U.S. patent application number 14/721508 was filed with the patent office on 2015-12-24 for chemical mechanical polishing conditioner.
The applicant listed for this patent is KINIK COMPANY. Invention is credited to CHIA-FENG CHIU, JUI-LIN CHOU, HSIN-YING LIN, CHIA-CHUN WANG.
Application Number | 20150367480 14/721508 |
Document ID | / |
Family ID | 54868841 |
Filed Date | 2015-12-24 |
United States Patent
Application |
20150367480 |
Kind Code |
A1 |
CHOU; JUI-LIN ; et
al. |
December 24, 2015 |
CHEMICAL MECHANICAL POLISHING CONDITIONER
Abstract
Provided is a CMP conditioner comprising: a substrate comprising
multiple concave parts, the concave parts formed in a surface of
the substrate and each concave part having a side wall; multiple
fixed plates, each fixed plate comprising a bottom, a top, a
concavity and an inclined plane, the bottom fixed into the concave
part, the top integrated with the bottom with a contact surface
formed between the top and the bottom, the concavity formed in the
top and opposite the bottom, the inclined plane formed between the
contact surface and the concavity, an angle and a space formed
between the inclined plane and the side wall; and multiple abrasive
units, each abrasive unit mounted in the concavity. When the CMP
conditioner is applied to a pad, the thickness of the pad can
recover to its original thickness; i.e., the cutting depth is
increased to improve the dressing performance.
Inventors: |
CHOU; JUI-LIN; (NEW TAIPEI
CITY, TW) ; WANG; CHIA-CHUN; (NEW TAIPEI CITY,
TW) ; CHIU; CHIA-FENG; (NEW TAIPEI CITY, TW) ;
LIN; HSIN-YING; (TAIPEI, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KINIK COMPANY |
TAIPEI |
|
TW |
|
|
Family ID: |
54868841 |
Appl. No.: |
14/721508 |
Filed: |
May 26, 2015 |
Current U.S.
Class: |
451/443 |
Current CPC
Class: |
B24B 53/017
20130101 |
International
Class: |
B24B 53/017 20060101
B24B053/017 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 18, 2014 |
TW |
TW103120952 |
Claims
1. A chemical mechanical polishing conditioner comprising: a
substrate comprising multiple concave parts, the concave parts
formed in a surface of the substrate, and each concave part having
a side wall; multiple fixed plates, each fixed plate comprising a
bottom, a top, a concavity and an inclined plane, the bottom fixed
into the concave part, the top formed on the bottom in an integral
configuration with a contact surface formed between the top and the
bottom, the concavity formed in the top and opposite the bottom,
the inclined plane formed between the contact surface and the
concavity, a space formed between the inclined plane and the side
wall, an angle formed between the inclined plane and the side wall,
the angle ranging from 30.degree. to 60.degree., inclusive; and
multiple abrasive units, each abrasive unit mounted in the
concavity.
2. The chemical mechanical polishing conditioner as claimed in
claim 1, wherein each fixed plate is fixed into the concave part
through a binding layer, the binding layer is consisted of a
ceramic material, a brazing material, an electroplating material, a
metallic material, or a polymeric material.
3. The chemical mechanical polishing conditioner as claimed in
claim 1, wherein each fixed plate is fixed into the concave part
through a binding layer, the binding layer is selected from the
group consisting of iron, cobalt, nickel, chromium, manganese,
silicon, aluminum, and any combination thereof.
4. The chemical mechanical polishing conditioner as claimed in
claim 1, wherein each fixed plate is fixed into the concave part
through a binding layer, the binding layer is consisted of epoxy
resin, polyester resin, polyacrylate resin, or phenol resin.
5. The chemical mechanical polishing conditioner as claimed in
claim 1, wherein the concave parts are arranged on the surface of
the substrate in concentric circles.
6. The chemical mechanical polishing conditioner as claimed in
claim 1, wherein each abrasive unit has a tip opposite the
concavity, and a vertical distance between the surface of the
substrate and the tip of each abrasive unit ranges from 20 .mu.m to
300 .mu.m, inclusive.
7. The chemical mechanical polishing conditioner as claimed in
claim 6, wherein the vertical distance between the surface of the
substrate and the tip of each abrasive unit ranges from 100 .mu.m
to 300 .mu.m, inclusive.
8. The chemical mechanical polishing conditioner as claimed in
claim 1, wherein the chemical mechanical polishing conditioner has
at least two vertical distances between the surface of the
substrate and the tip of each abrasive unit, a difference between
the vertical distances ranges from 20 .mu.m to 100 .mu.m,
inclusive.
9. The chemical mechanical polishing conditioner as claimed in
claim 1, wherein a cutting angle of each abrasive unit ranges from
30.degree. to 150.degree., inclusive.
10. The chemical mechanical polishing conditioner as claimed in
claim 1, wherein a crystal structure of each abrasive unit is
hexahedral or octahedral.
11. The chemical mechanical polishing conditioner as claimed in
claim 1, wherein the concave parts are formed through the
substrate.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a chemical mechanical
polishing conditioner, especially to a chemical mechanical
polishing conditioner comprising an inclined plane.
[0003] 2. Description of the Prior Art(s)
[0004] Chemical Mechanical Polishing (abbreviated as CMP) is a
necessary method in semiconductor process. During a CMP process, a
pad is loaded on a rotating support and introduced with a suitable
slurry. The rotating pad is then in contact with a wafer, so as to
polish and planarize a surface of the wafer. In order to ensure the
polishing efficiency of the pad, the surface roughness of the pad
is required to be kept above a certain level. However, the
polishing debris produced during the CMP process accumulates and
stagnates on the surface of the pad, forming a hardened layer. The
hardened layer deteriorates the surface roughness of the pad, and
thus decreases the polishing efficiency of the pad and shortens the
lifetime of the pad.
[0005] Therefore, a CMP conditioner is used during CMP process to
dress the surface of the pad, so as to maintain the surface
roughness of the pad and prolong the lifetime of the pad.
[0006] With reference to FIG. 10, a conventional CMP conditioner 8
comprises a substrate 80, multiple metal bars 81, multiple abrasive
units 82, and multiple holes 83. The holes 83 are formed through
the substrate 80. The metal bars 81 are correspondingly mounted in
the holes 83. Each abrasive unit 82 is correspondingly mounted on
an end of the metal bar 81 and partially protrudes from a surface
of the substrate 80. When the CMP conditioner 8 is applied to a pad
90, the surface of the substrate 80 is pressed on the pad 90 and
the abrasive units 82 are used to dress the surface of the pad 90.
However, a cutting depth D of the CMP conditioner 8 is constrained
by the dimensions of the abrasive units 82. When the cutting depth
D may decrease due to the abrasion of the abrasive units 82 and the
abrasive units 82 may become blunt after being used for a period of
time, the dressing efficiency of the CMP conditioner 8 is thus
decreased. Furthermore, the slurry cannot be mixed uniformly in the
limited cutting depth D, thereby affecting the dressing efficiency
of the CMP conditioner 8.
[0007] To overcome the shortcomings, the present invention provides
a CMP conditioner to mitigate or obviate the aforementioned
problems.
SUMMARY OF THE INVENTION
[0008] The main objective of the present invention is to provide a
CMP conditioner to mitigate the limitation of cutting depth
constrained by the dimension of the abrasive unit. The other
objective of the present invention is to provide a CMP conditioner
to mitigate the problem of decreased dressing efficiency caused by
the abrasion of the abrasive units.
[0009] To achieve the abovementioned objective, the present
invention provides a CMP conditioner. The CMP conditioner
comprises: a substrate comprising multiple concave parts, multiple
fixed plates, and multiple abrasive units. The concave parts are
formed in a surface of the substrate, each concave part having a
side wall. Each fixed plate comprises a bottom, a top, a concavity
and an inclined plane, and the bottom is fixed into the concave
part. The top is formed on the bottom in an integral configuration
and a contact surface is formed between the top and the bottom. The
concavity is formed in the top and opposite the bottom. The
inclined plane is formed between the contact surface and the
concavity. A space is formed between the inclined plane and the
side wall, and an angle is formed between the inclined plane and
the side wall, the angle ranging from 30.degree. to 60.degree.,
inclusive. Each abrasive unit is mounted in the concavity. Each
abrasive unit and the top form a pyramidal structure.
[0010] When the CMP conditioner is applied to a pad, the slurry
introduced on a surface of the pad is fluctuated in turbulence and
irregularly moved within the space, allowing the concentration of
the slurry to become more uniform in the space. Furthermore, the
thickness of the pad can also be recovered to its original
thickness in the space. That is to say, a cutting depth of the
abrasive units applied to the pad is not further limited by the
dimension of the abrasive units, and thus the cutting depth is
increased to improve the dressing performance of the CMP
conditioner.
[0011] Preferably, each fixed plate is fixed into the concave part
through a binding layer and the binding layer is consisted of a
ceramic material, a brazing material, an electroplating material, a
metallic material, or a polymeric material. More preferably, the
brazing material is selected from the group consisting of iron,
cobalt, nickel, chromium, manganese, silicon, aluminum, and any
combination thereof. More preferably, the polymeric material is
epoxy resin, polyester resin, polyacrylate resin, or phenol
resin.
[0012] Preferably, each fixed plate is fixed into the concave part
by a ceramic sintering method, a brazing method, an electroplating
method, a metallic sintering method, or a polymeric curing method
through the binding layer.
[0013] Preferably, the concave parts are arranged on the surface of
the substrate in concentric circles. Alternatively, the concave
parts are arranged on the surface of the substrate in a radial
pattern.
[0014] Preferably, the concave parts are formed through the
substrate.
[0015] Preferably, the inclined plane is formed between the contact
surface and the concavity by a surface processing method. The
surface processing method is a mechanical polishing method, a
chemical etching method, or a laser processing method.
[0016] Preferably, each abrasive unit has a tip opposite the
concavity, and a vertical distance between the surface of the
substrate and the tip of each abrasive unit ranges from 20 .mu.m to
300 .mu.m, inclusive. More preferably, the vertical distance
between the surface of the substrate and the tip of each abrasive
unit ranges from 100 .mu.m to 300 .mu.m, inclusive.
[0017] Preferably, the chemical mechanical polishing conditioner
has at least two vertical distances between the surface of the
substrate and the tip of each abrasive unit, a difference between
the vertical distances ranges from 20 .mu.m to 100 .mu.m,
inclusive.
[0018] Preferably, the CMP conditioner has a first vertical
distance between the surface of the substrate and the tip of each
abrasive unit, defined as an exposing degree H, and a second
vertical distance between the surface of the substrate and the tip
of each abrasive unit, defined as an exposing degree H'. A
difference between the first vertical distance and the second
vertical distance ranges from 20 .mu.m to 100 .mu.m, inclusive.
More preferably, the difference between the first vertical distance
and the second vertical distance ranges from 40 .mu.m to 60 .mu.m,
inclusive.
[0019] When the pad to be dressed has a non-uniform thickness,
i.e., the surface of the pad is not smooth, using the CMP
conditioner, which has two different exposing degrees H, H' and
said arrangement of the fixed plates, provides a more uniform
dressing performance of the CMP conditioner.
[0020] Preferably, the abrasive units are consisted of artificial
diamond, natural diamond, polycrystalline diamond, or cubic boron
nitride.
[0021] Preferably, dimensions of the abrasive units range from 30
.mu.m to 2000 .mu.m, inclusive. More preferably, the dimensions of
the abrasive units range from 600 .mu.m to 1000 .mu.m, inclusive,
and the diameter of the smallest dimension of the abrasive unit is
80% to the diameter of the largest dimension of the abrasive
unit.
[0022] Preferably, each abrasive unit is mounted on the concavity
of the top by an electroplating method, a sintering method, or a
brazing method.
[0023] Preferably, each abrasive unit is processed by a surface
processing method to form a specific cutting angle, a crystal
structure, a tip height, and an alignment direction. The surface
processing method is a mechanical grinding or lapping method, a
chemical etching method, or a laser processing method.
[0024] Preferably, the cutting angle of each abrasive unit ranges
from 30.degree. to 150.degree., inclusive. More preferably, the
cutting angle of each abrasive unit is 60.degree. or
90.degree..
[0025] Preferably, the crystal structure of each abrasive unit is
hexahedral or octahedral.
[0026] Preferably, the substrate is a stainless steel substrate, a
die steel substrate, a metal alloy substrate, a ceramic substrate,
or a plastic substrate.
[0027] Preferably, number of the concave parts ranges from 50 to
300, inclusive. More preferably, the number of the concave parts
ranges from 60 to 100, inclusive.
[0028] Preferably, a shape of a cross-section of each concave part
is circular. A diameter of the cross-section of each concave part
ranges from 2.6 mm to 3.6 mm, inclusive.
[0029] Preferably, a shape of each fixed plate is cylindrical and
the fixed plates are consisted of stainless steel. A cross-section
of each fixed plate ranges from 2.6 mm to 3.6 mm, inclusive.
[0030] Other objectives, advantages and novel features of the
invention will become more apparent from the following detailed
description when taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a cross-sectional view of a CMP conditioner in
accordance with Embodiment 1 of the present invention;
[0032] FIG. 2 is a cross-sectional view in partial section of a
fixed plate of the CMP conditioner in accordance with Embodiment 1
of the present invention;
[0033] FIG. 3 is an exploded cross-sectional view of the fixed
plate and the abrasive unit of the CMP conditioner in accordance
with Embodiment 1 of the present invention;
[0034] FIG. 4 is a scanning electron microscope image of the fixed
plate and the abrasive unit of the CMP conditioner in accordance
with Embodiment 1 of the present invention;
[0035] FIG. 5 is an operational view of the CMP conditioner in
accordance with Embodiment 1 of the present invention with a
pad;
[0036] FIG. 6 is a cross-sectional view of a CMP conditioner in
accordance with Embodiment 2 of the present invention;
[0037] FIG. 7 is a cross-sectional view in partial section of the
CMP conditioner in accordance with Embodiment 2 of the present
invention;
[0038] FIG. 8 is a cross-sectional view in partial section of a CMP
conditioner in accordance with Embodiment 3 of the present
invention;
[0039] FIG. 9 is a cross-sectional view in partial section of a
fixed plate of a CMP conditioner in accordance with Embodiment 4 of
the present invention;
[0040] FIG. 10 is an operational view of a conventional CMP
conditioner with a pad.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
[0041] With reference to FIG. 1 and FIG. 2, the chemical mechanical
polishing conditioner 1 (abbreviated as CMP conditioner) of
Embodiment 1 comprises a substrate 10, multiple fixed plates 20,
and multiple abrasive units 30.
[0042] A shape of the substrate 10 is circular, and the substrate
10 has multiple concave parts 11. The concave parts 11 are formed
in a surface of the substrate 10. Each concave part 11 has a side
wall 111. In the present embodiment, the substrate 10 is consisted
of stainless steel and has a thickness of 6.35 mm. The number of
the concave parts 11 is sixty-six, and the concave parts 11 are
arranged on the surface of the substrate 10 in concentric circles.
More specifically, thirty-six of the concave parts 11 are arranged
at the outer circle, and the other thirty concave parts 11 are
arranged at the inner circle. It can be seen that FIG. 1 is merely
a schematic view for illustration. Each concave part 11 has a
circular cross-section with a diameter of 2.6 mm.
[0043] The fixed plates 20 are mounted in the concave parts 11, and
each fixed plate 20 has a bottom 21, a top 22, a concavity 23, and
an inclined plane 24. In the present embodiment, the fixed plate 20
made of stainless steel is formed as a cylindrical structure, and a
diameter C of a cross-section of each fixed plate 20 is 2.5 mm.
[0044] The bottoms 21 of the fixed plates 20 are each respectively
fixed into the concave parts 11 through binding layers 40. In the
present embodiment, the bottoms 21 of the fixed plates 20 are each
respectively fixed into the concave parts 11 by a brazing method
through the binding layers 40. The binding layer 40 is consisted of
a brazing material. The brazing material is aluminum.
[0045] The top 22 is formed on the bottom 21 in an integral
configuration, and a contact surface is formed between the top 22
and the bottom 21. The concavity 23 is formed in the top 22 and
opposite the bottom 21. The inclined plane 24 is formed obliquely
and inwardly from the contact surface toward the concavity 23. A
space 25 is formed between the inclined plane 24 and the side wall
111, and an angle .alpha. is formed between an extending plane of
the inclined plane 24 and the side wall 111. In the present
embodiment, the angle .alpha. is 45.degree..
[0046] With reference to FIG. 3 and FIG. 4, the abrasive units 30
are each respectively mounted in the concavities 23 to form a
pyramidal structure. In the present embodiment, each of the
abrasive units 30 is mounted in the concavity 23 by a brazing
method and has a tip 31. The abrasive units 30 are consisted of
artificial diamond. A dimension of each abrasive unit 30 is 800
.mu.m. The tip 31 of each abrasive unit 30 is opposite the
concavity 23. A vertical distance between the surface of the
substrate 10 and the tip of each abrasive unit 30 is defined as an
exposing degree H of each abrasive unit 30, being 100 .mu.m. Each
abrasive unit 30 has a specific cutting angle .theta. and a crystal
structure. In the present embodiment, the cutting angle .theta. of
each abrasive unit 30 is 60.degree. as shown in FIG. 3, and the
crystal structure of each abrasive unit 30 is hexahedral. A ratio
of the exposing degree H of each abrasive unit 30 to the diameter C
of the cross-section of each fixed plate 20 is 1:25. A ratio of the
dimension of each abrasive unit 30 to the diameter C of the
cross-section of each fixed plate 20 is 8:25.
[0047] With reference to FIG. 5, when the CMP conditioner 1 is
applied to a pad 90, the slurry introduced on a surface of the pad
90 is fluctuated in turbulence and irregularly moved within the
space 25, allowing the concentration of the slurry to become more
uniform in the space 25. Furthermore, the thickness of the pad 90
can also be recovered to its original thickness in the space 25.
That is to say, a cutting depth D of the abrasive units 30 applied
to the pad 90 is not further limited by the dimension of the
abrasive units 30, and thus the cutting depth D is increased to
improve the dressing performance of the CMP conditioner 1.
Embodiment 2
[0048] With reference to FIG. 6 and FIG. 7, the CMP conditioner 1A
of Embodiment 2 is similar to the CMP conditioner 1 of Embodiment
1. The differences between these two embodiments are described
hereinafter.
[0049] In the instant Embodiment, the substrate 10A is made of a
ceramic material. The concave parts 11A are formed through the
substrate 10A. The number of the concave parts 11A is one hundred,
and the concave parts 11A are arranged on the surface of the
substrate in a radial pattern. The diameter of the cross-section of
each concave part 11A is 3.6 mm.
[0050] The diameter C of a cross-section of each fixed plate 20A is
3.5 mm. The bottoms 21A of the fixed plates 20A are each
respectively fixed into the concave parts 11A by a polymeric curing
method through the binding layer 40A made of a polymeric material.
The polymeric material is epoxy resin.
[0051] The abrasive units 30A made of cubic boron nitride are
mounted on the concavities 23A by a sintering method. A dimension
of each abrasive unit 30A is 2000 .mu.m. The exposing degree H of
each abrasive unit 30A is 300 .mu.m. The cutting angle .theta. of
each abrasive unit 30A is 90.degree.. It can be seen that FIG. 7 is
a schematic view for illustration. The crystal structure of each
abrasive unit 30A is octahedral. The ratio of the exposing degree H
of each abrasive unit 30A to the diameter C of the cross-section of
each fixed plate 20A is 3:35. The ratio of the dimension of each
abrasive unit 30A to the diameter C of the cross-section of each
fixed plate 20A is 4:7.
Embodiment 3
[0052] With reference to FIG. 8, the CMP conditioner 1B of
Embodiment 3 is similar to the CMP conditioner 1 of Embodiment 1.
The differences between these two embodiments are described
hereinafter.
[0053] In the instant Embodiment, the CMP conditioner 1B has two
different exposing degrees of the abrasive units 30B, the first
exposing degree H of the abrasive units 30B and the second exposing
degree H' of the abrasive units 30B. A distance between the first
exposing degree H of the abrasive units 30B and the second exposing
degree H' of the abrasive units 30B ranges from 20 .mu.m to 100
.mu.m. The ratio of the dimension of each abrasive unit 30B to the
diameter of the cross-section of each fixed plate 20B is 1:2.
[0054] When the pad 90 to be dressed has a non-uniform thickness,
i.e., the surface of the pad 90 is not smooth, using the CMP
conditioner 1B, which has two different exposing degrees H, H' and
said arrangement of the fixed plates 20B, provides a more uniform
dressing performance of the CMP conditioner 1B.
Embodiment 4
[0055] With reference to FIG. 9, the CMP conditioner 1C of
Embodiment 4 is similar to the CMP conditioner 1 of Embodiment 1.
The differences between these two embodiments are described
hereinafter.
[0056] Each fixed plate 20C of the instant Embodiment has two
concavities 23C and the inclined plane 24C. The concavities 23C are
formed in the top 22C. The inclined plane 24C is formed obliquely
and inwardly from the contact surface toward the concavities 23C.
The abrasive units 30C made of polycrystalline diamond are mounted
on the concavities 23C. The dimension of each abrasive unit 30C is
300 .mu.m. The diameter of the cross-section of each fixed plate
20C is 2.5 mm. The ratio of the dimension of each abrasive unit 30C
to the diameter of the cross-section of each fixed plate 20C is
1:8. In the present embodiment, each fixed plate 20C is mounted
with more abrasive units 30C than in the Embodiment 1 to improve
the dressing efficiency when the CMP conditioner 1C is applied to
the pad.
Experimental Embodiment
[0057] The CMP conditioner of Embodiment 1 and the conventional CMP
conditioner described in background of the invention, as a control
sample, are respectively applied to two pads, and the thicknesses
of the pads are recorded at different dressing time (x, unit:
hour). Results are listed in Table 1.
[0058] The dressing efficiency is calculated by dividing the
thickness difference of the pad before and after dressing by the
dressing time. The average dressing efficiencies of the CMP
conditioner 1 of Embodiment 1 and of the conventional CMP
conditioner are also listed in Table 1.
TABLE-US-00001 TABLE 1 CMP conditioner of CMP conditioner of
Embodiment 1 Control Sample Thicknesses x = 0 2031 .mu.m 1993 .mu.m
of the pad x = 1 1912 .mu.m 1898 .mu.m x = 2 1800 .mu.m 1815 .mu.m
x = 3 1668 .mu.m 1723 .mu.m x = 4 1563 .mu.m 1634 .mu.m Average
dressing 118 .mu.m per hour 89.7 .mu.m per hour efficiency
[0059] The average dressing efficiency of the CMP conditioner of
Embodiment 1 was 118 .mu.m per hour. Compared to the conventional
CMP conditioner, the average dressing efficiency of the
conventional CMP conditioner was 90 .mu.m per hour; the average
dressing efficiency of the CMP conditioner of Embodiment 1 was
improved by 31%. When the CMP conditioner of Embodiment 1 is
applied to the pad, the space between the inclined plane and the
side wall of the concave part makes the thickness of the pad
recover to its original thickness; hence, the cutting depth is
increased and the dressing performance of the CMP conditioner is
also improved.
[0060] Even though numerous characteristics and advantages of the
present invention have been set forth in the foregoing description,
together with details of the structure and features of the
invention, the disclosure is illustrative only. Changes may be made
in the details, especially in matters of shape, size, and
arrangement of parts within the principles of the invention to the
full extent indicated by the broad general meaning of the terms in
which the appended claims are expressed.
* * * * *