U.S. patent application number 12/028844 was filed with the patent office on 2008-08-28 for apparatus for processing wafer.
This patent application is currently assigned to NEC ELECTRONICS CORPORATION. Invention is credited to Masanori GOTO.
Application Number | 20080207095 12/028844 |
Document ID | / |
Family ID | 39716433 |
Filed Date | 2008-08-28 |
United States Patent
Application |
20080207095 |
Kind Code |
A1 |
GOTO; Masanori |
August 28, 2008 |
APPARATUS FOR PROCESSING WAFER
Abstract
An apparatus for processing wafer is provided, in which a
re-adhesion of the slurry to the wafer edge, which has been adhered
to the elastic abrasion member, can be inhibited, since a stronger
contact of the rotating elastic abrasion member with the wafer
edge, which is occurred when the rotating elastic abrasion member
enters to the surface of the wafer, is avoided, and further, an
abrasion of the elastic abrasion member can be inhibited. The
apparatus for processing wafer is an apparatus for processing
wafers, wherein a shaft center of the mechanism for rotating the
wafer is inclined relative to a shaft center of the
abrading-rotating mechanism, so that a distance between the support
member and the wafer in a position where the elastic abrasion
member enters the inner side of the surface of the wafer from the
outer side thereof due to the actuation toward the predetermined
direction by the abrading-rotating mechanism is larger than the
distance between the support member and the wafer in a position
where the elastic abrasion member escapes from the inner side of
the surface of the wafer to the outer side thereof.
Inventors: |
GOTO; Masanori; (Kawasaki,
JP) |
Correspondence
Address: |
YOUNG & THOMPSON
209 Madison Street, Suite 500
ALEXANDRIA
VA
22314
US
|
Assignee: |
NEC ELECTRONICS CORPORATION
KAWASAKI
JP
|
Family ID: |
39716433 |
Appl. No.: |
12/028844 |
Filed: |
February 11, 2008 |
Current U.S.
Class: |
451/177 ;
451/398 |
Current CPC
Class: |
B08B 1/04 20130101; B24B
37/04 20130101; B24B 41/047 20130101; B24B 47/10 20130101 |
Class at
Publication: |
451/177 ;
451/398 |
International
Class: |
B24B 7/00 20060101
B24B007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 23, 2007 |
JP |
2007-044539 |
Claims
1. An apparatus for processing wafers, which is adopted to abrade
at least one side of a disc-shaped wafer, comprising: a
wafer-rotating mechanism, capable of actuating a rotation of said
wafer; an abrasion unit configured to have an elastic abrasion
member supported by a support member, said elastic abrasion member
being capable of abrading a surface of said wafer; and an
abrading-rotating mechanism for actuating said abrasion unit to be
rotated for a predetermined direction to cause a revolution of said
elastic abrasion member, in a position where at least a portion of
said elastic abrasion member travels between an inner portion in
the surface of said wafer and an outer portion thereof, wherein a
shaft center of said wafer-rotating mechanism is inclined relative
to a shaft center of said abrading-rotating mechanism, so that a
distance between said support member and said wafer in a position
where said elastic abrasion member enters the inner side of the
surface of said wafer from the outer side thereof due to the
actuation toward the predetermined direction by said
abrading-rotating mechanism is larger than the distance between
said support member and said wafer in a position where said elastic
abrasion member escapes from the inner side of the surface of said
wafer to the outer side thereof.
2. The apparatus for processing wafers as set forth in claim 1,
wherein a plurality of said elastic abrasion members are radially
supported by said elastic abrasion member in said abrasion
unit.
3. The apparatus for processing wafers as set forth in claim 1,
wherein the surface of said wafer is cleaned by abrading the
surface with said elastic abrasion member of said abrasion
unit.
4. The apparatus for processing wafers as set forth in claim 2,
wherein the surface of said wafer is cleaned by abrading the
surface with said elastic abrasion member of said abrasion unit.
Description
[0001] This application is based on Japanese patent application No.
2007-44,539, the content of which is incorporated hereinto by
reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to an apparatus for processing
wafers that is capable of fretting at least one side of a
disc-shaped wafer.
[0004] 2. Related Art
[0005] Conventionally, a typical apparatus for processing wafers
includes, for example, an apparatus described in Japanese Patent
Laid-Open No. 2002-177,898. The apparatus for processing wafers
described in Japanese Patent Laid-Open No. 2002-177,898 is shown in
FIG. 4. In this apparatus for processing wafers, a wafer 10 is held
with a roller chuck, sponge-like brushes 12 are installed to a
disc-shaped brush base 11. Further, the surface of the wafer 10 is
in parallel with the lower surface of the brush base 11. In order
to conduct a scrub-cleaning over the edge of the wafer 10, an
offset positional relationship between a shaft center of the wafer
10 and a shaft center of the brush base 11 is employed. Further,
portions of the brush 12 installed to the brush base 11 are
protruded beyond the surface of the wafer 10. When the wafer 10 is
scrub-cleaned, both of the wafer 10 and the brush base 11 rotate,
and the sponge-like brushes 12 are pressed to the front and the
back surface of the wafer 10. Then, a liquid or slurry (L) for
rinsing is discharged from the center of the brush base 11 to clean
the wafer 10.
[0006] However, the apparatus for processing wafers disclosed in
Japanese Patent Laid-Open No. 2002-177,898 bears improvements in
terms of re-adhesion of particles in the slurry.
[0007] For example, since the lower surface of the brush 12 (brush
base 11) is arranged to be in parallel with the surface of the
wafer 10 in the apparatus for processing wafers disclosed in
Japanese Patent Laid-Open No. 2002-177,898, the apparatus is
configured that the entire lower surface of the brush 12 is
uniformly pressed against the surface of the wafer 10 as shown in
FIG. 5B. As shown in FIGS. 5A and 5B, the shaft center 20 of the
wafer the central axis 21 of the brush base are not relatively
inclined. When the scrub-cleaning is conducted, the brush 12 is
pushed onto the surface of the wafer 10 at a fixed pressure for
providing better scrub-cleaning. Therefore, a leading edge of the
brush 12 on the surface of the wafer 10 is squashed as shown in
FIG. 6, providing a lower height of the brush 12 (the brush on the
back side of the wafer is not illustrated).
[0008] On the other hand, the leading edge of the brush 12
protruding beyond the wafer 10 is not squashed. Since the brush
base 11 is rotated, actions of the portions of the brush 12 for
traveling from the "surface of the wafer 10" to the "protruded
section" (without wafer 10) and traveling from the "protruded
section" (without wafer 10) to the "surface of the wafer 10" are
repeated, while the portion of brush 12 are revolved. When the
action for traveling from the "protruded section" (without wafer
10) to the "surface of the wafer 10" is achieved, the protruded
portion of the brush 12 is in strong contact with the edge of the
wafer 10, and gradually runs on the surface of the wafer 10 while
being squashed. A section Z represented by a thick curved line in
FIG. 7 indicates a section where the brush 12 is in strong contact
with the wafer 10, when the protruded portion of the brush 12 is
entered onto the surface of the wafer 10 due to the rotation of the
brush 12. Therefore, particles originally contained in the slurry
and adhered in the brush 12 may possibly adhered again onto the
edge of the wafer 10 in the section Z.
[0009] Such re-adhesion is more considerably occurred as the
pushing pressure of the brush 12 onto the wafer 10 is larger.
Further, the strong contact between the protruded portion of the
brush 12 and the edge of the wafer 10 may accelerate an abrasion of
the leading edge of the brush 12 located in the outside of the
wafer 10.
[0010] Further, a reduced pushing pressure of the brush 12 onto the
wafer 10 leads to an insufficient removal-ability of the slurry,
causing problems such as debasements in the qualities of the
products.
SUMMARY
[0011] According to one aspect of the present invention, there is
provided an apparatus for processing wafers, which is adopted to
abrade at least one side of a disc-shaped wafer, comprising: a
wafer-rotating mechanism, capable of actuating a rotation of the
wafer; an abrasion unit configured to have an elastic abrasion
member supported by a support member, the elastic abrasion member
being capable of abrading a surface of the wafer; and an
abrading-rotating mechanism for actuating the abrasion unit to be
rotated for a predetermined direction to cause a revolution of the
elastic abrasion member, in a position where at least a portion of
the elastic abrasion member travels between an inner portion in the
surface of the wafer and an outer portion thereof, wherein a shaft
center of the wafer-rotating mechanism is inclined relative to a
shaft center of the abrading-rotating mechanism, so that a distance
between the support member and the wafer in a position where the
elastic abrasion member enters the inner side of the surface of the
wafer from the outer side thereof due to the actuation toward the
predetermined direction by the abrading-rotating mechanism is
larger than the distance between the support member and the wafer
in a position where the elastic abrasion member escapes from the
inner side of the surface of the wafer to the outer side
thereof.
[0012] In such apparatus for processing wafer, the distance between
the support member and the wafer in a position where the elastic
abrasion member enters the inner side of the surface of the wafer
from the outer side thereof is selected to be larger than the
distance therebetween in a position where the elastic abrasion
member escapes from the inner side of the surface of the wafer to
the outer side thereof, so that a stronger contact of the rotating
elastic abrasion member with the wafer edge, which is occurred when
the rotating elastic abrasion member enters to the surface of the
wafer, is avoided.
[0013] According to the present invention, an apparatus for
processing wafer is provided, in which a re-adhesion of the slurry
to the wafer edge, which has been adhered to the elastic abrasion
member, can be inhibited, since a stronger contact of the rotating
elastic abrasion member with the wafer edge, which is occurred when
the rotating elastic abrasion member enters to the surface of the
wafer, is avoided, and further, an abrasion of the elastic abrasion
member can be inhibited.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above and other objects, advantages and features of the
present invention will be more apparent from the following
description of certain preferred embodiments taken in conjunction
with the accompanying drawings, in which:
[0015] FIG. 1 is a schematic cross-sectional view, showing an
apparatus for processing wafers;
[0016] FIG. 2 is a schematic plan view, showing an apparatus for
processing wafers;
[0017] FIG. 3 is a schematic cross-sectional view, showing an
apparatus for processing wafers;
[0018] FIG. 4 is a schematic perspective view, showing a
conventional apparatus for processing wafers;
[0019] FIG. 5A is a schematic plan view, showing a conventional
apparatus for processing wafers;
[0020] FIG. 5B is a schematic cross-sectional view showing the
conventional apparatus for processing wafers;
[0021] FIG. 6 is a schematic cross-sectional view, showing a
conventional apparatus for processing wafers; and
[0022] FIG. 7 is a schematic plan view, showing a conventional
apparatus for processing wafers.
DETAILED DESCRIPTION
[0023] The invention will be now described herein with reference to
illustrative embodiments. Those skilled in the art will recognize
that many alternative embodiments can be accomplished using the
teachings of the present invention and that the invention is not
limited to the embodiments illustrated for explanatory
purposed.
[0024] An exemplary implementation of the present invention will be
described as follows in reference to FIGS. 1 and 2. In the
following description, an identical designation will be employed
for identifying an element, which also appears in the
above-described descriptions for the conventional technology, and
the duplicated description will not be presented.
[0025] FIG. 2 is a schematic plan view of an apparatus for
processing wafers. The apparatus for processing wafer in the
present embodiment is an apparatus for processing wafers, which is
adopted to abrade at least one side of a disc-shaped wafer 30,
comprising: a wafer-rotating mechanism 50, capable of actuating a
rotation of the wafer 30; an abrasion unit 33 configured to have an
elastic abrasion member 32 supported by a support member 31, the
elastic abrasion member 32 being capable of abrading a surface of
the wafer 30; and an abrading-rotating mechanism 51 for actuating
the abrasion unit 33 to be rotated toward a predetermined direction
to revolve the elastic abrasion member 32, in a position where at
least a portion of the elastic abrasion member 32 travels between
an inner portion in the surface of the wafer 30 and an outer
portion thereof, wherein a shaft center of wafer-rotating mechanism
50 for rotating the wafer 30 is inclined relative to a shaft center
of the abrading-rotating mechanism 51, so that a distance between
the support member 31 and the wafer 30 in a position where the
elastic abrasion member 32 enters the inner side of the surface of
the wafer 30 from the outer side thereof due to the actuation
toward the predetermined direction by the abrading-rotating
mechanism 51 is larger than the distance between the support member
31 and the wafer 30 in a position where the elastic abrasion member
32 escapes from the inner side of the surface of the wafer 30 to
the outer side thereof.
[0026] Further, a section Z represented by a thick curved line in
FIG. 2 indicates a section where a portion of the elastic abrasion
member 32 enters in the inner side in the surface of the wafer 30
from the outside thereof due to a revolution of the elastic
abrasion member 32. In particular, the section indicates a section
where the elastic abrasion member 32 is in strong contact with the
edge of the wafer 30.
[0027] The apparatus for processing wafers includes the
wafer-rotating mechanism 50, the abrasion unit 33 and the
abrading-rotating mechanism 51.
[0028] The wafer-rotating mechanism 50 is adopted to actuate the
wafer 30 to be rotated around a shaft center 40 thereof.
[0029] The abrasion unit 33 has a structure, in which the elastic
abrasion member 32 for abrading the surface of the wafer 30 is
supported by the support member 31. The abrasion unit 33 rotates
around the shaft center 41 of the abrading-rotating mechanism 51 to
provide a revolution of the elastic abrasion member 32. At least a
portion of the revolving elastic abrasion member 32 abrades the
surface of the wafer 30 while traveling between the inner side and
the outer side of the surface of the wafer 30. Such travelling of
the elastic abrasion member 32 achieves a cleaning of the entire
surface of the wafer 30.
[0030] Further, a plurality of elastic abrasion members 32 are
radially supported by the support member 31 in the abrasion unit
33. Even if a plurality of elastic abrasion members 32 are radially
supported, the strong contact of the rotating elastic abrasion
members 32 with the edge of the wafer 30 occurred when the elastic
abrasion members 32 enter to the surface of the wafer 30 is
avoided, so that a re-adhesion of the slurry, which may otherwise
adhered to the edge of the elastic abrasion member 32, can also be
inhibited.
[0031] The abrading-rotating mechanism 51 is adopted to actuate the
abrasion unit 33 to be rotated in a fixed direction in a position
where at least a portion of the revolving elastic abrasion member
32 moves between the inner side and the outer side in the surface
of the wafer 30.
[0032] FIG. 1 is a diagram, representing a cross section along line
A-A' in FIG. 2. A shaft center 40 of the wafer-rotating mechanism
50 is inclined relative to a shaft center 41 of the
abrading-rotating mechanism 51, so that a distance between the
support member 31 and the wafer 30 in a position where the elastic
abrasion member 32 enters the inner side of the surface of the
wafer 30 from the outer side thereof due to the actuation toward
the predetermined direction is larger than the distance between the
support member 31 and the wafer 30 in a position where the elastic
abrasion member 32 escapes from the inner side of the surface of
the wafer 30 to the outer side thereof. An angle of the inclination
between the shaft center 40 and the shaft center 41 may be
preferably, for example, within a range of from 0.6 degree to 1.2
degree.
[0033] The inclined spatial relationship of the shaft center 41 of
the abrading-rotating mechanism 51 achieves a condition that the
pressing pressure of the elastic abrasion member 32 is minimized in
the section for entering the surface of the wafer 30, and is
maximized at the opposite angle side on the wafer 30. This allows
preventing the elastic abrasion member 32 entering the surface of
the wafer 30 from being in strong contact with the edge of the
wafer 30. More specifically, a re-adhesion of the slurry, which has
been originally adhered to the elastic abrasion member 32, to the
edge of the wafer 30 can be inhibited, and further, an abrasion of
the elastic abrasion member 32 can also be inhibited.
[0034] While the configuration having the shaft center 41 of the
abrading-rotating mechanism 51, which is inclined relative to the
shaft center 40, is shown in the present embodiment, an alternative
configuration having the shaft center 40 of the wafer-rotating
mechanism 50, which is inclined relative to the shaft center 41,
may also be employed (FIG. 3).
[0035] In other words, the shaft center 40 of the wafer-rotating
mechanism 50 and the shaft center 41 of the abrading-rotating
mechanism 51 may be relatively tilted, so that the leading edge of
the elastic abrasion member 32 is not pushed against the edge of
the wafer 30 in the section Z.
[0036] While the configuration of the elastic abrasion members 32,
which are radially supported, is employed in the present
embodiment, an alternative configuration of the elastic abrasion
members 32, which are uniformly supported on the support member 31,
may also be employed. Members available for the elastic abrasion
member 32 may include elastic members such as brush, sponge and the
like. Further, tilting direction/angle, positions of the shaft
centers, diameter/geometry/dimension of the abrasion unit or the
like may be suitably optimized for solving the above-described
problems.
[0037] Further, while the configuration having three wafer-rotating
mechanisms 50 for rotating the wafer 30 is described in the present
embodiment, number and positions of the wafer-rotating mechanisms
50 may not be particularly limited thereto.
[0038] Further, while the configuration having the abrasion unit 33
and the abrading-rotating mechanism 51, both of which are present
on the front surface of the wafer 30, is described in the present
embodiment, an alternative configuration having these
unit/mechanism located on both the front and the back sides of the
wafer 30 may also be employed to achieve similar advantageous
effects.
[0039] Further, while the embodiment utilizing the wafer processing
apparatus for cleaning is described in the present embodiment,
other applications including polishing or the like, in addition to
cleaning, may also be adapted.
[0040] The present embodiment and possible modifications thereof
may be combined, unless the concepts thereof contradict.
* * * * *