Abrading – Abrading process – Abradant supplying
Reexamination Certificate
1999-06-25
2001-11-13
Eley, Timothy V. (Department: 3723)
Abrading
Abrading process
Abradant supplying
C451S446000, C451S285000
Reexamination Certificate
active
06315643
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a polishing apparatus and a polishing method which is, in particular, suitable for polishing of a semiconductor wafer.
FIG. 16
shows a typical semiconductor wafer polishing apparatus for conducting a precise polishing process for a semiconductor wafer which process is referred to as “chemical-mechanical planarization” (CMP). The polishing apparatus includes a turntable
100
and two wafer carriers
101
,
102
which are respectively rotated around their respective center axes in the directions designated by arrows A, B and C. The turntable is provided, on its top surface, with a polishing pad. Each of the wafer carriers
101
,
102
holds a wafer on the bottom surface thereof. The wafer carriers are symmetrically positioned relative to the center axis of the turntable. The apparatus further includes a slurry supply nozzle
104
. In operation, wafers carried by the carriers
101
,
102
are engaged with the polishing pad on the turntable
100
while the turntable and the wafer carriers
101
,
102
are rotated and the slurry supply nozzle
104
continuously supplies a slurry onto the polishing pad. The wafers are polished mechanically and chemically by means of the polishing pad and the slurry. The wafer carriers
101
,
102
are swingable in the directions designated by arrows D and E, respectively, to enable the wafers to be mounted on and removed from the wafer carriers.
In such a polishing apparatus, it is desirable that consumption of slurry, which is expensive, be minimized, so far as a high polishing performance in term of polishing rate, evenness of a polished surface of a wafer and so on is maintained. Thus, there is a need to effectively transfer the slurry to the wafers after the slurry is applied to the polishing pad.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a polishing apparatus and a polishing method which will meet such a need.
In accordance with the present invention, a polishing apparatus comprises a turntable having an upper polishing surface and a center axis about which the turntable is rotated, at least one carrier having a center axis and adapted to carry an article having a surface to be polished in such a manner that the surface is engaged with the upper polishing surface of the turntable, and at least one slurry supply nozzle provided for the carrier and adapted to supply a slurry onto a predetermined slurry supply point on the polishing surface of the turntable upstream of the carrier or upstream of a line connecting the center axes of the turntable and the carrier in the direction of rotation of the turntable while the turntable and the carrier are rotated around their respective center axes with the surface of the article kept in engagement with the polishing surface. The nozzle is preferably positioned such that the angle form between a line connecting the center axis of the turntable and the center axis of the corresponding wafer carrier and a line connecting the center axis of the wafer carrier and the predetermined slurry supply point is in the range of 5 degrees to 40 degrees. The arrangement of the wafer carrier and the nozzle as noted above will enable the slurry supplied on the polishing surface by the nozzle to be effectively transferred to the wafer carrier.
Specifically, the supply nozzle is positioned as represented by d/R ≦0.3 where d is a distance between the outer peripheral edge of the carrier and the predetermined slurry supply point and R is a radius of the carrier. The above-noted condition will facilitate the effective transfer of the slurry.
The apparatus may comprise a plurality of wafer carriers and corresponding slurry supply nozzles which are symmetrically positioned relative to the center axis of the turntable.
It is preferable for the slurry supply nozzle to be located in such a manner that the lower slurry exit end thereof is positioned within a range of 10.0-20.0 mm above the polishing surface of the turntable.
Further, in accordance with the present invention, there is provided a method for polishing a surface of an article which comprises the steps of turning a turntable having an upper polishing surface around its center axis, holding an article by a carrier, positioning the carrier in such a manner that a surface of the article is engaged with the upper polishing surface of the turntable, rotating the carrier about its center axis, and supplying a slurry onto a predetermined slurry supply point on the polishing surface of the turntable upstream of the carrier or upstream of a line connecting the center axes of the turntable and the carrier in the direction of the rotation of the turntable while rotating the turntable and the carrier around their respective center axes with the surface of the article kept in engagement with the polishing surface. The nozzle is positioned such that the angle formed between a line connecting the center of the rotation of the turntable and the center of the rotation of the carrier and a line connecting the center of the rotation of the carrier and the predetermined slurry supply point is in the range of from 5 degrees to 40 degrees.
REFERENCES:
patent: 5647792 (1997-07-01), Katsuoka et al.
patent: 5651725 (1997-07-01), Kikuta et al.
patent: 5679063 (1997-10-01), Kimura et al.
patent: 5702291 (1997-12-01), Isobe
patent: 5709593 (1998-01-01), Guthrie et al.
patent: 5837610 (1998-11-01), Lee et al.
patent: 5857898 (1999-01-01), Hiyama et al.
patent: 5997392 (1999-12-01), Chamberlin et al.
patent: 6116993 (2000-09-01), Tanaka
patent: 8-197427 (1996-08-01), None
patent: 9-29635 (1997-02-01), None
Hiyama Hirokuni
Maekawa Seiyo
Wada Yutaka
Ebara Corporation
Eley Timothy V.
Nguyen Dung Van
Wenderoth , Lind & Ponack, L.L.P.
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