U.S. patent application number 12/805306 was filed with the patent office on 2011-01-27 for substrate polishing apparatus and method of polishing substrate using the same.
This patent application is currently assigned to SEMES CO., LTD.. Invention is credited to Jang Hyun KIM, Oh Jin KWON, Sehoon OH.
Application Number | 20110021115 12/805306 |
Document ID | / |
Family ID | 43497738 |
Filed Date | 2011-01-27 |
United States Patent
Application |
20110021115 |
Kind Code |
A1 |
OH; Sehoon ; et al. |
January 27, 2011 |
Substrate polishing apparatus and method of polishing substrate
using the same
Abstract
Provided is a substrate polishing apparatus that includes a
polishing unit and a pad supporting member. The polishing unit
includes a polishing pad polishing a substrate seated on a
substrate supporting member, and a pad driving member moving the
polishing pad. The pad supporting member is disposed at a side of
the substrate supporting member to support a portion of a polishing
surface the polishing pad without contacting the substrate when an
edge of the substrate seated on the substrate supporting member is
polished. Accordingly, the substrate polishing apparatus prevents
the polishing pad from being inclined to the outer side of a
substrate while an edge of the substrate is polished, thereby
improving polishing efficiency and preventing the breakage of a
substrate during a polishing process.
Inventors: |
OH; Sehoon; (Seoul, KR)
; KWON; Oh Jin; (Cheonan-si, KR) ; KIM; Jang
Hyun; (Cheonan-si, KR) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 8910
RESTON
VA
20195
US
|
Assignee: |
SEMES CO., LTD.
|
Family ID: |
43497738 |
Appl. No.: |
12/805306 |
Filed: |
July 23, 2010 |
Current U.S.
Class: |
451/9 ; 451/10;
451/287; 451/41 |
Current CPC
Class: |
B24B 49/00 20130101;
B24B 37/04 20130101 |
Class at
Publication: |
451/9 ; 451/287;
451/41; 451/10 |
International
Class: |
B24B 49/00 20060101
B24B049/00; B24B 7/22 20060101 B24B007/22 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 24, 2009 |
KR |
10-2009-0067936 |
Claims
1. A substrate polishing apparatus comprising: a substrate
supporting member on which a substrate is seated; a polishing unit
including a polishing pad disposed above the substrate supporting
member to polish the substrate seated on the substrate supporting
member, and a pad driving member moving the polishing pad to vary a
relative position of the polishing pad to the substrate supporting
member; and at least one pad supporting member disposed at a side
of the substrate supporting member to support a portion of a
polishing surface the polishing pad without contacting the
substrate when an edge of the substrate seated on the substrate
supporting member is polished.
2. The substrate polishing apparatus of claim 1, further comprising
a substrate driving member rotating the substrate supporting member
about a central axis thereof.
3. The substrate polishing apparatus of claim 2, wherein the
polishing surface of the polishing pad has an area less than that
of a top surface of the substrate supporting member.
4. The substrate polishing apparatus of claim 3, wherein the pad
driving member swings the polishing pad.
5. The substrate polishing apparatus of claim 3, wherein the pad
driving member comprises: a vertical arm connected to the polishing
pad and vertically extending and rotating about a central axis
thereof to rotate the polishing pad; a swingable swing arm
connected to an upper end of the vertical arm to swing the
polishing pad; and a driving part connected to an end of the swing
arm and providing torque for swing the swing arm to the swing arm
and providing torque for rotating the vertical arm to the vertical
arm through the swing arm.
6. The substrate polishing apparatus of claim 4, wherein the pad
supporting member is disposed on a movement track of the polishing
pad or on an extension line of the movement track.
7. The substrate polishing apparatus of claim 6, wherein the
movement track has an arc shape.
8. The substrate polishing apparatus of claim 1, further comprising
a bowl unit having an open upper portion and an inside where the
pad supporting member is disposed.
9. The substrate polishing apparatus of claim 8, wherein the pad
supporting member comprises: a supporting body disposed at a side
of the substrate supporting member; and a supporting pad coupled to
an upper portion of the supporting body and spaced apart from the
substrate supporting member and supporting the polishing pad when
an edge of the substrate is polished.
10. The substrate polishing apparatus of claim 9, wherein the
supporting pad is removably coupled to the supporting body.
11. The substrate polishing apparatus of claim 9, further
comprising a first position sense part sensing a height of the pad
supporting member to output a position value of a top surface of
the supporting pad to sense a wear degree of the supporting
pad.
12. The substrate polishing apparatus of claim 11, wherein the
supporting body is fixed to a bottom surface of the bowl unit.
13. The substrate polishing apparatus of claim 9, wherein the pad
supporting member further comprises a position adjustment part
vertically moving the supporting body or the supporting pad to
adjust a vertical position of the supporting pad.
14. The substrate polishing apparatus of claim 13, wherein the
position adjustment part comprises a driving motor or a cylinder,
and the driving motor or the cylinder is fixed to a lower portion
of the supporting body.
15. The substrate polishing apparatus of claim 13, further
comprising: a first position sense part sensing a height of the pad
supporting member to output a vertical position value of a top
surface of the supporting pad to sense a wear degree of the
supporting pad; and a control unit receiving the vertical position
value of the top surface of the supporting pad output from the
first position sense part, and controlling the position adjustment
part according to the received vertical position value to adjust a
position of the top surface of the supporting pad.
16. The substrate polishing apparatus of claim 15, further
comprising a second position sense part sensing a relative
horizontal position of the polishing pad to the substrate
supporting member to provide a horizontal position value of the
polishing pad to the control unit
17. The substrate polishing apparatus of claim 16, wherein the
control unit controls the position adjustment part according to the
received horizontal position value of the polishing pad and the
vertical position value of the top surface of the supporting pad to
adjust the position of the upper surface of the supporting pad.
18. The substrate polishing apparatus of claim 17, wherein the
position adjustment part comprises a bellows expanded and
contracted by air pressure, and the bellows is disposed between the
supporting body and the supporting pad and adjusts a vertical
position of the supporting pad through contraction and
expansion.
19. The substrate polishing apparatus of claim 9, wherein the
supporting body has a column shape, and a top surface of the
supporting pad has an area less than that of the polishing surface
of the polishing pad.
20. The substrate polishing apparatus of claim 9, wherein the
polishing pad has a radius that is equal to or less than a sum of a
distance between the supporting pad and the substrate supporting
member and a width of the supporting pad.
21. The substrate polishing apparatus of claim 9, wherein the
supporting pad has a circular top surface, and the polishing pad
has a radius that is equal to or less than a sum of a distance
between the supporting pad and the substrate supporting member and
a width of the supporting pad.
22. The substrate polishing apparatus of claim 9, wherein the
supporting pad is formed of synthetic resin.
23. A substrate polishing apparatus comprising: a bowl unit having
an open upper portion; a rotatable substrate supporting member on
which a substrate is seated, and disposed in the bowl unit; a
polishing unit including a polishing pad disposed above the
substrate supporting member to polish the substrate seated on the
substrate supporting member in a polishing process, and a pad
driving member moving the polishing pad from a central region of
the substrate seated on the substrate supporting member to an edge
region of the substrate or to a position beyond the edge region of
the substrate; and a pad supporting member disposed in the bowl
unit and including a supporting pad spaced apart from the substrate
supporting member and disposed at a side of the substrate
supporting member
24. The substrate polishing apparatus of claim 23, wherein the pad
supporting member comprises: a supporting body disposed at a side
of the substrate supporting member; and a supporting pad coupled to
an upper portion of the supporting body and spaced apart from the
substrate supporting member and supporting the polishing pad when
an edge of the substrate is polished.
25. The substrate polishing apparatus of claim 24, wherein the pad
supporting member comprises a position adjustment part coupled to
the supporting body or the supporting pad and vertically moving the
supporting body or the supporting pad to adjust a vertical position
of the supporting pad.
26. The substrate polishing apparatus of claim 23, wherein the
polishing pad has a radius that is equal to or less than a sum of a
distance between the supporting pad and the substrate supporting
member and a width of the supporting pad.
27. A substrate polishing method comprising: seating a substrate on
a substrate supporting member; disposing a polishing pad above the
substrate supporting member; and pressing and polishing, by the
polishing pad, the substrate while at least one of the substrate
supporting member and the polishing pad is rotated, wherein the
polishing of the substrate includes polishing an edge of the
substrate while a portion of the polishing pad without contacting
the substrate is supported by a pad supporting member.
28. The substrate polishing method of claim 27, wherein the
polishing pad has a diameter less than that of the substrate, and
the polishing pad moves from a central region of the substrate to
the edge of the substrate to polish the substrate.
29. The substrate polishing method of claim 28, wherein the
polishing pad swings on an upper portion of the substrate to polish
the substrate.
30. The substrate polishing method of claim 27, wherein a top
surface of the pad supporting member and a top surface of the
substrate contacting the polishing pad are disposed on the same
line when being viewed from side.
31. The substrate polishing method of claim 30, wherein the
polishing of the edge of the substrate comprises: sensing a
vertical position of the top surface of the pad supporting member;
and adjusting a vertical position of a top surface of a horizontal
adjustment part according to a value of the sensed vertical
position such that, when being viewed from side, the top surface of
the pad supporting member and the top surface of the substrate are
disposed on the same line.
32. The substrate polishing method of claim 31, wherein the sensing
of the vertical position of the top surface of the pad supporting
member and the adjusting of the vertical position of the top
surface of the pad supporting member are performed while the
polishing pad polishes the edge of the substrate.
33. The substrate polishing method of claim 27, wherein the
polishing of the substrate comprises: sensing a horizontal position
of the polishing pad on the substrate; and adjusting a vertical
position of a top surface of the pad supporting member according to
a value of the horizontal position of the polishing pad
34. The substrate polishing method of claim 33, wherein the
adjusting of the vertical position of the top surface of the pad
supporting member comprises: moving the top surface of the pad
supporting member downward to dispose, when being viewed from side,
the top surface of the pad supporting member below a top surface of
the substrate when the polishing pad is disposed in a region except
for the edge of the substrate; and moving the top surface of the
pad supporting member upward such that the pad supporting member
supports a portion of a polishing surface of the polishing pad
without contacting the substrate when the polishing pad is disposed
at the edge of the substrate.
35. The substrate polishing method of claim 34, wherein the moving
of the top surface of the pad supporting member upward comprises:
sensing a vertical position of a top surface of a horizontal
adjustment part; and adjusting the vertical position of the top
surface of the pad supporting member such that, when being viewed
from side, the top surface of the pad supporting member and the top
surface of the substrate are disposed on the same line.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This U.S. non-provisional patent application claims priority
under 35 U.S.C. .sctn.119 of Korean Patent Application No.
10-2009-0067936, filed on Jul. 24, 2009, the entire contents of
which are hereby incorporated by reference.
BACKGROUND
[0002] The present disclosure herein relates to an apparatus and a
method for manufacturing a semiconductor, and more particularly, to
substrate processing apparatus and method for polishing and
cleaning a semiconductor substrate in a single wafer processing
manner.
[0003] In a general semiconductor device manufacturing process, a
plurality of unit processes such as a deposition process, a
photolithography process, and an etch process should be repeatedly
performed to form and stack a thin film. These processes are
repeated until desired predetermined circuit patterns are formed on
a wafer. After the circuit patterns are formed, many irregularities
are formed on a surface of the wafer. As semiconductor devices are
now highly integrated and also multilayered in structure, the
number of irregularities on a surface of a wafer and a height
difference between the irregularities increase. As a result, due to
the non-planarization of the surface of the wafer, defocus may
occur in a photolithography process. Thus, to realize the
planarization of the surface of the wafer, the wafer surface should
be periodically polished.
[0004] Various surface planarization techniques have been developed
for planarizing the surface of a wafer. Among these, a chemical
mechanical polishing (CMP) technique is widely used because wide
surfaces as well as narrow surfaces may be planarized with good
flatness by using the CMP technique. A CMP apparatus is used to
polish the surface of a wafer coated with tungsten or an oxide, by
using mechanical friction and chemical abrasives, and very fine
polishing is possible using the CMP apparatus.
[0005] When a polishing apparatus polishes a wafer, the polishing
apparatus disposes the wafer on the top surface of a polishing pad,
and then, presses and rotates the wafer to the polishing pad. Such
a polishing apparatus includes a retainer ring surrounding a wafer
to prevent an edge of a wafer from being excessively polished.
However, since an expensive retainer ring is polished together with
a wafer all through a wafer polishing process, a replacement cycle
of the retainer ring is short, and a disassembling process thereof
is complicated.
SUMMARY OF THE PRESENT INVENTION
[0006] Embodiments of the present invention provide a substrate
polishing apparatus that can improve polishing efficiency.
[0007] Embodiments of the present invention also provide a method
of polishing a substrate using the above-described substrate
polishing apparatus.
[0008] Embodiments of the present invention provide substrate
polishing apparatuses including: a substrate supporting member, a
polishing unit, and at least one pad supporting member.
[0009] A substrate is seated on the substrate supporting member.
The polishing unit includes a polishing pad disposed above the
substrate supporting member to polish the substrate seated on the
substrate supporting member, and a pad driving member moving the
polishing pad to vary a relative position of the polishing pad to
the substrate supporting member. The pad supporting member is
disposed at a side of the substrate supporting member to support a
portion of a polishing surface the polishing pad without contacting
the substrate when an edge of the substrate seated on the substrate
supporting member is polished.
[0010] In other embodiments of the present invention, substrate
polishing apparatuses include: a bowl unit, a rotatable substrate
supporting member, a polishing unit, and at least one pad
supporting member.
[0011] The bowl unit has an open upper portion. The substrate
supporting member on which a substrate is seated is rotatably
disposed in the bowl unit. The polishing unit includes a polishing
pad disposed above the substrate supporting member to polish the
substrate seated on the substrate supporting member in a polishing
process, and a pad driving member moving the polishing pad from a
central region of the substrate seated on the substrate supporting
member to an edge region of the substrate or to a position beyond
the edge region of the substrate. The pad supporting member is
disposed in the bowl unit, and includes a supporting pad spaced
apart from the substrate supporting member and disposed at a side
of the substrate supporting member.
[0012] In still other embodiments of the present invention,
substrate polishing methods are as follows.
[0013] A substrate is seated on a substrate supporting member. A
polishing pad is disposed above the substrate supporting member.
The substrate is pressed and polished by the polishing pad while at
least one of the substrate supporting member and the polishing pad
is rotated. When the substrate is polished, an edge of the
substrate is polished while a portion of the polishing pad without
contacting the substrate is supported by a pad supporting
member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings are included to provide a further
understanding of the present invention, and are incorporated in and
constitute a part of this specification. The drawings illustrate
exemplary embodiments of the present invention and, together with
the description, serve to explain principles of the present
invention. In the figures:
[0015] FIG. 1 is a schematic view of a single wafer type polishing
system according to an embodiment of the present invention;
[0016] FIG. 2 is a perspective view illustrating the wafer
polishing unit of FIG. 1;
[0017] FIG. 3 is a partial cut-away perspective view illustrating a
substrate supporting unit and a bowl unit of FIG. 2;
[0018] FIG. 4 is a perspective view illustrating the polishing unit
of FIG. 2;
[0019] FIG. 5 is a partial cut-away side view illustrating the
polishing unit of FIG. 4;
[0020] FIG. 6 is a vertical cross-sectional view illustrating a
pressing part and a vertical arm part of FIG. 5;
[0021] FIG. 7 is a perspective view illustrating the pad supporting
member illustrated in FIG. 3;
[0022] FIG. 8 is a schematic view illustrating relative positions
between the pad supporting member illustrated in FIG. 7, a
substrate supporting unit, and a polishing unit;
[0023] FIG. 9 is a flowchart illustrating a process in which the
wafer polishing part illustrated in FIG. 2 polishes a wafer;
[0024] FIG. 10 is a schematic view illustrating a process in which
the pad supporting member illustrated in FIG. 8 supports a
polishing pad when an edge of a wafer is polished;
[0025] FIG. 11 is a schematic view illustrating another example of
the pad supporting member illustrated in FIG. 8;
[0026] FIG. 12 is a schematic view illustrating a process in which
the pad supporting member illustrated in FIG. 11 supports a
polishing pad when an edge of a wafer is polished;
[0027] FIG. 13 is a schematic view illustrating another example of
the pad supporting member illustrated in FIG. 8; and
[0028] FIGS. 14A and 14B are schematic views illustrating a height
variation of the top surface of the pad supporting member
illustrated in FIG. 13 according to positions of a polishing pad
when a wafer is polished.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0029] Preferred embodiments of the present invention will be
described below in more detail with reference to the accompanying
drawings. The present invention may, however, be embodied in
different forms and should not be construed as limited to the
embodiments set forth herein. Rather, these embodiments are
provided so that this disclosure will be thorough and complete, and
will fully convey the scope of the present invention to those
skilled in the art. For example, although a wafer is used as a
semiconductor substrate, technical scope and sprite of the present
invention is not limited thereto.
[0030] FIG. 1 is a schematic view of a single wafer type polishing
system according to an embodiment of the present invention.
[0031] Referring to FIG. 1, a substrate processing system 2000
according to present invention may include a loading/unloading unit
10, an index robot 20, a buffer unit 30, a main transfer robot 50,
a plurality of substrate polishing units 1000, and a control unit
60.
[0032] The loading/unloading unit 10 includes a plurality of load
ports 11a, 11b, 11c, and 11d. Although the loading/unloading unit
10 includes four load ports 11a, 11b, 11c, and 11d in this
embodiment, the number of the load ports 11a, 11b, 11c, and 11d may
increase and decrease according to process efficiency and foot
print conditions of the substrate processing system 2000.
[0033] Front open unified pods (FOUPs) 12a, 12b, 12c, and 12d in
which wafers are received are seated on the load ports 11a, 11b,
11c, and 11d, respectively. A plurality of slots for receiving the
wafers in a horizontal direction with respect to a ground surface
are disposed in the respective FOUPs 12a, 12b, 12c, and 12d. The
FOUPs 12a, 12b, 12c, and 12d receive wafers that have been
processed in the respective substrate polishing units 1000 or
wafers that will be loaded into the respective substrate polishing
units 1000. Hereinafter, for convenience of description, the wafers
that have been processed in the respective substrate polishing
units 1000 are referred to as processed wafers, and the wafers that
are not processed yet are referred to as primitive wafers.
[0034] A first transfer path 41 is disposed between the
loading/unloading unit 10 and the buffer unit 30. A first transfer
rail 42 is disposed in the first transfer path 41. The index robot
20 is disposed on the first transfer rail 42. The index robot 20
moves along the first transfer rail 42 to transfer the wafers
between the loading/unloading unit 10 and the buffer unit 30. That
is, the index robot 20 takes out at least one primitive wafer from
FOUPs 12a, 12b, 12c, and 12d seated on the loading/unloading unit
10 to load the wafer on the buffer unit 30. Also, the index robot
20 takes out at least one processed wafer from the buffer unit 30
to load the wafer on the FOUPs 12a, 12b, 12c, and 12d seated on the
loading/unloading unit 10.
[0035] The buffer unit 30 is disposed at a side of the first
transfer path 41. The buffer unit 30 receives the primitive wafers
transferred by the index robot 20 and the wafers processed in the
substrate polishing units 1000.
[0036] The main transfer robot 50 is disposed in a second transfer
path 43. A second transfer rail 44 is disposed in the second
transfer path 43. The main transfer robot 50 is disposed on the
second transfer rail 44. The main transfer robot 50 moves along the
second transfer rail 44 to transfer the wafers between the buffer
unit 30 and the substrate polishing units 1000. That is, the main
transfer robot 50 takes out at least one primitive wafer from the
buffer unit 30 to provide the wafer to the substrate polishing
units 1000. Also, the main transfer robot 50 loads a wafer
processed from the substrate polishing units 1000, that is, a
processed wafer on the buffer unit 30.
[0037] The substrate polishing units 1000 are disposed at both
sides of the second transfer path 43. The respective substrate
polishing units 1000 polish and clean the primitive wafer to
manufacture the processed wafer. In the substrate polishing units
1000, at least two substrate polishing units face each other with
the second transfer path 43 therebetween. In an example of the
present invention, when viewed in plan, although two pairs of
substrate polishing units 1000 are disposed at both sides of the
second transfer path 43 and parallelly disposed along the second
transfer path 43, respectively, the number of the substrate
polishing units 1000 disposed at both sides of the second transfer
path 43 may increase and decrease according to the process
efficiency and the foot print conditions of the substrate
processing system 2000.
[0038] Each of the substrate polishing units 1000 is connected to
the control unit 60 to polish and clean the primitive wafer
according to the control of the control unit 60. That is, the
control unit 60 controls the substrate polishing unit 1000 to
control the polishing of each of the substrate polishing units
1000.
[0039] Hereinafter, a configuration of the substrate polishing unit
1000 will be described in detail with reference to accompanying
drawings.
[0040] FIG. 2 is a perspective view illustrating a substrate
polishing unit of FIG. 1, and FIG. 3 is a partial cut-away
perspective view illustrating a substrate supporting unit and a
bowl unit of FIG. 2.
[0041] Referring to FIGS. 1 through 3, in the substrate processing
system 2000, a polishing process in which a top surface of a wafer
70 is polished and a cleaning process in which a surface of the
wafer 70 is cleaned after the polishing process is performed may be
sequentially performed within one substrate polishing unit
1000.
[0042] Particularly, the substrate polishing unit 1000 may include
a substrate supporting unit 100, a bowl unit 200, a polishing unit
300, a pad supporting member 401, first and second process fluid
supply units 510 and 520, a brush unit 610, an aerosol unit 620,
and a pad conditioning unit 700.
[0043] The wafer 70 transferred from the main transfer robot 50 is
seated on the substrate supporting unit 100. The substrate
supporting unit 100 supports and fixes the wafer 70 during the
polishing process and the cleaning process of the wafer 70. The
substrate supporting unit 100 may include a spin head 110 on which
the wafer 70 is seated, a supporting part 120 supporting the spin
head 110, and a spin driving part providing torque.
[0044] The spin head 110 has a substantially circular shape when
viewed in plan, and a width thereof gradually decreases from a top
surface thereof to a bottom surface. In an example of the present
invention, the top surface of the spin head 110 supporting the
wafer 70 has an area less than that of the wafer 70. Thus, when
being viewed from side, an end of the wafer 70 seated on the spin
head 110 protrudes outward from a top end of the spin head 110.
[0045] The supporting part 120 is disposed below the spin head 110,
and connected to the spin driving part. The supporting part 120 has
an approximately cylindrical shape, and is coupled to the spin head
110. The spin driving part rotates the supporting part 120, and
torque of the supporting part 120 is transmitted to the spin head
110 to rotate the spin head 110. During the polishing and cleaning
processes, the spin head 110 fixing the wafer 70 on the top surface
is rotated by the torque provided from the spin driving part.
[0046] The substrate supporting unit 100 is received into the bowl
unit 200. The bowl unit 200 may include first and second process
bowls 210 and 220, first and second recovery vats 230 and 240,
first and second recovery tubes 251 and 252, and an
ascending/descending member 260.
[0047] Particularly, the first and second process bowls 210 and 220
surround the substrate supporting unit 100 to provide a space in
which the polishing and cleaning processes are performed on the
wafer 70. Each of the first, and second process bowls 210 and 220
has an open upper portion through which the spin head 110 is
exposed. Although each of the first and second process bowls 210
and 220 has a circular ring shape in this embodiment, the present
invention is not limited thereto.
[0048] Particularly, the first process bowl 210 may include a
sidewall 211, a top plate 212, and a guide part 213. The sidewall
211 may have an approximately circular ring shape to surround the
substrate supporting unit 100.
[0049] An upper end of the sidewall 211 is connected to the top
plate 212. The top plate 212 extends from the sidewall 211 and has
a surface inclined upward away from the sidewall 211. The top plate
212 has an approximately circular ring shape. When viewed in plan,
the top plate 212 is spaced from the spin head 110 to surround the
spin head 110.
[0050] The guide part 213 includes first and second guide walls
213a and 213b. The first guide wall 213a protrudes from an inner
wall of the sidewall 211 to face the top plate 212. Also, the first
guide wall 213a has a surface inclined downward away from the
sidewall 211. The first guide wall 213a has a circular ring shape.
The second guide wall 213b vertically extends downward from the
first guide wall 213a to face the sidewall 211. The second guide
wall 213b has a circular ring shape. The guide part 213 guides a
flow of a process liquid, scattered onto inner surfaces of the
sidewall 211 and the top plate 212 of the first process bowl 210
during the polishing process of the wafer 70, toward the first
recovery vat 230. \
[0051] The second process bowl 220 is disposed outside the first
process bowl 210. The second process bowl 220 surrounds the first
process bowl 210, and is larger than the first process bowl
210.
[0052] Particularly, the second process bowl 220 may include a
sidewall 221 and a top plate 222. The sidewall 221 may have an
approximately circular ring shape to surround the sidewall 211 of
the first process bowl 210. The sidewall 221 is spaced from the
sidewall 211 of the first process bowl 210 and connected to the
first process bowl 210.
[0053] An upper end of the sidewall 221 is connected to the top
plate 222. The top plate 222 extends from the sidewall 221 and has
a surface inclined upward away from the sidewall 221. The top plate
222 has an approximately circular ring shape. When viewed in plan,
the top plate 222 is spaced from the spin head 110 to surround the
spin head 110. The top plate 222 is disposed above the top plate
211 of the first process bowl 210. Also, the top plate 222 faces
the top plate 211 of the first process bowl 210 and is spaced from
the top plate 211 of the first process bowl 210.
[0054] The first and second recovery vats 230 and 240 are disposed
below the first and second process bowls 210 and 220 to recover the
process liquids used for the polishing and cleaning processes. Each
of the first and second recovery vats 230 and 240 has an
approximately circular ring shape with an open upper portion.
Although each of the first and second recovery vats 230 and 240 has
the circular ring shape in this embodiment, the present invention
is not limited thereto.
[0055] The first recovery vat 230 is disposed below the first
process bowl 210 to recover the process liquid used for the
polishing process. The second recovery vat 240 is disposed below
the second process bowl 220 to recover the process liquid used for
the cleaning process.
[0056] Particularly, the first recovery vat 230 may include a
bottom plate 231, a first sidewall 232, a second sidewall 233, and
a connection part 234. The bottom plate 231 has an approximately
circular ring shape to surround the supporting part 120. In an
example of the present invention, the bottom plate 231 has a `V`
shaped vertical cross-section to easily discharge the process
liquid recovered into the first recovery vat 230. Thus, a recovery
flow path 231a having a ring shape is disposed in the bottom plate
231 to easily discharge and recover the process liquid.
[0057] The first sidewall 232 vertically extends from the bottom
plate 231 to provide a first recovery space RS1 for recovering the
process liquid. The second sidewall 233 is spaced from the first
sidewall 232 to face the first sidewall 232. The connection part
234 is connected to the upper end of the first sidewall 232 and the
upper end of the second sidewall 233. The connection part 234 has a
surface inclined upward from the first sidewall 232 toward the
second sidewall 233. The connection part 234 guides the process
liquid dropped outside the first recovery space RS1 toward the
first recovery space RS1 to introduce the process liquid into the
first recovery space RS1.
[0058] The second recovery vat 240 is disposed outside the first
recovery vat 230. The second recovery vat 240 surrounds the first
recovery vat 230 and is spaced from the first recovery vat 230.
Particularly, the second recovery vat 240 may include a bottom
plate 241, a first sidewall 242, and a second sidewall 243. The
bottom plate 241 has an approximately circular ring shape to
surround the bottom plate 231 of the first recovery vat 230. In an
example of the present invention, the bottom plate 241 has a `V`
shaped vertical cross-section to easily discharge the process
liquid recovered into the second recovery vat 240. Thus, a recovery
flow path 241a having a ring shape is disposed in the bottom plate
241 to easily discharge and recover the process liquid.
[0059] The first and second sidewalls 242 and 243 vertically extend
from the bottom plate 241 to provide a second recovery space RS2
for recovering the process liquid. Each of the first and second
sidewalls 242 and 243 has a circular ring shape. The first sidewall
242 is disposed between the first and second sidewalls 232 and 233
of the first recovery vat 230 to surround the first sidewall 232 of
the first recovery vat 230. The second sidewall 243 of the second
recovery vat 240 faces the first sidewall 242 with the bottom plate
241 therebetween to surround the first sidewall 242. The second
sidewall 243 of the second recovery vat 240 surrounds the second
sidewall 233 of the first recovery vat 230, and an upper end
thereof is disposed outside the sidewall 221 of the second process
bowl 220.
[0060] When the polishing and cleaning processes are performed on
the wafer 70, vertical positions between the spin head 110 and the
first and second process bowls 210 and 220 are changed according to
each process. Thus, the first and second recovery vats 230 and 240
respectively recover process liquids used for processes different
from each other.
[0061] Particularly, when the polishing process is performed, the
spin head 110 is disposed within the first process bowl 210 to
perform the polishing process on the wafer 70 within the first
process bowl 210. During the polishing process, the wafer 70 is
rotated by the rotation of the spin head 110. Thus, during the
polishing process, a process liquid sprayed onto the wafer 70 is
scattered toward an inner surface of the sidewall 211 and an inner
surface of the top plate 212 of the first process bowl 210 due to
torque of the wafer 70. The process liquid adhered to the inner
surfaces of the sidewall 211 and the top plate 212 of the first
process bowl 210 flows along the sidewall 211 and the top plate 212
of the first process bowl 210 in a gravity direction to reach the
guide part 213, and then, the process liquid flows along an inner
surface of the guide part 213 in the gravity direction and is
recovered into the first recovery vat 230.
[0062] When the cleaning process is performed after the polishing
process is performed, the spin head 110 is disposed below the top
plate 222 of the second process bowl 220 and above the first
process bowl 210. During the cleaning process, the spin head 110 is
rotated. Thus, a process liquid sprayed onto the wafer in the
cleaning process is scattered toward inner surfaces of the top
plate 222 and the sidewall 221 of the second process bowl 220 and
an outer surface of the first process bowl 210. The sidewall 211 of
the first process bowl 210 is disposed above the bottom plate 241
of the second recovery vat 240. The process liquid adhered to the
outer surface of the first process bowl 210 flows along the outer
surface of the first process bowl 210 in the gravity direction and
is recovered into the second recovery vat 240. Also, the process
liquid adhered to the inner surface of the second process bowl 220
flows along the inner surface of the second process bowl 220 in the
gravity direction and is recovered into the second recovery vat
240.
[0063] As described above, the first recovery vat 230 recovers the
process liquid used for the polishing process, and the second
recovery vat 240 recovers the process liquid used for the cleaning
process. As a result, since the bowl unit 200 may separately
recover the process liquid used for each process performed within
the bowl unit 200, the process liquid may be easily reused and
recovered.
[0064] The first recovery vat 230 is connected to the first
recovery tube 251, and the second recovery vat 240 is connected to
the second recovery tube 252. The first recovery tube 251 is
coupled to the bottom plate 231 of the first recovery vat 230. A
first recovery hole 231b communicating with the first recovery tube
251 is defined in the bottom plate 231 of the first recovery vat
230. The process liquid recovered into the first recovery space RS1
of the first recovery vat 230 is discharged to the outside through
the first recovery tube 251 via the first recovery hole 231b.
[0065] Although the bowl unit 200 includes the two process bowls
210 and 220 and the two recovery vats 230 and 240 in this
embodiment, the number of the process bowls 210 and 220 and the
recovery vats 230 and 240 may increase according to the number of
the process liquids used for the polishing and cleaning processes
and the number of the process liquids to be separately
recovered.
[0066] The second recovery tube 252 is coupled to the bottom plate
241 of the second recovery vat 240. A second recovery hole 241b
communicating with the second recovery tube 252 is defined in the
bottom plate 241 of the second recovery vat 240. The process liquid
recovered into the second recovery space RS2 of the second recovery
vat 240 is discharged to the outside through the second recovery
tube 252 via the second recovery hole 241b.
[0067] Although the first recovery tube 251 and the second recovery
tube 252 are respectively provided in singularity, the number of
the first and second recovery tubes 251 and 252 may increase
according to sizes and recovery efficiency of the first and second
recovery vats 230 and 240.
[0068] The vertically movable ascending/descending member 260 is
disposed outside the second process bowl 220. The
ascending/descending member 260 is coupled to the sidewall 221 of
the second process bowl 220 to adjust vertical positions of the
first and second process bowls 210 and 220. Particularly, the
ascending/descending member 260 may include a bracket 261, a
movement shaft 262, and a driver 263. The bracket 261 is fixed to
the outer sidewall 221 of the second process bowl 220 and coupled
to the movement shaft 262. The movement shaft 262 is connected to
the driver 263 and vertically moved by the driver 263.
[0069] The first and second process bowls 210 and 220 descend by
the ascending/descending member 260 to allow the spin head 110 to
protrude upward from the first and second process bowls 210 and 220
when the wafer 70 is seated on the spin head 110 or lifted from the
spin head 110. When the first and second process bowls 210 and 220
descend, the first and second sidewalls 232 and 233 and the
connection part 234 of the first recovery vat 230 are inserted into
a space defined by the sidewall 211 of the first process bowl 210
and the first and second guide walls 213a and 213b.
[0070] Also, when the polishing and cleaning processes are
performed on the wafer 10, the first and second process bowls 210
and 220 ascend and descend by the ascending/descending member 260
to adjust a relative vertical position between the first and second
process bowls 210 and 220 and the spin head 110, thereby separately
recovering the process liquid used for the polishing process and
the process liquid used for the cleaning process.
[0071] In this embodiment, although the first and second process
bowls 210 and 220 are vertically moved to change the relative
vertical position between the first and second process bowls 210
and 220 and the spin head 110 in the substrate polishing unit 1000,
the present invention is not limited thereto. For example, the spin
head 110 may be vertically moved to change the relative vertical
position between the first and second process bowls 210 and 220 and
the spin head 110.
[0072] The polishing unit 300, the first and second process fluid
supply units 510 and 520, the brush unit 610, the aerosol unit 620,
and the pad conditioning unit 700 are disposed outside the bowl
unit 200.
[0073] The polishing unit 300 chemically and mechanically polishes
a surface of the wafer 70 fixed to the substrate supporting unit
100 to planarize the surface of the wafer 70.
[0074] FIG. 4 is a perspective view illustrating a polishing unit
of FIG. 2, and FIG. 5 is a partial cut-away side view illustrating
the polishing unit of FIG. 4.
[0075] Referring to FIGS. 3, 4 and 5, the polishing unit 300 may
include a pressing part 310, a vertical arm part 320, a swing arm
part 330, and a driving part 340.
[0076] Particularly, the pressing part 310 is disposed above the
wafer 70 fixed to the spin head 110 during the polishing process.
The pressing part 310 is rotated in a state where it contacts the
wafer 70 to polish the wafer 70. While the pressing part 310
polishes the wafer 70, chemical liquid for the wafer 70, that is,
slurry is supplied on the top surface of the wafer 70.
[0077] The vertical arm part 320 is fixed to the upper end of the
pressing part 310. The vertical arm part 320 extends vertically
from the top surface of the spin head 110, and is rotated about a
longitudinal central axis by torque provided from the driving part
340. Configurations of the pressing part 310 and the vertical arm
part 320 will be described later in detail with reference to FIG.
6.
[0078] The swing arm part 330 is disposed above the vertical arm
part 320. The swing arm part 330 may include a rotation case 331
having a bar shape and a belt-pulley assembly transmitting torque
from the driving part 340 to the vertical arm part 320. The
rotation case 331 has one side coupled to the vertical arm part 320
and the other side coupled to the driving part 340.
[0079] The driving part 340 may include a first driving motor 341
for rotating the swing arm part 330, a second driving motor 342 for
rotating the vertical arm part 320, and a vertical movement part
343 for adjusting a vertical position of the pressing part 310.
[0080] The first driving motor 341 is coupled to the rotation case
331 to provide the torque to the rotation case 331. The first
driving motor 341 may alternately and repeatedly provide clockwise
torque and counter-clockwise torque. Thus, the swing arm part 330
is swung by the driving part 340 about a central axis at which it
is coupled to the driving part 340. When the polishing process is
performed, the pressing part 310 may be horizontally reciprocated
in a circular arc shape at an upper portion of the wafer 70 due to
the swing operation of the swing arm part 330.
[0081] The second driving motor 342 is disposed below the first
driving motor 341. The second driving motor 342 provide torque to
the belt-pulley assembly. The belt-pulley assembly transmits the
torque of the second driving motor 342 to the vertical arm part
320. The belt-pulley assembly is built in the rotation case 331 and
may include a driving pulley 332, a driven pulley 333, and a belt
334. The driving pulley 332 is disposed above the first driving
motor 341 and coupled to one side of a vertical arm 344 passing
through the first driving motor 341. The second driving motor 342
is coupled to the other side of the vertical arm 344.
[0082] The driven pulley 333 faces the driving pulley 332. The
driven pulley 333 is disposed above the vertical arm part 320 and
coupled to the vertical arm part 320. The driving pulley 332 and
the driven pulley 333 are connected to each other through the belt
334. The belt 334 is wound around the driving pulley 332 and the
driven pulley 333.
[0083] The torque of the second driving motor 342 is transmitted to
the driving pulley 332 through the vertical arm 344. Thus, the
driving pulley 332 is rotated. The torque of the driving pulley 332
is transmitted to the driven pulley 333 through the belt 334. Thus,
the driven pulley 333 is rotated. The torque of the driven pulley
333 is transmitted to the vertical arm part 320. Thus, the pressing
part 310 and the vertical arm part 320 are rotated.
[0084] The vertical movement part 343 is disposed at a rear side of
the first driving motor 341 and the second driving motor 342. The
vertical movement part 343 may include a ball screw 343a, a nut
343b, and a third driving motor 343c. The ball screw 343a has a bar
shape and is vertically disposed with respect to a ground surface.
The nut 343b is fitted on the ball screw 343a and fixed to the
second driving motor 342. The third driving motor 343c is disposed
below the ball screw 343a. The third driving motor 343c may be
coupled to the ball screw 343a to provide clockwise torque and
counter-clockwise torque to the ball screw 343a. The ball screw
343a is rotated clockwise or counter-clockwise by the third driving
motor 343c. The nut 343b is vertically moved along the ball screw
343a by the rotation of the ball screw 343a. Thus, the second
driving motor 342 coupled to the nut 343b is vertically moved
together with the nut 343b. As the second driving motor 342 is
vertically moved, the first driving motor 341 and the swing arm
part 330 are vertically moved, and thus, the vertical arm part 320
and the pressing part 310 are vertically moved also.
[0085] Although the vertical movement part 343 includes the ball
screw 343a, the nut 343b, and the third driving motor 343c to
provide a vertical movement force using a linear motor method in
this embodiment, the present invention is not limited thereto. For
example, the vertical movement part 343 may include a cylinder to
provide a vertical movement force.
[0086] The first driving motor 341, the second driving motor 342,
the ball screw 343a, the nut 343b, and the vertical arm 344 are
built in a driving case 345. The driving case 345 has a long bar
shape in a vertical direction.
[0087] Hereinafter, the pressing part 310 and the vertical arm part
320 will now be described in detail with reference to accompanying
drawings.
[0088] FIG. 6 is a vertical cross-sectional view illustrating a
pressing part and a vertical arm part of FIG. 5.
[0089] Referring to FIGS. 2, 5 and 6, the vertical arm part 320 is
rotated by the torque transmitted from the driving part 340 to
rotate the pressing part 310, and provides air to the pressing part
310 to control a pressure for pressing the wafer 70.
[0090] Particularly, the vertical arm part 320 may include a
housing 321, a rotation shaft 322, a rotary joint 323, first and
second bearings 324a and 324b, and first and second auxiliary
shafts 325a and 325b.
[0091] The housing 321 has an approximately cylindrical tube shape.
An upper end of the housing 321 is inserted into the rotation case
331 of the swing arm part 330. Thus, the housing 321 has the upper
end coupled to the rotation case 331 and a lower end coupled to the
pressing part 310.
[0092] The rotation shaft 322 is disposed within the housing 321
and spaced apart from the housing 321. The rotation shaft 322
extends in the longitudinal direction of the housing 321, and
includes an air passage 322a in a central portion. The air passage
322a extends in the longitudinal direction of the rotation shaft
322. The rotation shaft 322 is connected to the driven pulley 333,
and is rotated about a longitudinal central axis by the torque of
the driven pulley 333. The upper end of the rotation shaft 322 is
coupled to the rotary joint 323, and the rotary joint 323 supplies
air to the air passage 322a of the rotation shaft 322, and is fixed
to the driven pulley 333. The rotary joint 323 includes a rotation
part and a fixation part, and the rotation part is fixed to the
driven pulley 333 such that the rotation part is rotated by the
torque of the driven pulley 333. The fixation part of the rotary
joint 323 is connected to an air line 80 for supplying air. Air
supplied from the air line 80 is introduced through the rotary
joint 323 to the air passage 322a, and flows along the air passage
322a to the pressing part 310.
[0093] The first and second bearings 324a and 324b are disposed
between the housing 321 and the rotation shaft 322. The first and
second bearings 324a and 324b connect the housing 321 to the
rotation shaft 322 and support the rotation shaft 322 such that the
rotation shaft 322 is stably rotated. The first bearing 324a is
disposed adjacent to the swing arm part 330, and the second bearing
324b is disposed adjacent to the pressing part 310. Inner races of
the first and second bearings 324a and 324b are fitted on the
rotation shaft 322, and thus rotated together with the rotation
shaft 322. Outer races of the first and second bearings 324a and
324b are coupled to the housing 321, and thus not rotated when the
rotation shaft is rotated. Thus, only the rotation shaft 322 is
rotated, and the housing 321 is not rotated.
[0094] The first and second auxiliary shafts 325a and 325b may be
disposed between the rotation shaft 322 and the housing 321. The
first auxiliary shaft 325a is disposed along the inner wall of the
housing 321 and protects the housing 321. The second auxiliary
shaft 325b surrounds an outer wall of the rotation shaft 322, and
protects the rotation shaft 322.
[0095] The pressing part 310 is fixed to the lower end of the
rotation shaft 322. The pressing part 310 may include a polishing
pad 311, a polishing case 312, upper and lower plates 313 and 314,
a pad holder 315, a coupling plate 316, and a bellows 317.
[0096] The polishing pad 311 has a plate shape and an approximately
circular ring shape. The polishing pad 311 is rotated to polish the
wafer in a state where a bottom surface of the polishing pad 311
contacts a top surface of the wafer during the polishing process.
The polishing pad 311 has a diameter less than that of the wafer.
During the polishing process, the polishing pad 311 is swung by the
driving part 340 to polish the wafer. As described above, since the
polishing pad 311 has a diameter less than that of the wafer, the
polishing unit 300 may locally polish the wafer, and prevent a
specific region from being excessively polished.
[0097] The polishing case 312 is disposed above the polishing pad
311. The polishing case 312 has an approximately circular ring
shape, and includes the upper and lower plates 313 and 314 and the
bellows 317 therein. A coupling hole is disposed in the central top
surface of the polishing case 312, and the coupling plate 316 is
disposed in the coupling hole. The coupling plate 316 is spaced
apart from the polishing case 312, and is fixed to the rotation
shaft 322 of the vertical arm part 320.
[0098] The upper plate 313 is fixed to the bottom surface of the
coupling plate 316, and the lower plate 314 is spaced apart from
below the upper plate 313. The pad holder 315 is coupled to the
bottom surface of the lower plate 314, and the polishing pad 311 is
coupled to the bottom surface of the pad holder 315.
[0099] The bellows 317 is disposed within a space between the lower
plate 314 and the upper plate 313. The bellows 316 is formed of a
metallic material, and receives air supplied from the air passage
322a of the rotation shaft 322. The bellows 316 is vertically
expanded and contracted by air pressure. When the polishing process
is performed, the bellows 317 is vertically expanded such that the
polishing pad 311 closely contacts the wafer by air pressure. When
the bellows 316 waits above the substrate supporting unit 100
(refer to FIG. 2), the bellows 316 is contracted by vacuum pressure
provided from the air passage 322a. Thus, the polishing pad 311 is
spaced apart from a wafer seated on the substrate supporting unit
100.
[0100] As described above, since the pressing part 310 uses the
bellows 317 that is expanded and contracted by air pressure, the
polishing pad 311 can be tilted according to the top surface shape
of the wafer during the polishing process.
[0101] Referring again to FIGS. 1 through 3, the pad supporting
member 401 is disposed at a side of the substrate supporting unit
100, and the pad supporting member 401 is disposed in the bowl unit
200. When an edge of the wafer 70 is polished, the pad supporting
member 401 supports a portion of the polishing pad 311 (refer to
FIG. 6) to prevent the polishing pad 311 from being inclined to the
outer side of the wafer 70. The configuration of the pad supporting
member 401 will be described later in detail with reference to
FIGS. 7 and 8.
[0102] The first and second process fluid supply units 510 and 520
disposed at the outer side of the bowl unit 200 spray process
fluids, needed for the polishing and cleaning processes for the
wafer 70, to the wafer 70 fixed to the substrate supporting unit
100. In detail, the first process fluid supply unit 510 is fixed to
the sidewall 221 of the second process bowl 220. When the polishing
process or the cleaning process is performed, the first process
fluid supply unit 510 sprays the process fluid onto the wafer 70
fixed to the spin head 110 to process the wafer 70. In the current
embodiment, the process fluid sprayed from the first process fluid
supply unit 510 may be process liquid for cleaning or drying the
wafer 70 or dry gas for drying the wafer 70.
[0103] In an example of the present invention, although the first
process fluid supply unit 510 includes four injection nozzles, the
number of the injection nozzles may increase or decrease according
to the number of the process fluid used for cleaning the wafer
70.
[0104] The second process fluid supply unit 520 can be swung, and
sprays the process liquid onto the wafer 70 fixed to the spin head
110. Process liquid supplied to the second process fluid supply
unit 520 may be slurry. In the polishing process, the slurry may be
sprayed to the wafer 70 by a discrete chemical liquid injection
member (not shown), not the second process fluid supply unit
520.
[0105] The brush unit 610 physically removes foreign substances
remaining on the surface of the wafer 70 after the polishing
process is performed. The brush unit 610 can be swung and includes
a brush pad. The brush pad contacts the surface of the wafer 70 to
physically brush foreign substances remaining on the surface of the
wafer 70. When the cleaning process is performed, the brush unit
610 disposes the brush pad above the spin head 110 through its
swing operation, and rotates the brush pad to clean the wafer 70
fixed to the spin head 110.
[0106] The aerosol unit 620 is disposed at a side of the brush unit
610. The aerosol unit 620 sprays the process liquid having fine
particles onto the wafer 70 fixed to the spin head 110 at a high
pressure to remove the foreign substances remaining on the surface
of the wafer 70. For example, the aerosol unit 620 sprays the
process liquid in fine particle forms, using supersonic waves. The
brush unit 610 is used for removing foreign substances having
relatively large particles, and the aerosol unit 620 is used for
removing foreign substances having relatively small particles.
[0107] The pad conditioning unit 700 cleans and recycles the
polishing unit 300 when the polishing unit 300 is disposed within a
home port in a standby state. That is, a predetermined polishing
pattern is formed on a surface of the polishing pad 311 (refer to
FIG. 6) contacting the wafer to improve efficiency of the polishing
process. The polishing pattern may be gradually worn by the
friction of the wafer when the polishing process is performed on
the wafer. Also, the chemical liquids used for the polishing
process may be hardened within the polishing pattern. The pad
conditioning unit 700 may polish the surface of the polishing pad
311 to recycle the polishing pad 311.
[0108] Hereinafter, a configuration of the pad supporting member
401 will now be described in detail with reference to the
accompanying drawings.
[0109] FIG. 7 is a perspective view illustrating the pad supporting
member illustrated in FIG. 3. FIG. 8 is a schematic view
illustrating relative positions between the pad supporting member
illustrated in FIG. 7, a substrate supporting unit, and a polishing
unit.
[0110] Referring to FIGS. 2, 7 and 8, the pad supporting member 401
is disposed at a side of the substrate supporting unit 100, and is
spaced apart from the substrate supporting unit 100. When an edge
of the wafer 70 is polished, a polishing surface of the polishing
pad 311, which does not contact the wafer 70, is partially
supported by the pad supporting member 401 to prevent the polishing
pad 311 from being inclined to the outer side of the wafer 70.
[0111] In detail, the pad supporting member 401 may include a
supporting body 410 and a pad part 420. The supporting body 410 is
fixed to the bottom surface 231 of the bowl unit 200, and has a
column shape extending from the bottom surface 231 to the top
surface of the bowl unit 200.
[0112] The pad part 420 is fixed to the upper end of the supporting
body 410, and is adjacent to the spin head 110. The pad part 420 is
spaced apart from the spin head 110, and supports a portion of the
polishing pad 311 when an edge of the wafer 70 is polished.
[0113] The pad part 420 may include a coupling body 421 fixed to
the supporting body 410, a supporting plate 422 coupled to the top
surface of the coupling body 421, and a supporting pad 424
supporting a portion of the polishing pad 311 when an edge of the
wafer 70 is polished. The coupling body 421 is removably coupled to
the supporting body 410 by a first screw 430, and has a column
shape. The supporting plate 422 is removably coupled to the
coupling body 421 by a second screw 423, and has top and side
surfaces that are covered with the supporting pad 424.
[0114] The supporting pad 424 is formed of synthetic resin, and
supports a portion of the polishing pad 311, exposed to the outer
side of the wafer 70 without contacting the wafer 70, when an edge
of the wafer 70 is polished. For example, the supporting pad 424
has a circular top surface and an area less than that of the
polishing pad 311.
[0115] When being viewed from side, the top surface of the
supporting pad 424 and the top surface of the wafer 70 are disposed
on the same line. That is, the top surface of the supporting pad
424 has the same height as that of the wafer 70 fixed to the spin
head 110. The supporting pad 424 is disposed on a movement track of
the polishing pad 311 or an extension line thereof. That is, the
supporting pad 424 is disposed on a movement path where the
polishing pad 311 can move through its swing operation. For
example, the radius of the polishing pad 311 is equal to or less
than the sum of the distance between the supporting pad 424 and the
spin head 110 and the width of the supporting pad 424. Thus, the
supporting pad 424 can stably support the polishing pad 311.
[0116] As such, when an edge of the wafer 70 is polished, the
polishing pad 311 is stably supported by the spin head 110 and the
supporting pad 424, and thus, the polishing pad 311 is prevented
from being inclined to the outer side of the wafer 70. Accordingly,
while an edge of the wafer 70 is polished, the substrate polishing
unit 1000 can prevent an edge breakage of the wafer 70 and a
polishing defect due to inclining of the polishing pad 311, and
improve the product yield.
[0117] Since the supporting pad 424 and the spin head 110 support
the polishing pad 311 when an edge of the wafer 70 is polished, the
top surface of the supporting pad 424 is worn by the polishing pad
311. When the wear of the supporting pad 424 is excessive, the top
surface of the supporting pad 424 is even lower than the top
surface of the wafer 70. As a result, although the supporting pad
424 supports the polishing pad 311 when an edge of the wafer 70 is
polished, the polishing pad 311 may be inclined to the outer side
of the wafer 70. To prevent the polishing pad 311 from being
inclined, the supporting pad 424 is replaced. At this point, the
supporting pad 424 may be replaced with a new supporting pad after
the supporting pad 424 is removed from the supporting plate 422, or
the supporting plate 422 may be removed together with the
supporting pad 424 for replacement.
[0118] To sense a wear degree of the supporting pad 424, the
substrate supporting unit 100 may include a first position sense
part 710 that senses the height of the top surface of the
supporting pad 424 to output a vertical position value of the top
surface of the supporting pad 424. The first position sense part
710 is disposed above the supporting pad 424, and provides the
control unit 60 with a vertical position value of the top surface
of the supporting pad 424. The control unit 60 checks whether a
vertical position value of the supporting pad 424 is out of a
preset vertical position range, and determines whether the
supporting pad 424 is replaced.
[0119] Hereinafter, a process in which the pad supporting member
401 supports the polishing pad 311 when an edge of the wafer 70 is
polished will now be described in detail with reference to the
accompanying drawings.
[0120] FIG. 9 is a flowchart illustrating a process in which the
substrate polishing part illustrated in FIG. 2 polishes a wafer.
FIG. 10 is a schematic view illustrating a process in which the pad
supporting member illustrated in FIG. 8 supports a polishing pad
when an edge of a wafer is polished.
[0121] Referring to FIGS. 9 and 10, in operation S110, the wafer 70
is seated on the top surface of the spin head 110.
[0122] Subsequently, in operation S120, the polishing pad 311 is
disposed on the top surface of the wafer 70.
[0123] Subsequently, in operation S130, the spin head 110 is
rotated to rotate the wafer 70, and simultaneously, the polishing
pad 311 rotates and presses the wafer 70 to polish the wafer 70.
When the wafer 70 is polished, slurry is supplied to the top
surface of the wafer 70, and the polishing pad 311 polishing the
wafer 70 is rotated and swung to vary a relative position to the
wafer 70.
[0124] When the wafer 70 is polished, the polishing pad 311 moves
to an edge of the wafer 70 through its swing operation to polish
the edge of the wafer 70. At this point, the top surface of the
supporting pad 424 supports a portion of the polishing pad 311
without contacting the wafer 70, that is, a portion of the
polishing pad 311 exposed to the outer side of the wafer 70.
Accordingly, the pad supporting member 401 prevents the polishing
pad 311 from being inclined to the outer side of the wafer 70.
[0125] FIG. 11 is a schematic view illustrating another example of
the pad supporting member illustrated in FIG. 8. FIG. 12 is a
schematic view illustrating a process in which the pad supporting
member illustrated in FIG. 11 supports a polishing pad when an edge
of a wafer is polished.
[0126] Referring to FIGS. 11 and 12, a pad supporting member 402
may include the supporting body 410, the pad part 420, and a
position adjustment part 440. The pad supporting member 402 is the
same in configuration as the pad supporting member 401 illustrated
in FIG. 8, except the position adjustment part 440. Thus, the same
components as those of the pad supporting member 401 illustrated in
FIG. 8 are denoted by reference numerals, and detailed descriptions
thereof will be omitted.
[0127] The position adjustment part 440 is fixed to the lower
portion of the supporting body 410, and vertically moves the
supporting body 410 to adjust the top surface of the pad part 420,
that is, the height of the top surface of the supporting pad 424.
In the current embodiment, the position adjustment part 440 is
constituted by a cylinder, but may be constituted by a driving
motor.
[0128] The position adjustment part 440 may be connected to the
control unit 60 and be controlled by the control unit 60. That is,
the control unit 60 receives a vertical position value of the top
surface of the supporting pad 424, which is a value output from the
first position sense part 710, and controls the position adjustment
part 440 according to the received vertical position value to
adjust the height of the top surface of the supporting pad 424 to
be the same as a preset height, for example, the same as the height
of the top surface of the wafer 70.
[0129] FIG. 13 is a schematic view illustrating another example of
the pad supporting member illustrated in FIG. 8.
[0130] Referring to FIG. 13, a pad supporting member 403 is
disposed at a side of the substrate supporting unit 100, and is
spaced apart from the substrate supporting unit 100. When an edge
of the wafer 70 is polished, a polishing surface of the polishing
pad 311, which does not contact the wafer 70, is partially
supported by the pad supporting member 403 to prevent the polishing
pad 311 from being inclined to the outer side of the wafer 70.
[0131] In detail, the pad supporting member 403 may include a
supporting body 450, a pad part 460, a connection part 470, and a
position adjustment part 480. The supporting body 450 is fixed to
the bottom surface 231 of the bowl unit 200 (refer to FIG. 3), and
has a column shape extending from the bottom surface 231 to the top
surface of the bowl unit 200.
[0132] The connection part 470 is coupled to the upper end of the
supporting body 450 such that the connection part 470 is vertically
movable, and the pad part 460 is fixed to the upper end of the
connection part 470. The pad part 460 is adjacently spaced apart
from the spin head 110, and supports a portion of the polishing pad
311 when an edge of the wafer 70 is polished.
[0133] The pad part 460 may include a supporting plate 461 coupled
to the top surface of the connection part 470, and a supporting pad
462 supporting a portion of the polishing pad 311 when an edge of
the wafer 70 is polished. The upper and side surfaces of the
supporting plate 461 may be covered with the supporting pad
462.
[0134] The supporting pad 462 is formed of synthetic resin, and
supports a portion of the polishing pad 311, exposed to the outer
side of the wafer 70 without contacting the wafer 70, when an edge
of the wafer 70 is polished. For example, the supporting pad 462
has a circular top surface and an area less than that of the
polishing pad 311.
[0135] The supporting pad 462 is disposed on a movement track of
the polishing pad 311 or an extension line thereof. That is, the
supporting pad 462 is disposed on a movement path where the
polishing pad 311 can move through its swing operation. For
example, the radius of the polishing pad 311 is equal to or less
than the sum of the distance between the supporting pad 462 and the
spin head 110 and the width of the supporting pad 462. Thus, the
supporting pad 462 can stably support the polishing pad 311.
[0136] As such, when an edge of the wafer 70 is polished, the
polishing pad 311 is stably supported by the spin head 110 and the
supporting pad 462, and thus, the polishing pad 311 is prevented
from being inclined to the outer side of the wafer 70. Accordingly,
while an edge of the wafer 70 is polished, the substrate polishing
unit 1000 can prevent an edge breakage of the wafer 70 and a
polishing defect due to inclining of the polishing pad 311, and
improve the product yield.
[0137] The supporting pad 462 is removably coupled to the
supporting plate 461. Thus, when the supporting pad 462 is worn a
predetermined amount or greater by the polishing pad 311, the
supporting pad 462 can be removed and replaced.
[0138] The position adjustment part 480 is disposed between the
supporting plate 461 and the supporting body 450. The position
adjustment part 480 is contracted and expanded by air pressure to
adjust the vertical position of the supporting pad 462.
[0139] A second position sense part 720 may be disposed between the
substrate supporting unit 100 and the pad supporting member 403.
The second position sense part 720 senses a relative position of
the polishing pad 311 to the substrate supporting unit 100 to
provide a horizontal position value of the polishing pad 311 to the
control unit 60. In the current embodiment, the second position
sense part 720 is discretely disposed at a side of the pad
supporting member 403, but may be disposed in the polishing unit
300.
[0140] The control unit 60 controls the position adjustment part
480 according to a received horizontal position value of the
polishing pad 311 and a vertical position value of the top surface
of the supporting pad 462 to adjust the position of the top surface
of the supporting pad 462.
[0141] FIGS. 14A and 14B are schematic views illustrating a height
variation of the top surface of the pad supporting member
illustrated in FIG. 13 according to positions of a polishing pad
when a wafer is polished.
[0142] Referring to FIG. 14A, when the polishing pad 311 is
disposed in a region except the edge of the wafer 70, the position
adjustment part 480 are contracted to move the supporting pad 462
downward. As a result, the top surface of the supporting pad 462 is
lower than the top surface of the wafer 70.
[0143] Referring to FIG. 14B, when the polishing pad 311 is
disposed in the edge of the wafer 70, the position adjustment part
480 are expanded to move the supporting pad 462 upward. As a
result, the top surface of the supporting pad 462 partially
contacts the polishing surface of the polishing pad 311 exposed to
the outer side of the wafer 70, to support the polishing pad
311.
[0144] According to the above-described embodiments, when an edge
of a wafer is polished, the pad supporting member partially
supports the polishing pad exposed to the outer side of the wafer,
and thus, the pad supporting member prevents the polishing pad from
being inclined to the outer side of the wafer while the edge of the
wafer is polished. Accordingly, the substrate polishing unit
improves polishing efficiency, and prevents the breakage of a
substrate during a polishing process.
[0145] The above-disclosed subject matter is to be considered
illustrative, and not restrictive, and the appended claims are
intended to cover all such modifications, enhancements, and other
embodiments, which fall within the true spirit and scope of the
present invention. Thus, to the maximum extent allowed by law, the
scope of the present invention is to be determined by the broadest
permissible interpretation of the following claims and their
equivalents, and shall not be restricted or limited by the
foregoing detailed description.
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