JPH10244458A - Grinding pad dressing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinding pad dressing device capable of dressing without damaging or contaminating grinding pad. SOLUTION: The surface of a grinding pad 50 is rubbed by a brush 14, and washing liquid is injected at a high pressure from a nozzle toward a part brought in contact with the brush 14 of the grinding pad 50. Therefore scraped- off ground waste can be washed out immediately. Also, because it is washed out by high-pressure washing liquid, the grinding pad 50 does not need to be strongly rubbed by the brush 14. In addition, because the size of fog drop of washing liquid impacted to the grinding pad 50 and impact speed are optimized so that the washing liquid can sufficiently reach the deep layer of the grinding pad 50, the brush 14 strikes the grinding pad 50 so as to produce a grinding pad 50 push-washing effect. Thus the ground-off waste accumulated in the deep layer of the grinding pad 50 can be floated, for removal, to the surface layer of the grinding pad 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dressing apparatus for a polishing pad of a polishing apparatus, and more particularly to a dressing apparatus for dressing a polishing pad of a semiconductor wafer polishing apparatus by rubbing the polishing pad with a brush or a grindstone.

[0002]

2. Description of the Related Art One of the methods for polishing a semiconductor wafer is a chemical mechanical polishing method. In this polishing method, a polishing liquid in which abrasive grains made of silica or the like are suspended in an alkaline solution is dropped on a polishing pad, and the semiconductor wafer and the polishing pad are relatively moved while being pressed, and the action of the polishing liquid and the abrasive grains is performed. The reaction products generated on the surface of the semiconductor wafer are scraped off by the abrasive grains and the polishing pad. The polishing pad needs to be dressed because the pad is clogged with polishing debris such as the reaction product and abrasive grains as the polishing pad is repeatedly used.

[0003] As such a dressing apparatus, there is one which sweeps out polishing debris by rubbing the surface of a polishing pad with a brush or a grindstone.

[0004]

However, with the conventional dressing apparatus, it is not possible to remove the polishing debris accumulated in the deep layer of the polishing pad. Further, since it is necessary to strongly rub the polishing pad with a brush or grindstone, there is a disadvantage that the polishing pad is damaged or the polishing pad is contaminated by dust generated from the brush or grindstone.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a dressing apparatus for a polishing pad capable of dressing without damaging or contaminating the polishing pad.

[0006]

To achieve the above object, a polishing pad dressing apparatus according to the present invention is a polishing pad dressing apparatus for dressing by polishing a polishing pad of a polishing apparatus with a brush. A nozzle for spraying a cleaning liquid toward a place where the brush contacts. That is,
High-pressure cleaning liquid is injected from this nozzle, and the cleaning liquid is
It is characterized in that it collides with the polishing pad at a speed of not less than / s and not more than 500 m / s.

In the dressing apparatus of the present invention, the high-pressure cleaning liquid is sprayed toward the place where the brush contacts the polishing pad, so that the polishing debris scraped out by the brush can be immediately washed away. Further, since the polishing pad is washed away with a high-pressure cleaning solution, it is not necessary to rub the polishing pad with a brush. Further, in the dressing apparatus of the present invention, the size and the collision speed of the mist of the cleaning liquid that collides with the polishing pad are optimized so that the cleaning liquid sufficiently reaches the deep layer of the polishing pad. The effect of pressing and washing the polishing pad by tapping can be produced. Therefore, the polishing debris accumulated in the deep layer of the polishing pad can be lifted up on the surface layer of the polishing pad and removed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a dressing apparatus for a polishing pad according to the present invention will be described below in detail with reference to the accompanying drawings. 1 and 2 show a dressing apparatus 10 for a polishing pad according to a first embodiment of the present invention. The dressing device 10 dresses the polishing pad 50 by rubbing the surface of the polishing pad 50 of the polishing device with the brush 14 and injecting a cleaning liquid such as pure water from the nozzle 20 toward the polishing pad 50. .

In FIG. 1, the brush 14 is connected to a motor 18 via a rod 16 and is rotated in the direction of arrow a. The distance between the rod 16 and the surface of the polishing pad 50 is adjusted so that the pressing force of the brush 14 against the polishing pad 50 is optimized. The nozzle 20
The direction of the brush and the relative position to the brush 14 are set such that the cleaning liquid ejected from the nozzle 20 collides with the polishing pad 50 at a place where the cleaning liquid comes into contact with the brush 14. Nozzle 2
0 is connected via a pipe 22 to a pump 24 which is connected to a tank 28 via a flexible hose 26. The cleaning liquid stored in the tank 28 is pressurized by the pump 24 and sent to the nozzle 20, and is jetted toward the polishing pad 50 at a high pressure in a range indicated by a broken line in FIG.

In FIG. 1, the motor 18 and the pump 24 are installed on a table 30. The table 30 is placed on a rail 34 installed on a base 32 and is moved in the direction of arrow b by a table moving mechanism (not shown). The polishing pad 50 includes a platen 52
It is adhered on the upper side and rotated in the direction of arrow c by a platen rotating mechanism (not shown).

Next, the operation of the dressing apparatus 10 configured as described above will be described. When the polishing operation is performed on the polishing pad 50 and the dressing of the polishing pad 50 becomes necessary, the table moving mechanism (not shown) is operated to move the table 30 so that the brush 14 is positioned on the center of the polishing pad 50. Then, the motor 18 is operated to rotate the brush 14 in the direction of arrow a, and the pump 24 is operated to inject the cleaning liquid from the nozzle 20.

The brush 14 scrapes off the polishing debris accumulated on the polishing pad 50 toward the outer periphery of the polishing pad 50. The cleaning liquid sprayed from the nozzle 20 has a particle size of 1 μm or more and 30 μm or more.
It becomes mist of 0 μm or less and 10 m / s or more and 500 m
At a speed of not more than / s, it collides with the place where the brush 14 of the polishing pad 50 contacts. Then, the cleaning liquid immediately flushes the polishing debris scraped off by the brush 14 toward the outer periphery of the polishing pad 50. Since the scraped-out polishing debris is washed away with the high-pressure cleaning liquid, it is not necessary to rub the polishing pad 50 with the brush 14 strongly. Therefore, damage to the polishing pad 50 can be prevented, and furthermore, generation of dust due to wear of the brush 14 can be suppressed, and contamination of the polishing pad 50 can be prevented.

In the present dressing apparatus 10, the size of the mist of the cleaning liquid and the collision speed are optimized and the polishing pad 50 is adjusted.
Since the cleaning liquid sufficiently reaches the deep layer of the polishing pad, a clean cleaning liquid is always supplied to the polishing pad 50 immediately below the place where the brush 14 is in contact. Therefore, by rotating the brush 14 and continuously hitting the polishing pad 50 with the bristles of the brush 14, an effect of pressing and washing the polishing pad 50 is produced. Thereby, the polishing debris accumulated in the deep layer of the polishing pad 50 can be removed by floating on the surface layer of the polishing pad 50.

While rotating the brush 14 and spraying the cleaning liquid from the nozzle 20 as described above, the polishing pad 50 is rotated in the direction of arrow c by a platen rotating mechanism (not shown), and the table is moved by a table moving mechanism (not shown). 30 is moved upward in FIG. Thus, the polishing pad 50 can be dressed over the entire surface while sweeping the polishing debris on the polishing pad 50 toward the outer periphery of the polishing pad 50.

It is desirable that the particle size of the mist of the cleaning liquid that collides with the polishing pad 50 is 1 μm or more and 300 μm or less, more preferably 1 μm or more and 100 μm or less. Mist particles that are too small tend to lose kinetic energy due to air resistance and collision with the polishing pad 50, and too large mist particles cannot enter the holes of the polishing pad 50, and all reach the deep layer of the polishing pad 50. Can not do.

The speed at which the mist of the cleaning liquid collides with the polishing pad 50 is preferably 10 m / s or more and 500 m / s or less, more preferably 30 m / s or more and 150 m / s or less. If the collision speed of the mist is too low, kinetic energy is insufficient to reach the deep layer of the polishing pad 50,
If the collision speed of the mist is too high, the polishing pad 50 may be damaged.

In order to realize the size of the mist of the cleaning liquid and the collision speed, the discharge port of the nozzle 20 must have a short diameter of 400 mm.
In the case of an elliptical shape having a long diameter of 600 μm, it is necessary to supply the cleaning liquid to the nozzle 20 at a pressure of more than 10 MPa and 30 MPa or less. 3 and 4 show a dressing apparatus 11 for a polishing pad according to a second embodiment of the present invention. 3 and 4, members that are the same as or similar to the dressing device 10 of the polishing pad of the first embodiment shown in FIGS. 1 and 2 are given the same reference numerals as in FIGS. Description is omitted.

In the dressing apparatus 11, the grinding stone 36
Rubs the surface of the polishing pad 50 of the polishing apparatus. The grindstone 36 is, for example, made of ceramic and formed in an annular shape, and has a diamond coating on the lower surface in contact with the polishing pad 50. This grindstone 36 is attached to the lower surface of the plate 38. The plate 38 has a spindle of a motor 40 connected to the center of the upper surface, and is rotated by the motor 40 in the direction of arrow d. This motor 4
Numeral 0 is attached to the tip of the robot arm 42.

When the polishing operation is performed on the polishing pad 50 and the dressing of the polishing pad 50 becomes necessary, the robot arm 42 is operated to bring the grindstone 36 into contact with the surface of the polishing pad 50. Then, the motor 40 is operated to set the grinding stone 36.
Is rotated in the direction of arrow d, and the cleaning liquid is jetted from the nozzle 20. Note that the grindstone 36 is not limited to a ring shape, and may be a plate shape such that the entire lower surface contacts the polishing pad 50. Further, the plate 38 is not rotated by the motor 40, and is simply rotated by the robot arm 42.
It may be simply supported rotatably on the surface. In this case, when the grindstone 36 is brought into contact with the polishing pad 50 rotating in the direction of the arrow c, the peripheral speed of the place where the polishing pad 50 is in contact with the grindstone 36 is proportional to the distance from the center of the polishing pad 50. Since it has become larger, the grindstone 36 has an arrow d
Rotate in the direction.

In the above description, as an example of a dressing object, a polishing pad (for example, made of polyurethane) of a semiconductor wafer polishing apparatus is taken as an example. In addition, a polishing buff of another polishing apparatus, a porous grindstone, or the like can be dressed.

[0021]

As described above, in the polishing pad dressing apparatus of the present invention, since the cleaning liquid is sprayed toward the place where the brush contacts the polishing pad, the polishing pad may be damaged or contaminated. Dressing can be performed without the need to do so.

[Brief description of the drawings]

FIG. 1 is a main part structural diagram of a polishing pad dressing apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a main part structural diagram of a polishing pad dressing apparatus according to a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

[Description of Signs] 10 ... Dressing device 14 ... Brush 18 ... Motor 20 ... Nozzle 24 ... Pump 28 ... Tank 36 ... Whetstone 40 ... Motor 42 ... Robot arm 50 ... Polishing pad

Continued on the front page (72) Inventor Takaho Saito 5050 Nitta-dong, Asamae-cho, Owariasahi-shi, Aichi Prefecture Inside Asahi Sunac Co., Ltd. (72) Inventor Yoshiyuki Seike 5050 Nitta-dong, Asamae-machi, Owariasahi-shi, Aichi Prefecture Asahi Sunac Corporation

Claims (3)

[Claims] 1. A polishing pad dressing apparatus for dressing a polishing pad of a polishing apparatus by rubbing the polishing pad with a brush, wherein a nozzle for spraying a cleaning liquid toward a place where the brush of the polishing pad contacts the polishing pad is provided. Polishing pad dressing device. 2. A polishing pad dressing apparatus for dressing by polishing a polishing pad of a polishing apparatus with a grindstone, wherein a nozzle for spraying a cleaning liquid toward a place of the polishing pad contacting the grindstone is provided. Polishing pad dressing device. 3. The cleaning liquid sprayed from the nozzle is 10 m
3. The polishing pad dressing apparatus according to claim 1, wherein the polishing pad is caused to collide with the polishing pad at a speed of not less than / m and not more than 500 m / s.