substrate
uniformly distributes drag forces across substantially each
abrasive segment.
17. The pad conditioner of claim 13, wherein a longitudinal axis of
each of the plurality of abrasive segments is aligned along a
radius of the pad conditioner substrate.
18. The pad conditioner of claim 13, wherein each of the abrasive
layers includes an abrading surface or point, and wherein the
abrading surfaces or points are leveled relative to one another
such that no abrading surface or point protrudes above another
abrading surface or point by more than about 30 microns.
19. The pad conditioner of claim 13, wherein each of the abrasive
layers includes an abrading surface or point, and wherein at least
one abrading surface or point is oriented at a greater elevation
than is an abrading surface or point of an immediately adjacent
abrasive layer.
20. A method of conditioning a CMP pad comprising: providing a pad
conditioner as recited in claim 1; and actuating the conditioner
against the pad in a manner sufficient to remove debris therefrom.
Description
PRIORITY CLAIM
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/846,740, filed on Mar. 18, 2013, which is a
continuation of U.S. patent application Ser. No. 12/168,110, filed
on Jul. 5, 2008, now issued as U.S. Pat. No. 8,398,466, which
claims the benefit of U.S. Provisional Patent Application Ser. No.
60/976,198, filed Sep. 28, 2007, and which is also a
continuation-in-part of U.S. patent application Ser. No.
11/560,817, filed Nov. 16, 2006, now issued as U.S. Pat. No.
7,762,872, each of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to CMP pad
conditioners used to remove material from (e.g., smooth, polish,
dress, etc.) CMP pads. Accordingly, the present invention involves
the fields of chemistry, physics, and materials science.
BACKGROUND OF THE INVENTION
[0003] The semiconductor industry currently spends in excess of one
billion U.S. Dollars each year manufacturing silicon wafers that
must exhibit very flat and smooth surfaces. Known techniques to
manufacture smooth and even-surfaced silicon wafers are plentiful.
The most common of these involves the process known as Chemical
Mechanical Polishing (CMP) which includes the use of a polishing
pad in combination with an abrasive slurry. Of central importance
in all CMP processes is the attainment of high performance levels
in aspects such as uniformity of polished wafer, smoothness of the
IC circuitry, removal rate for productivity, longevity of
consumables for CMP economics, etc.
SUMMARY OF THE INVENTION
[0004] In accordance with one embodiment, the present invention
provides a CMP pad conditioner, including a plurality of abrasive
segments. Each abrasive segment can include a segment blank and an
abrasive layer attached to the segment blank.
[0005] The abrasive layer can include a superhard abrasive
material. A pad conditioner substrate is also provided and each of
the plurality of abrasive segments can be permanently affixed to
the pad conditioner substrate in an orientation that enables
removal of material from a CMP pad by the abrasive layer as the pad
conditioner and the CMP pad are moved relative to one another.
[0006] In accordance with another aspect of the invention, a CMP
pad conditioner is provided, including a plurality of abrasive
segments. Each abrasive segment can include a segment blank, an
organic adhesive layer, and an abrasive layer attached to the
segment blank by the organic adhesive layer. The abrasive layer can
include a superhard abrasive material. A pad conditioner substrate
is also provided, with each of the plurality of abrasive segments
being permanently affixed to the pad conditioner substrate in an
orientation that enables removal of material from a CMP pad by the
abrasive layer as the pad conditioner and the CMP pad are moved
relative to one another.
[0007] In accordance with another aspect of the invention, a CMP
pad conditioner is provided, including a plurality of abrasive
segments. Each abrasive segment can include a segment blank and an
abrasive layer attached to the segment blank by a brazing alloy.
The abrasive layer can include a superhard abrasive material. A pad
conditioner substrate is also provided, with each of the plurality
of abrasive segments being permanently affixed to the pad
conditioner substrate in an orientation that enables removal of
material from a CMP pad by the abrasive layer as the pad
conditioner and the CMP pad are moved relative to one another.
[0008] In accordance with another aspect of the invention, a CMP
pad conditioner is provided, including a plurality of abrasive
segments. Each abrasive segment can include a segment blank and an
abrasive layer attached to the segment blank. The abrasive layer
can include a superhard abrasive blade. A pad conditioner substrate
is also provided, with each of the plurality of abrasive segments
being permanently affixed to the pad conditioner substrate in an
orientation that enables removal of material from a CMP pad by the
abrasive layer as the pad conditioner and the CMP pad are moved
relative to one another.
[0009] In accordance with another aspect of the invention, a CMP
pad conditioner is provided, including a plurality of abrasive
segments. Each abrasive segment can include a segment blank and an
abrasive layer attached to the segment blank. The abrasive layer
can include a cutting face angled at 90 degrees or less relative to
a finished surface to be applied to the CMP pad. A pad conditioner
substrate is also provided, with each of the plurality of abrasive
segments being permanently affixed to the pad conditioner substrate
in an orientation that enables removal of material from a CMP pad
by the abrasive layer as the pad conditioner and the CMP pad are
moved relative to one another.
[0010] In accordance with another aspect of the invention, a method
of forming a CMP pad conditioner is provided, including: obtaining
at least one abrasive segment, the abrasive segment including: a
segment blank; and an abrasive layer attached to the segment blank,
the abrasive layer including a superhard abrasive material. The
method can include positioning the at least one abrasive segment on
a face of a pad conditioner substrate in an orientation that
enables removal of material from a CMP pad by the abrasive layer as
the pad conditioner and the CMP pad are moved relative to one
another; and permanently affixing the at least one abrasive segment
to the pad conditioner substrate. There has thus been outlined,
rather broadly, various features of the invention so that the
detailed description thereof that follows may be better understood,
and so that the present contribution to the art may be better
appreciated. Other features of the present invention will become
clearer from the following detailed description of the invention,
taken with any accompanying or following claims, or may be learned
by the practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic, top plan view of an exemplary pad
conditioner in accordance with an embodiment of the invention;
[0012] FIG. 1A is an enlarged, perspective schematic view of an
exemplary abrasive segment that can be used in the pad conditioner
of FIG. 1;
[0013] FIG. 1B is an end, schematic view of the abrasive segment of
FIG. 1A, shown with one exemplary abrasive profile;
[0014] FIG. 1C is an end, schematic view of the abrasive segment of
FIG. 1A, shown with another exemplary abrasive profile;
[0015] FIG. 2 is a schematic, top plan view of another pad
conditioner in accordance with an embodiment of the invention;
[0016] FIG. 2A is an enlarged, perspective schematic view of an
abrasive segment of the pad conditioner of FIG. 2;
[0017] FIG. 3A is a side, schematic view of an abrasive segment
having a cutting face shown removing material from a section of a
CMP pad;
[0018] FIG. 3B is a side, schematic view of an abrasive segment
having a differently configured cutting face shown removing
material from a section of a CMP pad;
[0019] FIG. 3C is a side, schematic view of an abrasive segment
having a differently configured cutting face shown removing
material from a section of a CMP pad;
[0020] FIG. 4A is a schematic, perspective view of an abrasive
segment formed in a blade configuration in accordance with an
embodiment of the invention;
[0021] FIG. 4B is a schematic, perspective view of another abrasive
segment formed in a blade configuration in accordance with an
embodiment of the invention; and
[0022] FIG. 5 is a schematic, side view of a portion of a CMP pad
dresser having a series of abrasive segments arranged at varying
elevations relative to one another.
[0023] It will be understood that the above figures are merely for
illustrative purposes in furthering an understanding of the
invention. Further, the figures may not be drawn to scale, thus
dimensions, particle sizes, and other aspects may, and generally
are, exaggerated to make illustrations thereof clearer. For
example, an abrasive layer is illustrated in some of the figures as
including a plurality of abrasive particles: however, many of the
specific embodiments disclosed herein do not necessarily include
abrasive particles. Therefore, it will be appreciated that
departure can and likely will be made from the specific dimensions
and aspects shown in the figures in order to produce the pad
conditioners of the present invention.
DETAILED DESCRIPTION
[0024] Before the present invention is disclosed and described, it
is to be understood that this invention is not limited to the
particular structures, process steps, or materials disclosed
herein, but is extended to equivalents thereof as would be
recognized by those ordinarily skilled in the relevant arts. It
should also be understood that terminology employed herein is used
for the purpose of describing particular embodiments only and is
not intended to be limiting.
[0025] It must be noted that, as used in this specification and any
appended or following claims, the singular forms "a," "an" and
"the" include plural referents unless the context clearly dictates
otherwise. Thus, for example, reference to "an abrasive segment"
can include one or more of such segments.
Definitions
[0026] In describing and claiming the present invention, the
following terminology will be used in accordance with the
definitions set forth below.
[0027] All mesh sizes that may be referred to herein are U.S. mesh
sizes unless otherwise indicated. Further, mesh sizes are generally
understood to indicate an average mesh size of a given collection
of particles since each particle within a particular "mesh size"
may actually vary over a small distribution of sizes.
[0028] As used herein, the term "substantially" refers to the
complete or nearly complete extent or degree of an action,
characteristic, property, state, structure, item, or result. As an
arbitrary example, when two or more objects are referred to as
being spaced a "substantially" constant distance from one another,
it is understood that the two or more objects are spaced a
completely unchanging distance from one another, or so nearly an
unchanging distance from one another that a typical person would be
unable to appreciate the difference. The exact allowable degree of
deviation from absolute completeness may in some cases depend upon
the specific context. However, generally speaking the nearness of
completion will be so as to have the same overall result as if
absolute and total completion were obtained.
[0029] The use of "substantially" is equally applicable when used
in a negative connotation to refer to the complete or near complete
lack of an action, characteristic, property, state, structure,
item, or result. As an arbitrary example, a cavity that is
"substantially free of" foreign matter would either completely lack
any foreign matter, or so nearly completely lack foreign matter
that the effect would be the same as if it completely lacked
foreign matter. In other words, a cavity that is "substantially
free of" foreign matter may still actually contain minute portions
of foreign matter so long as there is no measurable effect upon the
cavity as a result thereof.
[0030] As used herein, a pad conditioner "substrate" means a
portion of a pad conditioner that supports abrasive materials, and
to which abrasive materials and/or segment blanks that carry
abrasive materials may be affixed. Substrates useful in the present
invention may of a variety of shapes, thicknesses, or materials
that are capable of supporting abrasive materials in a manner that
is sufficient to provide a pad conditioner useful for its intended
purpose. Substrates may be of a solid material, a powdered material
that becomes solid when processed, or a flexible material. Examples
of typical substrate materials include without limitation, metals,
metal alloys, ceramics, relatively hard polymers or other organic
materials, glasses, and mixtures thereof. Further, the substrate
may include a material that aids in attaching abrasive materials to
the substrate, including, without limitation, brazing alloy
material, sintering aids and the like.
[0031] As used herein, "segment blank" refers to a structure
similar in many respects to the pad conditioner substrates defined
above. Segment blanks are utilized in the present invention to
carry abrasive layers: attachment of the abrasive layers to the pad
conditioner substrates is typically achieved by way of attaching
the segment blanks to the pad conditioner substrates. It is
important to note that a variety of manners of attaching the
segment blanks to the substrates, and a variety of manners of
attaching the abrasive layers to the segment blanks, are discussed
herein. It is to be understood that all of these various attachment
mechanisms can be used interchangeably herein: that is, if a method
of attaching a segment blank to a substrate is discussed herein,
the method of attachment discussed can also be used to attach an
abrasive layer to a segment blank. For any particular CMP pad
dresser being discussed, however, it is understood that attachment
methods of the abrasive layers to the segment blanks can differ
from, or can be the same as, the method used to attach the segment
blanks to the pad conditioner substrate.
[0032] As used herein, "geometric configuration" refers to a shape
that is capable of being described in readily understood and
recognized mathematical terms. Examples of shapes qualifying as
"geometric configurations" include, without limitation, cubic
shapes, polyhedral (including regular polyhedral) shapes,
triangular shapes (including equilateral triangles, isosceles
triangles and three-dimensional triangular shapes), pyramidal
shapes, spheres, rectangles, "pie" shapes, wedge shapes, octagonal
shapes, circles, etc.
[0033] As used herein, "vapor deposition" refers to a process of
depositing materials on a substrate through the vapor phase. Vapor
deposition processes can include any process such as, but not
limited to, chemical vapor deposition (CVD) and physical vapor
deposition (PVD). A wide variety of variations of each vapor
deposition method can be performed by those skilled in the art.
Examples of vapor deposition methods include hot filament CVD,
rf-CVD, laser CVD (LCVD), metal-organic CVD (MOCVD), sputtering,
thermal evaporation PVD, ionized metal PVD (IMPVD), electron beam
PVD (EBPVD), reactive PVD, and the like.
[0034] As used herein, "abrasive profile" is to be understood to
refer to a shape, configuration, or a space defined by abrasive
materials that can be used to remove material from a CMP pad.
Examples of abrasive profiles include, without limitation,
rectangular shapes, tapering rectangular shapes, truncated wedge
shapes, wedge shapes, a "saw tooth" profile and the like. In some
embodiments, the abrasive profile exhibited by abrasive segments of
the present invention will apparent when viewed through a plane in
which the CMP pad will be oriented during removal of material from
the CMP pad.
[0035] As used herein, an "abrading surface or point" may be used
to refer to a surface, edge, face, point or peak of an abrasive
segment that contacts and removes material from a CMP pad.
Generally speaking, the abrading surface or point is the portion of
the abrasive segment that first contacts the CMP pad as the
abrasive segment and the CMP pad are brought into contact with one
another.
[0036] As used herein, "superhard" may be used to refer to any
crystalline, or polycrystalline material, or mixture of such
materials which has a Mohr's hardness of about 8 or greater. In
some aspects, the Mohr's hardness may be about 9.5 or greater. Such
materials include but are not limited to diamond, polycrystalline
diamond (PCD), cubic boron nitride (cBN), polycrystalline cubic
boron nitride (PcBN), corundum and sapphire, as well as other
superhard materials known to those skilled in the art. Superhard
materials may be incorporated into the present invention in a
variety of forms including particles, grits, films, layers, pieces,
segments, etc. In some cases, the superhard materials of the
present invention are in the form of polycrystalline superhard
materials, such as PCD and PcBN materials.
[0037] As used herein, "organic material" refers to a semisolid or
solid complex or mix of organic compounds. As such, "organic
material layer" and "organic material matrix" may be used
interchangeably, refer to a layer or mass of a semisolid or solid
complex amorphous mix of organic compounds, including resins,
polymers, gums, etc. Preferably the organic material will be a
polymer or copolymer formed from the polymerization of one or more
monomers. In some cases, such organic material may be adhesive.
[0038] As used herein, the process of "brazing" is intended to
refer to the creation of chemical bonds between the carbon atoms of
the superabrasive particles/materials and the braze material.
Further, "chemical bond" means a covalent bond, such as a carbide
or boride bond, rather than mechanical or weaker inter-atom
attractive forces. Thus, when "brazing" is used in connection with
superabrasive particles a true chemical bond is being formed.
However, when "brazing" is used in connection with metal to metal
bonding the term is used in the more traditional sense of a
metallurgical bond. Therefore, brazing of a superabrasive segment
to a tool body does not necessarily require the presence of a
carbide former.
[0039] As used herein, "particle" and "grit" may be used
interchangeably.
[0040] As used herein, an "abrasive layer" describes a variety of
structures capable of removing (e.g., cutting, polishing, scraping)
material from a CMP pad. An abrasive layer can include a mass
having several cutting points, ridges or mesas formed thereon or
therein. It is notable that such cutting points, ridges or mesas
may be from a multiplicity of protrusions or asperities included in
the mass. Furthermore, an abrasive layer can include a plurality of
individual abrasive particles that may have only one cutting point,
ridge or mesa formed thereon or therein. An abrasive layer can also
include composite masses, such as PCD pieces, segment or blanks,
either individually comprising the abrasive layer or collectively
comprising the abrasive layer.
[0041] As used herein, "metallic" includes any type of metal, metal
alloy, or mixture thereof, and specifically includes but is not
limited to steel, iron, and stainless steel.
[0042] As used herein, a plurality of items, structural elements,
compositional elements, and/or materials may be presented in a
common list for convenience. However, these lists should be
construed as though each member of the list is individually
identified as a separate and unique member. Thus, no individual
member of such list should be construed as a de facto equivalent of
any other member of the same list solely based on their
presentation in a common group without indications to the
contrary.
[0043] Concentrations, amounts, particle sizes, volumes, and other
numerical data may be expressed or presented herein in a range
format. It is to be understood that such a range format is used
merely for convenience and brevity and thus should be interpreted
flexibly to include not only the numerical values explicitly
recited as the limits of the range, but also to include all the
individual numerical values or sub-ranges encompassed within that
range as if each numerical value and sub-range is explicitly
recited.
[0044] As an illustration, a numerical range of "about 1 micrometer
to about 5 micrometers" should be interpreted to include not only
the explicitly recited values of about 1 micrometer to about 5
micrometers, but also include individual values and sub-ranges
within the indicated range. Thus, included in this numerical range
are individual values such as 2, 3, and 4 and sub-ranges such as
from 1-3, from 2-4, and from 3-5, etc. This same principle applies
to ranges reciting only one numerical value. Furthermore, such an
interpretation should apply regardless of the breadth of the range
or the characteristics being described.
The Invention
[0045] The present invention generally provides pad conditioners
and associated methods that can be utilized in conditioning (e.g.,
smoothing, polishing, dressing) or otherwise affecting a CMP pad to
remove material from the CMP pad in order to provide a finished,
smooth and/or flat surface to the pad. Pad conditioners of the
present invention can be advantageously utilized, for example, in
dressing CMP pads that are used in polishing, finishing or
otherwise affecting silicon wafers.
[0046] In the embodiment of the invention illustrated in FIG. 1, a
CMP pad conditioner 10 is provided. The pad conditioner can include
at least one abrasive segment 12a, 12b, 12c and 12d (sometimes the
varied and numerous abrasive segments discussed herein are
collectively referred to as "12x"). As best appreciated from the
example shown in FIG. 1A, each abrasive segment 12 can include a
segment blank 14 and an abrasive layer 16 attached to the segment
blank. The abrasive layer 16 can include a superhard abrasive
material: in the exemplary embodiment of FIG. 1A, the superhard
abrasive material includes a plurality of superhard particles 18. A
pad conditioner substrate 20 (FIG. 1) can also be provided. The pad
conditioner substrate can vary according to the applications for
which the pad conditioner is designed, but generally includes a
face on which the abrasive segments can be affixed to allow the pad
conditioner to be used to grind, plane, cut or otherwise remove
material from a CMP pad (not shown).
[0047] The at least one abrasive segment 12x can be permanently
fixed to the pad conditioner 20 in an orientation that enables
removal of material from the CMP pad by the abrasive layer as the
pad conditioner and the pad are moved relative to one another. For
example, in the embodiment shown in FIG. 1, the abrasive segments
12x are arranged radially along an edge of a substantially circular
pad conditioner substrate. Such an arrangement has been found well
suited to remove material from a CMP pad (while "dressing" the pad)
by rotating the pad conditioner substrate relative to the pad.
[0048] The present invention provides a number of advantages over
conventional devices. One such advantage lies in the ability to
customize methods of attachment of the abrasive layer 16 to the
segment blank 14 independently of methods of attachment of the
segment blank or blanks to the pad conditioner substrate. For
example, as various attachment methods may involve very high
temperatures and/or pressures, very demanding environmental
conditions, or simply are very labor intensive when attempted with
pad conditioners of large or complex surface areas, performing the
attachment method on distinct, easily handled segment blanks can
improve costs, efficiencies and integrities of the attachment
process. Also, leveling of the components of the abrasive layer on
each segment blank can be performed more easily when done in
discrete, relatively small lots. The resulting plurality of
abrasive segments can likewise be more easily positioned, leveled,
spaced, oriented, etc., across the face of the pad conditioner
substrate 20 after the abrasive layer is individually attached to
each of the abrasive segments.
[0049] In addition, by obtaining a plurality of abrasive segments
12x, each with an abrasive layer 16 already attached thereto, an
abrasive pattern across the face of the pad conditioner substrate
20 can be designed to optimize various conditioning procedures. For
example, the spacing between adjacent abrasive segments can be
carefully selected to aid in, or better control, the flow of
various fluids (e.g., slurry) around and through the abrasive
segments to increase the efficacy and efficiency of the material
removing process. Also, as shown in FIG. 1, segment blanks having
differing abrasive profiles (e.g., different sizes, shapes,
abrasive aggressiveness, etc.) can be used on a single substrate,
to enable customization of an abrading profile of the pad
conditioner as a whole.
[0050] As will be discussed in further detail below, not only can
the abrasive profile of each abrasive segment be customized, the
type of, or composition of, the abrasive segment can vary from one
segment 12x to another. For example, segment 12c may include a
plurality of individual abrasive grits 18 attached to the segment
blank 14 via an organic adhesive material layer 16. Segment 12a can
include a substantially continuous piece of PCD compact attached to
a segment blank via a differing attachment mechanism. Also,
relative height or elevation of abrasive segments can be varied on
any particular pad dresser. For example, the abrasive segment 12a
of FIG. 1 can be elevated slightly higher than or lower than
abrasive segment 12c of FIG. 1.
[0051] The various segment blanks 14 shown and discussed herein can
be formed from a variety of materials, including, without
limitation, metallic materials such as aluminum, copper, steel,
metal alloys, etc., ceramic materials, glasses, polymers, composite
materials, etc. Generally speaking, virtually any material to which
an abrasive segment 12x can be attached will suffice.
[0052] In some embodiments, the material of the segment blank can
be chosen to provide superior results during the process of
attaching the abrasive layer thereto. As discussed above, the
abrasive layer can be attached to the segment blank in a variety of
manners, including epoxy bonding methods (e.g., organic bonding
methods), metal brazing, sintering, electrodeposition, etc. The
material of the segment blank can be chosen based upon the
attachment process anticipated. For example, a segment blank formed
partially or fully from nickel, or stainless steel, can be utilized
in some processes involving brazing and/or sintering. Also, ceramic
or metallic materials might be utilized in organic attachment
methods.
[0053] Various embodiments of the invention employ various methods
of attachment of the abrasive layer 16 to the segment blank 14. In
one embodiment, an organic material layer can be deposited on the
segment blank, and one or more abrasive particles, chips, segments,
etc., can be fixed to the segment blank by way of the organic
material layer. Examples of suitable organic materials include,
without limitation, amino resins, acrylate resins, alkyd resins,
polyester resins, polyamide resins, polyimide resins, polyurethane
resins, phenolic resins, phenolic/latex resins, epoxy resins,
isocyanate resins, isocyanurate resins, polysiloxane resins,
reactive vinyl resins, polyethylene resins, polypropylene resins,
polystyrene resins, phenoxy resins, perylene resins, polysulfone
resins, acrylonitrile-butadiene-styrene resins, acrylic resins,
polycarbonate resins, polyimide resins, and mixtures thereof.
[0054] So-called "reverse casting" methods can be used to
accurately and controllably orient and attach the abrasive material
on the segment blank (and to orient and attach the segment blanks
to the pad conditioner substrate). Such methods can include
initially securing a superabrasive material, e.g., a plurality of
superabrasive grits, to a substrate using a "mask" material. The
portions of the particles protruding from the mask material can
then be attached to a pad conditioner substrate using the methods
discussed herein, after which (or during which), the masking
material can be removed. It has been found that these reverse
casting techniques can increase the amount of abrasive particles
(or other abrasive contact points) to as much as 10% and more of
the total amount of abrasive particles or contact points. Suitable
reverse casting methods can be found in various patents and patent
applications to the present inventor, including U.S. patent
application Ser. No. 60/992,966, filed Dec. 6, 2007; U.S. patent
application Ser. No. 11/804,221, filed May 16, 2007; and U.S.
patent application Ser. No. 11/805,549,filed May 22, 2007, each of
which is hereby incorporated herein by reference. These techniques
can be used when attaching the abrasive segments of the present
invention to pad conditioner substrate: and when attaching the
abrasive layers of the present invention to the segment blanks.
Such techniques allow very precise control of lateral placement of
the abrasive segments or abrasive layers, as well as very precise
control of relative elevation of the abrasive segments or abrasive
layers.
[0055] When an organic bonding material layer is utilized, methods
of curing the organic material layer can be a variety of processes
known to one skilled in the art that cause a phase transition in
the organic material from at least a pliable state to at least a
rigid state. Curing can occur, without limitation, by exposing the
organic material to energy in the form of heat, electromagnetic
radiation, such as ultraviolet, infrared, and microwave radiation,
particle bombardment, such as an electron beam, organic catalysts,
inorganic catalysts, or any other curing method known to one
skilled in the art.
[0056] In one aspect of the present invention, the organic material
layer may be a thermoplastic material. Thermoplastic materials can
be reversibly hardened and softened by cooling and heating
respectively. In another aspect, the organic material layer may be
a thermosetting material. Thermosetting materials cannot be
reversibly hardened and softened as with the thermoplastic
materials. In other words, once curing has occurred, the process
can be essentially irreversible, if desired.
[0057] Organic materials that may be useful in embodiments of the
present invention include, but are not limited to: amino resins
including alkylated urea-formaldehyde resins, melamine-formaldehyde
resins, and alkylated benzoguanamine-formaldehyde resins; acrylate
resins including vinyl acrylates, acrylated epoxies, acrylated
urethanes, acrylated polyesters, acrylated acrylics, acrylated
polyethers, vinyl ethers, acrylated oils, acrylated silicons, and
associated methacrylates; alkyd resins such as urethane alkyd
resins; polyester resins; polyamide resins; polyimide resins;
reactive urethane resins; polyurethane resins; phenolic resins such
as resole and novolac resins; phenolic/latex resins; epoxy resins
such as bisphenol epoxy resins; isocyanate resins; isocyanurate
resins; polysiloxane resins including alkylalkoxysilane resins;
reactive vinyl resins; resins marketed under the Bakelite.sup.TM
trade name, including polyethylene resins, polypropylene resins,
epoxy resins, phenolic resins, polystyrene resins, phenoxy resins,
perylene resins, polysulfone resins, ethylene copolymer resins,
acrylonitrile-butadiene-styrene (ABS) resins, acrylic resins, and
vinyl resins; acrylic resins; polycarbonate resins; and mixtures
and combinations thereof. In one aspect of the present invention,
the organic material may be an epoxy resin. In another aspect, the
organic material may be a polyimide resin. In yet another aspect,
the organic material may be a polyurethane resin. In yet another
aspect, the organic material may be a polyurethane resin.
[0058] Numerous additives may be included in the organic material
to facilitate its use. For example, additional crosslinking agents
and fillers may be used to improve the cured characteristics of the
organic material layer. Additionally, solvents may be utilized to
alter the characteristics of the organic material in the uncured
state. Also, a reinforcing material may be disposed within at least
a portion of the solidified organic material layer. Such
reinforcing material may function to increase the strength of the
organic material layer, and thus further improve the retention of
the individual abrasive segments. In one aspect, the reinforcing
material may include ceramics, metals, or combinations thereof.
Examples of ceramics include alumina, aluminum carbide, silica,
silicon carbide, zirconia, zirconium carbide, and mixtures
thereof.
[0059] Additionally, in one aspect a coupling agent or an
organometallic compound may be coated onto the surface of each
superabrasive material to facilitate the retention of the
superabrasive material in the organic material via chemical
bonding. A wide variety of organic and organometallic compounds is
known to those of ordinary skill in the art and may be used.
Organometallic coupling agents can form chemicals bonds between the
superabrasive materials and the organic material matrix, thus
increasing the retention of the superabrasive materials therein. In
this way, the organometallic coupling agent can serve as a bridge
to form bonds between the organic material matrix and the surface
of the superabrasive material. In one aspect of the present
invention, the organometallic coupling agent can be a titanate,
zirconate, silane, or mixture thereof.
[0060] Specific non-limiting examples of silanes suitable for use
in the present invention include: 3-glycidoxypropyltrimethoxy
silane (available from Dow Corning as Z-6040); .gamma.-methacryloxy
propyltrimethoxy silane (available from Union Carbide Chemicals
Company as A-174); .beta.-(3,4-epoxycyclohexyl)ethyltrimethoxy
silane, .gamma.-aminopropyltriethoxy silane,
N-(.beta.-aminoethyl)-.gamma.-aminopropylmethyldimethoxy silane
(available from Union Carbide, Shin-etsu Kagaku Kogyo K.K.,
etc.).
[0061] Specific non-limiting examples of titanate coupling agents
include: isopropyltriisostearoyl titanate,
di(cumylphenylate)oxyacetate titanate,
4-aminobenzenesulfonyldodecylbenzenesulfonyl titanate,
tetraoctylbis (ditridecylphosphite) titanate,
isopropyltri(N-ethylamino-ethylamino) titanate (available from
Kenrich Petrochemicals. Inc.), neoalkyoxy titanates such as
LICA-01, LICA-09, LICA-28, LICA-44 and LICA-97 (also available from
Kenrich), and the like.
[0062] Specific non-limiting examples of aluminum coupling agents
include acetoalkoxy aluminum diisopropylate (available from
Ajinomoto K.K.), and the like.
[0063] Specific non-limiting examples of zirconate coupling agents
include: neoalkoxy zirconates, LZ-01, LZ-09, LZ- 12, LZ-38, LZ-44,
LZ-97 (all available from Kenrich Petrochemicals, Inc.), and the
like. Other known organometallic coupling agents, e.g., thiolate
based compounds, can be used in the present invention and are
considered within the scope of the present invention.
[0064] The amount of organometallic coupling agent used can depend
upon the coupling agent and on the surface area of the
superabrasive material. Oftentimes, 0.05% to 10% by weight of the
organic material layer can be sufficient.
[0065] Metal brazing can also be utilized to attach the abrasive
layer 16 to the segment blank 14. Metal brazing techniques are
known in the art. For example, in fabricating a diamond saw blade,
the process can include mixing diamond particles (e.g., 40/50 U.S.
mesh saw grit) with a suitable metal support matrix (bond) powder
(e.g., cobalt powder of 1.5 micrometer in size). The mixture is
then compressed in a mold to form the right shape (e.g., a saw
segment). This "green" form of the tool can then be consolidated by
sintering at a temperature between 700-1200 degrees C. to form a
single body with a plurality of abrasive particles disposed
therein. Finally, the consolidated body can be attached (e.g., by
brazing) to a tool body; such as the round blade of a saw, to form
the final product. Many other exemplary uses of this technology are
known to those having ordinary skill in the art.
[0066] Various sintering methods can also be utilized to attach the
abrasive layer 16 to the segment blank 14. Suitable sintering
methods will be easily appreciated by one of ordinary skill in the
art having possession of this disclosure.
[0067] The abrasive layer 16 can also be attached to the segment
blank 14 by way of known electroplating and/or electrodeposition
processes. As an example (not shown in the figures) of a suitable
method for positioning and retaining abrasive materials prior to
and during the electrodeposition process, a mold can be used that
includes an insulating material that can effectively prevent the
accumulation of electrodeposited material on the molding surface.
Abrasive particles can be held on the molding surface of the mold
during electrodeposition. As such, the accumulation of
electrodeposited material can be prevented from occurring on the
particle tips and the working surface of the pad conditioner
substrate. Such techniques are described in U.S. patent application
Ser. No. 11/292,938, filed Dec. 2, 2005, which is hereby
incorporated herein by reference.
[0068] One or more apertures can extend through the insulating
material to allow for circulation of an electrolytic fluid from an
area outside the mold through the mold and to the surface of the
pad conditioner substrate in order to effect electrodeposition of
the material used to secure the abrasive particles to the pad
conditioner substrate. Such circulation can be advantageous as it
is generally necessary to keep a sufficient concentration of the
ions (not shown) in an electrolytic fluid at the location of
electrodeposition. Other well known techniques can also be
utilized, it being understood that the above-provided example is
only one of many suitable techniques.
[0069] The segment blank can similarly be attached to the pad
conditioner substrate in a variety of manners. Depending upon the
material from which the segment blank is formed, various manners of
fixing the segment blank to the pad conditioner substrate may be
utilizing. Suitable attachment methods include, without limitation,
organic binding, brazing, welding, etc.
[0070] The geometric configuration of the abrasive segment 12 can
vary. In the embodiment illustrated in FIG. 1A and 1B, the abrasive
segment includes a generally rectangular segment blank 14 with a
layer 16 of abrasive material (that can include abrasive particles
18) attached to an upper portion thereof. The size of the segment
blank can vary. In one aspect of the invention, segment size can be
adjusted to achieve uniform distribution of diamond grits about an
annular ring array. Each segment can contain up to about a thousand
diamond grits with pitch set from 3.times. to 10.times. of the
diamond size. Smaller segments can be better distributed to share
the loading during dressings.
[0071] As will be appreciated, in the embodiment of FIG. 1B, the
layer 16 of abrasive material extends partially onto (or "down")
side edges of the segment blank 14. In the embodiment of FIG. 1C,
the abrasive layer extends onto (or down) the side edges to a much
lesser degree. The modular nature of the present systems allows a
great deal of flexibility in attaching the abrasive layer 16 to the
segment blanks 14. As the segment blanks can be prepared separately
from the pad conditioner substrate, a variety of manufacturing
advantages can be realized when applying the abrasive layer to the
segment blank, without regard to the size, shape, mass, material,
etc., of the pad conditioner substrate to which the segment blanks
will eventually be attached.
[0072] While not so required, in one aspect of the invention, the
plurality of abrasive segments can each include a substantially
matching geometric configuration. In the embodiment illustrated in
FIG. 2, each of the plurality of abrasive segments 12e presents a
substantially wedge-shaped superabrasive profile (that can be
truncated, if so desired). The abrasive layer 16e can be attached
to segment blank 14e in a variety of manners, much the same as
discussed above.
[0073] The plurality of abrasive segments 12x can be radially
distributed about a face of the pad conditioner substrate 20, and
can include a substantially uniform spacing between each segment.
Also, a longitudinal axis of each of the plurality of abrasive
segments can be aligned along a radius of the pad conditioner
substrate. The abrasive segments 12e of the embodiment shown in
FIGS. 2 and 2A can be arranged across the face of the pad
conditioner substrate 20 in alternating or varying alignments: as
shown, the tapering portion of the segments can be aligned toward
or away from a center of the pad conditioner substrate in
alternating stages.
[0074] The abrasive segments arranged about the face of the
conditioner substrate can each be substantially the same in size,
shape, abrasive composition, height relative to one another, etc.
In other embodiments, the size, shape, abrasive composition, height
relative to one another, etc., can be purposefully varied, to
achieve optimal design flexibility for any particular application.
Also, each of the afore-mentioned qualities can be varied from
segment to another: e.g., alternating segments can include PCD
abrasive pieces, chips or slats, with adjacent segments including
abrasive particles.
[0075] The retention of abrasive segments 12x on the pad
conditioner substrate 20 can be improved by arranging the abrasive
segments such that mechanical stress impinging on any individual
abrasive segment is minimized. By reducing the stress impinging on
each abrasive segment they can be more readily retained in place on
the substrate, particularly for delicate tasks. Minimizing of
stress variations between segments can be accomplished by spacing
the segments evenly (or consistently) from one another, leveling to
a uniform height (relative to the face of the pad conditioner
substrate) an uppermost portion of each segment, radially aligning
the segments about the face of the pad conditioner substrate, etc.
Various other height and spacing techniques can be utilized to
obtain a desired affect.
[0076] In one embodiment of the invention, the spacing of the
abrasive segments can be adjusted to alter the contact pressure of
the contact portion (e.g., the portion of the segment that engages
and removes material from the CMP pad) of each segment. In general,
the farther the segments are spaced from one another, the higher
the contact pressure between the segment and the CMP pad. Thus, a
higher density of abrasive segments across the face of the pad
conditioner substrate can, in some cases, provide a more desirable
abrasive interface between the pad conditioner substrate and the
CMP pad. In other applications, a lower density of abrasive
segments may be beneficial. In either case, the present invention
provides a great deal of design flexibility to obtain the optimal
abrading profile.
[0077] By forming the abrasive segments in individual units having
defined geometric shapes, arrangement of the abrasive segments in a
very precise manner becomes much easier. As the defined geometric
shapes can be replicated fairly precisely from one abrasive segment
to another, the positioning of, and accordingly, the stress
impinged upon, each abrasive segment can be accomplished fairly
consistently across the face of the pad conditioner substrate in
question. With prior art abrasive grits, for example, the overall
shape and size of each a plurality of grits might change
considerably from one grit to another, making precise placement of
the grits difficult to accomplish. This problem is adequately
addressed by the advantageous features of the present
invention.
[0078] It has been found that diamond pad conditioners used
commercially normally contain about ten thousand diamond grits. Due
to the distortion of the substrate, particularly when the disk is
manufactured by a high temperature process (e.g. by brazing), and
also the distribution of grit sizes and diamond orientations, the
cutting tips are located at different heights. When they are
pressed against a polishing pad, only about 1% of the protruded
diamond can be in engagement with a pad. This can increase the
stress on the diamond cutting most deeply into the pad, and the
diamond may break and cause catastrophic scratching of the
expensive wafers.
[0079] By utilizing the present invention, the height difference of
between particles can be greatly reduced. In one aspect of the
invention, the segments are set on a flat metal (e.g. stainless
steel) mold with designed spacing in a retainer ring. Epoxy with
hardener fully mixed can be poured into the retainer ring to fill
up and cover all segments. The diamond grits on the mold can be
shielded by the penetration of the epoxy flow. After curing (with
or without heating), the retainer ring and the mold can be removed.
The diamond segments are thereby firmly embedded in the epoxy
matrix. Due to the leveling of diamond by the flat mold, the tip
height variations of the tallest diamond grits are minimized.
[0080] The mosaic disk thusly formed can be pressed against the
polishing pad with the same fixed load. Resulting tests show that
the engagement ratio can be over 50%. In other words, the number of
working crystals can be increased many times so that the disk life
can be greatly extended. In addition, due to the avoidance of deep
cutting, the polishing pad can be used with a much longer life.
Also, the dressed grooves can be made much more shallow and less
dense. The slurry retention and abrasive utility are both improved.
The CMP's cost of consumable (CoC) and cost of ownership (CoO) are
both reduced. The wafer polished is more uniform without scratching
so the die yield can be higher.
[0081] Turning now to FIGS. 3A-5, a variety of differing
embodiments of the invention are illustrated. In FIGS. 3A-3C, an
embodiment is shown which aids in addressing issues relating to
plastic deformation of a CMP pad (shown by example and in sectioned
view at 24). This embodiment reduces the downward force required
between the pad conditioner and the CMP pad. As a result, the CMP
pad is left with a conditioned surface that is much more smooth and
level than that obtained using conventional methods.
[0082] The conditioner shown in FIGS. 3A-3C can include abrasive
layer 12f (only a section of which is shown). The abrasive layer
can include a cutting face 26 angled at 90 degrees or less relative
to a finished surface to be applied to the CMP pad (e.g., relative
to movement of the cutting face away from the finished
surface--sometimes referred to as a positive cutting angle). The
face 26 of the abrasive layer 12f can be oriented such that
relative movement of the pad conditioner (in the direction
indicated at 23 in FIG. 3A) and the CMP pad 24 results in clean
removal of material from the CMP pad with the cutting face to
thereby condition the CMP pad.
[0083] By angling the cutting face 26 at 90 degrees or less,
relative to a finished surface to be applied to the pad 24, the
dressing process can cleanly shave a layer of pad material from the
pad. The resultant surface applied to the pad can be safely used in
the CMP process without damaging expensive silicon wafers. The
present pad conditioners can be used to shave even a very shallow,
thin layer of material from the pad and leave behind a clean,
smooth and even finished surface on the pad. This technique can be
used to remove thin layers of glaze that can be formed on the
surface of the CMP pad.
[0084] The cutting face 26 is shown in FIGS. 3A and 3B oriented at
an angle .alpha..sub.1 of about 90 degrees relative to the finished
surface to be applied to the CMP pad. Cutting face 26a of FIG. 3C
is oriented at angle .alpha..sub.2 that is less than 90 degrees
relative to the finished surface to be applied to the CMP pad, on
the order of about 60 degrees. The cutting faces can be oriented at
a variety of angles, and in one embodiment vary from about 45
degrees to about 90 degrees relative to the finished surface of the
CMP pad. It has been found that reducing the angle creates an even
sharper cutting interface between the cutting element and the
pad.
[0085] The abrasive layers 12f, 12f' and 12f'' of FIGS. 3A-3C can
be formed (along with their corresponding segment blank, not shown
in these figures) as elongate cutting blades. These blades can
include a significantly longer length than a width, similar to
blade of a conventional kitchen knife. In this aspect of the
invention, the blade can be used to cut, scrape or carve a
relatively wide swath of material from the PCD pad (24 in FIGS.
3A-3C). As shown by example in FIGS. 4A and 4B, the abrasive layer,
shown by example at 12f and 12f', can include either a
substantially continuous cutting edge (as shown in FIG. 4A), or a
series of cutting teeth can be formed in the blade (as shown in
FIG. 4B). Examples of ways in which such cutting teeth can be
formed are detailed in U.S. Provisional Patent Application Ser. No.
60/987,687, filed Nov. 13, 2007, which is hereby incorporated
herein by reference.
[0086] Those embodiment illustrated in the figures that include
angled cutting faces each include a cutting face that is formed
having the corresponding angle. In some embodiments, however, it is
to be understood that a relatively normal (e.g., 90 degree) cutting
face can be utilized, except that the abrasive segment on which the
cutting face is formed can be "tilted" when attached to the
substrate. In other words, the cutting face is not angled relative
to the abrasive segment, rather angling of the abrasive segment
results in angling of the cutting face. In this manner, an angled
cutting face is provided without requiring that the referenced
angle be formed on (or in) the abrasive segment.
[0087] Additional and varying abrasive segments for use in the
present invention are also contemplated. For example, use is
contemplated of the various cutting elements/abrasive segments
detailed in U.S. patent application Ser. No. 11/357,713, filed Feb.
17, 2006, which is hereby incorporated herein by reference.
[0088] In addition, formation of the abrasive layer on the segment
blanks can be accomplished by way of a variety of techniques,
including but not limited to vapor deposition techniques similar to
those outlined in U.S. patent application Ser. No. 11/512,755,
filed Aug. 29, 2006, which is hereby incorporated herein by
reference. In addition, the abrasive segments can be formed
utilizing ceramic components (as either or both the segment blank
and/or the abrasive layer); electroplating techniques, etc.
[0089] In the embodiment illustrated in FIG. 5, a series of
abrasive layers 14g, 14g' and 14g'' is provided, each of which
includes a cutting tip oriented at a different elevation. In this
aspect of the invention, the leading abrasive segment (of which
abrasive layer 14g forms a part) is generally at a relatively
higher elevation than are trailing abrasive layers 14g' and 14g'',
as the trailing layers would not otherwise contact pad material
remaining after the leading blade has passed. The abrasive segments
having abrasive layers 14g, 14g' and 14g'' can be formed in a
variety of manners and in a variety of shapes, sizes and
configurations, as detailed, for example, in U.S. Provisional
Patent Application Ser. 60/988,643, filed Nov. 16, 2007, which is
hereby incorporated herein by reference in its entirety. This
embodiment can utilize intentionally cascaded cutting elements to
achieve a desired abrading affect.
[0090] The following examples present various methods for making
the pad conditioners of the present invention. Such examples are
illustrative only, and no limitation on the present invention is to
be thereby realized.
EXMAPLES
Example 1
[0091] A pad conditioner was formed by first arranging diamond grit
(e.g. 50/60 mesh) on a stainless steel flat mold (also, a slightly
convex or contoured mold can be utilized) having a layer of
adhesive (e.g. acrylic). A hard rubber material was used to press
individual diamond grits into the adhesive while tips of the grits
were leveled by the flat mold. A mixture of epoxy and hardener was
then poured onto the grit protruding outside the adhesive (a
containment ring oriented outside the mold can retain the epoxy).
After curing, the mold was then removed and the adhesive was peeled
away. The remaining ODD contains diamond grit protruding outside a
solidified epoxy substrate. The back of the epoxy can be machined
and the disk adhered to a stainless steel (e.g. 316) plate with
fastening holes for mounting on a CMP machine.
Example 2
[0092] A pad conditioner was formed by radially arranging serrated
PCD blades. As in the previous example, the teeth of the PCD blade
were leveled with a mold that can be positioned either on the
bottom or on the top of the pad conditioner. Epoxy was then cast as
in the previous example. In the case that the mold is on the top,
the blades are pressed slightly into the slot of a substrate and
the slot is sealed by epoxy or silicone.
Example 3
[0093] A composite design married the embodiments of Example 1 and
Example 2 discussed above. This design leverages the many cutting
tips of Example 1 with the cutting efficiency of Example 2. In this
Example 3, smaller organic abrasive segments were formed by using a
fiber reinforced polymer that is generally harder than epoxy. The
organic segments were then radially arranged about a pad
conditioner substrate with the blades of Example 2 interspersed
therebetween. The cutting tips of the blades were leveled so as to
be about 20 microns higher than were the tips of the organic
abrasive segments. In this manner, the penetration depth of blade
cutting teeth is controlled, while the organic cutting teeth play a
secondary role in dressing the pad with the effect of removing
glaze and also grooving the pad.
[0094] It is to be understood that the above-described arrangements
are only illustrative of the application of the principles of the
present invention. Numerous modifications and alternative
arrangements may be devised by those skilled in the art without
departing from the spirit and scope of the present invention and
any appended or following claims are intended to cover such
modifications and arrangements. Thus, while the present invention
has been described above with particularity and detail in
connection with what is presently deemed to be the most practical
and preferred embodiments of the invention, it will be apparent to
those of ordinary skill in the art that numerous modifications,
including, but not limited to, variations in size, materials,
shape, form, function and manner of operation, assembly and use may
be made without departing from the principles and concepts set
forth herein.
* * * * *