U.S. patent application number 10/002385 was filed with the patent office on 2003-01-30 for polishing assistant apparatus of polishing assistant system.
This patent application is currently assigned to Winbond Electronics Corp.. Invention is credited to Chen, Ting-Kuo, Chou, Liang-Kuei, Hsu, Lu-Lang, Lee, Chi-Hung.
Application Number | 20030022594 10/002385 |
Document ID | / |
Family ID | 21678895 |
Filed Date | 2003-01-30 |
United States Patent
Application |
20030022594 |
Kind Code |
A1 |
Lee, Chi-Hung ; et
al. |
January 30, 2003 |
Polishing assistant apparatus of polishing assistant system
Abstract
A polishing assistant system applied to a polished wafer
polished by a chemical mechanical polishing (CMP) is disclosed. The
polishing assistant system includes a monitoring device for
detecting a first polishing parameter of the polished wafer, and a
polishing assistant apparatus. The polishing assistant apparatus
further includes a platen for placing the polished wafer, a liquid
supplier for supplying a slurry, a polishing controller for
receiving the first polishing parameter and outputting a first
control signal which is relative to a certain region of the
polished wafer in response to the first polishing parameter, and a
polish head electrically connected to the polishing controller and
polishing the certain region of the polished wafer in response to
the first control signal.
Inventors: |
Lee, Chi-Hung; (Hsinchu,
TW) ; Chou, Liang-Kuei; (Hsinchu, TW) ; Chen,
Ting-Kuo; (Hsinchu, TW) ; Hsu, Lu-Lang;
(Hsinchu, TW) |
Correspondence
Address: |
VOLPE AND KOENIG, P.C.
SUITE 400, ONE PENN CENTER
1617 JOHN F. KENNEDY BOULEVARD
PHILADELPHIA
PA
19103
US
|
Assignee: |
Winbond Electronics Corp.
Hsinchu
TW
|
Family ID: |
21678895 |
Appl. No.: |
10/002385 |
Filed: |
October 26, 2001 |
Current U.S.
Class: |
451/5 |
Current CPC
Class: |
B24B 37/005 20130101;
B24B 49/08 20130101; H01L 21/67253 20130101 |
Class at
Publication: |
451/5 |
International
Class: |
B24B 049/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 27, 2001 |
TW |
090118439 |
Claims
What is claimed is:
1. A polishing assistant system applied to a polished wafer
polished by a chemical mechanical polishing (CMP), comprising: a
monitoring device for detecting a first polishing parameter of said
polished wafer; and a polishing assistant apparatus further
comprising: a platen for placing said polished wafer; a liquid
supplier for supplying a slurry; a polishing controller for
receiving said first polishing parameter and outputting a first
control signal which is relative to a certain region of said
polished wafer in response to said first polishing parameter; and a
polish head electrically connected to said polishing controller and
polishing said certain region of said polished wafer in response to
said first control signal.
2. The polishing assistant system according to claim 1 wherein said
monitoring device further detects a second, a third, and a fourth
polishing parameters.
3. The polishing assistant system according to claim 2 wherein said
second, third, and fourth polishing parameters are a polish head
down force, a polish head rotation speed, and a polishing time,
respectively.
4. The polishing assistant system according to claim 3 wherein in
response to said second, third, and fourth polishing parameters,
said polishing controller outputs a second, third, and fourth
control signals, respectively, and said polish head polishes said
certain region of said polished wafer in response to said second,
third, and fourth control signals, respectively.
5. The polishing assistant system according to claim 3 wherein said
polishing controller comprises: a pressure controlling unit for
controlling a pressure when said polish head polishing in response
to said second polishing parameter; and a movable arm electrically
connected to said pressure controlling unit and carrying said
polish head to move to said certain region of said polished wafer
in response to said first polishing parameter.
6. The polishing assistant system according to claim 5 wherein said
pressure controlling unit has a control pressure ranged from 0.1 to
10 psi.
7. The polishing assistant system according to claim 5 wherein said
movable arm has an internal channel communicating between said
pressure controlling unit and said polish head.
8. The polishing assistant system according to claim 7 wherein said
internal channel is poured thereinto a medium and said control
pressure is achieved by pressurizing said medium.
9. The polishing assistant system according to claim 8 wherein said
medium is one of a liquid oil and a gas.
10.The polishing assistant system according to claim 1 wherein said
monitoring device further comprises: a detector for detecting a
surface of said polished wafer to obtain a data; and a server
electrically connected to said detector, obtaining said first
polishing parameter according to said data, and transmitting said
first polishing parameter to said polishing controller.
11. The polishing assistant system according to claim 1 wherein
said platen is a rotating platen.
12. The polishing assistant system according to claim 1 wherein
said rotating platen has a rotation speed ranged from 1 to 50
revolutions per minute (rpm).
13. The polishing assistant system according to claim 1 wherein
said polish head is made of polyvinyl alcohol (PVA).
14. The polishing assistant system according to claim 1 wherein
said polish head is a rotatable polish head.
15. The polishing assistant system according to claim 14 wherein
said polish head has a diameter ranged from 1 to 3 cm.
16. The polishing assistant system according to claim 15 wherein
said polish head has a rotation speed ranged from 1 to 50 rpm.
17. The polishing assistant system according to claim 1 further
comprising a polish head film disposed between said platen and said
polished wafer for protecting said polished wafer.
18. A polishing assistant system applied to a polished wafer
polished by a chemical mechanical polishing (CMP), comprising: a
monitoring device for detecting a first polishing parameter of said
polished wafer; and a polishing assistant apparatus further
comprising: a platen for placing said polished wafer; a liquid
supplier for supplying a slurry; and a polishing device polishing a
certain region of said polished wafer in response to said first
polishing parameter.
19. The polishing assistant system according to claim 18 wherein
said monitoring device further detects a second, a third, and a
fourth polishing parameters, and said second, third, and fourth
polishing parameters are a polish head down force, a polish head
rotation speed, and a polishing time, respectively.
20. The polishing assistant system according to claim 19 wherein
said polishing device comprises: a polishing controller for
receiving said first, second, third and fourth polishing parameters
and outputting a first, second, third and fourth control signals in
response to said first, second, third and fourth polishing
parameters, respectively; and a polish head electrically connected
to said polishing controller and polishing said certain region of
said polished wafer in response to said first, second, third, and
fourth control signals.
21. The polishing assistant system according to claim 20 wherein
said polishing controller comprises: a pressure controlling unit
for controlling a pressure when said polish head is polishing in
response to said second polishing parameter; and a movable arm
electrically connected to said pressure controlling unit and
carrying said polish head to move to said certain region of said
polished wafer in response to said first polishing parameter.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a polishing assistant
system, and more particularly to a polishing assistant system
applied to a polished wafer which has been polished by a chemical
mechanical polishing.
BACKGROUND OF THE INVENTION
[0002] Chemical mechanical polishing is a planarization technique
to step by step remove the deposited layer on the wafer by a
chemical reaction providing form the slurry and a mechanical
polishing. Along the semiconductor production technology is
developed from 0.25 .mu.m into 0.175 .mu.m level, the CMP is more
and more important in the semiconductor procedure. However, the
current CMP machine only includes a rotary polish unit and a clean
unit to polish and clean the wafer.
[0003] FIG. 1 is a cutaway view illustrating a conventional
polishing apparatus. A polish pad 10 is adhered on a platen 11 and
used as a pad for a wafer 12 when polishing. A back side pressure
13 is applied to a carrier film 15, which is further controlling a
removal rate and an uniformity of a polish head 14 to polish the
wafer 12. However, the fuzz of the polish pad surface is deformed
after long time polishing, so the polish pad 10 will loss the
characteristic of absorbing the slurry. Thus, the removal rate of
the wafer further decreases.
[0004] FIG. 2 is a plot illustrating a ratio of the maximum and the
minimum of removal rate in a wafer surface along time according to
the prior art. As shown in FIG. 2, along the using time of the
polish pad (from the 25.sup.th wafer to the 725.sup.th wafer), the
ratio of the maximum and the minimum of the removal rate for the
wafer surface increases. That is, the removal rate non-uniformity
also increases, and it is hard to achieve the planarization of the
wafer.
[0005] Therefore, the purpose of the present invention is to
develop a polishing assistant system to deal with the above
situations encountered in the prior art.
SUMMARY OF THE INVENTION
[0006] It is therefore an object of the present invention to
provide a polishing assistant system for compensating the removal
rate non-uniformity resulted from the deformations of polish pad,
carrier film, or relative consumables.
[0007] It is therefore another object of the present invention to
provide a polishing assistant system for controlling the removal
amount of every region of the wafer surface.
[0008] It is therefore an additional object of the present
invention to provide a polishing assistant system for proceeding a
fine polish process to achieve the planarization of the wafer.
[0009] According to an aspect of the present invention, there is
provided a polishing assistant system applied to a polished wafer
polished by a chemical mechanical polishing (CMP). The polishing
assistant system includes a monitoring device for detecting a first
polishing parameter of the polished wafer, and a polishing
assistant apparatus. The polishing assistant apparatus further
includes a platen for placing the polished wafer, a liquid supplier
for supplying a slurry, a polishing controller for receiving the
first polishing parameter and outputting a first control signal
which is relative to a certain region of the polished wafer in
response to the first polishing parameter, and a polish head
electrically connected to the polishing controller and polishing
the certain region of the polished wafer in response to the first
control signal.
[0010] Preferably, the monitoring device further detects a second,
a third, and a fourth polishing parameters. The second, third, and
fourth polishing parameters are preferably a polish head down
force, a polish head rotation speed, and a polishing time,
respectively. In response to the second, third, and fourth
polishing parameters, the polishing controller outputs a second,
third, and fourth control signals, respectively, and the polish
head polishes the certain region of the polished wafer in response
to the second, third, and fourth control signals, respectively.
[0011] Preferably, the polishing controller includes a pressure
controlling unit for controlling a pressure when the polish head
polishing in response to the second polishing parameter, and a
movable arm electrically connected to the pressure controlling unit
and carrying the polish head to move to the certain region of the
polished wafer in response to the first polishing parameter. The
pressure controlling unit preferably has a control pressure ranged
from 0.1 to 10 psi.
[0012] Preferably, the movable arm has an internal channel
communicating between the pressure controlling unit and the polish
head. The internal channel is preferably poured thereinto a medium
and the control pressure is achieved by pressurizing the medium.
For example, the medium is a liquid oil or a gas.
[0013] Preferably, the monitoring device further includes a
detector for detecting a surface of the polished wafer to obtain a
data, and a server electrically connected to the detector,
obtaining the first polishing parameter according to the data, and
transmitting the first polishing parameter to the polishing
controller.
[0014] Preferably, the platen is a rotating platen. The rotating
platen has preferably a rotation speed ranged from 1 to 50
revolutions per minute (rpm).
[0015] Preferably, the polish head is made of polyvinyl alcohol
(PVA).
[0016] Preferably, the polish head is a rotatable polish head. The
polish head preferably has a rotation speed ranged from 1 to 50
rpm.
[0017] Preferably, the polish head has a diameter ranged from 1 to
3 cm.
[0018] Preferably, the polishing assistant system further includes
a polish head film disposed between the platen and the polished
wafer for protecting the polished wafer.
[0019] According to an aspect of the present invention, there is
provided a polishing assistant system applied to a polished wafer
polished by a chemical mechanical polishing (CMP). The system
includes a monitoring device for detecting a first polishing
parameter of the polished wafer, and a polishing assistant
apparatus. The polishing assistant apparatus further includes a
platen for placing the polished wafer, a liquid supplier for
supplying a slurry, and a polishing device polishing a certain
region of the polished wafer in response to the first polishing
parameter.
[0020] Preferably, the monitoring device further detects a second,
a third, and a fourth polishing parameters, and the second, third,
and fourth polishing parameters are a polish head down force, a
polish head rotation speed, and a polishing time, respectively.
[0021] Preferably, the polishing device includes a polishing
controller for receiving the first, second, third and fourth
polishing parameters and outputting a first, second, third and
fourth control signals in response to the first, second, third and
fourth polishing parameters, respectively, and a polish head
electrically connected to the polishing controller and polishing
the certain region of the polished wafer in response to the first,
second, third, and fourth control signals.
[0022] Preferably, the polishing controller includes a pressure
controlling unit for controlling a pressure when the polish head is
polishing in response to the second polishing parameter, and a
movable arm electrically connected to the pressure controlling unit
and carrying the polish head to move to the certain region of the
polished wafer in response to the first polishing parameter.
[0023] The present invention may best be understood through the
following description with reference to the accompanying drawings,
in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a cutaway view illustrating a conventional
polishing apparatus;
[0025] FIG. 2 is a plot illustrating a ratio of the maximum and the
minimum of removal rate in a wafer surface along time according to
the prior art;
[0026] FIG. 3A is a diagram illustrating a preferred embodiment of
a monitoring device in a polishing assistant system according to
the present invention;
[0027] FIG. 3B is a diagram illustrating a preferred embodiment of
a polishing assistant apparatus in a polishing assistant system
according to the present invention;
[0028] FIG. 3C is a top view illustrating a movable arm path in the
preferred embodiment of a polishing assistant system of FIG.
3B;
[0029] FIG. 4A is a plot illustrating an oxide thickness
distribution on a surface of a polished wafer without treated by
the polishing assistant system according to the present invention;
and
[0030] FIG. 4B is a plot illustrating an oxide thickness
distribution on a surface of a polished wafer with treated by the
polishing assistant system according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] The present invention will now be described more
specifically with reference to the following embodiments. It is to
be noted that the following descriptions of preferred embodiments
of this invention are presented herein for purpose of illustration
and description only; it is not intended to be exhaustive or to be
limited to the precise form disclosed.
[0032] The present invention provides a polishing assistant system
applied to further fine polish a polished wafer which has been
polished by a chemical mechanical polishing (CMP). The polishing
assistant system includes a monitoring device and a polishing
assistant apparatus. The monitoring device is used for detecting a
surface of a polished wafer to obtain a first, second, third, and
fourth polishing parameters which are a certain region of the
polished wafer for fine polishing, i.e. a polish position, a polish
head down force, a polish head rotation speed, and a polishing
time, respectively. FIG. 3A is a diagram illustrating a preferred
embodiment of a monitoring device in a polishing assistant system
according to the present invention. The monitoring device further
includes a detector 31 for detecting a surface of a polished wafer
30 to obtain a data, and a server 32 electrically connected to the
detector 31, obtaining the first polishing parameter according to
the data, and transmitting the first polishing parameter to the
polishing assistant apparatus. In addition, the server 32 has a
program, and the polishing parameters are obtained by applying the
program to process the data.
[0033] As shown in FIG. 3B, the polishing assistant apparatus
includes a platen 40, a liquid supplier 41, a polishing controller
422 and a polish head 421. The platen 40 is used for holding the
polished wafer 30 and the liquid supplier 41 is used for supplying
a slurry during polishing. In addition, the platen 40 is a rotating
platen, so the polished wafer 30 will be carried to rotate in a
rotation speed ranged from 1 to 50 revolutions per minute (rpm).
Furthermore, a carrier film 43 disposed between the polished wafer
30 and the platen 40 is used for protecting the polished wafer
30.
[0034] The polishing controller 422 is used for receiving the
first, second, third, and fourth polishing parameters transmitted
from the server 32, outputting a first, second, third, and fourth
control signals in response to the first, second, third, and fourth
polishing parameters, respectively, and transmitting the first,
second, third, and fourth control signals to the polish head 421
which is electrically connected to the polishing controller 422.
The polish head 421 cooperated with the liquid supplier 41 proceeds
a fine polish for a certain region of the polished wafer 30 in
response to those polishing signals for improving the planarization
of the surface of the polished wafer 30.
[0035] The polishing controller 422 further includes a pressure
controlling unit 4221 and a movable arm 4222 electrically connected
to the pressure controlling unit 4221. According to the second
polishing parameter, the pressure controlling unit 4221 will
control the polish head down force, ranged from 0.1 to 10 psi, when
the polish head 421 polishes the polished wafer 30. Furthermore,
the movable arm 4222 will move the polish head 421 to polish the
certain regions of the polished wafer 30 in response to the first
polishing parameter. FIG. 3C is a top view illustrating the movable
arm path in FIG. 3B. As shown in FIG. 3C, the movable arm can move
between A end and B end of the polished wafer 30.
[0036] In addition, the polish head down force is controlled by the
pressure controlling unit 4221 through the following methods:
[0037] 1. The required pressure is directly imposed on the movable
arm 4222 carrying into the polish head 421.
[0038] 2. The movable arm can have an internal channel 42221
communicating between the pressure controlling unit 4221 and the
polish head 421. Thus, a liquid oil can be poured into the internal
channel 42221 and the polish head down force can be indirectly
controlled by directly imposing pressure on the liquid oil.
Moreover, the liquid oil can be replaced by gas.
[0039] In addition, the polish head is a rotatable polish head
having a rotation speed ranged from 1 to 50 rpm. The diameter range
of the polish head is from 1 to 3 cm. The polish head is made of
polyvinyl alcohol (PVA).
[0040] FIGS. 4A and 4B are plots illustrating an oxide thickness
distribution on the surface of the polished wafer without and with
treated by the polishing assistant system according to the present
invention. Comparing FIG. 4A with FIG. 4B, the surface of the
polished wafer treated by the polishing assistant system according
to the present invention is more uniform than that without the
treatment. Therefore, the present invention can improve the
planarization of the wafer.
[0041] In sum, the polishing assistant system according to the
present invention has the following advantages:
[0042] 1. The present invention can proceed a find polish onto the
polished wafer to compensate the removal rate non-uniformity, which
is resulted from the deformations of polish pad, carrier film, or
relative consumables, causing to loss the planarization.
[0043] 2. The present invention can control the removal amount of
every region on the wafer. Thus, it can solve the problems of
over-removing in the partial surface of the wafer by the W-CMP, and
the central-remaining in the surface of the wafer by the
inter-layer dielectrics chemical mechanical polishing (ILD-CMP) or
inter-metal dielectrics chemical mechanical polishing
(IMD-CMP).
[0044] 3. The present invention also can solve the layer is
non-uniformly formed on the wafer surface during the former
process.
[0045] While the invention has been described in terms of what are
presently considered to be the most practical and preferred
embodiments, it is to be understood that the invention need not to
be limited to the disclosed embodiment. On the contrary, it is
intended to cover various modifications and similar arrangements
included within the spirit and scope of the appended claims which
are to be accorded with the broadest interpretation so as to
encompass all such modifications and similar structures.
* * * * *