Abrading – Precision device or process - or with condition responsive... – Computer controlled
Reexamination Certificate
2000-03-31
2002-10-08
Eley, Timothy V. (Department: 3723)
Abrading
Precision device or process - or with condition responsive...
Computer controlled
C451S006000, C451S041000, C451S287000
Reexamination Certificate
active
06461222
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a planarizing and polishing-apparatus and a planarizing and polishing method for polishing flat a plated film or an insulating film formed, for example, on the surface of a wafer.
BACKGROUND OF THE INVENTION
FIGS. 1A
to
1
F are side elevation views of cross-sections illustrating the fabrication process of a metal interconnection type substrate. On the surface of a wafer
1
formed of silicon, an interconnection pattern
2
formed of copper (Cu) is formed and the surface of wafer
1
including interconnection pattern
2
is covered with an insulating film
3
formed of silicon dioxide (SiO2) (in FIG.
1
A). A conducting hole
4
for laminated interconnection pattern is formed by etching to an insulating film
3
(in FIG.
1
B), the surface of the insulating film
3
including the internal surface of the conducting hole
4
is covered with a barrier film
5
formed of tantalum (Ta) and titanium (Ti) or the like (in
FIG. 1C
) and a seed film
6
of copper (Cu) is formed by the sputtering method (in FIG.
1
D). A rather thick laminated interconnection pattern film
7
formed of copper (Cu) is formed by the plating process in such a way as perfectly filling the inside of conductive hole
4
(in FIG.
1
E). Thereafter, unwanted laminated interconnection pattern film
7
on the insulating film
3
is removed by the polishing process to form the laminated interconnection pattern
8
in order to attain the final metal interconnection type substrate (in FIG.
1
F).
In the polishing process for fabricating the metal interconnection type substrate
9
explained above, a planarizing and polishing apparatus is used.
FIG. 2
is a perspective view schematically illustrating the planarizing and polishing apparatus of the related art. This planarizing and polishing apparatus
20
is provided with a rotatable disk type surface plate
22
on which surface a polishing cloth
21
is stuck, a disk type mounting plate
23
which can rotate horizontally and move vertically, (in the Z direction) to hold a wafer
1
at the lower surface thereof and a nozzle
24
for supplying a kind of polishing liquid P onto the polishing cloth
21
. In such a configuration, first, the surface of wafer
1
on which the laminated interconnection pattern film
7
is formed is directed downward and the rear surface of wafer
1
is then bonded or vacuum-absorbed to the lower surface of the mounting plate
23
. Next, the surface plate
22
and mounting plate
23
are rotated and the polishing liquid P is supplied onto the polishing cloth
21
from the nozzle
24
. Moreover, the mounting plate
23
is moved downward to press the surface of wafer
1
with the polishing cloth
21
to polish the laminated interconnection pattern film
7
formed on the surface of wafer
1
.
The planarizing and polishing apparatus
20
of the related art has a disadvantage that a degree of polishing of the laminated interconnection pattern film
7
by this polishing apparatus is not constant because of time management and an accurate degree of polishing cannot be detected until the end of the polishing process. Moreover, measurement for a degree of polishing is accompanied by a disadvantage that an additional exclusive thickness measuring device is required and many processing steps are also required. In addition, here rises a problem that polishing accuracy is unstable because this polishing accuracy changes depending on the condition of polishing cloth
21
; moreover, this polishing accuracy also changes depending on experience and intuition of worker Therefore, in some cases, the fault such as dishing, erosion (thinning), recess, scratch, chemical damage, over-polishing and under-polishing are generated as will be described later.
FIG. 3A
illustrates an example of dishing. In this fault, the center area of the wide laminated interconnection pattern film
7
is polished excessively in the shape of a dish and thereby the cross-sectional area of the laminated interconnection pattern
8
becomes insufficient.
FIG. 3B
illustrates an example of erosion (thinning). In this fault, the insulating film
3
is also polished excessively together with the laminated interconnection pattern film
7
having higher pattern density and thereby the cross-sectional area of the laminated interconnection pattern
8
also becomes insufficient.
FIG. 3C
illustrates an example of scratch and chemical damage. In this fault, an open-circuit or a short-circuit or defective resistance value of the laminated interconnection pattern
8
is generated.
FIG. 3D
illustrates an example of over-polishing and under-polishing. In these faults, the laminated interconnection pattern film
7
is left at the surface because the setting for a degree of polishing of the laminated interconnection pattern film
7
is insufficient and this remaining laminated interconnection pattern film
7
results in short-circuit of interconnection, or over-setting for a degree of polishing of the laminated interconnection pattern film
17
results in dishing or erosion.
OBJECT AND SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a planarizing and polishing apparatus and method for obtaining a fault-free polishing work by measuring polishing condition of a polishing work.
According to one aspect of the present invention, the planarizing and polishing apparatus comprising a polishing means for polishing flat a surface of a polishing work through relative movement in one direction can be realized by providing A detecting means for detecting a change in surface reflectivity of the polishing work, a control means for recognizing the part to be polished further (i.e., an additional polishing part) of the polishing work based on the detection value from the detecting means, and automatically generating polishing conditions of the additional polishing part and the other portions in order to feed back such polishing conditions.
Moreover, according to an other aspect of the present invention, the planarizing and polishing method for polishing flat the surface of a polishing work through relative movement of the polishing means in one direction at the surface of polishing work can be realized by polishing the surface of the polishing work, detecting a change in surface reflectivity of the polishing work, recognizing the part, in which the detected value is higher than the predetermined value, as the additional polishing part of the polishing work, relatively moving at a high speed the polishing means at the portion other than the additional polishing part and relatively moving at a low speed the polishing means at the additional polishing part in view of polishing again the surface of the polishing work.
According to the present invention explained above, since difference of surface reflectivity due to the difference of material is utilized for detection of polishing condition, the polishing condition of the polishing work in which different materials are particularly laminated can easily be measured. Therefore, it is now possible to identify, during the polishing process, the additional polishing part of the polishing work and then conduct the centralized polishing to the additional polishing, part. Accordingly, polishing accuracy can be improved, under-polishing can be prevented and over-polishing can also be reduced.
REFERENCES:
patent: 5245794 (1993-09-01), Salugsugan
patent: 5597341 (1997-01-01), Kodera et al.
patent: 5597442 (1997-01-01), Chen et al.
patent: 5853317 (1998-12-01), Yamamoto
patent: 5899792 (1999-05-01), Yagi
patent: 6113465 (2000-09-01), Kim et al.
patent: 6120349 (2000-09-01), Nyui et al.
patent: 6213844 (2001-04-01), Lenkersdorfer
patent: 6238271 (2001-05-01), Cesna
patent: 6257953 (2001-07-01), Gitis et al.
patent: 6293846 (2001-09-01), Oguri
Eley Timothy V.
Kananen, Esq. Ronald P.
Rader & Fishman & Grauer, PLLC
Sony Corporation
Thomas David B.
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