U.S. patent application number 10/042252 was filed with the patent office on 2003-07-17 for device for chemical mechanical polishing.
Invention is credited to Huang, Chao-Yuan, Lin, Tsang Jung, Wang, Hsing Maw.
Application Number | 20030134581 10/042252 |
Document ID | / |
Family ID | 21920872 |
Filed Date | 2003-07-17 |
United States Patent
Application |
20030134581 |
Kind Code |
A1 |
Wang, Hsing Maw ; et
al. |
July 17, 2003 |
Device for chemical mechanical polishing
Abstract
The present invention provides a chemical mechanical polishing
device for polishing a wafer. The chemical mechanical polishing
device comprises a platen, an outer polishing pad, an inner
polishing pad, a slurry providing system, and a rotating carrier.
The inner polishing pad is located on the platen. The outer
polishing pad is mounted on the outer polishing pad and peeled off
when abraded from overuse. The slurry providing system provides a
slurry to the surface of the outer polishing pad. The rotating
carrier holds the wafer and contacts the surface of the wafer with
the slurry and the polishing pad to carry out the chemical
mechanical polishing process.
Inventors: |
Wang, Hsing Maw; (Kaohsiung,
TW) ; Lin, Tsang Jung; (Taoyuan Hsien, TW) ;
Huang, Chao-Yuan; (Hsingchu, TW) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
21920872 |
Appl. No.: |
10/042252 |
Filed: |
January 11, 2002 |
Current U.S.
Class: |
451/57 |
Current CPC
Class: |
B24D 18/0045 20130101;
B24D 9/085 20130101; B24B 37/22 20130101 |
Class at
Publication: |
451/57 |
International
Class: |
B24B 007/22 |
Claims
What is claimed is:
1. A chemical mechanical polishing device for polishing a wafer,
comprising: a platen; an inner polishing pad locating on the
platen; an outer polishing pad removeably located on the outer
polishing pad; a slurry providing system, which provides a slurry
to the surface of the outer polishing pad; and a rotating carrier
for holding the wafer and contacting the surface of the wafer with
the slurry and the polishing pad to carry out the chemical
mechanical polishing process.
2. The chemical mechanical polishing device as claimed in claim 1,
wherein the outer polishing pad and the inner polishing pad are
stacked on the platen.
3. The chemical mechanical polishing device as claimed in claim 2,
wherein the bottoms of the outer polishing pad and the inner
polishing pad have adhesive tape fixing the outer polishing pad and
the inner polishing pad.
4. A chemical mechanical polishing method for polishing a wafer,
comprising the following steps: providing a plurality of stacked
polishing pads, whereby the outer polishing pad contacts the wafer;
providing a slurry to the surface of the outer polishing pad;
polishing the wafer by the relative motion between the wafer and
the polishing pad; and peeling the outer polishing pad when abraded
from overuse, and polishing the wafer by inner polishing pad.
5. The chemical mechanical polishing method as claimed in claim 4,
wherein adhesive tapes are located between the polishing pads to
fix the polishing pads.
6. The chemical mechanical polishing method as claimed in claim 5,
wherein the adhesive tapes are located on the respective undersides
of the polishing pads.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates in general to a chemical
mechanical polishing device (CMP device). In particular, the
present invention relates to a plurality of polishing pads stacked
on the platen in advance. Abraded polishing pads are peeled off of
the other stacked polishing pads. After the stack is re-settled,
chemical mechanical polishing is resumed with the new polishing
pad.
[0003] 2. Description of the Related Art
[0004] At present, chemical mechanical polishing (CMP) is the only
way to realize a true global planarization in the manufacture of
integrated circuits. A semiconductor substrate is bathed or rinsed
in polishing slurry while an elastomeric pad is pressed against the
substrate and rotated so that the slurry particles are pressed
against the substrate under load. The lateral motion of the pad
causes the slurry particles to move across the substrate surface,
resulting in chemical and mechanical removal of the substrate
surface.
[0005] FIG. 1 shows a sectional view of the conventional CMP
device. A rotating carrier 110 comprising a transmission shaft 100
is used for holding and rotating a wafer 120. A platen 140 rotates
by a spindle 130. The polishing pad 150 is fixed on the platen 140
by the adhesive tape 160. In addition, slurry 180 is provided on
the surface of the pad 150 by a slurry providing system 170. The
wafer 120 is bathed or rinsed in polishing slurry 180 while the
polishing pad 150 is pressed against the wafer 120 and rotated so
that the slurry particles 180 are pressed against the wafer 120 to
carry out CMP.
[0006] However, the polishing pad 150 will inevitably be worn
during CMP, and the uneven surface of the polishing pad 150
negatively impacts the result of CMP. Therefore, the polishing pad
150 has to be changed after a specific time to ensure the result of
CMP. During the replacement of the polishing pad 150, however, the
CMP system must be shut down and additional operating personnel are
needed to change the polishing pad. Moreover, as the polishing pad
150 must be fixed accurately on the platen 140 by the adhesive tape
160, errors caused by imprecision can negatively influence the
result of the process.
SUMMARY OF THE INVENTION
[0007] The object of the present invention is to provide a CMP
device and method. Stacked polishing pads are set on the platen in
advance, whereby the polishing pads are aligned with each other.
The polishing pad in use is peeled off of the stack when abraded
due to overuse. After the stack is re-settled, chemical mechanical
polishing is resumed with the new polishing pad. The replacement
operation is simple, involving only removal of the abraded
polishing pad and the adhesive tape. Therefore, additional
operating personnel are not needed to change the polishing pad, and
the operation of adjusting the polishing pads is omitted to
eliminate human error. Hence, the stability of the CMP system is
improved and the burden of staff resources is reduced.
[0008] To achieve the above-mentioned object, the present invention
provides a chemical mechanical polishing device for polishing a
wafer. The chemical mechanical polishing device comprises a platen,
an outer polishing pad, an inner polishing pad, a slurry providing
system, and a rotating carrier. The inner polishing pad is located
on the platen. The outer polishing pad is located on the inner
polishing pad and is peeled off when abraded from overuse. The
slurry providing system provides slurry to the surface of the outer
polishing pad. The rotating carrier holds the wafer and contacts
the surface of the wafer with the slurry and the polishing pad to
carry out the chemical mechanical polishing process.
[0009] Moreover, the present invention provides a chemical
mechanical polishing method for polishing a wafer, comprising the
following steps. First, a plurality of stacked polishing pads is
provided, whereby the outer polishing pad contacts the wafer. A
slurry is provided to the surface of the outer polishing pad, and
then, the wafer is polished by the relative motion between the
wafer and the polishing pad. Finally, the outer polishing pad is
peeled when abrading, then the wafer is polished by the polishing
pad beneath the abraded polishing pad.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will become more fully understood from
the detailed description given hereinbelow and the accompanying
drawings, given by way of illustration only and thus not intended
to be limitative of the present invention.
[0011] FIG. 1 shows a sectional view of the conventional CMP
device.
[0012] FIG. 2 shows a sectional view of the CMP device according to
the embodiment of the present invention.
[0013] FIG. 3 shows a lateral view of the polishing pad set on the
platen according to the embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] FIG. 2 shows a sectional view of the CMP device according to
the embodiment of the present invention.
[0015] A rotating carrier 210 comprising a transmission shaft 200
is used for holding and rotating a wafer 220. A platen 240 rotates
by a spindle 230, the rotating direction is shown by the arrows in
FIG. 2. The stacked polishing pads (2501-2503) are fixed by
adhesive tapes (2601-2603) on their respective undersides. In FIG.
2, the polishing pad 2501 is fixed on the polishing pad 2502 by
adhesive tape 2601, the polishing pad 2502 is fixed on the
polishing pad 2503 by adhesive tape 2602, and the polishing pad
2503 is fixed on the platen 240 by adhesive tape 2603.
[0016] FIG. 3 shows a lateral view of the polishing pads
(2501-2503) set on the platen 240 according to the embodiment of
the present invention. In FIG. 3, the stacked polishing pads are
fixed on the platen 240, and the gap 2504 is used for tearing the
polishing pad away.
[0017] In addition, slurry 280 is provided on the surface of the
pad 2501 by a slurry providing system 270. The wafer 220 is bathed
or rinsed in polishing slurry 280 while the polishing pad 2501 is
pressed against the wafer 220 and rotated so that the slurry
particles 280 are pressed against the wafer 220 to carry out
CMP.
[0018] In the present invention, when the polishing pad 2501 is too
worn or is used for a predetermined time (life time) to carry out
CMP, operators need only peel off the polishing pad 2501 with a
cylinder. After performing a Pad Break-In process to the polishing
pad 2502 to remove the adhesive tape 2601 from the polishing pad
2502 and break in the polishing pad 2502, the wafer 220 is polished
with the polishing pad 2502 till CMP is finished. Here, the
operation of changing the polishing pad is simplified because the
polishing pads are stacked and aligned in advance, so the
additional adjusting operation in the prior art is abbreviated.
[0019] Accordingly, the invention not only simplifies the pad
changing procedure and decreases maintenance time, but also
decreases the cost of the process and human resources. Furthermore,
the operation of replacing polishing pad according to the present
invention is very simple, requiring only removal of the abraded
polishing pad and the adhesive tape. Therefore, additional
operating personnel are not needed to change the polishing pad, and
the operation of adjusting the polishing pads is omitted to
eliminate human error. Hence, the stability of the CMP system is
improved and the burden of staff resources is reduced.
[0020] The foregoing description of the preferred embodiments of
this invention has been presented for purposes of illustration and
description. Obvious modifications or variations are possible in
light of the above teaching. The embodiments were chosen and
described to provide the best illustration of the principles of
this invention and its practical application to thereby enable
those skilled in the art to utilize the invention in various
embodiments and with various modifications as are suited to the
particular use contemplated. All such modifications and variations
are within the scope of the present invention as determined by the
appended claims when interpreted in accordance with the breadth to
which they are fairly, legally, and equitably entitled.
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