U.S. patent application number 12/162184 was filed with the patent office on 2009-02-26 for chemical mechanical polishing pad and method for manufacturing same.
This patent application is currently assigned to JSR CORPORATION. Invention is credited to Yukio Hosaka, Shoei Tsuji.
Application Number | 20090053983 12/162184 |
Document ID | / |
Family ID | 38309314 |
Filed Date | 2009-02-26 |
United States Patent
Application |
20090053983 |
Kind Code |
A1 |
Hosaka; Yukio ; et
al. |
February 26, 2009 |
CHEMICAL MECHANICAL POLISHING PAD AND METHOD FOR MANUFACTURING
SAME
Abstract
There is provided a chemical mechanical polishing pad which has
a circular polishing surface and a non-polishing surface that is
the back side of the polishing surface and incorporates an
information recording medium that is readable or readable/writable
by an electromagnetic wave in a noncontact manner and in which the
position of the center of gravity of the information recording
medium in the radial direction of the polishing surface is
preferably within a range of 0 to 10% or 80 to 100% of the radius
of the polishing surface in the direction from the center on the
radius of the polishing surface toward the periphery of the
polishing surface.
Inventors: |
Hosaka; Yukio; (Tokyo,
JP) ; Tsuji; Shoei; (Tokyo, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
JSR CORPORATION
Chuo-ku, Tokyo
JP
|
Family ID: |
38309314 |
Appl. No.: |
12/162184 |
Filed: |
January 22, 2007 |
PCT Filed: |
January 22, 2007 |
PCT NO: |
PCT/JP2007/051315 |
371 Date: |
July 25, 2008 |
Current U.S.
Class: |
451/527 ; 51/293;
51/296; 51/298; 51/299 |
Current CPC
Class: |
B24D 18/00 20130101;
B24B 37/20 20130101; H01L 21/67294 20130101 |
Class at
Publication: |
451/527 ; 51/293;
51/299; 51/298; 51/296 |
International
Class: |
B24D 11/00 20060101
B24D011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 25, 2006 |
JP |
2006-015944 |
Claims
1. A chemical mechanical polishing pad having a circular polishing
surface and a non-polishing surface which is the back side of the
polishing surface and incorporating an information recording medium
which is readable or readable/writable by an electromagnetic wave
in a noncontact manner.
2. The chemical mechanical polishing pad of claim 1, wherein the
position of the center of gravity of the information recording
medium in the radial direction of the polishing surface is within a
range of 0 to 10%- or 80 to 100% of the radius of the polishing
surface in the direction from the center on the radius of the
polishing surface toward the periphery of the polishing
surface.
3. The chemical mechanical polishing pad of claim 1, wherein the
position of the center of gravity of the information recording
medium in the thickness direction of the pad is within a range of
50 to 100% of the thickness of the pad in the direction from the
polishing surface toward the non-polishing surface.
4. The chemical mechanical polishing pad of claim 1, wherein the
non-polishing surface has a hollow, and a part or all of the shape
of the information recording medium projected onto the
non-polishing surface is within the range of the hollow.
5. A method for producing the chemical mechanical polishing pad of
claim 1, comprising the following steps: (A1) a step of preparing a
composition for the chemical mechanical polishing pad, (A2) a step
of molding a rough pad form from the composition, the rough pad
form having a surface that is to be a circular polishing surface
and a surface that is to be a non-polishing surface which is the
back side of the polishing surface, the rough pad form having an
opening where an information recording medium is to be placed, on
the surface that is to be the non-polishing surface of the pad,
(A3) a step of placing the information recording medium in the
opening and filling the remaining space in the opening with the
composition for the chemical mechanical polishing pad, and (A4) a
step of heating the rough pad form to a temperature of 150 to
180.degree. C. under a pressure of 1 to 20 MPa.
6. A method for producing the chemical mechanical polishing pad of
claim 1, comprising the following steps: (B1) a step of preparing a
composition for the chemical mechanical polishing pad, (B2) a step
of molding a rough pad form from the composition, the rough pad
form having a surface that is to be a circular polishing surface
and a surface that is to be a non-polishing surface which is the
back side of the polishing surface, the rough pad form having an
opening where an information recording medium is to be placed, on
the surface that is to be the non-polishing surface of the pad, and
(B3) a step of attaching the information recording medium to the
opening.
7. The method of claim 5 or 6, wherein the composition for the
chemical mechanical polishing pad comprises (a) at least one
selected from the group consisting of a thermoplastic resin, an
elastomer, rubber and a curable resin and (b) water-soluble
particles.
8. The method of claim 5 or 6, wherein the composition for the
chemical mechanical polishing pad comprises (1) a polyol, (2) a
polyisocyanate and (3) a foaming agent.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a chemical mechanical
polishing pad and a method for producing the same.
BACKGROUND ART
[0002] In formation of a semiconductor device, chemical mechanical
polishing (generally abbreviated as "CMP") has been widely employed
as a polishing method by which a surface having excellent flatness
can be formed on a silicon substrate or a silicon substrate having
wires, electrodes and other components formed thereon (hereinafter,
these silicon substrates may be collectively referred to as
"semiconductor wafers"). About this chemical mechanical polishing,
it is known that the result of polishing is greatly affected by the
characteristics and properties of chemical mechanical polishing
pad, and a variety of chemical mechanical polishing pads have
heretofore been proposed.
[0003] JP-A Nos. 11-70463 and 8-216029 propose a chemical
mechanical polishing method which uses a polyurethane foam
containing a number of fine holes as a chemical mechanical
polishing pad and carries out polishing with an aqueous dispersion
for chemical mechanical polishing kept in the holes (hereinafter
also referred to as "pores") opened on the surface of the pad.
[0004] Further, JP-A Nos. 8-500622 and 2000-34416 propose a
polishing pad having a water-soluble polymer dispersed in a matrix
resin. In this polishing pad, the water-soluble polymer dissolves
or swells by contacting an aqueous dispersion for chemical
mechanical polishing at the time of polishing and thereby detaches
from the pad, and the resulting spaces have a function of retaining
the aqueous dispersion for chemical mechanical polishing.
[0005] Meanwhile, in the case of chemical mechanical polishing
pads, there are cases where one needs to know information specific
to the polishing pads, such as model numbers, production numbers,
production records, actual measurement values of the actual sizes
and physical properties of the products (i.e. individual
characteristics of individual products within allowable error
ranges of product characteristics specified by the model numbers)
and usage records, for the purpose of managements of manufacturing,
delivery, distribution and maintenance.
[0006] As a method of attaching the specific information to
individual products, it has been practiced to print a bar code
directly on a packaging material for the chemical mechanical
polishing pad or attach a sticker having the bar code printed
thereon to the packaging material. However, the amount of
information that can be held in the bar code is limited, and there
is also a problem that it is complicated to manage correspondence
between a chemical mechanical polishing pad and a bar code attached
on a packaging material after the packaging material is opened once
and the chemical mechanical polishing pad has started to be used.
Accordingly, there is a growing demand for implantation of an
information recording medium (generally referred to as "IC tag",
"electronic tag", "RFID (Radio Frequency IDentification)" or the
like) which is readable or readable/writable by an electromagnetic
wave in a noncontact manner.
[0007] However, in the chemical mechanical polishing pad whose
characteristics and properties greatly affect the result of
polishing, the presence of the information recording medium which
is a foreign object on the front or rear face of the pad or inside
the pad has an undesirable effect on polishing performance. For
example, it causes poor uniformity of polished surface, and
scratches and erosion which degrade surface flatness occur.
Further, unavoidable distortion of the pad itself which occurs when
the pad is attached to a polishing apparatus may damage the
information recording medium itself.
[0008] Due to technical progress in recent years, a reduction in
the size of such an information recording medium has been promoted.
However, since there is a limitation of frequencies which are easy
to use in a chemical mechanical polishing process with respect to
the electromagnetic wave to be used for reading or reading/writing,
an antenna which should be provided in the information recording
medium must have at least a given size, and a reduction in size of
the information recording medium to be embedded in the chemical
mechanical polishing pad is limited. Consequently, it is conceived
that the problem of degradation in the polishing performance of a
pad having the information recording medium embedded therein cannot
be solved by a reduction in the size of the medium.
DISCLOSURE OF THE INVENTION
[0009] The present invention has been conceived in view of the
above circumstances. An object of the present invention is to
provide a chemical mechanical polishing pad that has an information
recording medium which is readable or readable/writable by an
electromagnetic wave in a noncontact manner and exerts excellent
polishing performance, i.e. achieves excellent uniformity and
surface flatness of polished surface by inhibiting the occurrence
of scratches and erosion, and a production method of the chemical
mechanical polishing pad.
[0010] According to the present invention, firstly, the above
object of the present invention is achieved by a chemical
mechanical polishing pad having a circular polishing surface and a
non-polishing surface which is the back side of the polishing
surface and incorporating an information recording medium which is
readable or readable/writable by an electromagnetic wave in a
noncontact manner.
[0011] Secondly, the above object of the present invention is
achieved by a method for producing the above chemical mechanical
polishing pad, comprising the following steps:
(A1) a step of preparing a composition for the chemical mechanical
polishing pad, (A2) a step of molding a rough pad form from the
composition, the rough pad form having an opening where an
information recording medium is to be placed, on the surface that
is to be the non-polishing surface of the pad, (A3) a step of
placing the information recording medium in the opening and filling
the remaining space in the opening with the composition for the
chemical mechanical polishing pad, and (A4) a step of heating the
rough pad form to a temperature of 150 to 180.degree. C. under a
pressure of 1 to 20 MPa.
[0012] Thirdly, the above object of the present invention is
achieved by a method for producing the above chemical mechanical
polishing pad, comprising the following steps:
(B1) a step of preparing a composition for the chemical mechanical
polishing pad, (B2) a step of molding a rough pad form from the
composition, the rough pad form having an opening where an
information recording medium is to be placed, on the surface that
is to be the non-polishing surface of the pad, and (B3) a step of
attaching the information recording medium to the opening.
BEST MODE FOR CARRYING OUT THE INVENTION
[0013] The chemical mechanical polishing pad of the present
invention has a circular polishing surface and a non-polishing
surface which is the back side of the polishing surface. The pad of
the present invention preferably has a disk shape (right
cylindrical shape) or a shape based on the disk shape. The present
pad may have a side face which defines the polishing surface and
the non-polishing surface or may have no distinct side face and
have gradually decreased thickness in the most peripheral area of
the pad.
[0014] The polishing pad of the present invention has a diameter of
the polishing surface of preferably 150 to 1,200 mm, more
preferably 500 to 800 mm and has a thickness of preferably 1.0 to
5.0 mm, more preferably 1.5 to 3.0 mm.
[0015] The chemical mechanical polishing pad of the present
invention may have a groove or other hollow of any shape on the
polishing surface. Illustrative examples of the shape of the groove
include concentric grooves, a spiral groove, lattice-shaped
grooves, radial grooves, and grooves resulting from combining any
of these grooves. The shape of a cross section in the width
direction, i.e. normal direction of the groove is not particularly
limited. For example, the cross section may have a polygonal shape
formed by flat side faces and, in some cases, the flat bottom
surface, or a horseshoe shape. The shape of the cross section may
be bilaterally axisymmetric or non-axisymmetric. Illustrative
examples of the shape of the above other hollow include a circular
hollow and a polygonal hollow. It is to be understood that in the
above circular hollow and polygonal hollow, its inside surrounded
by the circle or the polygon is also hollow.
[0016] The chemical mechanical polishing pad of the present
invention may have a groove or other hollow of any shape on the
non-polishing surface. By the presence of such a groove or other
hollow, the occurrence of scratches on an object to be polished can
be further suppressed. The shape of the groove or other hollow
which may be formed on the non-polishing surface is the same as the
shape of the above groove or other hollow which may be formed on
the polishing surface.
[0017] It is preferred that the groove or other hollow on the
non-polishing surface do not reach the periphery of the pad.
[0018] The above other hollow (especially a circular hollow or
polygonal hollow) which may be formed on the non-polishing surface
is preferably positioned in the center of the non-polishing
surface. The phrase "positioned in the center" not only indicates
that these hollows are positioned in the center of the
non-polishing surface in a mathematically strict sense but also
indicates that the center of the non-polishing surface of the pad
is positioned within the range of the above hollow. When the shape
of the hollow on the non-polishing surface is circular, the upper
limit of its diameter is preferably 100%, more preferably 75%, much
more preferably 50% of the maximum diameter of an object to be
polished (for instance, the diameter of a disk-shaped semiconductor
wafer when the object to be polished is the wafer). When the shape
of the hollow on the non-polishing surface is circular, the lower
limit of its diameter is preferably 2 mm, more preferably 10 mm,
regardless of the size of the object to be polished. For example,
when the diameter of the wafer which is the object to be polished
is 300 mm, the diameter when the hollow on the non-polishing
surface is circular is preferably 2 to 300 mm, more preferably 10
to 225 mm, much more preferably 10 to 150 mm. Further, when the
diameter of the wafer which is the object to be polished is 200 mm,
the diameter when the hollow on the non-polishing surface is
circular is preferably 2 to 200 mm, more preferably 10 to 150 mm,
much more preferably 10 to 100 mm.
[0019] The chemical mechanical polishing pad of the present
invention may have a translucent area which optically leads from
the non-polishing surface to the polishing surface. When the pad
has such a translucent area, the end point of polishing can be
optically detected, when the pad is attached to a chemical
mechanical polishing apparatus having an optical polishing end
point detector and used. The planar shape of the translucent area
is not particularly limited, and the shape of the periphery of the
area may be circular, oval, sectoral or polygonal. The position of
the translucent area should match the position of the optical
polishing end point detector provided in the chemical mechanical
polishing apparatus to which the chemical mechanical polishing pad
of the present invention is attached. The present pad may have one
or more translucent areas. When the present pad has a plurality of
translucent areas, their arrangement is not particularly limited,
as long as the above positional relationship is satisfied. A method
of forming the translucent area is not particularly limited. For
example, the translucent area may be formed by a method comprising
constituting the area to have translucency on the pad by a member
having translucency, or when the pad comprises a material having a
certain degree of translucency, the translucent area may be formed
by a method comprising forming a hollow in a portion corresponding
to the area to have translucency on the pad to thin the portion so
as to secure translucency required to detect the end point of
polishing. When the latter method is used, the hollow of the
translucent area can also serve as the aforementioned hollow for
suppressing the occurrence of scratches.
[0020] An information recording medium (hereinafter referred to as
"IC tag") which is used in the present invention, i.e. an
information recording medium which is readable or readable/writable
by an electromagnetic wave in a noncontact manner comprises at
least an IC chip (Integrated Circuit Chip) and an antenna.
[0021] The above IC chip comprises at least an information storage
device (memory) and a radio circuit. The information storage device
may be a read-only memory (ROM) or a readable/writable memory
(RAM). The IC chip may further comprise a CPU (Central Processing
Unit) and the like as required. The radio circuit is preferably
communicatable in the long frequency (LF) band, very high frequency
(VHF) band, ultra high frequency (UHF) band, quasi microwave band
or microwave band. When information is read or read/written during
the chemical mechanical polishing process which is carried out by
use of the chemical mechanical polishing pad of the present
invention, this radio circuit is preferably communicatable in the
long frequency band or very high frequency band.
[0022] The IC tag used in the present invention may be an active
type having a battery or a passive type having no battery.
[0023] To the IC tag, various measurement devices may be connected.
Illustrative examples of the measurement devices include a
thermometer and a pressure sensor.
[0024] The IC tag may be of any shape. However, since it must be
able to house an antenna required to receive and transmit an
electromagnetic wave for reading or writing in a non-contact manner
and must have a shape and size which allow the IC tag to fit within
the range of the thickness of the chemical mechanical polishing pad
of the present invention, the IC tag is preferably in the shape of
a card. The planar shape of the card may be circular, oval or
polygonal. Illustrative examples of the polygonal shape include a
triangle, square, rectangle and rhombus. The concept of "polygonal"
as used herein includes shapes having rounded corners.
[0025] The size of the IC tag is not particularly limited. For
example, when the IC tag is in the shape of a square card, a side
of the square is preferably 10 to 300 mm, more preferably 10 to 50
mm. The thickness is preferably 0.1 to 4.0 mm, more preferably 0.2
to 2.5 mm.
[0026] When the IC tag is in the shape of a rectangular card, its
longer side is preferably 10 to 300 mm, more preferably 10 to 200
mm. Its shorter side is preferably 3 to 200 mm, more preferably 3
to 150 mm. The preferable thickness of the IC tag in the shape of a
rectangular card is the same as that of the IC tag in the shape of
a square card.
[0027] The chemical mechanical polishing pad of the present
invention comprises such an IC tag as described above. Although the
position of the center of gravity of the IC tag in the radial
direction of the polishing surface is not particularly limited, it
is preferably present in a range of 0 to 10% or 80 to 100% of the
radius of the polishing surface in the direction from the center on
the radius of the polishing surface toward the periphery of the
polishing surface. The "center of gravity of the IC tag" as used
herein is center of gravity in a geometrical sense, not in a
dynamic sense (same will apply to the following description). When
the IC tag is in the shape of a card, the thickness direction of
the IC tag is preferably parallel to the thickness direction of the
pad.
[0028] When the chemical mechanical polishing pad of the present
invention has a translucent area, all of the shape of the IC tag
projected onto the non-polishing surface is preferably outside of
the translucent area.
[0029] When the chemical mechanical polishing pad of the present
invention has a hollow on its non-polishing surface (except for a
case when the hollow also serves as the translucent area), a part
or all of the shape of the IC tag projected onto the non-polishing
surface is preferably within the range of the hollow. More
preferably, all of the shape is within the range of the hollow.
Much more preferably, the pad has a circular or polygonal hollow in
the center of the non-polishing pad, and a part or all of the shape
of the IC tag projected onto the non-polishing surface is within
the range of the hollow. Particularly preferably, all of the shape
is within the range of the hollow. When all of the shape of the IC
tag projected onto the non-polishing surface is within the range of
the hollow, the shape and size of the IC tag projected onto the
non-polishing surface may match the shape and size of the hollow.
Preferably, the hollow includes the shape and size of the IC tag
projected onto the non-polishing surface and is larger than the
size of the IC tag projected onto the non-polishing surface.
[0030] The position of the center of gravity of the IC tag in the
thickness direction of the chemical mechanical polishing pad of the
present invention is preferably within a range of 50 to 100% of the
thickness of the pad in the direction from the polishing surface
toward the non-polishing surface. That is, when a line AC which
extends from a point A on the polishing surface to a point C on the
non-polishing surface through the center of gravity B of the IC tag
is assumed, the position of the center of gravity B of the IC tag
is preferably within a range of 50 to 100% of the distance between
the point A and the point C. This value is more preferably 70 to
100%, much more preferably 80 to 100%.
[0031] When a part or all of the shape of the IC tag projected onto
the non-polishing surface is within the range of the hollow formed
on the non-polishing surface, the depth of the hollow is preferably
0.1 to 3.0 mm, more preferably 0.2 to 2.0 mm.
[0032] Further, it is preferable that all of the IC tag be included
inside the chemical mechanical polishing pad of the present
invention and any part thereof be not exposed to the outside of the
pad.
[0033] When the IC tag included in the chemical mechanical
polishing pad of the present invention is positioned at such a
position as described above, the present pad is less likely to
impair the uniformity and surface flatness of polished surface upon
chemical mechanical polishing and can provide a high-quality
polished surface, and breakage of the IC tag during handling of the
pad, e.g. attachment of the pad to a polishing apparatus, can also
be prevented.
[0034] The above chemical mechanical polishing pad of the present
invention can be produced by a proper method such as the following
production method A or production method B.
[0035] The production method A comprises the following steps:
(A1) a step of preparing a composition for a chemical mechanical
polishing pad, (A2) a step of molding a rough pad form from the
composition, the rough pad form having a surface that is to be a
circular polishing surface and a surface that is to be a
non-polishing surface which is the back side of the polishing
surface, the rough pad form having an opening where an IC tag is to
be placed, on the surface that is to be the non-polishing surface
of the pad, (A3) a step of placing the IC tag in the opening and
filling the remaining space in the opening with the composition for
a chemical mechanical polishing pad, and (A4) a step of heating the
rough pad form to a temperature of 150 to 180.degree. C. under a
pressure of 1 to 20 MPa.
[0036] The production method B comprises the following steps:
(B1) a step of preparing a composition for a chemical mechanical
polishing pad, (B2) a step of molding a rough pad form from the
composition, the rough pad form having a surface that is to be a
circular polishing surface and a surface that is to be a
non-polishing surface which is the back side of the polishing
surface, the rough pad form having an opening where an IC tag is to
be placed, on the surface that is to be the non-polishing surface
of the pad, and (B3) a step of attaching the IC tag to the
opening.
[0037] Hereinafter, each of the steps in each of the above
production methods will be described in detail.
Production Method A
(A1) Step of Preparing Composition for Chemical Mechanical
Polishing Pad
[0038] Illustrative examples of the composition for a chemical
mechanical polishing pad include a composition for a chemical
mechanical polishing pad comprising (a) at least one selected from
the group consisting of a thermoplastic resin, an elastomer, rubber
and a curable resin and (b) water-soluble particles (hereinafter
may be referred to as "first composition") and a composition for a
chemical mechanical polishing pad comprising (1) a polyol, (2) a
polyisocyanate and (3) a foaming agent (hereinafter may be referred
to as "second composition").
[0039] Illustrative examples of thermoplastic resins which can be
used as the component (a) in the first composition include
1,2-polybutadiene resins; polyolefin resins such as polyethylene;
polystyrene resins; polyacrylic resins such as (meth)acrylic
resins; vinylester resins (excluding polyacrylic resins); polyester
resins; polyamide resins; fluorine resins such as polyvinylidene
fluoride; polycarbonate resins; and polyacetal resins.
[0040] Illustrative examples of the elastomer include diene
elastomers such as 1,2-polybutadiene; polyolefin elastomers (TPO);
styrene-based elastomers such as a styrene-butadiene-styrene block
copolymer (SBS) and a hydrogenated block copolymer thereof (SEBS);
thermoplastic elastomers such as thermoplastic polyurethane
elastomers (TPU), thermoplastic polyester elastomers (TPEE) and
polyamide elastomers (TPAE); silicone resin elastomers; and
fluorine resin elastomers.
[0041] Illustrative examples of the rubber include conjugated diene
rubbers such as butadiene rubbers (high-cis butadiene rubber,
low-cis butadiene rubber, and the like), isoprene rubber,
styrene-butadiene rubber, and styrene-isoprene rubber; nitrile
rubbers such as acrylonitrile-butadiene rubber; acrylic rubbers;
ethylene-.alpha.-olefin rubbers such as ethylene-propylene rubber
and ethylene-propylene-diene rubber; and other rubbers such as
butyl rubber, silicone rubber and fluorine-containing rubber.
[0042] The curable resin may be either a thermosetting resin or a
light curable resin. Illustrative examples thereof include urethane
resins, epoxy resins, acrylic resins, unsaturated polyester resins,
polyurethane-urea resins, urea resins, silicon resins, phenolic
resins, and vinylester resins.
[0043] The above component (a) may be partially or wholly modified
with an acid anhydride group, carboxyl group, hydroxyl group, epoxy
group, amino group or the like.
[0044] Of those described above, the rubber, curable resin,
thermoplastic resin or elastomer is preferably used as the
component (a). The thermoplastic resin or elastomer is more
preferred, and 1,2-polybutadiene is particularly preferred. The
component (a) may be a partially crosslinked polymer. Crosslinking
can be carried out by, for example, chemical crosslinking using an
organic peroxide, sulfur, a sulfur compound or the like or
radiation crosslinking involving electron irradiation.
[0045] Illustrative examples of a material which constitutes the
water-soluble particles (b) in the first composition include sugars
(e.g. polysaccharides such as starch, dextrin and cyclodextrin,
lactose, mannitol), celluloses (e.g. hydroxypropylcellulose and
methylcellulose), proteins, polyvinyl alcohol, polyvinyl
pyrrolidone, polyacrylic acid, polyethylene oxide, water-soluble
photosensitive resins, sulfonated polyisoprene, and sulfonated
polyisoprene copolymers. Illustrative examples of a material for
inorganic water-soluble particles include potassium sulfate,
potassium nitrate, potassium carbonate, potassium bicarbonate,
potassium chloride, potassium bromide, potassium phosphate, and
magnesium nitrate. The above materials for these water-soluble
particles may be used alone or in combination of two or more.
Further, the water-soluble particles may be water-soluble particles
comprising a predetermined material or two or more water-soluble
particles comprising different materials.
[0046] The water-soluble particles are preferably such that they
dissolve in water only when exposed to the surface layer in the
polishing pad and do not absorb water and swell inside the
polishing pad. To this end, the water-soluble particle may have an
outer shell for inhibiting moisture absorption at least in a
portion of the outermost part thereof. This outer shell may be
physically adsorbed to and/or chemically bonded to the
water-soluble particle. Illustrative examples of a material which
constitutes such an outer shell include an epoxy resin, polyimide,
polyamide and polysilicate. In this case, the water-soluble
particles may comprise water-soluble particles having the outer
shell and water-soluble particles having no outer shell, and the
above effect can be attained to a sufficient extent even if the
entire surface of the water-soluble particle having the outer shell
is not covered with the outer shell.
[0047] The average particle diameter of the water-soluble particles
is preferably 0.1 to 500 .mu.m, more preferably 0.5 to 100 .mu.m.
The size of pores is preferably 0.1 to 500 .mu.m, more preferably
0.5 to 100 .mu.m. When the average particle diameter of the
water-soluble particles is less than 0.1 .mu.m, the size of the
pores formed becomes smaller than that of abrasive grains used, so
that a polishing pad which can retain slurry sufficiently becomes
liable to be difficult to obtain. Meanwhile, when the average
particle diameter is larger than 500 .mu.m, the size of the pores
formed becomes so large that the mechanical strength and polishing
rate of the polishing pad obtained are liable to deteriorate.
[0048] The content of the water-soluble particles (b) is preferably
2 to 90% by volume, more preferably 2 to 606 by volume, much more
preferably 2 to 40% by volume, when the total of the component (a)
and the water-soluble particles (b) is 100% by volume. With the
content of the water-soluble particles (b) within the above range,
a good balance can be achieved between the polishing rate of the
polishing pad obtained and the proper hardness and mechanical
strength thereof.
[0049] The first composition can further comprise (c) a
crosslinking agent. Illustrative examples of the crosslinking agent
(c) include an organic peroxide, sulfur, and a sulfur compound. Of
these, the organic peroxide is preferably used. Illustrative
example of the organic peroxide include dicumyl peroxide, diethyl
peroxide, di-t-butyl peroxide, diacetyl peroxide and diacyl
peroxide. The crosslinking agent is used in an amount of preferably
0.01 to 5.0 parts by weight, more preferably 0.2 to 4.0 parts by
weight, based on 100 parts by weight of crosslinkable polymers used
as the component (a). When the crosslinking agent (c) is used in
the above amount, a polishing pad which produces few scratches in a
chemical mechanical polishing process and has a high polishing rate
can be obtained.
[0050] Illustrative examples of the polyol (1) in the second
composition include a polyhydric alcohol, polyether polyol, and
polyester polyol. Specific examples of the above polyhydric alcohol
include ethylene glycol, diethylene glycol, propylene glycol,
dipropylene glycol, glycerin, trimethylolpropane, diethanolamine,
triethanolamine, and pentaerythritol. The above polyester polyol
can be suitably produced by reacting a polycarboxylic acid or a
derivative thereof with a polyhydroxyl compound.
[0051] Illustrative examples of the polyisocyanate (2) include
2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate, and
polyphenyl polymethylene polyisocyanate. These polyisocyanates may
partially or wholly contain a carboimide group, urethane group,
isocyanurate group or the like. The polyisocyanate (2) is used in
an amount of preferably 0.9 to 1.4 equivalents, more preferably
0.95 to 1.3 equivalents, in terms of the amount of isocyanate
groups per equivalent of hydroxyl groups contained in the polyol
(1).
[0052] Illustrative examples of the foaming agent (3) include water
and freon. The foaming agent (3) is used in an amount of preferably
4 to 10 parts by weight based on 100 parts by weight of the polyol
(1).
[0053] The second composition can further comprise (4) a catalyst,
in addition to the above components. Illustrative examples of the
catalyst (4) include an amine compound and an organometallic
compound. Specific examples of the amine compound include
triethylene diamine, triethylamine, tetramethyl
hexamethylenediamine, pentamethyl diethylenetriamine, and dimethyl
cyclohexylamine. Specific examples of the organometallic compound
include stannous chloride, and dibutyltin laurate. The catalyst (4)
is used in an amount of preferably not larger than 1 part by
weight, more preferably 0.05 to 1 part by weight, much more
preferably 0.05 to 0.5 parts by weight, based on 100 parts by
weight of the polyol (1).
[0054] The second composition may also comprise a foaming adjuster,
other resins, a flame retardant, a surfactant or the like, in
addition to the above components.
[0055] A method for preparing the above composition for a chemical
mechanical polishing pad is not particularly limited. For example,
the composition can be obtained by kneading the predetermined
materials in a mixing device or the like. Illustrative examples of
the mixing device include a roll, kneader, Banbury mixer, and
extruder (single-screw or multi-screw).
[0056] When the composition for a chemical mechanical polishing pad
is the first composition, the water-soluble particles are
preferably solid at the time of kneading. By kneading the component
(a) with the water-soluble particles (b) which have been classified
to fall within the above preferred average particle diameter range
in advance under conditions where the water-soluble particles (b)
are solid, the water-soluble particles (b) can be dispersed with
the above preferred average particle diameter, regardless of the
degree of compatibility between the water-soluble particles (b) and
the component (a). Therefore, according to the processing
temperature of the component (a) used, water-soluble particles (b)
having a melting point higher than the processing temperature are
preferably selected.
(A2) Step of Molding Rough Pad Form Having Surface that is to be
Circular Polishing Surface and Surface that is to Be Non-Polishing
Surface which is the Back Side of the Polishing Surface and Having
Opening Where IC Tag is to be Placed on the Surface that is to be
the Non-Polishing Surface of the Pad, from the Composition
[0057] To mold a rough pad form from the above composition for a
chemical mechanical polishing pad, a method comprising molding the
rough pad form by use of a mold having a shape that corresponds to
a desired rough pad form or a method comprising molding the
composition into a sheet and punching a desired rough form out of
the sheet can be employed, for example. The opening where an IC tag
is to be placed can be formed on the surface that is to be the
non-polishing surface of the pad by use of a mold having a
projection which corresponds to the opening or by a method
comprising molding the shape having no opening and then forming the
opening by cutting, in the case of the above molding method.
Meanwhile, when the method involving sheet molding is employed, the
opening may be formed by cutting after the shape is punched
out.
[0058] The shape and size of the opening on the surface that is to
be the non-polishing surface may match the shape and size of the IC
tag projected onto the non-polishing surface when the IC tag is
used in the pad. However, they may not necessarily have to match
each other. The opening may be of any shape and size, as long as
the IC tag to be used can be housed in the opening in the direction
in which the IC tag is to be used in the next step (A3). However,
it is preferable that the shape of the opening be nearly the same
as the shape of the IC tag projected onto the non-polishing surface
when the IC tag is used in the pad and that the size in the radial
direction and size in the tangential direction of the pad be about
0.1 to 5.0 mm larger than the IC tag.
[0059] When the chemical mechanical polishing pad of the present
invention has a hollow on its non-polishing surface, all of the
shape of the IC tag projected onto the non-polishing surface is
within the range of the hollow and the size of the hollow on the
non-polishing surface is significantly larger than the size of the
IC tag projected onto the non-polishing surface, an opening that is
to be the hollow may be formed on the non-polishing surface and an
opening in which the IC tag is to be housed may be further formed
in a portion of a surface that is to be the bottom surface of the
hollow. Such a two-level opening may be formed by molding the rough
pad form by use of a mold having a two-level projection which
corresponds to a desired opening shape or by molding a rough form
having no opening and then subjecting the rough form to two-level
cutting. It is also possible that a rough form is molded by use of
a mold having a one-level projection and then the opening for the
IC tag is formed by cutting.
(A3) Step of Placing the IC Tag in the Opening and Filling the
Remaining Space in the Opening with the Composition for Chemical
Mechanical Polishing Pad
[0060] Then, the IC tag is placed in the opening formed as
described above in a desired direction, and the above composition
for a chemical mechanical polishing pad is filled in the remaining
space. The composition for a chemical mechanical polishing pad used
for this purpose is preferably the same as that used for molding
the rough pad form.
(A4) Step of Heating the Rough Pad Form to Temperature of 150 to
180.degree. C. under Pressure of 1 to 20 MPa
[0061] Then, the rough pad form is heated to a temperature of 150
to 180.degree. C. under a pressure of 1 to 20 MPa to embed the IC
tag in the pad. The pressure applied here is preferably 1 to 18
MPa, more preferably 2 to 15 MPa. Further, the heating temperature
is preferably 160 to 180.degree. C. The heating time is preferably
1 to 60 minutes, more preferably 10 to 30 minutes. The step (A4) is
preferably carried out in a mold.
[0062] Throughout the step (A3) and the step (A4), the IC tag and
the rough pad form are subjected to neither a pressure of higher
than 20 MPa nor a temperature of higher than 180.degree. C. By
processing the rough pad form under such pressure and temperature
conditions, the function of the IC tag is not impaired, and the IC
tag can suitably serve as a non-contact information recording
medium.
[0063] The chemical mechanical polishing pad of the present
invention can be produced in the manner as described above. When
the pad of the present invention has a groove or other hollow on
one or both of the polishing surface and the non-polishing surface,
the groove or other hollow can be formed by using a mold having a
projection which corresponds to the shape of a desired groove or
other hollow in the above step (A2) or by performing proper cutting
after the above step (A4).
Production Method B
(B1) Step of Preparing Composition for Chemical Mechanical
Polishing Pad
[0064] In the production method B, all steps after the IC tag is
placed in the rough pad form may be carried out under normal
pressure at low temperatures ranging from room temperature to lower
than 180.degree. C. Accordingly, as a composition for a chemical
mechanical polishing pad which is used in the step (B1), the same
composition as that used in the above step (A1) can be used, and it
can also be preferably used for composition required to be
processed at high temperatures exceeding 180.degree. C.
(B2) Step of Molding Rough Pad Form Having Surface that is to be
Circular Polishing Surface and Surface that is to be Non-Polishing
Surface which is the Back Side of the Polishing Surface and Having
Opening where IC Tag is to be Placed on the Surface that is to be
the Non-Polishing Surface of the Pad, from the Composition
[0065] The step (B2) is nearly the same as the above step (A2).
[0066] However, it is preferable that the shape and size of the
opening be nearly the same as the shape and size of the IC tag
projected onto the non-polishing surface when the IC tag is placed
in the pad and be a shape and size which make at least a large
portion of the side face of the IC tag adhere closely to the side
face of the opening.
[0067] The depth of the opening is preferably nearly the same as or
deeper than the distance to be occupied by the IC tag in the pad
thickness direction in the pad.
[0068] When the chemical mechanical polishing pad of the present
invention has a hollow on its non-polishing surface, all of the
shape of the IC tag projected onto the non-polishing surface is
within the range of the hollow and the size of the hollow on the
non-polishing surface is significantly larger than the size of the
IC tag projected onto the non-polishing surface, an opening that is
to be the hollow may be formed on the non-polishing surface and an
opening in which the IC tag is to be housed may be further formed
in a portion of a surface that is to be the bottom surface of the
hollow. Such a two-level opening can be formed in the same manner
as described in the step (A2) of the production method A.
(B3) Step of Attaching the IC Tag to the Opening.
[0069] Then, after an adhesive layer is formed on at least one of
the formed opening and the IC tag, the IC tag is placed and
attached in the opening in a given direction. Illustrative examples
of a method of forming the adhesive layer include a method of
applying an adhesive and a method of applying a double-stick tape.
The method of applying a double-stick tape is preferred.
[0070] The adhesive strength of the double-stick tape is preferably
100 to 3,000 g/25 mm, more preferably 500 to 2,000 g/25 mm, as
strength measured in accordance with a method specified in JIS
Z1528. Both surfaces of the double-stick tape may have the same
adhesive strength or different adhesive strengths. In both cases,
the double-stick tape can be preferably used.
[0071] When the chemical mechanical polishing pad of the present
invention has a groove or other hollow on one or both of the
polishing surface and the non-polishing surface, the groove or
other hollow can be formed by using a mold having a projection
which corresponds to the shape of a desired groove or other hollow
in the above step (B2) or by performing proper cutting after the
above step (B2) or (B3).
[0072] The chemical mechanical polishing pad of the present
invention may be a single-layer pad which is the pad produced as
described above or a double-layer pad having a support layer on the
non-polishing surface. The above support layer is a layer which
supports the chemical mechanical polishing pad from the back side
of the polishing surface. Although the characteristics of the
support layer are not particularly limited, the support layer is
preferably softer than the pad itself. The support layer may be a
porous body (foam) or a nonporous body. Further, its planar shape
may be circular or polygonal, for example. The support layer
preferably has the same planar shape and size as those of the
polishing pad. Although its thickness is also not particularly
limited, it is preferably 0.1 to 5 mm, more preferably 0.5 to 2
mm.
[0073] A material constituting the support layer is not
particularly limited. However, an organic material is preferably
used, because it can be easily molded into a given shape and
characteristic and can impart moderate elasticity. As the organic
material, those enumerated as examples of the component (a) of the
first composition in the above step (A1) can be used.
[0074] To form the support layer on the non-polishing surface, a
double-stick tape or a proper method such as lamination may be
employed.
[0075] The chemical mechanical polishing pad of the present
invention can be attached to a known polishing apparatus and used
in a chemical mechanical polishing process in accordance with a
known method. In addition, various information can be recorded in
the IC tag incorporated in the pad and can be used according to
need. Illustrative examples of the information to be recorded in
the IC tag include the model number, production number and
production record of the chemical mechanical polishing pad, and the
results of quality examination on the actual size, physical
properties and shape of the product. Further, when the information
storage device incorporated in the IC tag is a RAM, usage records
after the start of use of the pad may be recorded in turn.
[0076] The chemical mechanical polishing pad of the present
invention achieves excellent uniformity and surface flatness of
polished surface and exerts an excellent function as a chemical
mechanical polishing pad, as exemplified by providing a
high-quality polished surface. In addition, information recorded in
the IC tag as described above can be read out according to need and
used for managements of manufacturing, delivery, distribution and
maintenance and setting of optimum polishing conditions which
reflect the individual characteristics of each product. Further,
when various measurement devices are connected to the IC tag, the
information can be used for fine adjustments of polishing
conditions to be adapted to the specific environment to which the
pad in the chemical mechanical polishing process is being
exposed.
EXAMPLES
Example 1
(1) Production of Chemical Mechanical Polishing Pad
(1-1) Preparation of Composition for Chemical Mechanical Polishing
Pad
[0077] 80 parts by volume (corresponding to 72.2 parts by weight)
of 1,2-polybutadiene (product of JSR Corporation, trade name "JSR
RB830") and 20 parts by volume (corresponding to 27.2 parts by
weight) of .beta.-cyclodextrin (product of Bio Research Corporation
of Yokohama, trade name "DEXIPAL .beta.-100", average particle
diameter: 20 .mu.m) were kneaded at 60 rpm for 2 minutes by an
extruder adjusted to 160.degree. C. Then, 0.6 parts by weight
(corresponding to 0.33 parts by weight in terms of the amount of
dicumyl peroxide per 100 parts by weight of 1,2-polybutadiene) of
"PERCUMYL D40" (trade name, product of NOF Corporation, containing
40 wt % of dicumyl peroxide) was added, and the resulting mixture
was kneaded at 120.degree. C. and 60 rpm for 2 minutes to obtain
pellets of a composition for a chemical mechanical polishing
pad.
(1-2) Production of Rough Pad Form Having Opening
[0078] The pellets were heated at 160.degree. C. for 5 minutes in a
mold having a circular projection (diameter: 75 mm, height: 1.2 mm)
in the center of the lower plate and crosslinked to obtain a
disk-shaped molded article having a diameter of 600 mm and a
thickness of 2.5 mm and having an opening in the center of a
surface that was to be a back surface (non-polishing surface).
(1-3) Production of Rough Pad Form
[0079] The thus produced disk-shaped molded article was placed in a
mold having no projection inside with the opening facing up. In the
center of the bottom surface of the opening, a commercially
available IC tag (shape: nearly square card, size: 50 mm.times.50
mm.times.0.2 mm,
[0080] operating frequency: 13.5 MHz, material of the outer surface
of the card: ABS resin, memory capacity: 512 bits, 512 bits of data
was written in the memory in advance) was placed with one of its
surfaces having a size of 50 mm.times.50 mm contacting the bottom
surface of the opening, the pellets prepared in the above (1-1)
were filled in the remaining space of the opening, and the mold was
closed.
[0081] Then, the mold was heated at 14 MPa and 170.degree. C. for
18 minutes, resulting in a disk-shaped rough pad form having a
diameter of 600 mm and a thickness of 2.5 mm.
(1-4) Production of Chemical Mechanical Polishing Pad
[0082] Then, on the polishing surface of the above molded article,
concentric grooves (having a rectangular cross section) having a
width of 0.5 mm, a pitch of 2.0 mm and a depth of 1.0 mm were
formed by means of a commercially available cutting machine.
[0083] Further, in the center of the non-polishing surface of the
molded article, a circular hollow having a diameter of 75 mm and a
depth of 0.6 mm was formed by means of a commercially available
cutting machine to obtain a chemical mechanical polishing pad. The
position of the center of gravity of the IC tag contained in this
chemical mechanical polishing pad is the center of the polishing
surface in the radial direction of the polishing surface and is a
position corresponding to 56% of the thickness of the pad in the
pad thickness direction in the direction from the polishing surface
toward the non-polishing surface. Further, this chemical mechanical
polishing pad has a circular hollow in the center of the
non-polishing surface and has all of the shape of the IC tag
projected onto the non-polishing surface within the range of the
hollow.
(2) Evaluation of Function of IC Tag
[0084] When the reading part of a commercially available
reader/writer for an IC tag (output: 0.1 W) was brought close to a
position that was 5 cm away from the hollow in the center of the
non-polishing surface of the chemical mechanical polishing pad
produced above to check whether the data could be read, it was
confirmed that the prerecorded 512-bit data was intact.
(3) Evaluation of Polishing Performance
[0085] The chemical mechanical polishing pad produced above was
mounted on the platen of chemical mechanical polishing apparatus
"EPO112" (product of Ebara Corporation), and chemical mechanical
polishing was conducted on a wafer having a diameter of 200 mm and
having a patternless PETEOS film (silicon oxide film produced by
plasma-enhanced chemical vapor deposition using tetraethyl
orthosilicate as a raw material) on the surface thereof under the
following conditions.
[0086] Aqueous Dispersion for Chemical Mechanical
Polishing: CMS-1101 (trade name, product of JSR Corporation,
containing silica as abrasive grains) diluted to three times with
ion exchange water. Aqueous Dispersion Feed Rate: 200 ml/min
Number of Revolutions of Surface Plate: 70 rpm
Number of Revolutions of Head: 63 rpm
Head Pressing Pressure: 4 psi
[0087] Polishing Time: 2 minutes
[0088] In the above chemical mechanical polishing, the polishing
rate was 200 nm/min, the in-plane uniformity of polishing amount
was 1.2%, and the number of scratches was 3 across the whole
surface of the wafer.
[0089] The above polishing rate, in-plane uniformity of polishing
amount and number of scratches were measured in the following
manner.
[0090] The film thickness before and after polishing was measured
by an optical film thickness meter at 49 points that were located
at intervals of 3.75 mm in the diameter direction, the outermost
points thereamong being located at 10 mm inside from the edge of
the wafer, the average of differences in the film thickness between
before and after polishing at these 49 points was taken as the
polishing rate, and the in-plane uniformity was calculated in
accordance with the following expression based on the differences
in the film thickness at these 49 points.
In-Plane Uniformity (%)=(Standard Deviation of Film Thickness
Differences)/(Average of Film Thickness Differences).times.100
[0091] Further, the number of scratches was determined by counting
the total number of produced scratches on the whole polished
surface of the wafer by means of a wafer defect inspection device
(product of KLA-Tencor Corporation, type "KLA2351", threshold was
set at 100).
Example 2
(1) Production of Chemical Mechanical Polishing Pad
(1-1) Preparation of Composition for Chemical Mechanical Polishing
Pad
[0092] Pellets of a composition for a chemical mechanical polishing
pad were obtained in the same manner as in "(1-1) Preparation of
Composition for Chemical Mechanical Polishing Pad" of Example
1.
(1-2) Production of Rough Pad Form Having Opening
[0093] The pellets were heated at 170.degree. C. for 18 minutes in
a mold having a circular projection (diameter: 75 mm, height: 1.2
mm) in the center of the lower plate and crosslinked to obtain a
disk-shaped molded article having a diameter of 600 mm and a
thickness of 2.5 mm and having an opening in the center of a
surface that was to be a back surface (non-polishing surface).
(1-3) Application of IC Tag to Opening
[0094] A double-stick tape (product of Nitto Denko Corporation,
product name "No. 500", adhesive strength: 1,550 g/25 mm on both
sides) cut in a rectangular shape of 70 mm.times.4.8 mm was applied
such that the center of gravity of the rectangle matched the center
of the above opening.
[0095] Then, a commercially available IC tag (shape: nearly
rectangular card, size: 70 mm.times.4.8 mm.times.0.2 mm, operating
frequency: 2.45 GHz, memory capacity: 128 byte, 110 byte of data
was written in the memory in advance) was attached such that one of
its surfaces having a size of 70 mm.times.4.8 mm matched the
rectangle of the above double-stick tape.
(1-4) Production of Chemical Mechanical Polishing Pad
[0096] Then, on the polishing surface of the above molded article,
concentric grooves (having a rectangular cross section) having a
width of 0.5 mm, a pitch of 2.0 mm and a depth of 1.0 mm were
formed by means of a commercially available cutting machine so as
to produce a chemical mechanical polishing pad. The position of the
center of gravity of the IC tag contained in this chemical
mechanical polishing pad is the center of the polishing surface in
the radial direction of the polishing surface and is a position
corresponding to 64% of the thickness of the pad in the pad
thickness direction in the direction from the polishing surface
toward the non-polishing surface. Further, this chemical mechanical
polishing pad has a circular hollow in the center of the
non-polishing surface and has all of the shape of the IC tag
projected onto the non-polishing surface within the range of the
hollow.
(2) Evaluation of Function of IC Tag
[0097] When the reading part of a commercially available
reader/writer for an IC tag (output: 0.1 W) was brought close to a
position that was 5 cm away from the hollow in the center of the
non-polishing surface of the chemical mechanical polishing pad
produced above to check whether the data could be read, it was
confirmed that the prerecorded 110-byte data was intact.
(3) Evaluation of Polishing Performance
[0098] Chemical mechanical polishing performance was evaluated in
the same manner as in Example 1 except that the above produced
chemical mechanical polishing pad was used. As a result, the
polishing rate was 210 nm/min, the in-plane uniformity of polishing
amount was 1.5%, and the number of scratches was 5 across the whole
surface of the wafer.
Example 3
(1) Production of Chemical Mechanical Polishing Pad
(1-1) Preparation of Composition for Chemical Mechanical Polishing
Pad
[0099] Pellets of a composition for a chemical mechanical polishing
pad were obtained in the same manner as in "(1-1) Preparation of
Composition for Chemical Mechanical Polishing Pad" of Example
1.
(1-2) Production of Rough Pad Form Having Opening
[0100] The pellets were heated at 170.degree. C. for 18 minutes in
a mold having a cylindrical metallic block (diameter: 75 mm,
height: 0.6 mm) placed on the lower plate with the center of the
block located at a point which was 540 mm from the center of the
lower plate and crosslinked to obtain a disk-shaped molded article
having a diameter of 600 mm and a thickness of 2.5 mm and having an
opening in the center of a surface that was to be a back surface
(non-polishing surface).
(1-3) Production of Rough Pad Form
[0101] The thus produced disk-shaped molded article was placed in a
mold having no metallic block inside with the opening facing up. In
the center of the bottom surface of the opening, a commercially
available IC tag (shape: nearly square card, size: 50 mm.times.50
mm.times.0.2 mm, operating frequency: 13.5 MHz, material of the
outer surface of the card: ABS resin, memory capacity: 512 bits,
512 bits of data was written in the memory in advance) was placed
with one of its surfaces having a size of 50 mm.times.50 mm
contacting the bottom surface of the opening such that a 50-mm side
of the IC tag became parallel to the tangential direction of the
non-polishing surface, the pellets prepared in the above (1-1) were
filled in the remaining space of the opening, and the mold was
closed.
[0102] Then, the mold was heated at 14 MPa and 170.degree. C. for
18 minutes, resulting in a disk-shaped rough pad form having a
diameter of 600 mm and a thickness of 2.5 mm.
(1-4) Production of Chemical Mechanical Polishing Pad
[0103] Then, on the polishing surface of the above molded article,
concentric grooves (having a rectangular cross section) having a
width of 0.5 mm, a pitch of 2.0 mm and a depth of 1.0 mm were
formed by means of a commercially available cutting machine to
obtain a chemical mechanical polishing pad. The position of the
center of gravity of the IC tag contained in this chemical
mechanical polishing pad is a position corresponding to 90% in the
direction from the center of the polishing surface toward its
periphery in the radial direction of the polishing surface and is a
position corresponding to 80% of the thickness of the pad in the
pad thickness direction in the direction from the polishing surface
toward the non-polishing surface.
(2) Evaluation of Function of IC Tag
[0104] When the reading part of a commercially available
reader/writer for an IC tag (output: 0.1 W) was brought close to a
position that was 5 cm away from the hollow in the center of the
non-polishing surface of the chemical mechanical polishing pad
produced above to check whether the data could be read, it was
confirmed that the prerecorded 512-bit data was intact.
(3) Evaluation of Polishing Performance
[0105] Chemical mechanical polishing performance was evaluated in
the same manner as in Example 1 except that the above produced
chemical mechanical polishing pad was used. As a result, the
polishing rate was 210 nm/min, the in-plane uniformity of polishing
amount was 1.2%, and the number of scratches was 3 across the whole
surface of the wafer.
Example 4
(1) Production of Chemical Mechanical Polishing Pad
(1-1) Preparation of Composition for Chemical Mechanical Polishing
Pad
[0106] Pellets of a composition for a chemical mechanical polishing
pad were obtained in the same manner as in "(1-1) Preparation of
Composition for Chemical Mechanical Polishing Pad" of Example
1.
(1-2) Production of Rough Pad Form Having Opening
[0107] The pellets were heated at 170.degree. C. for 18 minutes in
a mold having a cylindrical metallic block (diameter: 75 mm,
height: 1.1 mm) placed on the lower plate with the center of the
block located at a point which was 48 mm from the center of the
lower plate and crosslinked to obtain a disk-shaped molded article
having a diameter of 600 mm and a thickness of 2.5 mm and having an
opening in the center of a surface that was to be a back surface
(non-polishing surface).
(1-3) Production of Rough Pad Form
[0108] The thus produced disk-shaped molded article was placed in a
mold having no metallic block inside with the opening facing up. In
the center of the bottom surface of the opening, a commercially
available IC tag (shape: nearly square card, size: 50 mm.times.50
mm.times.0.2 mm, operating frequency: 13.5 MHz, material of the
outer surface of the card: ABS resin, memory capacity: 512 bits,
512 bits of data was written in the memory in advance) was placed
with one of its surfaces having a size of 50 mm.times.50 mm
contacting the bottom surface of the opening such that a 50-mm side
of the IC tag became parallel to the tangential direction of the
non-polishing surface, the pellets prepared in the above (1-1) were
filled in the remaining space of the opening, and the mold was
closed.
[0109] Then, the mold was heated at 14 MPa and 170.degree. C. for
18 minutes, resulting in a disk-shaped rough pad form having a
diameter of 600 mm and a thickness of 2.5 mm.
(1-4) Production of Chemical Mechanical Polishing Pad
[0110] Then, on the polishing surface of the above molded article,
concentric grooves (having a rectangular cross section) having a
width of 0.5 mm, a pitch of 2.0 mm and a depth of 1.0 mm were
formed by means of a commercially available cutting machine.
[0111] Further, by means of a commercially available cutting
machine, a circular hollow having a diameter of 75 mm and a depth
of 0.6 mm was formed such that the center of the hollow was located
at a point which was 48 mm from the center of the non-polishing
surface of the molded article to obtain a chemical mechanical
polishing pad. The position of the center of gravity of the IC tag
contained in this chemical mechanical polishing pad is a position
corresponding to 8% in the direction from the center of the
polishing surface toward its periphery in the radial direction of
the polishing surface and is a position corresponding to 60% of the
thickness of the pad in the pad thickness direction in the
direction from the polishing surface toward the non-polishing
surface. Further, this chemical mechanical polishing pad has a
circular hollow whose center is located at a point corresponding to
48 mm in the direction from the center of the non-polishing surface
toward its periphery and has all of the shape of the above IC tag
projected onto the non-polishing surface within the range of the
hollow.
(2) Evaluation of Function of IC Tag
[0112] When the reading part of a commercially available
reader/writer for an IC tag (output: 0.1 W) was brought close to a
position that was 5 cm away from the hollow in the center of the
non-polishing surface of the chemical mechanical polishing pad
produced above to check whether the data could be read, it was
confirmed that the prerecorded 512-bit data was intact.
(3) Evaluation of Polishing Performance
[0113] Chemical mechanical polishing performance was evaluated in
the same manner as in Example 1 except that the above produced
chemical mechanical polishing pad was used. As a result, the
polishing rate was 190 nm/min, the in-plane uniformity of polishing
amount was 1.5%, and the number of scratches was 3 across the whole
surface of the wafer.
Comparative Example 1
[0114] A chemical mechanical polishing pad was produced in the same
manner as in Example 1 except that the mold temperature was set at
250.degree. C. in "(1-3) Production of Rough Pad Form" in Example
1.
[0115] When the function of the IC tag was evaluated in the same
manner as in Example 1, the prerecorded data could not be read.
Comparative Example 2
(1) Production of Chemical Mechanical Polishing Pad
(1-1) Preparation of Composition for Chemical Mechanical Polishing
Pad
[0116] Pellets of a composition for a chemical mechanical polishing
pad were obtained in the same manner as in "(1-1) Preparation of
Composition for Chemical Mechanical Polishing Pad" of Example
1.
(1-2) Production of Rough Pad Form Having Opening
[0117] The pellets were heated at 170.degree. C. for 18 minutes in
a mold having a cylindrical metallic block (diameter: 75 mm,
height: 0.6 mm) placed on the lower plate with the center of the
block located at a point which was 300 mm from the center of the
lower plate and crosslinked to obtain a disk-shaped molded article
having a diameter of 600 mm and a thickness of 2.5 mm and having an
opening in the center of a surface that was to be a back surface
(non-polishing surface).
(1-3) Production of Rough Pad Form
[0118] A disk-shaped rough pad form having a diameter of 600 mm and
a thickness of 2.5 mm was obtained in the same manner as in Example
3 except that the above produced disk-shaped molded article was
used.
(1-4) Production of Chemical Mechanical Polishing Pad
[0119] A chemical mechanical polishing pad was obtained in the same
manner as in Example 3 except that the above produced rough pad
form was used. The position of the center of gravity of the IC tag
contained in this chemical mechanical polishing pad is a position
corresponding to 50% in the direction from the center of the
polishing surface toward its periphery in the radial direction of
the polishing surface and is a position corresponding to 80% of the
thickness of the pad in the pad thickness direction in the
direction from the polishing surface toward the non-polishing
surface.
(2) Evaluation of Function of IC Tag
[0120] When the reading part of a commercially available
reader/writer for an IC tag (output: 0.1 W) was brought close to a
position that was 5 cm away from the hollow in the center of the
non-polishing surface of the chemical mechanical polishing pad
produced above to check whether the data could be read, it was
confirmed that the prerecorded 512-bit data was intact.
(3) Evaluation of Polishing Performance
[0121] Chemical mechanical polishing performance was evaluated in
the same manner as in Example 1 except that the above produced
chemical mechanical polishing pad was used. As a result, the
polishing rate was 200 nm/min, the in-plane uniformity of polishing
amount was 5.0%, and the number of scratches was 52 across the
whole surface of the wafer.
Comparative Example 3
(1) Production of Chemical Mechanical Polishing Pad
(1-1) Preparation of Composition for Chemical Mechanical Polishing
Pad
[0122] Pellets of a composition for a chemical mechanical polishing
pad were obtained in the same manner as in "(1-1) Preparation of
Composition for Chemical Mechanical Polishing Pad" of Example
1.
(1-2) Production of Rough Pad Form Having Opening
[0123] The pellets were heated at 170.degree. C. for 18 minutes in
a mold having a cylindrical metallic block (diameter: 75 mm,
height: 1.6 mm) placed on the lower plate with the center of the
block located at a point which was 120 mm from the center of the
lower plate and crosslinked to obtain a disk-shaped molded article
having a diameter of 600 mm and a thickness of 2.5 mm and having an
opening in the center of a surface that was to be a back surface
(non-polishing surface).
(1-3) Production of Rough Pad Form
[0124] A disk-shaped rough pad form having a diameter of 600 mm and
a thickness of 2.5 mm was obtained in the same manner as in Example
3 except that the above produced disk-shaped molded article was
used.
(1-4) Production of Chemical Mechanical Polishing Pad
[0125] Then, on the polishing surface of the above molded article,
concentric grooves (having a rectangular cross section) having a
width of 0.5 mm, a pitch of 2.0 mm and a depth of 1.0 mm were
formed by means of a commercially available cutting machine.
[0126] Further, by means of a commercially available cutting
machine, a circular hollow having a diameter of 75 mm and a depth
of 1.0 mm was formed such that the center of the hollow was located
at a point which was 120 mm from the center of the non-polishing
surface of the molded article to obtain a chemical mechanical
polishing pad. The position of the center of gravity of the IC tag
contained in this chemical mechanical polishing pad is a position
corresponding to 20% in the direction from the center of the
polishing surface toward its periphery in the radial direction of
the polishing surface and is a position corresponding to 40% of the
thickness of the pad in the pad thickness direction in the
direction from the polishing surface toward the non-polishing
surface. Further, this chemical mechanical polishing pad has a
circular hollow whose center is located at a point corresponding to
120 mm in the direction from the center of the non-polishing
surface toward its periphery and has all of the shape of the above
IC tag projected onto the non-polishing surface within the range of
the hollow.
(2) Evaluation of Function of IC Tag
[0127] When the reading part of a commercially available
reader/writer for an IC tag (output: 0.1 W) was brought close to a
position that was 5 cm away from the hollow in the center of the
non-polishing surface of the chemical mechanical polishing pad
produced above to check whether the data could be read, it was
confirmed that the prerecorded 512-bit data was intact.
(3) Evaluation of Polishing Performance
[0128] Chemical mechanical polishing performance was evaluated in
the same manner as in Example 1 except that the above produced
chemical mechanical polishing pad was used. As a result, the
polishing rate was 190 nm/min, the in-plane uniformity of polishing
amount was 4.0%, and the number of scratches was 43 across the
whole surface of the wafer.
Comparative Example 4
(1) Production of Chemical Mechanical Polishing Pad
(1-1) Preparation of Composition for Chemical Mechanical Polishing
Pad
[0129] Pellets of a composition for a chemical mechanical polishing
pad were obtained in the same manner as in "(1-1) Preparation of
Composition for Chemical Mechanical Polishing Pad" of Example
1.
(1-2) Production of Rough Pad Form Having Opening
[0130] The pellets were heated at 170.degree. C. for 18 minutes in
a mold having a cylindrical metallic block (diameter: 75 mm,
height: 1.9 mm) placed on the lower plate with the center of the
block located at a point which was 420 mm from the center of the
lower plate and crosslinked to obtain a disk-shaped molded article
having a diameter of 600 mm and a thickness of 2.5 mm and having an
opening in the center of a surface that was to be a back surface
(non-polishing surface).
(1-3) Production of Rough Pad Form
[0131] A disk-shaped rough pad form having a diameter of 600 mm and
a thickness of 2.5 mm was obtained in the same manner as in Example
3 except that the above produced disk-shaped molded article was
used.
(1-4) Production of Chemical Mechanical Polishing Pad
[0132] A chemical mechanical polishing pad was obtained in the same
manner as in Comparative Example 3 except that the above produced
rough pad form was used. The position of the center of gravity of
the IC tag contained in this chemical mechanical polishing pad is a
position corresponding to 70% in the direction from the center of
the polishing surface toward its periphery in the radial direction
of the polishing surface and is a position corresponding to 28% of
the thickness of the pad in the pad thickness direction in the
direction from the polishing surface toward the non-polishing
surface.
(2) Evaluation of Function of IC Tag
[0133] When the reading part of a commercially available
reader/writer for an IC tag (output: 0.1 W) was brought close to a
position that was 5 cm away from the hollow in the center of the
non-polishing surface of the chemical mechanical polishing pad
produced above to check whether the data could be read, it was
confirmed that the prerecorded 512-bit data was intact.
(3) Evaluation of Polishing Performance
[0134] Chemical mechanical polishing performance was evaluated in
the same manner as in Example 1 except that the above produced
chemical mechanical polishing pad was used. As a result, the
polishing rate was 180 nm/min, the in-plane uniformity of polishing
amount was 6.0%, and the number of scratches was 100 across the
whole surface of the wafer.
* * * * *