U.S. patent application number 10/321372 was filed with the patent office on 2003-06-19 for apparatus for polishing semiconductor wafer.
Invention is credited to Choi, Jae-Won, Kim, Hyeung-Yeul.
Application Number | 20030111176 10/321372 |
Document ID | / |
Family ID | 19717248 |
Filed Date | 2003-06-19 |
United States Patent
Application |
20030111176 |
Kind Code |
A1 |
Choi, Jae-Won ; et
al. |
June 19, 2003 |
Apparatus for polishing semiconductor wafer
Abstract
A wafer planarizing apparatus includes a cleaner that prevents
contamination caused by a fume phenomenon occurring when slurry is
cleaned from a base of a polishing station. The cleaner has spout
holes through which a cleaning solution is applied to a side of a
platen of the polishing station. As the cleaning solution flows
along the side of the platen, the side of the platen is cleaned.
Beneficially, a main body of the cleaner has an arch-shaped upper
side so as to stream down foreign materials.
Inventors: |
Choi, Jae-Won; (Suwon-Shi,
KR) ; Kim, Hyeung-Yeul; (Youngin-Shi, KR) |
Correspondence
Address: |
VOLENTINE FRANCOS, P.L.L.C.
Suite 150
12200 Sunrise Valley Drive
Reston
VA
20191
US
|
Family ID: |
19717248 |
Appl. No.: |
10/321372 |
Filed: |
December 18, 2002 |
Current U.S.
Class: |
156/345.12 ;
257/E21.23 |
Current CPC
Class: |
H01L 21/30625 20130101;
B24B 53/017 20130101; H01L 21/67051 20130101 |
Class at
Publication: |
156/345.12 |
International
Class: |
C23F 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 19, 2001 |
KR |
2001-81318 |
Claims
What is claimed is:
1. A wafer planarizing apparatus comprising: a polishing station
with a base on which a platen having a polishing pad is placed; a
polishing head for polishing a wafer on the polishing pad of the
platen; and a cleaner disposed upon the base of the polishing
station, wherein the cleaner has a main body and a first cleaning
unit installed in the main body, the first cleaning unit being
adapted to clean a side of the platen.
2. The wafer planarizing apparatus of claim 1, wherein the first
cleaning unit includes at least one spout hole adapted to pour a
cleaning solution to the side of the platen such that the cleaning
solution flows along the side of the platen.
3. The wafer planarizing apparatus of claim 2, wherein the spout
hole is formed in the main body adjacent to the side of the
platen.
4. The wafer planarizing apparatus of claim 1, wherein the main
body is located between adjacent platens.
5. The wafer planarizing apparatus of claim 1, wherein the main
body has an arch-shaped upper side.
6. The wafer planarizing apparatus of claim 1, wherein the main
body has an inclined upper side so as to stream down foreign
materials.
7. The wafer planarizing apparatus of claim 1, wherein the cleaner
further includes: a second cleaning unit adapted to clean the base
of the polishing station; and a third cleaning unit adapted to
clean a polished surface of a wafer supported by the polishing head
and a carrier head.
8. The wafer planarizing apparatus of claim 7, wherein the second
cleaning unit includes second nozzles disposed at a side of the
main body.
9. The wafer planarizing apparatus of claim 7, wherein the main
body has an arch-shaped upper side, and the third cleaning unit
includes a plurality of third nozzles disposed at the arch-shaped
upper side.
10. The wafer planarizing apparatus of claim 7, wherein the cleaner
further includes: a first waterway fluid pathway disposed in the
main body and connected to the first and second cleaning units; a
second fluid pathway disposed in the main body and connected to the
third cleaning unit; and first and second cleaning solution supply
pipes that are coupled to the first and second fluid pathways to
supply a cleaning solution, respectively.
11. The wafer planarizing apparatus of claim 10, wherein the first
cleaning solution supply pipe supplies the cleaning solution in a
manual manner.
12. The wafer planarizing apparatus of claim 1, wherein the
cleaning solution employs deionized water (DI water).
13. A wafer planarizing apparatus, comprising: a polishing station,
comprising, a base, a platen mounted on the base, the platen having
a polishing means thereon; and a polishing head adapted to polish a
wafer on the polishing means; and a cleaner disposed on the base of
the polishing station, the cleaner having a first cleaning unit
adapted to apply a cleaning solution to clean a side of the
platen.
14. The apparatus of claim 13, wherein the cleaner includes a main
body having an upper side that is arched.
15. The apparatus of claim 13, wherein the cleaner further
comprises a second cleaning unit adapted to clean the base of the
polishing station.
16. The apparatus of claim 15, wherein the cleaner further
comprises a third cleaning unit adapted to clean a polished surface
of a wafer.
17. The apparatus of claim 16, wherein the cleaner further
includes: a first fluid pathway connected to the first and second
cleaning units; and a second fluid pathway connected to the third
cleaning unit.
18. The apparatus of claim 13, wherein the cleaner further includes
a fluid pathway connected between the first cleaning unit and a
cleaning solution supply pipe.
19. The apparatus of claim 13, wherein the cleaner comprises a main
housing and the first cleaning unit includes a main spout formed in
the housing.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. .sctn.119
from Korean Patent Application No. 2001-0081318, filed on Dec. 19,
2001, the contents of which are hereby incorporated by reference
herein in their entirety for all purposes as if fully set forth
herein.
BACKGROUND AND SUMMARY
[0002] 1. Technical Field
[0003] The present invention relates to an apparatus for
planarizing a wafer surface during a semiconductor fabricating
process and, more specifically, to a wafer polishing apparatus for
preventing a contamination caused by a slurry.
[0004] 2. Description
[0005] As semiconductor devices are continuously scaled down, the
interconnection structure trends toward a multi-layer structure.
Accordingly, a surface step difference between unit cells stacked
on a semiconductor substrate becomes increasingly high. In order to
reduce the step difference, various methods for planarizing a wafer
surface have been proposed.
[0006] Chemical mechanical polishing (CMP) is one method of
planarization. A conventional CMP apparatus includes a polishing
station and a polishing head assembly. The polishing station has
rotatable platens on each of which is mounted a polishing pad. A
wafer is placed on a polishing pad that is mounted on a platen. At
this time, a wafer surface to be polished (the process surface or
polishing surface) faces the polishing pad. The polishing head
provides a controllable pressing force (load) onto a rear side of
the wafer so as to press the wafer against the polishing pad. A
polishing agent (slurry) is supplied to the polishing pad. The
platen and the polishing head are moved relative to each other to
planarize concave/convex portions of the wafer surface chemically
and mechanically.
[0007] During the planarization, the polishing agent may partially
drop onto a side of the platen and a base of the polishing station.
The polishing station base contaminated by the polishing agent is
cleaned by a cleaner (so-called "interplaten cleaner") as shown in
FIG. 1.
[0008] Referring to FIG. 1, a cleaner 50 has first nozzles 52 and
second nozzles 54. The first nozzles 52 spray high-pressure
deionized (DI) water onto a base 22 of a polishing station 20. The
second nozzles 54 clean portions between a retaining ring and a
membrane, as well as a polished surface of a wafer.
[0009] The cleaner 50 suffers from the following problems.
[0010] A fume phenomenon is caused by the high-pressure DI water
that is sprayed onto the base 22 of the polishing station 20
through the first nozzles 52. Because of the fume phenomenon, the
DI water and slurry stick to an uncontaminated device or surface
(e.g., a side 24a of the platen 24) and are hardened. That is, a
second contamination occurs.
[0011] Also, unless a surface of the cleaner 50 is itself cleaned
frequently, foreign materials (created in grooves 56) lead to a
second contamination while the polishing head 30 is cleaned.
Moreover, it is difficult to clean the surface of the cleaner 50
because respective spacings between grooves 56 are very narrow.
[0012] In order to overcome the foregoing problems, it is an object
of the present invention to provide a wafer planarizing apparatus
capable of preventing platen contamination caused by a fume
phenomenon that occurs while a base of a polishing station is
cleaned.
[0013] Further, it is an object of the present invention to provide
a wafer planarizing apparatus capable of minimizing contamination
of a cleaner surface, and having a cleaner surface that is easier
to clean.
[0014] According to one or more aspects of the invention, a wafer
planarizing apparatus includes a polishing station with a base on
which a platen having a polishing pad is placed, a polishing head
for polishing a wafer on the polishing pad of the platen, and a
cleaner mounted upon the base of the polishing station. The cleaner
has a main body, and a first cleaning unit that is installed in the
main body and cleans the
[0015] The first cleaning unit is spout holes through which a
cleaning solution is poured to a side of the platen such that the
cleaning solution flows along the side of the platen. The spout
holes are formed at the main body adjacent to the side of the
platen. The main body has an arch-shaped or inclined upper side so
as to stream down foreign materials.
[0016] The cleaner further includes a second cleaning unit for
cleaning the base of the polishing station, and a third cleaning
unit for cleaning a polished surface of a wafer supported by the
polishing head and a carrier head.
[0017] The cleaner further includes a first waterway that is formed
at the main body and connected to the first and second cleaning
units, a second waterway that is formed at the main body and
connected to the third cleaning unit, and first and second cleaning
solution supply pipes that are coupled to the first and second
waterways to supply a cleaning solution, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a partial diagram of a cleaner in a CMP
apparatus.
[0019] FIG. 2 is an explosive perspective view of a CMP apparatus
including an embodiment of a novel cleaner.
[0020] FIG. 3 is a perspective view of the cleaner shown in FIG.
2.
[0021] FIG. 4 is a front view of the cleaner shown in FIG. 2.
[0022] FIG. 5 is a side view of the cleaner shown in FIG. 2.
[0023] FIG. 6 is a cross-sectional view taken along a line I-I of
FIG. 4.
[0024] FIG. 7 is a schematic diagram for explaining the steps of
cleaning a cleaner in the CMP apparatus of FIG. 2.
DETAILED DESCRIPTION
[0025] Referring to FIG. 2, a CMP apparatus 100 includes a
polishing station 110 and a polishing head assembly 150.
[0026] The polishing head assembly 150 has four polishing heads
152, a driving axis 154, and a motor 156. The polishing head 152
supports a wafer against a polishing pad 122 and uniformly
distributes a downward pressure to a rear side of the wafer. The
polishing head 152 is rotated by the driving axis 154 connected to
the motor 156. The rpm of the polishing head 152 is beneficially
from 40 to 70 rpm, but it may be lower. Beneficially, at least two
fluid supply channels for supplying an air pressure to the
polishing head 152 or for vacuum-absorbing a wafer may be connected
to the polishing head 152. Pumps are securely connected to the
fluid supply channels, respectively.
[0027] The polishing station 110 has a base 112 upon which
rotatable platens 124 are mounted. Polishing pads 122 are placed on
the respective platens 124. Each of the platens 124 is connected to
platen-rotating means (not shown). Beneficially, the
platen-rotating means rotates the platen 124 at 50 to 80 rpm.
However, the rotating speed may be lower. The polishing pad 122 may
be a composite material having a rough polished surface. The
polishing station 110 has conventional pad conditioning means 114
and slurry supply means 116 for supplying slurry onto a polishing
pad surface. The slurry contains a reaction reagent (e.g., DI water
for oxide polishing), friction articles (e.g., silicon dioxide for
oxide polishing), and a chemical reaction catalyst (e.g., potassium
hydroxide for oxide polishing). The polishing head assembly 150,
the pad conditioning means 114, and the slurry supply means 116
need not be explained in further detail to understand and
appreciate the invention.
[0028] The polishing station 110 includes a cleaner 130 that is
located between adjacent platens 124. The cleaner 130 cleans the
side 124a of the platen 124 and the base 112 of the polishing
station 110 that are contaminated by the slurry during the
planarization process, as well as a polished surface of a wafer
(not shown) that is supported by the polishing head 152 and a
carrier head.
[0029] Referring to FIG. 3 through FIG. 5, the cleaner 130 has a
main body 132 and a first cleaning unit 140 formed in the main body
132. The first cleaning unit 140 cleans the side 124a of the platen
124 adjacent to the cleaner 130. Beneficially, the first cleaning
unit 140 has spout holes 140a through which a cleaning solution is
poured.
[0030] Referring to FIG. 7, the cleansing solution poured through
the spout hole 140a flows along the side 124a of the platen 124 to
clean the side 124a of the platen 124. Therefore, it is possible to
prevent slurry from being hardened at the side 124a of the platen
124. For example, the spout hole 140a is preferably formed at a
side 132b corresponding to a center of the main body 132 that is
closest to the platen 124.
[0031] The cleaner 130 has a second cleaning unit 144 adapted to
clean the base 112 of the polishing station 110 and a third
cleaning unit 148 adapted to clean a polished surface of the wafer
supported by the polishing head 152 and a carrier head.
Beneficially, the second cleaning unit 144 has six side nozzles
144a mounted upon a side 132b of the main body 132. Also
beneficially, the third cleaning unit 148 has six upper nozzles
148a mounted upon an uppermost portion of an upper side 132a of the
main body 132.
[0032] In the cleaner 130, a cleaning solution is poured through
the spout hole 140 while being sprayed at a high pressure through
the upper nozzles 148a and the side nozzles 144a. Meanwhile, when a
spray hole size of the side nozzle 144a is sufficiently large, a
slurry fume can be suppressed even when a high-pressure cleaning
solution is sprayed.
[0033] Returning to FIG. 3, beneficially the main body 132 has an
arch-shaped upper side 132a so that any slurry dropping on the main
body 132 while cleaning the polishing head 152 and the polished
surface of the wafer can naturally flow to the base 112 of the
polishing station 110. Advantageously, the main body 132 having the
arch-shaped upper side 132a may minimize a contamination caused by
the slurry and enable a worker to easily clean a surface of the
cleaner as compared to the effort required to clean a conventional
cleaner. For example, in the embodiment of FIG. 3, it can be seen
that the upper side 132a of the main body 132 is arched or
inclined.
[0034] Referring to FIG. 5 and FIG. 6, the cleaner 130 has first
and second fluid pathways 134 and 136 formed in the main body 132.
The first fluid pathway 134 is connected to the spout holes 140a
and the side nozzles 144a, and the second fluid pathway 136 is
connected to the upper nozzles 148a. First and second cleaning
solution supply pipes 137 and 139 for supplying a cleaning solution
are connected to the first and second fluid pathways 134 and 136,
respectively. For example, the cleaning solution is supplied to the
first and second cleaning units 140 and 144 through the first
cleaning solution supply pipe 137 at a predetermined interval (for
example, for 60 seconds at an interval of 900 seconds). The
cleaning solution is supplied to the third cleaning unit 148
through the second cleaning solution supply pipe 139 by the
handling of a worker.
[0035] Disclosed herein therefore is a cleaner for preventing a
platen contamination caused by a fume phenomenon occurring when a
base of a polishing station is cleaned. Further, the cleaner has a
main body having an arch-shaped upper side so as to minimize a
contamination caused by slurry. Still further, the cleaner has
spout holes through which a cleaning solution is poured to a side
of the platen. The spout holes are formed in the cleaner. As the
cleaning solution flows along a side of a platen, the side of the
platen is cleaned.
[0036] As described above, it is possible to prevent a platen
contamination caused by a fume phenomenon occurring when a base of
a polishing station is cleaned. Further, since a cleaner has an
arch-shaped upper side, a main body contamination caused by slurry
can be minimized and a worker can easily clean the cleaner as
compared to the effort required to clean a conventional cleaner. In
addition, since a cleaning solution cleans a side of the platen
while flowing along the side of the platen, the slurry is not
hardened on the side of the platen.
[0037] While the invention has been illustrated and described in
detail in the foregoing drawings and description, the same is to be
considered as illustrative and not restrictive in character, it
being understood that only preferred embodiments thereof have been
shown and described and that all changes and modifications that
come within the spirit of the invention are desired to be
protected.
* * * * *