Information
-
Patent Grant
-
6386956
-
Patent Number
6,386,956
-
Date Filed
Monday, November 1, 199924 years ago
-
Date Issued
Tuesday, May 14, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Kananen, Esq.; Ronald P.
- Rader, Fishman & Grauer, PLLC
-
CPC
-
US Classifications
Field of Search
US
- 451 41
- 451 37
- 451 461
- 451 259
- 451 65
- 451 548
- 451 446
- 451 56
-
International Classifications
-
Abstract
A flattening polishing device and method of the present invention is provided with a first polishing buff and a second polishing wheel disposed coaxially, a moving mechanism for moving the respective polishing buff and wheel relative to each other in an axial direction and a rotary drive for rotating the respective polishing buff and wheel around a shaft, thus enabling flattening and polishing with high accuracy and no defects.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to flattening polishing devices and flattening polishing methods for flatly polishing plated films or insulating films formed on, for example, wafer surfaces.
2. Description of the Related Art
FIGS. 10A
to
10
F show sectional side elevation views illustrating manufacturing processes for a metal interconnection type board.
An interconnection pattern
2
composed of copper (Cu) is formed on a surface of a wafer
1
composed of silicon so as to coat the surface of the wafer
1
including the interconnection pattern
2
with an insulating film
3
composed of silicon dioxide (SiO
2
) (FIG.
10
A).
Further, conducting holes
4
for a laminated interconnection pattern are etched to be formed in the insulating film
3
(FIG.
10
B), so as to coat the surface of the insulating film
3
including inner surfaces of the conducting holes
4
with a barrier film
5
composed of tantalum (Ta) or titanium (Ti) or the like (FIG.
10
C), and seed films
6
composed of copper (Cu) are formed by sputtering(FIG.
10
D). Further, a film
7
for the laminated interconnection pattern composed of copper (Cu) is plated in a comparatively thick condition and is formed in such a manner that inner portions of the conducting holes
4
are completely blocked (FIG.
10
E). Thereafter, unnecessary films
7
for the laminated interconnection pattern on the barrier film
5
are machined to be polished so as to remove them and a laminated interconnection pattern
8
is formed so as to have a final metal interconnection type board
9
(FIG.
10
F).
FIG. 12
shows a sectional side elevation view illustrating a manufacturing process for an element separation type board.
Elements
12
are formed on a surface of a wafer
11
composed, for example, of silicon so as to coat the surface of the wafer
11
containing the elements
12
with stopper films
13
composed of silicon nitride (SiN). Further, element separating trench holes
14
are etched to be formed from the stopper films
13
over to the wafer
11
so as to coat the holes, in a relatively thick condition, with an insulating film
15
composed of silicon dioxide (SiO
2
) in such a manner that an inner portion of the trench holes
14
are completely blocked (FIG.
12
A). Thereafter, unnecessary insulating films
15
on the stopper films
13
are machined to be polished so as to remove them and trenches
16
are formed so as to have the final element separation type board
17
(FIG.
12
B).
In a polishing process, when manufacturing the above respective boards
9
and
17
, the flattening polishing device is used.
FIG. 14
shows a perspective view illustrating an outline of a related flattening polishing device.
This flattening polishing device
20
is provided with a rotatable surface plate
22
in a shape of a disk on a top face of which a polishing cloth
21
is stuck, a rotatable and vertically (along the Z axis) movable mounting plate
23
in a shape of a disk for holding wafers
1
and
11
by bottom faces thereof and a nozzle
24
for supplying a polishing liquid P on the polishing cloth
21
.
In such constitution, first, the surfaces of the wafers
1
and
11
on which the films
7
and
15
are formed are faced downward, a reverse face of the wafer
1
is bonded or is vacuum-adsorbed to the bottom face of the mounting plate
23
. Next, while the surface plate
22
and the mounting plate
23
are rotated, the polishing solution P is supplied on the polishing cloth
21
from the nozzle
24
. Further, the mounting plate
23
is lowered, the surfaces of the wafers
1
and
11
are forcedly pressed on the polishing cloth
21
so as to polish the films
7
and
15
formed on the surfaces of the wafers
1
and
11
.
In an initial stage of the polishing process on the occasion of respectively manufacturing the above described boards
9
and
17
, only a kind of film that is respectively the film
7
for the laminated interconnection pattern or the insulating film
15
may well be polished. However, in the final stage, since it is respectively necessary to expose the barrier film
5
or the stopper film
13
, two kinds of films should concurrently be polished, that is, not only the film
7
for the laminated interconnection pattern or the insulating film
15
, but also the barrier film
5
or the stopper film
13
.
When the films of different kinds, in other words, the films of different hardness are polished using the related flattening polishing device
20
, there are such cases where defects such as dishing, erosion (thinning) recess, scratch, chemical damage, overpolishing, and underpolishing are formed.
FIG. 11
shows a sectional side elevation view illustrating defects in the metal interconnection type board
9
and
FIG. 13
shows a sectional side elevation view illustrating defects in the element separation type board
17
.
FIG.
11
A and
FIG. 13A
are examples of the dishing, wherein at central portions of the film
7
for the laminated interconnection board and of the insulating film
15
over broad areas are caved in due to too much polishing so as to result in a shortage of sectional areas for the laminated interconnection pattern
8
and the trench
16
, to eventually become the defects.
FIG.
11
B and
FIG. 13B
are examples of the erosion (thinning), wherein portions whose pattern density are high are caved in due to excessive polishing so as to result in a shortage of sectional areas for the laminated interconnection pattern
8
and the trench
16
, to eventually become the defects.
FIG.
11
C and
FIG. 13C
are examples of the recesses, wherein a side of the laminated interconnection pattern
8
and a side of the trench
16
are lowered at boundaries between the laminated interconnection pattern
8
and the insulating films
3
and between the trench
16
and the stopper film
13
so as to generate level differences, to consequently become defects.
FIG. 11D
is an example of the scratch or the chemical damage, wherein an open circuit or short circuit or a failure in a resistance value of the laminated interconnection pattern
8
is generated, to eventually become faults.
FIG. 13D
is an example such as the overpolishing and the underpolishing, wherein due to a shortage in relation to a set removal amount of the insulating films
15
, the insulating films
15
remain on the surface of the board to consequently become defects, or due to an excessive amount in relation to the set removal amount of the insulating films
15
the sectional area of the trench
16
results in shortage to eventually become defects.
SUMMARY OF THE INVENTION
The present invention is planned and constituted according to the above-described circumstances, and it is an object of the present invention to provide a flattening polishing device and a flattening polishing method capable of conducting a flattening polishing with high accuracy and no defects.
In the present invention, and in the flattening polishing device for flatly polishing a surface of an object to be polished, the above-described object can be attained by providing the device with first polishing means and second polishing means which are coaxially disposed, moving means for moving the respective polishing means relative to each other in an axial direction and rotary means for rotating the respective polishing means around a shaft.
Further, in the present invention, and in the flattening polishing method for flatly polishing a surface of an object to be polished, the above-described object can be attained by providing the method with a process for rotating two polishing means disposed in shapes of concentric circles, a process for protruding a polishing surface of one of the polishing means more than a polishing surface of the other polishing means to a side of the object to be polished, a process for polishing the surface of the object to be polished by one of the polishing means, a process for protruding the polishing surface of the other polishing means more than the polishing surface of the one of the polishing means to the side of the object to be polished and a process for polishing the surface of the object to be polished by the other polishing means.
According to the above-described constitution, since the two polishing means are arranged coaxially, the device can be made in compact size without any need for installation of a plurality of large surface plates as in the related device. Further, since the object to be polished can be machined in multi-steps by one chuck, variations in machining accuracy due to rechucking can be suppressed. Furthermore, since fixed size and highly efficient machining or fixed pressure and highly graded chemical machining can be carried out in multi-steps, it is possible to machine the object to be polished with no defects.
Further, in the case of polishing process for compound semiconductor, two-step polishing is performed with liquid polishing agents changed. A series process for performing two-step polishing and a parallel process for performing one-step polishing in parallel can therefore be selectively carried out in one polishing device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
shows a plan view illustrating the entire constitution of the embodiments for a flattening polishing device of the present invention.
FIG. 2
shows a partial sectional side elevation view illustrating details of the machining parts in the flattening polishing device shown in FIG.
1
.
FIGS. 3A and 3B
show a plan view and a sectional side elevation view illustrating a detailed example of a metal surface plate shown in FIG.
2
.
FIGS. 4A and 4B
show plan views illustrating detailed example of buffs shown in FIG.
2
.
FIG. 5
shows a sectional side elevation view illustrating another example of a flange which connects the metal surface plate and a shaft in the flattening polishing device shown in FIG.
1
.
FIG. 6
shows a first sectional side elevation view illustrating an example of operation in the flattening polishing device shown in FIG.
1
.
FIG. 7
shows a second sectional side elevation view illustrating another example of operation in the flattening polishing device shown in FIG.
1
.
FIGS. 8A and 8B
show graphs illustrating dishing evaluation with regard to the flattening polishing device shown in
FIG. 1 and a
related polishing device.
FIGS. 9A and 9B
shows graphs illustrating erosion evaluation with regard to the flattening polishing device shown in
FIG. 1 and a
related polishing device.
FIGS. 10A
to
10
F show sectional side elevation views illustrating manufacturing processes for a metal interconnection type board.
FIGS. 11A
to
11
D show sectional side elevation views illustrating defects in the metal interconnection type board.
FIGS. 12A and 12B
show sectional side elevation views illustrating manufacturing processes for an element separation type board.
FIGS. 13A
to
13
D show sectional side elevation views illustrating defects in the element separation type board.
FIG. 14
shows a perspective view illustrating an outline of a related flattening polishing device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
Meanwhile, since these embodiments are specific, favorable examples of the present invention, they include technically various preferable limitations, but they are not to be construed to limit the scope of the present invention, unless there are any particular mentions with respect to the limitation of the present invention in the following description.
FIG. 1
shows a plan view illustrating the entire constitution of the embodiment for a flattening polishing device of the present invention.
This flattening polishing device
100
is roughly constituted of; a cassette port
110
section into which wars
101
, being objects to be polished, are loaded; a handling system
120
section for positioning the wafers
101
unloaded from the cassette port
110
; a polishing head
130
section for conducting chemical mechanical polishing on the wafers
101
positioned by the handling system
120
and a cleaner
140
section for cleaning the wafers
101
which have been conducted with the chemical mechanical polishing by the polishing head
130
. Further, the wafers
101
are carried among respective sections by a robot not shown.
In such constitution, a polishing process conducted within the flattening polishing device
100
will be described.
First, a plurality of wafers
101
are stored inside of cassette
102
in parallel, and the cassettes
102
are set in the cassette port
110
. Further, a sheet of wafer
101
is unloaded from the cassette
102
and carried to the handling system
120
.
The wafer
101
which has been carried is transferred to a positioning part
122
by a conveyer
121
and the centering and orientation and flattening alignment are performed, then again transferred back to an original position by the conveyer. The transferred-back wafer
101
is transported to the polishing head
130
. The transported wafer
101
is loaded into a buffer
131
once, being set in a machining part
132
thereafter, and being subjected to the chemical mechanical polishing. The wafer
101
, having been polished, is once unloaded in a wet station
133
and then transported to the cleaner
140
.
The transported wafer
101
is, after passing through the cleaning part
141
for cleaning the wafer of a chemical, transferred to a drying part for drying a cleaning solution. The wafer
101
which has been dried is transported again to the handling system
120
and stored in a vacant portion of the cassette
102
. The cassettes
102
whose entire stored wafers
101
are finished passing through the above-mentioned process are unloaded from the cassette port
110
and are transported to a next process.
FIG. 2
shows a partial sectional side elevation view illustrating details of the machining part
132
in the flattening polishing device
100
shown in FIG.
1
.
The machining part is roughly constituted of a machining table
150
and a machining head
160
.
The machining table
150
has functions to rotate the wafer
101
while placing and fixing it on the table as well as to move it along the X axis.
A wafer chuck
152
is disposed on the top face of a weighing table
151
capable of vacuum-adsorbing the wafer
101
, and the support part
154
having an X-axis ball nut
153
is disposed in the bottom face of the weighing table
151
.
An X-axis ball screw
156
which is connected with an X-axis servomotor
155
and extended along the X axis is threadedly engaged with the X-axis ball nut
153
. Further, a nozzle
157
for supplying a polishing solution is disposed above the weighing table
151
. Furthermore, a mechanism, not shown, for rotating the wafer chuck
152
is incorporated in the weighing table
151
.
The machining head
160
has functions such that it moves along the Z axis and conducts the chemical mechanical polishing in two stages on the wafer
101
fixed on the machining table
150
. A buff (first polishing means)
161
in a shape of a disk having substantially the same diameter as that of the wafer
101
and a wheel (second polishing means)
162
in a shape of an annular ring having a larger inside diameter than a diameter of the buff
161
are disposed coaxially, namely, in a shape of a concentric circle. Further, the buff
161
is bonded and fixed on the bottom face of a metal surface plate (the first polishing means)
163
in a shape of an annular ring, and the wheel
162
is bonded and fixed on the bottom face of a metal tool flange (the second polishing means)
164
in a shape of an annular ring.
One end of a shaft i.e., a (fixed shaft)
165
is fixed in a center hole of the metal surface plate
163
via a flange
167
having a bearing
166
. An outer peripheral surface of this flange
167
is formed in a taper shape, and fitted and fixed into an inner peripheral surface of a hole bored in a central portion of the metal surface plate
163
which is formed in a similar taper shape as that of the flange
167
. Counterbores
168
are arranged in an equal angular space on a side of a top face of the metal tool flange
164
.
Pins
170
having springs
169
are inserted in the inner portions of the counterbores
168
in such a manner that each pin
170
is pierced through to a side of a bottom face of the metal tool flange
164
. A tip end of each pin
170
is threadedly engaged with the top face of the metal surface plate
163
. A main spindle (rotary means)
172
having a main spindle motor (rotary means)
171
is fixed on the top face of the metal tool flange
164
, and further, an air cylinder (moving means)
173
is fixed above the main spindle motor
171
.
The shaft
165
is disposed so as to be pierced through from a central hole of the metal tool flange
164
via central portions of the main spindle
172
, the main spindle motor
171
and the air cylinder
173
. Further, a piston
173
a
of the air cylinder
173
is fixed on the other end of the shaft
165
.
Further, the shaft
165
is formed in a shape of a hollow cylinder in order to supply the polishing solution.
A supporting portion
175
having a Z-axis ball nut
174
is disposed on an outer peripheral surface of the main spindle motor
171
. Further, the supporting portion
175
is engaged with a Z-axis guide
176
, and a Z-axis ball screw
178
which is connected with a Z-axis servomotor
177
and extends along the Z axis is threadedly engaged with the Z-axis ball nut
174
.
FIGS. 3A and 3B
respectively show a plan view and a sectional side elevation view illustrating a detailed example of a metal surface plate
163
shown in FIG.
2
.
A cruciform groove
163
a
is formed on the bottom face of the metal surface plate
163
, namely on the surface where the buff
161
is bonded and fixed. Further, through holes
163
b
are provided at tip end parts of the cruciform groove
163
a
piercing through from a bottom portion of the groove
163
a
to a peripheral surface of the metal surface plate
163
.
FIGS. 4A and 4B
show plan views illustrating detailed examples of buffs
161
shown in FIG.
2
.
A plurality of holes
161
A
a
are arranged in a cruciform on a buff
161
A shown in
FIG. 4A
in accordance with the groove
163
a
of the metal surface plate
163
. Further, a plurality of holes
161
B
a
are further arranged in a shape of radiation on a buff
161
B shown in FIG.
4
B. The buff
161
A or
161
B is bonded and fixed on the bottom face of the metal surface plate
163
having a constitution described above, namely on the surface formed with the groove
163
a.
Accordingly, the polishing solution supplied from the hollow portion of the shaft
165
flows into the groove
163
a
after passing through a central hole
163
c
of the metal surface plate
163
. Further, on the way the polishing solution flows into the groove
163
a
, a part of the polishing solution flows into a polishing surface of the buffs
161
A or
161
B after passing through the holes
161
A
a
or
161
B
a
of the buffs
161
A and
161
B and a residual part, in other words a surplus part of the polishing liquid is discharged from the outer peripheral surface of the buff
161
A or
161
B after passing through the through holes
163
b
of the metal surface plate
163
. Accordingly, the polishing accuracy and polishing efficiency can be improved since the polishing liquid is evenly spread over the entire polishing surface of the buff
161
A or
161
B.
FIG. 5
shows a sectional side elevation view illustrating another example of a flange which connects a metal surface plate with the shaft. An outer peripheral surface of this flange
167
′ is formed in a semi-spherical shape, and is closely adhered in a slidable manner on an inner peripheral surface in a hole of a central portion of a metal surface plate
163
′ formed in a similar semi-spherical shape.
According to the constitution, in cases where, for example, a surface of the wafer
101
is inclined, when the polishing surface of the buff
161
is in contact with the surface of the wafer
101
, since the metal surface plate
163
′ is pivoted around the flange
167
′, the polishing surface of the buff
161
always can horizontally be in contact with the surface of the wafer
101
. Therefore, the flatness of the surface of the wafer
101
can be made up of high preciseness.
In the above-mentioned constitutions, operational examples of them will be described with reference to FIG.
6
and FIG.
7
.
Here, as a material of the buff
161
, a soft quality buff, for example, is used and as a polishing solution, a liquid chemical of, for example, etchant of a nitric acid (HNO
3
) or the like is used. Further, as the wheel
162
, for example, a hard quality wheel in which hard alumina abrasive grains are solidified is used and as its polishing solution, for example, slurry in which hard alumina abrasive grains are dispersed by weak acid is used.
As a first stage, polishing with the usage of the buff
161
is performed (refer to
FIG. 6
) and as a second stage, polishing using the wheel
162
is performed (refer to FIG.
7
).
First, the wafer
101
is vacuum-adsorbed to the wafer chuck
152
, then the X-axis ball screw
156
is rotated by driving the X-axis servomotor
155
, and then the weighing table
151
is moved until the wafer
101
arrives at a prescribed polishing start position via the support part
154
. Further, the rotary mechanism incorporated in the weighing table
151
is driven so as to rotate the wafer
101
via the wafer chuck
152
. Simultaneously, the main spindle motor
171
is driven so as to rotate the wheel
162
via the main spindle
172
, further to rotate the buff
161
via the pins
170
.
Next, the Z-axis servomotor
177
is driven so as to rotate the Z-axis ball screw
178
, then the supporting portion
175
is lowered until it becomes in such a condition that the polishing surface of the wheel
162
is separated with a prescribed space from the surface of the vacuum-adsorbed wafer
101
along the Z-axis guide
176
. Further, liquid chemical is supplied from a supply device, not shown, to the buff
161
via the hollow portion of the shaft
165
and the groove
163
a
of the metal surface plate
163
. Simultaneously, air is supplied to a pressurized side supply port
173
c
provided in a cylinder
173
b
of the air cylinder
173
and the metal surface plate
163
is lowered via the piston
173
a
and the shaft
165
.
At this time, it becomes in such a condition that the metal surface plate
163
gives compression to the spring
169
and the polishing surface of the buff
161
is more protruded than the polishing surface of the wheel
162
. Further, the polishing surface of the buff
161
is forcedly pressed on the surface of the wafer
101
, the X-axis servomotor
155
is driven so as to rotate the X-axis ball screw, the weighing table
151
is reciprocatingly moved via the support part
154
and the chemical mechanical polishing is conducted on the wafer
101
. Furthermore, an absolute value of a polishing amount can be controlled mainly by a pressure within the air cylinder
173
and by a passing speed of the buff
161
in relation to the wafer
101
. Further, after finishing the polishing, the supply of the liquid chemical is stopped, pure water is supplied on the surface of the wafer
101
through a not-illustrated nozzle and the liquid chemical remained on the surface of the wafer
101
is cleaned to be removed.
As described above, on the reason that the soft quality buff is used and that etching is performed using the acid, in the polishing process of this first stage, a selective ratio, that is for example, a ratio of polishing rates between a film
7
for a laminated interconnection pattern and a barrier film
5
in cases where the wafer
101
is a metal interconnection type board or a ratio of polishing rates between an insulating film
15
and a stopper film
13
in cases where the wafer
101
is a element separation type board becomes large and the stopping accuracy at the barrier film
5
and the stopper film
13
is enhanced.
Accordingly, dishing and erosion become large and a polishing and removing speed becomes slow; however, absolute values of the dishing and the the erosion can be made small and polishing process time can be shortened by setting small an absolute value of a total polishing and removing amount at the first stage. Further, since the polishing process is the strong machining in a chemical reaction with the usage of the buff
161
, the surface of the wafer
101
is hardly damaged so as to have a mechanically smooth face.
Succeedingly, air is supplied to a refuge side supplying port
173
d
provided in the cylinder
173
b
of the air cylinder
173
and the metal surface plate
163
is lifted via the piston
173
a
and the shaft
165
so as to separate the polishing surface of the buff
161
from the surface of the wafer
101
. At this time, the top face of the metal surface plate
163
is forcedly pressed against the bottom face of the metal tool flange
164
by a restoring force of the springs
169
, the polishing surface of the buff
161
becomes more retracted than the polishing surface of the wheel
162
.
Further, the slurry is supplied from a supply device, not shown, to the surface of the wafer
101
via the nozzle
157
. Simultaneously, the Z-axis servomotor
177
is driven in the direction opposite to the prior case so as to rotate the Z-axis ball screw
178
and to lower the supporting portion
175
along the Z-axis guide
176
. Further, the polishing surface of the wheel
62
is forcedly pressed against the surface of the wafer
101
so as to rotate the shaft ball screw
156
by driving the X-axis servomotor
155
and to conduct the chemical mechanical polishing on the wafer
101
by reciprocatingly moving the weighing table
151
via the support part
154
. Furthermore, the absolute value of the polishing amount at this time, can be controlled mainly by a thrust amount with the aid of the Z-axis servomotor
177
and by a passing speed of the wheel
162
in relation to the wafer
101
. Further, after finishing the polishing, the supply of the slurry is stopped so as to supply the pure water and the liquid chemical on the surface of the wafer
101
through the not-illustrated nozzle, to clean and remove the slurry and particles remaining on the surface of the wafer
101
.
As described above, a reason that the hard quality wheel is used, and that since the slurry is a weak acid, the above mentioned selection ratio is small, in the polishing process of this second stage, the polishing of the portion of the film
7
for the laminated interconnection pattern and of the portion where the barrier films
5
start to be exposed can be uniformly progressed in cases where, for example, the wafer
101
is the metal interconnection type board, and the polishing of the portion of the insulating films
15
and of the portion where the stopper films
13
start to be exposed can also be uniformly progressed in cases where the wafer
101
is the element separation type board. Therefore, the dishing and the erosion is small compared with the cases where the related pad and slurry are used, and highly efficient polishing with comparatively high polishing and removing speed can be made possible.
Furthermore, in the above-mentioned embodiments of the flattening polishing method, rough polishing by means of the buff
161
is conducted at the first stage and finish polishing by means of the wheel
162
is conducted at the second stage. However rough polishing by means of the wheel
162
may be conducted at the first stage and finish polishing by means of the buff
161
may be conducted at the second stage. In that case, since dimensional accuracy and stoppage accuracy is insufficient because of smallness in the selection ratio, and moreover since micro roughness and damage remain on the surface of the wafer
101
because of high efficient polishing by means of the hard quality wheel, the polishing by means of the wheel
162
is to be finished in a rough range. The polishing is in a condition that the film
7
for the laminating interconnection pattern slightly remains on the barrier film
5
in cases, for example, where the wafer
101
is the metal interconnection type board, or in a condition that the insulating films
15
slightly remain on the stopper films
13
in cases where the wafer
101
is the element separation type board.
Further, the dimensional accuracy is enhanced with the polishing by means of the buff
161
so as to remove remaining damaged layers.
Furthermore, the polishing by means of the buff
161
and the polishing by means of the wheel
162
may concurrently be conducted. According to this method, the rough and finish polishing can be conducted in one operation, and a polishing man-hour can remarkably be reduced.
FIG.
8
and
FIG. 9
illustrate dishing evaluation and erosion evaluation by a surface profile observation when conducting the polishing of the present embodiment and a related polishing. Furthermore, related polishing conditions have been that while a pad (a polyurethane foam pad IC-1000 (a product of Rodel, Inc. in the United States) is rotated at a rotational speed of 30 rpm to 60 rpm, the pad is forcedly pressed with a pressure of 150 kgf/cm
2
to 250 kgf/cm
2
and that a prescribed kind of slurry (an alumina slurry C4010 (a product of Cabot Corporation in U.S.)) is supplied.
FIG. 8A
illustrates the dishing condition of an interconnection pattern having a width 500 μm by the polishing of the present embodiment, and a dishing amount has been about 300 Å.
FIG. 8B
illustrates a relationship between an interconnection width and the dishing amount, points indicated by white circle marks show data obtained by the related polishing and points indicated by black painted round marks show data illustrated in FIG.
8
A. According to the polishing in the present embodiments, as will be clear from these figures, the dishing can more remarkably be improved than the related polishing.
FIG. 9A
illustrates an erosion condition of parts where an interconnection density is 50%, a line and space is 100 μm by the polishing of the present embodiment, the erosion amount has been about a maximum of 80 Å.
FIG. 9B
illustrates the relationship of area dependency of the erosion, though there are no data corresponding to
FIG. 11A
, according to the polishing of the present embodiments, as will be clear from a comparison that the erosion amount is 75 nm (750 Å) at the amount 2.00 μm and that the erosion is 30 nm (300 Å) at the amount 0.25 μm, the erosion can more remarkably be improved than the related polishing.
As mentioned above, according to the present invention, the highly accurate and non-defective flattening polishing can be conducted.
Claims
- 1. A flattening polishing device adapted to flatly polish a surface of an object to be polished, comprising:first polishing means and second polishing means both having polishing surfaces and being coaxially disposed around a shaft, said first polishing means being disposed at an end of said shaft via a flange incorporating a bearing; moving means for moving said first polishing means, together with said shaft, relative to each of the polishing surfaces of said respective polishing means in an axial direction; rotary means for rotating said respective polishing means around said shaft; and a rotary table for disposing and rotating an object to be polished by said first and second polishing means.
- 2. A flattening polishing device as claimed in claim 1, wherein said shaft is formed in a shape of a hollow cylinder in order to supply a polishing solution through said cylinder.
- 3. A flattening polishing device as claimed in claim 1, wherein said respective polishing means are disposed in shapes of concentric circles.
- 4. A flattening polishing device adapted to flatly polish a surface of an object to be polished, comprising:a fixed shaft formed in a shape of a hollow cylinder in order to supply a polishing solution through said hollow cylinder; first polishing means having a shape of a disk disposed at one end of said fixed shaft and rotatable around the shaft; second polishing means in a shape of an annulus ring engaged with said first polishing means, arranged on an outer periphery of said first polishing means and rotatable around the shaft; moving means disposed on the outer end of said fixed shaft, moving said first polishing means together with said fixed shaft relative to each of the polishing surfaces of said respective polishing means; rotary means for rotating said respective polishing means around the shaft; and a rotary table for disposing and rotating an object to be polished by said respective polishing means.
- 5. A flattening polishing device as claimed in claim 4, wherein said first polishing means is disposed at the one end of said fixed shaft via a flange having a bearing.
- 6. A flattening polishing device as claimed in claim 5, wherein a surface of said flange in contact with said first polishing means is formed in a taper shape.
- 7. A flattening polishing device as claimed in claim 5, wherein a surface of said flange in contact with said first polishing means is formed in a spherical shape.
- 8. A flattening polishing method adapted to flatly polish a surface of an object to be polished, comprising the steps of:rotating two polishing means, disposed in shapes of concentric circles, around a coaxial shaft, said first polishing means being disposed at an end of said shaft via a flange incorporating a bearing; moving said shaft together with one of said polishing means so that a polishing surface of said one of said polishing means protrudes more than a polishing surface of the other of said polishing means; polishing a surface of said object to be polished by said one of said polishing means while rotating said object to be polished on a rotating table; protruding the polishing surface of the other polishing means more than the polishing surface of the one polishing means; and polishing a surface of said object to be polished by the other polishing means while rotating said object to be polished on a rotating table.
- 9. A flattening polishing method as claimed in claim 8, wherein a polishing solution is injected into a hollow portion of a central shaft to thereby supply the solution to the polishing surface when polishing the surface with said polishing means disposed inside.
- 10. A flattening polishing method adapted to flatly polish a surface of an object to be polished, comprising the steps of:rotating two polishing means disposed in shapes of concentric circles around a fixed shaft, said first polishing means having a shape of a disk disposed at one end of said fixed shaft and rotatable around the shaft, and said second polishing means being in a shape of an annulus ring engaged with said first polishing means, arranged on an outer periphery of said first polishing means and rotatable around the shaft; and concurrently polishing the surface of said object to be polished by said respective polishing means while rotating said object to be polished on a rotating table.
- 11. A flattening polishing method as claimed in claim 10, wherein a polishing solution injected into a hollow portion of a central shaft so as to supply the solution to a polishing surface when polishing the surface with said respective polishing means.
Priority Claims (1)
Number |
Date |
Country |
Kind |
10-314685 |
Nov 1998 |
JP |
|
US Referenced Citations (9)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0857541 |
Aug 1998 |
EP |