JP2001179602A - Polishing device and polishing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a yield of polishing process without damaging a substrate to be polished by eliminating dropping off of abrasive grains from a pad conditioner. SOLUTION: In a polishing device 1 polishing a substrate 50 to be polished by contacting and sliding the substrate 50 to be polished on a polishing pad 12 through slurry including polishing fluid while rotating the substrate 50 to be polished, dressing fluid 61 is sprayed on the polishing surface of the polishing pad 12 and a pad conditioner 3 arranged at a location facing the polishing surface of the polishing pad 12 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a polishing apparatus and a polishing method, and more particularly, to a polishing apparatus and a polishing method for preventing clogging of a polishing pad.

[0002]

2. Description of the Related Art An example of a conventional polishing apparatus will be described with reference to a schematic diagram of FIG. As shown in FIG. 4, the polishing apparatus 100 includes a polishing platen 101 rotatably supported by a driving unit (not shown), and a polishing pad 102 fixed on the upper surface with, for example, a double-sided tape. ing. The substrate 1 to be polished is positioned at a position facing the polishing surface of the polishing pad 102 via an attraction film 103.
A polishing head 104 that holds 20 is attached to a drive unit 106 that can move up and down via a rotation shaft 105. In addition, a retainer ring 107 is provided on the outer peripheral portion of the polishing head 104 on the substrate holding side so that the substrate to be polished 120 does not protrude from the polishing head 104.

A polishing agent supply unit 111 for supplying a polishing agent to a polishing surface of the polishing pad 102 is provided with a polishing pad 10.
2 above.

At another position on the polishing pad 102, a pad conditioner 108 made of, for example, a diamond grindstone is driven by a driving unit 110 via a rotating shaft 109.
Is mounted to be rotatable. And (1) of FIG.
As shown in the bottom view of FIG. 1 and the cross-sectional view of (2), the pad conditioner 108 is
1 adopts a structure in which a diamond dresser 132 is attached concentrically. Diamond dresser 13
2 is a large number of abrasive grains (such as diamonds) 13
4 is fixed by vapor deposition of nickel 135.

In order to polish the substrate to be polished 120 by the polishing apparatus 100, the polishing platen 101 and the polishing head 104 to which the substrate to be polished 120 is fixed via the suction film 103 are rotated. Then, the rotating polishing head 104 is lowered while supplying the abrasive onto the polishing pad 102, and the polishing target surface of the polishing target
Then, polishing is performed while pressing the substrate to be polished 120 such that the polishing pressure on the substrate to be polished 120 becomes a predetermined pressure.

Further, in order to smooth the pad surface roughened by polishing, the pad conditioner 108 is rotated while pressing against the polishing surface of the polishing pad 102 during polishing or independently, and conditioning of the polishing surface of the polishing pad 102 is performed. Do.

[0007]

However, in a pad conditioner provided in a conventional polishing apparatus, abrasive grains are peeled off from a base during processing of a substrate to be polished.
The substrate to be polished is damaged, which causes a decrease in yield.

Further, in the conventional polishing apparatus, a pad conditioner is directly pressed against the polishing pad surface to level the polishing surface of the polishing pad after polishing, so that the polishing surface of the polishing pad is inclined. as a result,
The polished surface of the polishing pad and the polished surface of the substrate to be polished come into contact with a small angle, which greatly affects the in-plane uniformity of the polished substrate after processing. in this way,
The phenomenon in which the polishing surface of the polishing pad is inclined is also caused by polishing the substrate to be polished when the polishing head is inclined from a normal position with respect to the polishing surface of the polishing pad.

For example, as shown in FIG. 6, the polishing head 104 is usually assumed to have a uniform thickness of the substrate 120 to be polished.
Α (hereinafter referred to as an accuracy error) between the surface to be processed of the substrate to be polished 120 held by the polishing pad 102 and the polishing surface of the polishing pad 102
Is about 1/2000 in the circumferential direction. For this reason, when the polishing head is brought into contact with the polishing pad during polishing and pressed, the processed surface of the substrate to be polished is unevenly pressed due to this accuracy error. When polishing is performed in such a state, the amount of polishing increases on a surface to be polished of the substrate to be polished (surface to be polished), and the amount of processing decreases on a portion where the pressure is weak. As a result, the in-plane uniformity of the substrate to be polished deteriorates.

In the state shown in FIG. 6, it is difficult to perform polishing by rotating the polishing head and the polishing pad at a high speed in order to obtain good in-plane uniformity. Must be polished.
As a result, the polishing time is prolonged, and the productivity is deteriorated.
Further, because the in-plane uniformity is poor, the polishing pad must be replaced frequently, which increases the cost of parts and requires labor.

[0011]

SUMMARY OF THE INVENTION The present invention is a polishing apparatus and a polishing method for solving the above-mentioned problems.

A first polishing apparatus according to the present invention is a polishing apparatus for polishing a substrate to be polished by rotating the substrate to be polished and bringing the substrate into sliding contact with a polishing pad via a polishing liquid containing a slurry. The polishing pad is provided with a pad conditioner provided at a position facing the polishing surface of the polishing pad.

In the first polishing apparatus, the dressing liquid
(E.g., a polishing liquid containing water, a polishing liquid or a slurry) is provided with a pad conditioner that sprays the polishing surface of the polishing pad, so that the polishing is performed by spraying a dressing liquid from the pad conditioner onto the polishing surface of the polishing pad. Dressing of the polishing surface of the pad becomes possible. Since the pad conditioning is performed by spraying the dressing liquid in this manner, the abrasive grains do not fall off unlike the conventional pad conditioning. Therefore, the processing quality of the substrate to be polished is improved.

Further, by adjusting the pressure and flow rate of the spraying of the dressing liquid, desired pad conditioning can be performed. When a slurry-containing liquid is used as the dressing liquid, it can be used as a polishing slurry.

A second polishing apparatus according to the present invention is a polishing apparatus for polishing a substrate to be polished by rotating the substrate to be polished and slidingly contacting the polishing pad with a polishing liquid containing slurry. An angle adjusting means for adjusting an angle of a polishing head for holding a substrate is provided.

In the second polishing apparatus, since the angle adjusting means for adjusting the angle of the polishing head is provided, the contact angle between the surface to be processed of the substrate to be polished and the polishing surface of the polishing pad is finely adjusted. The entire surface of the work surface can always be brought into contact with the polished surface, so that an optimum contact state can be maintained. As a result, when the polishing head is lowered in the direction of the polishing pad and the processing surface of the substrate to be polished is pressed against the polishing surface of the polishing pad and pressed, a uniform force is applied to the entire processing surface of the substrate to be polished. Work surface is polished uniformly. Further, since a uniform force is applied to the entire surface to be processed, good in-plane uniformity can be obtained on the surface to be processed even when the polishing head and the polishing pad are rotated at a high speed.

A first polishing method according to the present invention is a polishing method for polishing a substrate to be polished by rotating the substrate to be polished and bringing the substrate into sliding contact with a polishing pad via a polishing liquid containing a slurry. During or after polishing, a dressing liquid is sprayed toward the polishing surface of the polishing pad to dress the polishing surface of the polishing pad.

In the first polishing method, the dressing liquid
(For example, a polishing liquid containing water, a polishing liquid or a slurry) is sprayed onto the polishing surface of the polishing pad to perform pad conditioning, so that the polishing surface of the polishing pad is dressed by the dressing liquid sprayed on the polishing surface of the polishing pad. Is done. Since the pad conditioning is performed by spraying the dressing liquid in this manner, the abrasive grains do not fall off unlike the conventional pad conditioning. Therefore, the processing quality of the substrate to be polished is improved.

Further, by adjusting the pressure and flow rate of the dressing liquid, desired pad conditioning can be performed. When a slurry-containing liquid is used as the dressing liquid, it can be used as a polishing slurry.

A second polishing method according to the present invention is a polishing method for polishing the substrate to be polished by rotating the substrate to be polished and slidingly contacting the polishing pad with a polishing liquid containing slurry. The angle of the polishing head that holds the substrate to be polished is adjusted so that the entire surface of the substrate to be polished contacts the polishing surface of the polishing pad.

In the second polishing method, the angle of the polishing head that holds the substrate to be polished is adjusted so that the entire surface of the surface to be polished of the substrate is in contact with the polishing surface of the polishing pad. Can always be brought into contact with the polished surface, so that an optimal contact state can be maintained. As a result, when the polishing head is lowered in the direction of the polishing pad and the processing surface of the substrate to be polished is pressed against the polishing surface of the polishing pad and pressed, a uniform force is applied to the entire processing surface of the substrate to be polished. Work surface is polished uniformly. Further, since a uniform force is applied to the entire surface to be processed, good in-plane uniformity can be obtained on the surface to be processed even when the polishing head and the polishing pad are rotated at a high speed.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the polishing apparatus of the present invention will be described with reference to the schematic configuration diagram of FIG.

As shown in FIG. 1, the polishing apparatus 1 includes a polishing apparatus main body 2 and a pad conditioner 3.

The polishing apparatus main body 2 includes a polishing platen 11 rotatably supported by a driving unit (not shown) via a rotary shaft 10 and a double-sided tape (not shown) on the upper surface thereof.
And a polishing pad 12 fixedly installed in the apparatus. A polishing head 14 for holding a substrate 50 to be polished via an attraction film 13 is attached to a driving unit 16 which can move up and down via a rotation shaft 15 at a position facing the polishing surface of the polishing pad 12. Have been. A substrate 50 to be polished is provided around the polishing head 14 around the polishing head 14.
A retainer ring 17 is provided so as not to protrude from the second. A pad measuring device 81 for measuring the shape of the polishing surface of the polishing pad 12 is provided on the side of the polishing head 14.

The above-mentioned pad measuring device 81 measures, for example, the shape of the polishing pad 12 in the radial direction before and after polishing by rotating the polishing head 14.

The driving section 16 is supported by an arm 18, and the arm 18 is supported by a column 20 installed on a base 19. Although not shown, an angle adjusting means for adjusting the angle of the polishing head 14 is provided between the driving section 16 and the arm 18, between the arm 18 and the support 20, or at the base of the support 20. Have been. This angle adjusting means makes the entire surface of the processing surface of the substrate 50 to be polished held by the polishing head 14 contact with the polishing surface of the polishing pad 12 based on the inclination of the polishing surface of the polishing pad 12 detected by the pad measuring device 81. The inclination of the polishing head 14 is adjusted within a range of several degrees, for example.

For example, when the angle adjusting means is provided between the drive unit 16 and the arm 18, the drive unit 16
At the same time, the polishing head 14 is tilted to adjust the tilt.

An abrasive supply unit (not shown) for supplying an abrasive to the polishing surface of the polishing pad 12 is provided above the polishing pad 12.

Further, a pad conditioner 3 is provided at another position on the polishing pad 12. The pad conditioner 3 sprays a dressing liquid 61 toward the polishing surface of the polishing pad 12 and is provided at a position facing the polishing surface of the polishing pad 12.
The pad conditioner 3 includes a dressing liquid 61
Jetting portion 31 for jetting the polishing surface of the polishing pad 12 with
In the example shown in the drawing, a first arm 33 provided in the dressing liquid supply unit 32 and a first arm 33 supported by the first arm 33 are provided. A second arm 34 for supporting the ejection portion 31 is provided. Inside the first and second arms 33 and 34, a pipe (not shown) for supplying a dressing liquid from the dressing liquid supply unit 32 to the ejection unit 31 is provided.

The jetting part 3 of the pad conditioner 3
1 is provided with a large number of ejection holes (not shown) for ejecting a dressing solution pressurized toward the polishing pad 12 side. The arrangement of the ejection holes may be formed, for example, over the entire surface of the ejection portion 31 on the polishing pad 12 side, or may be formed in a circular or concentric shape.

The dressing liquid 61 includes, for example,
A polishing liquid containing water, a polishing liquid or a slurry can be used. When the slurry is supplied, it is not always necessary to provide the abrasive supply section.

Next, an example of the dressing liquid supply section 32 will be described.
This will be described with reference to the schematic configuration diagram of FIG.

As shown in FIG. 2, it is constituted by a dressing liquid tank 33, a hydraulic section 34, a pressure increasing section 35, a piping system for connecting these, and various valves.

More specifically, a dressing liquid tank 33 is connected to the slurry supply section 36. Then, the slurry and the dressing liquid are mixed to a desired concentration in the slurry supply section 36, and the prepared dressing liquid is supplied to the pressure increasing section 34. The pressure increasing section 34 is driven by a hydraulic section 35. The hydraulic direction is switched and controlled by a control valve 37 provided in the middle of the pipe between the hydraulic section 35 and the pressure increasing section 34. The pressure increasing unit 34 converts the supplied dressing liquid into a high pressure state by hydraulic pressure. Booster section 3
Four check valves 38 for preventing backflow of the high-pressure dressing liquid are installed in a piping system connected to both ends of the four.

An accumulator 39 for reducing the pulsation of the high-pressure dressing liquid is connected to the discharge side of the pressure increasing section 34. Therefore, the pulsation of the high-pressure dressing liquid taken into the accumulator 39 is reduced. In this way, the high-pressure dressing liquid is supplied to the ejection section 31.

The slurry supply section 36 may be connected to a pipe connected from the dressing liquid tank 33 to the pressure increasing section 34 via an adjustment valve (not shown) for adjusting the amount of slurry.

As shown in FIG. 3, the polishing apparatus 1
In addition to the polishing apparatus main body 2, the pad conditioner 3, and the abrasive supply section 4 described with reference to FIG. 1, a transport section 5, a cleaning section 6, and a storage section 7 are provided. The abrasive supply section 4 includes an abrasive supply nozzle 41 and an abrasive supply unit 42 that stores and sends the abrasive.
The cleaning unit 6 is a device for cleaning and drying the polished substrate to be polished, and the storage unit 7 includes a first cassette 71 for storing the polished substrate before polishing, and a polished substrate to be polished. And a second cassette 72 for storing
The transport section 5 includes a storage section 7, a polishing apparatus main body 2, a cleaning section 6,
For example, it is a robot that transports the substrate to be polished between them.

In order to polish the substrate 50 to be polished by the polishing apparatus 1 described with reference to FIG.
And the polishing head 14 to which the substrate 50 to be polished is fixed via the suction film 13 is rotated. Then, the polishing head 14 that rotates while supplying the polishing agent onto the polishing pad 12 is rotated.
To be polished and the substrate 50 to be polished
Then, polishing is performed while pressing the substrate 50 so that the polishing pressure on the substrate 50 becomes a predetermined pressure.

Further, at the time of polishing, before or after polishing, in order to level the polishing pad surface 12 which has been roughened by polishing, the pad conditioner 3 is operated while rotating the polishing pad 12, and the dressing liquid is discharged from the ejection portion 31. The jet of 61 is sprayed on the polishing surface of the polishing pad 12,
Conditioning (dressing) of the polishing surface of the polishing pad 12 is performed.

That is, during the polishing process, the dressing liquid pressurized to a high pressure from the ejection hole of the ejection portion 31 is ejected toward the polishing surface of the polishing pad 12 to attack the polishing surface. Thus, conditioning of the polishing surface of the polishing pad 12 is performed. At the same time, the polishing pad 12
The slurry in the dressing liquid supplied to the polishing surface of
The state changes from a jet state to a gentle flow state, and enters between the polishing pad 12 and the substrate 50 to be polished, like a normal slurry, and functions as a slurry.

The ejection section 31 has a polishing pad 1
A large number of ejection holes are provided on the two sides.
The optimal pad conditioning can be performed by selecting the diameter of the ejection holes, the number of the ejection holes, the arrangement position of the ejection holes, and the like according to the material of No. 2, the type of the substrate to be polished, the polishing conditions, and the like. .

Further, based on the result of measuring the inclination of the polishing head 14 with respect to the polishing surface of the polishing pad 12 by the pad measuring device 81 described above, the angle adjusting means of the polishing head 14 adjusts the angle of the polishing head 14 with respect to the polishing pad 12. The angle is adjusted so that the entire surface of the processing surface of the substrate 50 to be polished contacts the polishing surface of the polishing pad 12. At the same time, the pressure and flow rate of the dressing liquid 61, the pad conditioning conditions for the desired processing conditions of the substrate 50 to be polished, the concentration of the slurry, and the like are adjusted.

Polishing apparatus 1 adjusted as described above
In the direction of the polishing surface of the polishing pad 12, the substrate 5 to be polished is
The polishing head 14 holding 0 is lowered, and the substrate 5 to be polished is lowered.
When 0 is pressed against the above-mentioned polished surface and pressure is applied for polishing, a uniform force is applied to the entire processed surface of the substrate 50 to be polished, so that the processed surface is polished uniformly. In addition, since a uniform force is applied to the entire processed surface, even if the polishing head 14 and the polishing pad 12 are rotated at a high speed, a good polishing result with excellent in-plane uniformity can be obtained.

[0044]

As described above, according to the first polishing apparatus of the present invention, a pad conditioner for spraying a dressing liquid (for example, a polishing liquid containing water, a polishing liquid or a slurry) onto a polishing surface of a polishing pad. Therefore, the conditioning of the polishing surface of the polishing pad can be performed by spraying a dressing liquid from the pad conditioner onto the polishing surface of the polishing pad. Since the pad conditioning is performed by spraying the dressing liquid in this manner, the abrasive grains do not fall off unlike the conventional pad conditioning. Therefore, the yield can be improved as well as the processing quality of the substrate to be polished. Further, when a liquid containing a slurry is used as the dressing liquid, it can be used as a polishing slurry, so that there is no need to provide a separate supply section for the polishing slurry.

According to the second polishing apparatus of the present invention, since the angle adjusting means for adjusting the angle of the polishing head is provided, the contact angle between the processing surface of the substrate to be polished and the polishing surface of the polishing pad is finely adjusted. As a result, the entire surface of the work surface can always be brought into contact with the polished surface, and the optimum contact state can be maintained. Therefore, a uniform force is applied to the entire surface to be processed of the substrate to be polished, and the surface to be processed can be uniformly polished.
In addition, since uniform force is applied to the entire surface to be processed, good in-plane uniformity can be obtained on the surface to be processed even when the polishing head and the polishing pad are rotated at a high speed. It can be realized and the yield can be improved.

According to the first polishing method of the present invention, pad conditioning is performed by spraying a dressing liquid (for example, a polishing liquid containing water, a polishing liquid or a slurry) onto the polishing surface of the polishing pad. The polishing surface of the polishing pad is satisfactorily conditioned by the dressing liquid sprayed on the polishing surface. Also, since the abrasive grains do not fall off as in conventional pad conditioning,
The processing quality of the substrate to be polished is improved, and the yield can be improved. Further, when a liquid containing a slurry is used as the dressing liquid, it can be used as a polishing slurry, so that there is no need to separately supply a polishing slurry.

According to the second polishing method of the present invention, the angle of the polishing head that holds the substrate to be polished is adjusted so that the entire surface of the surface to be polished of the substrate is in contact with the polishing surface of the polishing pad. The entire surface of the work surface can always be brought into contact with the polished surface, and an optimum contact state can be maintained. As a result, when the polishing head is lowered in the direction of the polishing pad and the processing surface of the substrate to be polished is pressed against the polishing surface of the polishing pad and pressed, a uniform force is applied to the entire processing surface of the substrate to be polished. Therefore, the surface to be processed can be uniformly polished. In addition, since a uniform force is applied to the entire work surface,
Even when the polishing head and the polishing pad are rotated at a high speed, good in-plane uniformity can be obtained on the surface to be processed. Therefore, high-precision and high-yield polishing can be performed.

As described above, in the polishing apparatus and the polishing method of the present invention, an optimum pad condition is provided using a so-called high-speed jet (eg, a water jet), and at the same time, an optimum slurry is supplied, and the substrate to be polished is polished. Uniform pressure is applied to the pad surface to improve in-plane uniformity, and it is possible to perform polishing at high speed, thereby improving productivity.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment relating to a polishing apparatus of the present invention.

FIG. 2 is a schematic configuration diagram of an example of a dressing liquid supply unit 32 shown in FIG. 2;

FIG. 3 is an overall schematic configuration diagram of a polishing apparatus.

FIG. 4 is a schematic configuration diagram showing an example of a conventional polishing apparatus.

FIG. 5 is a schematic configuration diagram showing a pad conditioner of a conventional polishing apparatus.

FIG. 6 is a schematic configuration diagram showing a problem relating to a polishing head of a conventional polishing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Polishing apparatus, 3 ... Pad conditioner, 12 ... Polishing pad, 50 ... Substrate to be polished, 61 ... Dressing liquid

Claims (10)

[Claims] 1. A polishing apparatus for polishing a substrate to be polished by rotating the substrate to be polished while sliding the substrate to be polished through a polishing liquid containing slurry and polishing the substrate to be polished, wherein a dressing liquid is applied to a polishing surface of the polishing pad. And a pad conditioner provided at a position facing the polishing surface of the polishing pad. 2. The polishing apparatus according to claim 1, wherein the dressing liquid comprises a polishing liquid containing water, a polishing liquid or a slurry. 3. The polishing apparatus according to claim 1, wherein the pad conditioner is provided with a plurality of holes for ejecting the dressing liquid on a surface facing the polishing pad. 4. A polishing apparatus for polishing a substrate to be polished by rotating the substrate to be polished and slidingly contacting a polishing pad via a polishing liquid containing a slurry, the angle of a polishing head holding the substrate to be polished. A polishing apparatus provided with an angle adjusting means for adjusting the angle. 5. The polishing apparatus according to claim 4, wherein said angle adjusting means is provided between a drive unit for rotating said polishing head and an arm supporting said drive unit. 6. The apparatus according to claim 4, wherein said angle adjusting means is provided between an arm for supporting a drive unit for rotating said polishing head and a support for supporting said arm. Polishing equipment. 7. A polishing method for polishing a substrate to be polished by bringing the substrate to be polished into sliding contact with a polishing pad via a polishing liquid containing a slurry while rotating the substrate to be polished, wherein the polishing is performed before, during or after polishing. A polishing method, wherein a dressing liquid is sprayed toward the polishing surface of the pad to dress the polishing surface of the polishing pad. 8. The polishing method according to claim 7, wherein a polishing liquid containing water, a polishing liquid or a slurry is used as the dressing liquid. 9. The polishing method according to claim 7, wherein the dressing liquid is sprayed onto the polishing pad surface from a plurality of holes provided at positions facing the polishing pad. 10. A polishing method for polishing a substrate to be polished by rotating the substrate to be polished and bringing the substrate to be polished into sliding contact with a polishing pad via a polishing liquid containing a slurry, wherein the entire surface of the surface to be processed of the substrate to be polished is A polishing method, comprising: adjusting an angle of a polishing head that holds the substrate to be polished so as to contact a polishing surface of the polishing pad.