U.S. patent application number 10/065033 was filed with the patent office on 2004-02-26 for conditioner of chemical-mechanical polishing station.
Invention is credited to Cheng, Chi-Feng.
Application Number | 20040038632 10/065033 |
Document ID | / |
Family ID | 29708544 |
Filed Date | 2004-02-26 |
United States Patent
Application |
20040038632 |
Kind Code |
A1 |
Cheng, Chi-Feng |
February 26, 2004 |
Conditioner of chemical-mechanical polishing station
Abstract
A conditioner for conditioning the polishing pad of a
chemical-mechanical polishing station. The conditioner includes a
conditioning disk having an input surface and an output surface, a
tube with one end attached to the input surface of the conditioning
disk, a high-pressure fluid supplier connected to the other end of
the tube and a plurality of nozzles positioned on the output
surface of the conditioning disk.
Inventors: |
Cheng, Chi-Feng; (Chang-Hua
County, TW) |
Correspondence
Address: |
JIANQ CHYUN INTELLECTUAL PROPERTY OFFICE
7 FLOOR-1, NO. 100
ROOSEVELT ROAD, SECTION 2
TAIPEI
100
TW
|
Family ID: |
29708544 |
Appl. No.: |
10/065033 |
Filed: |
September 12, 2002 |
Current U.S.
Class: |
451/287 ;
257/E21.23; 451/443 |
Current CPC
Class: |
H01L 21/30625 20130101;
B24B 53/017 20130101 |
Class at
Publication: |
451/287 ;
451/443 |
International
Class: |
B24B 005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 23, 2002 |
TW |
91119090 |
Claims
1. A conditioner for conditioning the polishing pad of a
chemical-mechanical polishing station, comprising: a conditioning
disk having an input surface and an output surface; a tube having
one end connected to the input surface of the conditioning disk; a
high-pressure fluid supplier connected to the other end of the
tube; and a plurality of nozzles on the output surface of the
conditioning disk.
2. The conditioner of claim 1, wherein the high-pressure fluid
supplier is a pressurized liquid supplier.
3. The conditioner of claim 2, wherein the pressurized liquid
supplier provides a pressurized liquid including water.
4. The conditioner of claim 2, wherein the pressurized liquid
supplier provides a liquid at a pressure between 10 psi to 100
psi.
5. The conditioner of claim 1, wherein the high-pressure fluid
supplier is a pressurized gas supplier.
6. The conditioner of claim 5, wherein the pressurized gas supplier
provides a pressurized gas including nitrogen.
7. The conditioner of claim 5, wherein the pressurized gas supplier
provides a gas at a pressure between 10 psi to 100 psi.
8. A chemical-mechanical polishing station, comprising: a polishing
table; a polishing pad over the polishing table; a wafer carrier
over the polishing pad for gripping a wafer and pressing the front
surface of the wafer against the upper surface of the polishing
pad; a slurry tube over the polishing pad for delivering slurry to
the polishing pad; and a conditioner over the polishing pad for
conditioning the polishing pad, wherein the conditioner further
includes: a conditioning disk having an input surface and an output
surface; a tube having one end connected to the input surface of
the conditioning disk; a high-pressure fluid supplier connected to
the other end of the tube; and a plurality of nozzles on the output
surface of the conditioning disk.
9. The polishing station of claim 8, wherein the high-pressure
fluid supplier is a pressurized liquid supplier.
10. The polishing station of claim 9, wherein the pressurized
liquid supplier provides a pressurized liquid including water.
11. The polishing station of claim 9, wherein the pressurized
liquid supplier provides a liquid at a pressure between 10 psi to
100 psi.
12. The polishing station of claim 8, wherein the high-pressure
fluid supplier is a pressurized gas supplier.
13. The polishing station of claim 12, wherein the pressurized gas
supplier provides a pressurized gas including nitrogen.
14. The polishing station of claim 12, wherein the pressurized gas
supplier provides a gas at a pressure between 10 psi to 100 psi.
Description
BACKGROUND OF INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates to a chemical-mechanical
polishing (CMP) station. More particularly, the present invention
relates to the conditioner of a chemical-mechanical polishing
station.
[0003] 2. Description of Related Art
[0004] Chemical-mechanical polishing (CMP) is a major global
planarizing technique. The irregular surface of a wafer is
planarized through mechanical grinding normally with the assistant
of a chemical reagent.
[0005] FIG. 1 is a simplified top view of a conventional
chemical-mechanical polishing station. FIG. 2 is a side view of a
conventional chemical-mechanical polishing station.
[0006] As shown in FIGS. 1 and 2, the chemical-mechanical polishing
station includes a polishing table 100, a polishing pad 102, a
wafer carrier 104, a slurry tube 108 and a conditioner 110.
[0007] The polishing pad 102 is laid over the polishing table 100.
The wafer carrier 104 is placed on the polishing pad 102. The wafer
carrier 104 grips a wafer 106 and presses the wafer 106 against the
polishing pad 102 in a polishing session. The slurry tube 108 is
placed over the polishing pad 102 so that slurry is delivered to
the polishing pad 102 during a polishing operation. The conditioner
110 is also positioned over the polishing pad 102. Hard particles
such as diamond or ceramic grits are embedded on the under surface
of the conditioner 110 for conditioning the upper surface of the
polishing pad 102.
[0008] To conduct a chemical-mechanical polishing operation, the
polishing table 100 and the wafer carrier 104 both rotate in a
pre-defined direction. The wafer carrier 104 grips the backside of
the wafer 106 so that the front surface of the wafer 106 presses
against the polishing pad 102. In the meantime, the slurry tube
provides a continuous supply of slurry to the polishing pad 102.
The protruding peaks on the front surface of the wafer 106 in
contact with the polishing pad 102 react chemically with the
reagent in the slurry. Together with the abrasive action of the
abrasive particles in the slurry, the protruding peaks on the front
surface of the wafer 106 are gradually removed. After conducting
such chemical reaction and abrasive action for some time, the
entire front surface of the wafer 106 is planarized.
[0009] In general, the upper surface of the polishing pad 102 is
gritty having a degree of roughness between 1 to 2 .mu.m. However,
the upper surface of the polishing pad 102 may also be polished
after polishing a few pieces of wafers so that the polishing
capacity of the polishing pad is lowered. Moreover, residual
material from the wafers 106 may accumulate over the polishing pad
102 leading to a change of polishing power. To remove the residual
wafer material and to reconstitute the roughness of the polishing
pad 102, the upper surface of the polishing pad 102 is
re-conditioned using the conditioner 110 after the polishing pad
102 has polished a batch of wafers.
[0010] The conditioner 110 of a conventional chemical-mechanical
polishing station generally includes a conditioning disk 112 with
hardened particles (such as diamond or ceramic grits) embedded on
the conditioning surface of the conditioning disk 112. Yet, if any
of the hardened particles should drop onto the polishing pad 102
while the wafer 106 is being polished, the wafer 106 will be
scratched and damaged.
SUMMARY OF INVENTION
[0011] Accordingly, one object of the present invention is to
provide a conditioner for a chemical-mechanical polishing station
that prevents any hard particles from dropping and hence damaging a
polishing wafer.
[0012] To achieve these and other advantages and in accordance with
the purpose of the invention, as embodied and broadly described
herein, the invention provides a conditioner for a
chemical-mechanical polishing station. The conditioner includes a
conditioning disk, a tube, a high-pressure fluid supplier and a
plurality of nozzles. The conditioning disk has an input surface
and an output surface. One end of the tube is connected to the
input surface of the conditioning disk and the other end of the
tube is connected to the high-pressure fluid supplier. The nozzles
are positioned on the output surface of the conditioning disk. In
this invention, the high-pressure fluid supplier can be a provider
of high-pressure liquid or compressed air. The high-pressure liquid
includes water and the compressed air includes nitrogen. The
high-pressure liquid or compressed air from the high-pressure fluid
supplier has a liquid or gaseous pressure preferably between 10 psi
to 100 psi. The conditioner utilizes pressurized liquid or gases
emitted from the nozzles to recondition a polishing pad so that the
any residual wafer material lodged on the pad surface is removed
and roughness of the pad surface is reconstituted.
[0013] This invention also provides a chemical-mechanical polishing
station that includes a polishing table, a polishing pad, a wafer
carrier, a slurry tube and a conditioner. The polishing pad is laid
over the polishing table. The wafer carrier is placed on the
polishing pad. The wafer carrier grips a wafer and presses the
wafer against the polishing pad in a polishing session. The slurry
tube is placed over the polishing pad so that slurry is delivered
the polishing pad during a polishing operation. The conditioner is
also positioned over the polishing pad for conditioning the upper
surface of the polishing pad. The conditioner includes a
conditioning disk, a tube, a high-pressure fluid supplier and a
plurality of nozzles. The conditioning disk has an input surface
and an output surface. One end of the tube is connected to the
input surface of the conditioning disk and the other end of the
tube is connected to the high-pressure fluid supplier. The nozzles
are positioned on the output surface of the conditioning disk. In
this invention, the high-pressure fluid supplier can be a provider
of high-pressure liquid or compressed air. The high-pressure liquid
includes water and the compressed air includes nitrogen. The
high-pressure liquid or compressed air from the high-pressure fluid
supplier has a liquid or gaseous pressure preferably between 10 psi
to 100 psi. After polishing a few wafers, the polishing pad of the
chemical-mechanical polishing station is reconditioned by the
conditioner. To recondition the polishing pad, pressurized liquid
or gas is emitted from the nozzles on the output surface of the
conditioning disk so that any residual wafer material lodged on the
pad surface is removed and roughness of the pad surface is
reconstituted.
[0014] Since pressurized liquid or gas is used to recondition the
polishing pad, the dropping of hard particles from a conventional
conditioner onto the polishing pad is prevented and thus possible
damage to the wafer is greatly minimized. Moreover, the conditioner
has a relatively simple structure. Therefore, the invention may
increase wafer yield without incurring too much additional
cost.
[0015] It is to be understood that both the foregoing general
description and the following detailed description are exemplary,
and are intended to provide further explanation of the invention as
claimed.
BRIEF DESCRIPTION OF DRAWINGS
[0016] The accompanying drawings are included to provide a further
understanding of the invention, and are incorporated in and
constitute a part of this specification. The drawings illustrate
embodiments of the invention and, together with the description,
serve to explain the principles of the invention. In the
drawings,
[0017] FIG. 1 is a simplified top view of a conventional
chemical-mechanical polishing station;
[0018] FIG. 2 is a side view of a conventional chemical-mechanical
polishing station;
[0019] FIG. 3 is a simplified top view of a chemicai-mechanicai
polishing station according to one preferred embodiment of this
invention;
[0020] FIG. 4 is a side view of a chemical-mechanical polishing
station according to one preferred embodiment of this
invention;
[0021] FIG. 5 is a bottom view of the conditioner of a
chemical-mechanical polishing station according to one preferred
embodiment of this invention; and
[0022] FIG. 6 is a side view of the conditioner of a
chemical-mechanical polishing station according to one preferred
embodiment of this invention.
DETAILED DESCRIPTION
[0023] Reference will now be made in detail to the present
preferred embodiments of the invention, examples of which are
illustrated in the accompanying drawings. Wherever possible, the
same reference numbers are used in the drawings and the description
to refer to the same or like parts.
[0024] FIG. 3 is a simplified top view of a chemical-mechanical
polishing station according to one preferred embodiment of this
invention. FIG. 4 is a side view of a chemical-mechanical polishing
station according to one preferred embodiment of this invention. As
shown in FIGS. 3 and 4, the chemical-mechanical polishing station
includes a polishing table 100, a polishing pad 102, a wafer
carrier 104, a slurry tube 108 and a conditioner 220.
[0025] The polishing pad 102 is laid over the polishing table 100.
The wafer carrier 104 grips a wafer 106 and presses the wafer 106
against the polishing pad 102. The wafer carrier 104 includes a
plurality of vacuum holes (not shown) for gripping the wafer 106
and a retaining ring (not shown) for limiting horizontal wafer
movement. The slurry tube 108 is placed over the polishing pad 102
so that slurry is delivered to the polishing pad 102 during a
polishing operation. The conditioner 220 is also positioned over
the polishing pad 102 for conditioning the upper surface of the
polishing pad 102 so that any residual wafer material lodged on the
pad surface is removed and roughness of the pad surface is
reconstituted.
[0026] FIG. 5 is a bottom view of the conditioner of a
chemical-mechanical polishing station according to one preferred
embodiment of this invention. FIG. 6 is a side view of the
conditioner of a chemical-mechanical polishing station according to
one preferred embodiment of this invention. As shown in FIGS. 4, 5
and 6, the conditioner 220 on the chemical-mechanical polishing
station includes a conditioning disk 200, a tube 204, a
high-pressure fluid supplier 210 and a plurality of nozzles 202 (as
shown in FIG. 5) on the conditioning disk 200. The conditioning
disk 200 has an input surface 200a and an output surface 200b
(shown in FIG. 6). One end of the tube 204 is connected to the
input surface 200a of the conditioning disk 200. The other end of
the tube 204 is connected to the high-pressure fluid supplier 210.
The nozzles 202 are positioned on the output surface 200b of the
conditioning disk 200.
[0027] The high-pressure fluid supplier 210 in the conditioner 220
can be a pressurized liquid or gaseous provider. The pressurized
liquid supplier 210 provides a liquid 206 such as water or some
other suitable liquid. The pressurized gas supplier 210 provides a
gas 206 such as nitrogen or some other suitable gas. The
pressurized liquid or gas from the high-pressure fluid supplier 210
has a pressure preferably between 10 psi to 100 psi. After
polishing a few wafers, the polishing pad 102 on the
chemical-mechanical polishing station is reconditioned by the
conditioner 220. To recondition the polishing pad 102, pressurized
liquid or gas 206 is emitted from the nozzles 202 on the output
surface 200b of the conditioning disk 200 so that any residual
wafer material lodged on the pad surface is removed and roughness
of the pad surface 102 is reconstituted. In other words,
high-pressure liquid or gas provided by the high-pressure fluid
supplier 210 is transferred to the conditioning disk 200 via the
tube 204 and ejected from the nozzles 202 of the conditioner 220
directly against the polishing pad 102 with great pressure. Hence,
surface roughness on the polishing pad 102 necessary for a
polishing operation is reconstituted and any residual material
adhering to the polishing pad 102 is removed.
[0028] In this invention, the conditioner 220 of the
chemical-mechanical polishing station no longer uses a surface
impregnated with hardened particles to recondition the surface of
the polishing pad 102. Instead of a physical surface, this
invention uses jets of pressurized liquid or gas 206 to recondition
the polishing pad 102. Hence, damage to the wafer 106 due to the
dropping of hardened particles onto the polishing pad 102 no longer
occurs. Ultimately, reconditioning the polishing pad 102 using the
conditioner 220 in this invention will reduce wafer damage and
increase wafer yield.
[0029] In summary, major advantages of this invention include:
[0030] 1. Pressurized liquid or gas is used to recondition the
polishing pad. Hence, the dropping of hard particles from a
conventional conditioner onto the polishing pad is prevented and
possible damage to the wafer is greatly minimized.
[0031] 2. The conditioner has a relatively simple structure.
Therefore, the invention may increase wafer yield without incurring
too much additional cost.
[0032] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure of the
present invention without departing from the scope or spirit of the
invention. In view of the foregoing, it is intended that the
present invention cover modifications and variations of this
invention provided they fall within the scope of the following
claims and their equivalents.
* * * * *