Abrading – Machine – Rotary tool
Reexamination Certificate
2001-03-21
2003-02-18
Hall, III, Joseph J. (Department: 3723)
Abrading
Machine
Rotary tool
C451S290000, C451S343000
Reexamination Certificate
active
06520845
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for polishing workpieces such as semiconductor wafers, various kinds of hard disks, glass substrates and liquid crystal display panels.
2. Description of the Related Art
In a conventional chemical mechanical polishing (CMP) apparatus used in fabrication of a semiconductor integrated circuit, a semiconductor wafer is held by a holder called a “top ring” and is rotated and pressed against a polishing cloth mounted on a rotating turntable while being supplied with abrading slurry including free abrading grains at a sliding interface. However, such a CMP apparatus presents a problem that, depending on the type of surface patterns and differences in the heights of fine surface structures fabricated on the wafer, it is not possible to obtain a precisely polished flat surface.
Therefore, in place of the above-mentioned CMP process, another CMP technique has been developed, where the wafer is placed in sliding contact with a solid polishing member shaped usually in the form of a plate, in which abrading grains are bound in a matrix, while a polishing liquid or a polishing solution is supplied at the sliding interface. The solid polishing members include variations such as a ring-type member or a cup-type member having abrading pellets distributed in a ring shape.
FIG. 11
illustrates basic movements of a cup-type polishing member. A cup-type polishing member
80
has a ring-shaped abrading member
81
attached on the bottom surface of a polishing member holder
83
, and is pressed against a wafer
100
held in a wafer holder
85
. Both are rotated, for example, in the same G, H directions, and the wafer
100
is uniformly polished by moving the polishing member
80
linearly in the radial direction of the wafer
100
(indicated by the arrow I) so that the abrading member
81
polishes the entire surface of wafer
100
. The polishing member holder
83
is connected to the drive shaft
89
through a spherical bearing
87
so as to transmit a pressing force F from the drive shaft
89
through the spherical bearing
87
, and coupling of drive pin
91
passive pin
93
transmits the rotation H from the drive shaft
89
.
In general, the polishing member
80
is pressed on the wafer
100
through the drive shaft
89
, therefore, when drive axis k of the drive shaft
89
is projected within the wafer
100
, as shown in
FIG. 11
, there is no tilting of the polishing member
80
. But, when it is in the position shown in
FIG. 12
, the rotation axis k projects outside the wafer
100
, and even if a part of the abrading member
81
is on the wafer, a lever action produces tilting of the abrading member
81
about fulcrum at the edge of the wafer
100
. This prevents the abrading member
81
from having a planar contact with the wafer
100
, and polishing becomes impossible. Therefore, to avoid such a situation, conventional abrading member
81
could only move within an area of support for the drive axis k. This problem is the same in a conventional polishing apparatus using a top ring holding the wafer to press it against a polishing table.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a polishing apparatus using a polishing member that has a wide stable polishing range to perform effective polishing, even if the rotation axis moves away from the edge of a workpiece to be polished.
The object has been achieved in a polishing apparatus comprised by a polishing member holder for holding a polishing member and a workpiece holder for holding a workpiece to be polished; and a drive device to produce a relative sliding motion between the polishing member and the workpiece; wherein at least one holder of either the polishing member holder or the workpiece holder is rotatable about a rotation axis and is tiltable with respect to the other holder, and the one holder is provided with a mechanism to stabilize the orientation or desired posture of the one holder by applying an adjusting pressure to the one holder at a location away from the rotation axis.
The polishing apparatus of such a construction can maintain stable contact of the workpiece to be polished to the polishing member at all times to produce stable polishing, even when a projected line of the rotation axis is outside the workpiece to be polished, thereby widening the relative movable range of the polishing member to the workpiece and providing an increased selection for controlling parameters or controlled systems.
REFERENCES:
patent: 2546529 (1951-03-01), Speicher
patent: 2577042 (1951-12-01), Speicher
patent: 3130523 (1964-04-01), Monnet
patent: 5476414 (1995-12-01), Hirose et al.
patent: 5514025 (1996-05-01), Hasegawa et al.
patent: 5562529 (1996-10-01), Kishi et al.
patent: 5676025 (1997-10-01), Lulay
patent: 5679212 (1997-10-01), Kato et al.
patent: 5738568 (1998-04-01), Jurjevic et al.
patent: 6136138 (2000-10-01), Yagisawa
patent: 6227948 (2001-05-01), Khoury et al.
patent: 6270392 (2001-08-01), Hayashi et al.
patent: 6402588 (2002-06-01), Matsuo et al.
patent: 61-168462 (1986-07-01), None
Hirokawa Kazuto
Hiyama Hirokuni
Matsuo Hisanori
Wada Yutaka
Ebara Corporation
Hall, III Joseph J.
Ojini Anthony
Wenderoth , Lind & Ponack, L.L.P.
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