JP2001252861A - Polishing method, polishing apparatus and polishing pad - Google Patents

Abstract

[PROBLEMS] To provide a polishing apparatus and a polishing apparatus capable of efficiently supplying a fresh slurry as much as possible to a polishing area, and discharging a polished waste liquid to efficiently perform flattening with less scratches and the like. Getting the way. SOLUTION: The polishing apparatus 1A of the present invention mounts a protruding wall member 620 having an annular protruding wall 623 on an outer peripheral portion of a wafer chuck 610 and mounts between the outer peripheral surface of the wafer chuck 610 and the protruding wall 623. A slurry reservoir 70 is formed, and the semiconductor wafer W is polished by absorbing relatively fresh slurry by a pump action of compressing and releasing the water-absorbing elastic polishing pad Pa of the present invention with the protruding wall 623, and polishing the polishing pad. The activated slurry absorbed by Pa is released by the slurry reservoir 70, and the activated slurry absorbed by the polishing pad Pa is released to the outside of the slurry reservoir 70 and the projected wall 623 by a pumping action of compressing by the projected wall 623. It is configured to discharge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing apparatus and a polishing method capable of polishing a surface of an object to be processed such as a semiconductor wafer with high precision and flatness, and in particular, it is possible to effectively supply slurry to a polishing area. The present invention relates to a polishing method, a polishing apparatus, and a polishing pad.

[0002]

2. Description of the Related Art First, a conventional polishing apparatus and a conventional polishing method will be described with reference to the drawings.

FIG. 8 is a partial sectional view of a semiconductor wafer, FIG. 9 is a perspective view conceptually showing a conventional polishing apparatus, FIG. 10 is a perspective view conceptually showing another conventional polishing apparatus, FIG.
1 is an external perspective view of the polishing apparatus shown in FIG. 10, FIG. 12 is a cross-sectional side view of the polishing wheel shown in FIG. 11, and FIG.
FIG. 14 is a plan view showing a bottom surface of the polishing wheel shown in FIG. 2, and FIG. 14 is a schematic view showing a positional relationship between the semiconductor wafer and the polishing pad of the polishing apparatus shown in FIG. FIG. 15 is a schematic diagram showing the displacement of the polishing region of the semiconductor wafer by the polishing apparatus shown in FIG. 11, and FIG. 16 is a diagram showing the rotation center axis of the polishing pad of the polishing apparatus shown in FIG. FIG. 17 is a schematic cross-sectional side view schematically illustrating a state in which the polishing is performed while being inclined, and FIG. 17 is a schematic diagram illustrating a relationship between the inclination of the polishing pad and a polishing region.

In the following description, a semiconductor wafer will be described as one of the workpieces. Other workpieces include a slider head for a thin-film magnetic head and a control electrode for a liquid crystal display device. Surfaces, such as optical mirror surfaces of optical components such as lenses and prisms, can be mentioned, and it is to be noted that the present invention can be applied to flattening and polishing.

Conventionally, in a semiconductor manufacturing process, it is necessary to flatten the surface of a semiconductor wafer as necessary and form an electronic circuit having a fine structure on the surface with high precision. As shown in FIG. 8, in a manufacturing process of a semiconductor device, after forming a wiring pattern 2 and the like on a semiconductor wafer W, an insulating layer 3 of an oxide film is deposited. In the semiconductor manufacturing process, it is necessary to flatten the surface of the insulating layer 3 with a polishing device so that a desired pattern can be accurately exposed in a subsequent exposure process such as a wiring pattern.

[0006] Usually, a polishing apparatus, as shown in FIG.
While moving the semiconductor wafer W to be polished in the X-axis direction, the semiconductor wafer W is rotated at a predetermined number of rotations in a predetermined rotation direction R about the rotation axis Oa, and the slurry is dropped and supplied onto the surface thereof while being supplied. The pad P is rotated at a predetermined number of revolutions in the same rotational direction R, and while pressing the lower front surface of the polishing pad P against the surface to be polished of the semiconductor wafer W, from the outer peripheral portion of the semiconductor wafer W toward the central portion. Polish sequentially. The polishing pad P is made of a relatively flexible resin material, and is deformed in response to fine irregularities on the surface of the semiconductor wafer W shown in FIG. Is pressed to thereby planarize the surface of the semiconductor wafer W.

[0007] According to the polishing apparatus and the polishing method, the slurry waste liquid that has already acted in addition to the particles and the like mixed in the slurry and the powder itself of the workpiece removed by the polishing process slide on the semiconductor wafer W. Scratch occurs due to movement and rolling.

In addition, the portion where the slurry wraps well is good, and the portion having high polishing efficiency is polished too much and dented, and conversely, the removal amount of the portion where the slurry wrap is poor is insufficient and the uniformity of polishing is deteriorated.

Further, the polishing rate fluctuates due to a change over time in the surface state of the polishing pad P and a fluctuation in the state of the slurry wrapping, and it is difficult to secure the polishing stability.

Another conventional polishing apparatus shown in FIG. 10 has been proposed to solve the above problems of the polishing apparatus shown in FIG. 9 and the polishing method using the same. Even when the semiconductor wafer W is polished by this polishing apparatus, the semiconductor wafer W is also rotated at a predetermined number of rotations in a predetermined rotation direction R about the rotation axis Oa while moving the semiconductor wafer W in the X-axis direction. The polishing pad P is rotated at a predetermined number of revolutions in the same rotational direction R while supplying the solution by dropping, and only a part of the polishing pad P is brought into contact with the surface to be polished of the semiconductor wafer W. , And a partial polishing method for flattening the surface of the semiconductor wafer W is adopted.

A polishing apparatus 1 suitable for use in this partial polishing method comprises a polishing wheel 2 and a wafer chuck 10 as shown in FIGS.

The wafer chuck 10 holds the semiconductor wafer W on its horizontal upper surface, rotates about the rotation center Oa, and repeatedly moves at a predetermined speed in the X-axis direction.

The polishing wheel 2 to which the polishing pad P is attached is, as shown in FIG.
A disk 4, which is a surface plate, is fixed to the lower end of the disk 4. A ring-shaped polishing pad P is fixed to the outer peripheral portion of the lower surface of the disk 4. The disk 4 is attached to the rotating shaft 3 so that the outer peripheral surface of the lower surface is perpendicular to the rotation center Ob of the rotating shaft 3. A center hole is formed in the center of the disk 4 and communicates with the hollow of the rotating shaft 3, and the nozzle tube 5 is inserted into these center holes. The nozzle tube 5 is one supply means for supplying slurry to the polishing surface of the semiconductor wafer W.

A plurality of radial grooves 41 having one end communicating with the center hole and the other end communicating with the mounting surface of the polishing pad P are formed on the bottom surface of the disk 4 as shown in FIG. Are formed. A disk-shaped slurry distribution plate 6 is attached to the bottom surface at a slight interval.

When slurry is supplied from the nozzle tube 5 while the polishing wheel 2 is rotating, the slurry hits the slurry distribution plate 6 and polishes the semiconductor wafer W rotating by the radial grooves 41 of the disk 4 and its centrifugal force. It is supplied uniformly without unevenness on the surface.

The slurry is also separately supplied to the outer peripheral side of the polishing pad P by a separately provided nozzle as shown in FIG. The slurry contains, for example, 24.5 abrasive particles having a CeO2 particle size of 0.5 μm as a filler.
An aqueous solution mixed with Wt% is used.

When the semiconductor wafer W is polished by the polishing apparatus 1, as shown in FIG. 14, for example, the wafer chuck 10 is rotated at a rotation speed of 30 rpm, and X
It is linearly and repeatedly moved at a constant speed of 60 to 140 mm / min in the axial direction. Then, the grinding wheel 2 is rotated at 300 rpm.
Then, the polishing pad P is rotated and lowered so that the polishing pad P passes through the center from the outermost periphery of the semiconductor wafer W while pressing the surface of the semiconductor wafer W with a predetermined pressing force, and performs rotational polishing over the outermost periphery on the opposite side. During this time, the slurry is supplied to the polishing surface of the semiconductor wafer W from the nozzle tube 5 at the center of the rotating shaft 3 and the center of the polishing wheel 2, and is separately supplied to the outer peripheral side of the polishing pad P by the nozzle 7. By operating as described above, the polishing area Z by the polishing pad P becomes
As shown in FIG. 3A, the area becomes an approximately crescent-shaped area with diagonal lines. The range of the polishing region Z is smallest at the outer peripheral portion in contact with the semiconductor wafer W, and is largest at the central portion shown.

The repetitive movement range of the semiconductor wafer W is shown in FIG.
For example, as shown in FIG.
If it is 0 mm, it is 200 mm in the X-axis direction. That is, the position in the X-axis direction at which the outermost periphery of the polishing pad P has started to contact the outermost periphery (FIG. 15A) of the surface of the semiconductor wafer W is represented by X
= 0 mm, beyond the center (FIG. 15B), and further to the outermost periphery on the opposite side of the semiconductor wafer W (FIG. 15C).
X is a range up to the position of 200 mm.

Further, as shown in FIG. 16, the rotating shaft 3 of the polishing wheel 2 in the polishing apparatus 1 can be rotated and polished at a slight angle θ degrees from a vertical line. In this case, assuming that the pressing force F is constant, the polishing area Z on the polishing surface of the semiconductor wafer W becomes narrower as the inclination angle θ of the polishing wheel 2 increases, as shown in FIG.
The smaller the inclination angle θ is, the wider it becomes. In this embodiment of the polishing apparatus 1, the width of the polishing region Z is adjusted by appropriately selecting the inclination angle θ, and polishing can be performed under optimum conditions.

The inclination angle θ, rotation speed, pressing force of the polishing wheel 2, the rotation speed of the semiconductor wafer W, the feed speed in the X-axis direction, and the type of slurry are determined by the type of material of the polished surface of the semiconductor wafer W. It depends on the polishing thickness, etc., and is determined by the conditions.

Therefore, according to the polishing apparatus 1 and the polishing method of the prior art, since the polishing is partial polishing, the polishing rate can be improved, and the throughput can be improved.

[0022]

However, in the polishing apparatus 1 and the polishing method of the prior art, when the polishing rate differs due to a change in the surface state of the polishing pad P with time or different types, it is necessary to individually set a recipe. It is necessary to determine the conditions for polishing using a dummy wafer and take other measures.

As described above, the slurry is supplied from the outside of the polishing wheel 2 by dripping it onto the polishing surface of the semiconductor wafer W using the nozzle 7 from the outside of the polishing wheel 2, and is sprayed from the center of the polishing wheel 2 using the nozzle tube 5. Although not described so far, the method of directly exuding from the back surface of the polishing wheel 2 is adopted. In any case, when the polishing wheel 2 rotates at a high speed of 300 rpm or more,
Supply unevenness occurs in the crescent-shaped polishing area Z mainly due to the influence of centrifugal force.

Further, the amount and distribution of the slurry involved from the end face of the polishing wheel 2 are controlled by the influence of the slurry and waste slurry supplied onto the rotating semiconductor wafer W staying and flowing. It is difficult to uniformly supply the slurry to the effective point without waste due to the difference depending on the position with respect to W.

The excess slurry is discharged to the outside by the rotation of the polishing pad P, and further, by the rotation of the semiconductor wafer W, toward the tangential direction of the semiconductor wafer W and the polishing pad P as shown in FIG. Is discharged.

The present invention is intended to solve the above-mentioned problems, and can supply a fresh slurry as efficiently as possible to the polishing area, and discharge the polished waste liquid to reduce the number of scratches and the like. It is an object of the present invention to obtain a polishing method, a polishing apparatus, and a polishing pad capable of performing flattening.

[0027]

Therefore, according to the first aspect of the present invention, a water-absorbing elastic polishing pad is used, and the surface of the object to be polished is rotated while rotating the water-absorbing elastic polishing pad. Then, the water-absorbing elastic polishing pad itself compresses on the side of entering the surface of the object to be polished, absorbs fresh or relatively fresh slurry supplied by a pump operation generated by being released, and absorbs the slurry. The surface of the object to be polished is polished, and the water-absorbing elastic polishing pad is released and released on the side where the surface of the object to be polished is released from the surface of the object to be polished. The above problem is solved by adopting a polishing method of polishing the surface of the object to be polished by repeating the above.

Further, in the invention according to claim 2, the polishing apparatus is provided with a rotating body for rotating and holding the object to be polished at a predetermined number of rotations, and a rotating body for holding the object to be polished held on the upper surface of the rotating body. A water absorbing elastic polishing pad that contacts with a predetermined pressing force and rotates at a predetermined number of revolutions; a linear driving device that relatively reciprocates the water absorbing elastic polishing pad or the rotating body in one direction; A slurry pool surrounded by a projecting wall disposed outside of the object to be polished on the side where the elastic elastic polishing pad enters the surface of the object to be polished held by the rotating body; and the water-absorbing elastic polishing pad. Is provided outside of the object to be polished on the side detached from the surface of the object to be polished held by the rotating body, and supplies a slurry to the surface of the object to be polished and a slurry pool surrounded by a projecting wall. And a slurry supply device to solve the above problem. There.

Further, according to the third aspect of the present invention,
The protruding wall in the polishing apparatus according to claim 2, is formed in an annular shape so as to surround the outer peripheral end surface at a predetermined interval from the outer peripheral end surface of the object to be polished, and the outer peripheral end surface of the rotating body and The above problem is solved by forming a slurry pool.

Further, in the invention according to a fourth aspect, in the polishing apparatus according to the third aspect, the projecting wall is configured to be attached to the rotating body so that a height position thereof can be adjusted, and the problem is solved. Has been resolved.

According to the fifth aspect of the present invention, the above-mentioned object is achieved by forming the polishing pad in a ring-like structure using a water-absorbing and elastic resin having a continuous foam structure.

Therefore, according to the polishing method of the first aspect, the surface of the object to be polished can be polished with a fresh or relatively fresh slurry, so that it can be polished at a high polishing rate and particles and waste due to polishing waste liquid. Slurry and polishing debris can be reduced from remaining on the surface of the object.

According to the polishing apparatus of the second aspect, the presence of the projecting wall allows the water-absorbing elastic polishing pad to enter the surface of the object to be polished held by the rotating body. Fresh, supplied by the pump effect of the pad itself,
Alternatively, relatively fresh slurry can be absorbed, and the water-absorbing elastic polishing pad itself is absorbed by the pump effect of the water-absorbing elastic polishing pad itself on the side where the polishing pad is separated from the surface of the object to be polished held by the rotating body. The worked slurry can be discharged.

In the polishing apparatus according to the third aspect, in addition to the operation of the polishing apparatus according to the second aspect, the projecting wall and the slurry reservoir can be configured with a very simple structure. The whole can be made compact.

Further, in the polishing apparatus according to the fourth aspect, in addition to the operation of the polishing apparatus according to the third aspect, the height of the projecting wall and the slurry pool can be easily adjusted according to the thickness of the object to be polished. Can be adjusted.

Further, in the polishing pad according to the fifth aspect, the pumping function is exhibited in cooperation with the protruding wall, so that the slurry can be easily absorbed and discharged.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A polishing apparatus according to an embodiment of the present invention and a polishing pad suitable for use in the polishing apparatus will be described below with reference to FIGS.

FIG. 1 is a schematic perspective view showing the configuration of a polishing apparatus according to an embodiment of the present invention, FIG. 2 is a plan view showing only main components of the polishing apparatus shown in FIG. 1, and FIG. A in 2
FIG. 4 shows a ring-shaped projecting wall suitable for use in the polishing apparatus shown in FIG. 2; FIG. 4A shows a plan view thereof; FIG. A- in FIG.
FIG. 5C is a partially enlarged view of a portion surrounded by a circle indicated by an arrow C in FIG.
6 is a partially enlarged cross-sectional side view on line BB in FIG.
2 is a partially enlarged cross-sectional side view taken along the line CC in FIG. 2, and FIG. 7 is a graph showing the polishing rates of the polishing apparatus of the present invention and the conventional polishing apparatus.

First, the configuration and structure of a polishing apparatus according to an embodiment of the present invention will be described with reference to FIGS.
In FIG. 1, reference numeral 1A indicates the polishing apparatus of the present invention as a whole. This polishing apparatus 1A is roughly divided into polishing wheels 5
0 and a rotating body 60 that holds the semiconductor wafer W.

The polishing wheel 50 has substantially the same configuration as that of the prior art polishing wheel 2 and rotates at a predetermined number of rotations in a clockwise direction indicated by an arrow.
A disk 520, which is a surface plate, is fixed to the lower end of 0.
A ring-shaped polishing pad Pa, which is one of the present invention, is fixed to the outer periphery of the lower surface of the disk 520. Disk 520
Is attached to the rotating shaft 510 such that its outer peripheral surface is perpendicular to the rotation center Ob of the rotating shaft 510. A center hole is formed in the center of the disk 520 and communicates with the hollow of the rotating shaft 510. These center holes are provided with a nozzle tube (not shown) similar to the nozzle tube 5 of the prior art.
Is inserted as one supply means for supplying slurry to the polished surface of the semiconductor wafer W. Although not shown, the bottom of the disk 520 also has one end communicating with the center hole as shown in FIG. 13 used in the description of the related art.
A disk-shaped slurry distribution plate 6 having a plurality of radial grooves 41 whose other end communicates with the mounting surface of the polishing pad Pa is slightly spaced from the bottom surface. Attached.

The polishing pad Pa is formed in a ring-like structure with a resin having a continuous foam structure and a high water-absorbing and elastic property. For example, as the resin, polyvinyl acetal,
Polyurethane and the like can be mentioned, and those having a pore diameter of about 5 μm and a hardness of about 200 Rockwell superficial 15Y (JIS) can be cited.
O2).

One rotating body 60 is composed of a wafer chuck 610 for holding the semiconductor wafer W and an annular protruding wall member 620, and is rotated by a driving device (not shown) at a predetermined rotational speed in a clockwise direction indicated by an arrow. Grinding wheel 5
It is configured to be able to linearly reciprocate in the direction of the rotation center Ob of 0, that is, in the rotation radius direction (X-axis direction) of the polishing wheel 50.

The wafer chuck 610 has a circular mounting base 611 (FIGS. 2 and 3) having an area in which the semiconductor wafer W can be mounted at the center and the outer peripheral surface of the mounting base 611 is lowered.
Mounting plane 612 to which the projecting wall member 620 is mounted
(FIGS. 2 and 3) are members formed.

The protruding wall member 620 is, as shown in FIG.
In the center, a circular opening 621 having a diameter into which the mounting base 611 can be fitted has a flat portion 622 (FIGS. 3 and 4A) in which the upper surface on the entire inner peripheral side becomes the bottom surface of a slurry reservoir described later.
An annular member having a structure in which a protruding wall 623 (FIGS. 3 and 4A) having a height slightly higher than the flat portion 622 is formed on the entire outer peripheral side thereof. In the flat portion 622, mounting screw holes 624 of through holes are formed at 120 ° angular intervals.

As shown in the enlarged sectional side view of FIG. 3, the projecting wall member 620 is fitted into the circular opening 621 through the mounting base 611 of the wafer chuck 610, and the three heights are mounted on the mounting plane 612 of the wafer chuck 610. Adjustment screw 6
Attach using 30. 3 between the mounting plane 612 of the wafer chuck 610, the projecting wall member 620 and the lower surface.
A coil spring 640 is inserted into each of the mounting screw holes 624, and an adjusting screw 630 is inserted into each of the mounting screw holes 624, and tightened against the spring force of the coil spring 640.

By assembling the wafer chuck 610 and the protruding wall member 620 in this manner, the protruding wall 623 becomes an outer peripheral end surface of the semiconductor wafer W mounted on the mounting table 611,
Alternatively, the slurry pool 70 is formed at a predetermined interval from the outer peripheral surface of the mounting table 611 of the wafer chuck 610, and is formed between the protruding wall 623 and the flat portion 622 and the outer peripheral surface of the wafer chuck 610 or the outer peripheral end surface of the semiconductor wafer W. Is done.

As described above, according to the polishing apparatus 1A of the present invention, the rotating body 60 can be formed extremely compactly with members having an extremely simple structure, and at the same time, the means for compressing and releasing the polishing pad Pa and forming the slurry reservoir 70 are formed. be able to.

The height of the protruding wall 623 of the protruding wall member 620 is increased by tightening or loosening the three height adjusting screws 630 due to the presence of the three coil springs 640.
Can be finely adjusted in the vertical direction.

An embodiment of the rotating body 60 will be described. Assuming that the diameter of the semiconductor wafer W to be polished is 200 mm, the wafer chuck 610 uses a mounting table 611 for the semiconductor wafer W with a diameter of 200 mm, and the projecting wall member 620 in this case is The outer diameter φa is 280 mm, the inner diameter φb is 200 mm, the inner diameter φc of the projection wall 623 is 270 mm, and the projection wall 623 extends from the bottom.
It is preferable that the thickness Ta from the bottom to the top be 10 mm and the thickness Tb from the bottom surface to the plane portion 622 be 9 mm. Therefore, the depth H of the slurry reservoir 70 is 1 mm (FIG. 4C).

In the polishing apparatus 1A of this embodiment,
Although the configuration is shown in which the rotating body 60 can reciprocate in the X-axis direction, conversely, the rotating body 60 may be configured to rotate only, and reciprocate in the X-axis direction while rotating the polishing wheel 50. I refuse that.

Next, the polishing apparatus 1A thus configured
A polishing method, which is one of the present invention for polishing the surface of a semiconductor wafer W as an object to be polished by using the method, will be described with reference to FIGS.

First, the mounting table 61 of the wafer chuck 610
The semiconductor wafer W to be polished is mounted on the semiconductor wafer W. In this case, the semiconductor wafer W attached to the mounting table 611
Is slightly higher than the upper surface of the protruding wall 623, depending on the thickness to be polished, for example,
The mounting height of the projecting wall member 620 is adjusted with the height adjusting screw 630 so as to be positioned at a height of 0.5 to 1.0 mm (FIG. 3).

Next, the polishing pad Pa is adjusted. In this case, the polishing pad Pa is adjusted so as to lightly contact the protruding wall 623 during polishing. The lower surface of the polishing pad Pa may be disposed in parallel with the polishing surface of the semiconductor wafer W. Also, only a part of the lower surface of the polishing pad Pa is May be provided so as to come into contact with.

After performing these adjustments, the slurry is supplied to the polishing surface of the semiconductor wafer W while the rotating body 60 is rotated to repeatedly move in the X-axis direction, and reciprocate in the X-axis direction while rotating. A portion of the polishing pad Pa is brought into contact with the polishing surface and the protruding wall 623 of the semiconductor wafer W while rotating at a predetermined rotation speed under a predetermined pressing force to perform polishing.

During the polishing, as shown in FIG. 5, on the side where the polishing pad Pa enters the polishing surface of the semiconductor wafer W, a part of the polishing pad Pa is compressed by the protruding wall 623, and at the next moment, A part of the compressed polishing pad Pa is opened in the slurry reservoir 70, and the opened polishing pad P
a absorbs fresh or relatively fresh slurry in the slurry reservoir 70, and at the next moment, rotates from the outer peripheral surface to the central portion of the semiconductor wafer W and is supplied to the polishing surface of the semiconductor wafer W. The polished surface of the semiconductor wafer W is polished with the fresh slurry and the fresh or relatively fresh slurry absorbed by this pump effect.

On the side where the polishing pad Pa further rotates and separates from the polishing surface of the semiconductor wafer W, at the moment when the polishing pad Pa separates from the polishing surface of the semiconductor wafer W and enters the slurry pool 70 as shown in FIG. The part of the polishing pad Pa that has been pressed and compressed is released, and further rotated to project the protruding wall 6.
The absorbed working slurry is discharged to the outside of the slurry reservoir 70 and the protruding wall 623 by a pumping action compressed at the moment of riding on the 23.

Thereafter, each time the polishing pad Pa rotates, such a pumping operation is repeatedly performed, so that the unevenness of the polished surface of the semiconductor wafer W can be polished, and a desired surface property can be obtained.

In the polishing apparatus 1A of the above embodiment, the case where the polishing surface of the semiconductor wafer W is located at a position higher than the upper surface of the protruding wall 623 has been described. I will add it.

FIG. 7 shows the polishing rate Ra when the surface of the dummy wafer is polished using the polishing apparatus 1A and the polishing method of the present invention, and the same polishing rate Ra under the same conditions using the conventional polishing apparatus 1 and the polishing method. The polishing rate Rb when the surface of a dummy wafer made of a material is polished is compared with a graph and shown. As is clear from this graph, it can be seen that polishing can be performed more efficiently by using the polishing apparatus 1A and the polishing method of the present invention.

[0060]

As described above, according to the present invention, there are provided: 1. The projections can be flattened at a much higher polishing rate than the conventional polishing apparatus and polishing method. 2. It is possible to prevent particles, waste slurry, and polishing debris due to polishing waste liquid from remaining on the surface of the object to be polished. 3. Scratch generation can be reduced from the effect of the preceding paragraph. 4. Stability of polishing accuracy is improved. Numerous excellent effects can be obtained, such as effective use of slurry.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing the configuration of a polishing apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing only main components of the polishing apparatus shown in FIG.

FIG. 3 is an enlarged side view showing a cross section taken along line AA in FIG. 2;

4 shows a ring-shaped projecting wall suitable for use in the polishing apparatus shown in FIG. 2, FIG. 4A is a plan view thereof, FIG. 4B is a sectional side view taken along line AA of FIG. Figure C is Figure B
5 is a partially enlarged view of a portion circled by an arrow C in FIG.

FIG. 5 is a partially enlarged sectional side view taken on line BB in FIG. 2;

FIG. 6 is a partially enlarged cross-sectional side view taken along line CC in FIG. 2;

FIG. 7 is a graph showing the polishing rates of the polishing apparatus of the present invention and the conventional polishing apparatus.

FIG. 8 is a partial cross-sectional view of a semiconductor wafer.

FIG. 9 is a perspective view conceptually showing a conventional polishing apparatus.

FIG. 10 is a perspective view conceptually showing another conventional polishing apparatus.

11 is an external perspective view of the polishing apparatus shown in FIG.

FIG. 12 is a sectional side view of the polishing wheel shown in FIG. 11;

13 is a plan view showing a bottom surface of the polishing wheel shown in FIG.

FIG. 14 is a schematic cross-sectional side view showing a positional relationship between the semiconductor wafer and the polishing pad of the polishing apparatus shown in FIG.

FIG. 15 is a schematic diagram showing displacement of a polishing region of a semiconductor wafer by the polishing apparatus shown in FIG. 11;

FIG. 16 is a cross-sectional side view schematically showing a state in which polishing is performed with the rotation center axis of the polishing pad of the polishing apparatus shown in FIG. 9 slightly inclined.

FIG. 17 is a schematic diagram illustrating a relationship between a tilt of a polishing pad and a polishing area.

[Explanation of symbols]

1A: polishing apparatus of one embodiment of the present invention, 50: polishing wheel, 60: rotating body, 620: (annular) projecting wall member,
623: (annular) projecting wall, 70: slurry pool, P
a: (water-absorbing elasticity) polishing pad, W: semiconductor wafer (object to be polished)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shuzo Sato 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo F-term in Sony Corporation (reference) 3C058 AA07 AA09 AB04 AC04 BA02 CB01 CB03 DA17

Claims (5)

[Claims] 1. A water-absorbing elastic polishing pad is pressed and brought into contact with the surface of a rotating polishing object while rotating the water-absorbing elastic polishing pad, and the water-absorbing elastic polishing pad is brought into contact with the surface of the polishing object. On the entering side, it compresses itself, absorbs fresh or relatively fresh slurry supplied by a pump operation generated by being released, and polishes the surface of the object to be polished. A polishing method of discharging the worked slurry absorbed by a pump operation in which the slurry is released and compressed on the side detached from the surface of the object to be polished, and thereafter repeating these operations to polish the surface of the object to be polished. 2. A rotator for rotating and holding an object to be polished at a predetermined rotational speed, and contacting the surface of the object to be polished held on the upper surface of the rotator with a predetermined pressing force, and A water-absorbing elastic polishing pad, a linear drive device for relatively reciprocating the water-absorbing elastic polishing pad or the rotating body in one direction, and a surface holding the water-absorbing elastic polishing pad on the rotating body. A slurry pool surrounded by a projecting wall disposed outside of the object to be polished on the side of the surface of the object to be polished; and a water-absorbing elastic polishing pad for the object to be polished held by the rotating body. A slurry pool surrounded by a projecting wall disposed outside the object to be polished away from the surface, and a slurry supply device for supplying a slurry to the surface of the object to be polished, Polishing equipment. 3. The protruding wall is formed in an annular shape so as to surround the outer peripheral end face at a predetermined interval from the outer peripheral end face of the object to be polished, and the slurry pool is formed with the outer peripheral end face of the rotating body. 3. The semiconductor device according to claim 2, wherein:
A polishing apparatus according to claim 1. 4. The polishing apparatus according to claim 3, wherein the protruding wall is attached to the rotating body so that a height position thereof can be adjusted. 5. A polishing pad comprising a ring-shaped structure made of a resin having a continuous foaming structure and a high water-absorbing and elastic property.