JP2003048147A - Grinding pad conditioning device, and grinding device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinding pad conditioning device capable of reliably detecting abnormality in a conditioning work of a grinding pad for grinding a work, and a grinding device using the grinding pad conditioning device. SOLUTION: The grinding pad conditioning device comprises a rotatable conditioning means for conditioning a surface of the grinding pad, a drive source for rotating the conditioning means, and a rotation detecting means for detecting the detection of the conditioning means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing pad conditioning device and a polishing device using the same, and more particularly, to a polishing pad conditioning device capable of detecting abnormalities in the polishing pad conditioning. The present invention relates to an apparatus and a polishing apparatus using the apparatus.

[0002]

2. Description of the Related Art In recent years, along with the miniaturization of circuit wiring due to the high integration of semiconductor devices, it is required that the surface of a semiconductor wafer on which the circuit wiring is formed is highly flattened. As a means for flattening the surface of such a semiconductor wafer, chemical mechanical polishing is used.

A polishing apparatus for performing chemical mechanical polishing is a polishing platen having a polishing pad attached to the surface thereof, and a polishing device for holding a surface to be polished of an object to be polished such as a wafer so as to face the polishing pad. It has a head. The polishing head and the polishing platen are connected to a rotating shaft and are rotatable. In such a polishing device,
The object to be polished held by the polishing head is pressed against the polishing pad on the surface of the polishing platen, and the polishing platen and the polishing head are rotated at the same time. At this time, an abrasive containing fine particles such as silica particles is supplied to the polishing pad. As a result, the object to be polished is polished by the chemical action of the abrasive and the mechanical action of the fine particles.

It is known that when such a polishing process is continued for a certain period of time, the polishing surface on the surface of the polishing pad is scraped off and becomes flat, and the polishing ability is lowered. Therefore,
In order to recover the polishing action of such a polishing pad, a polishing pad conditioning device is used.
This conditioning device includes a disk-shaped end effector held so that its surface faces the polishing platen. This end effector is connected to a drive source such as a motor via a power transmission system such as a pulley and a drive belt so as to be rotatable.

The end effector is provided with a conditioning plate having diamond particles or the like attached to the surface thereof. In such a conditioning device, the polishing platen and the end effector are rotated while the conditioning plate is pressed against the polishing surface of the polishing pad. As a result, the polishing surface of the polishing pad that contacts the conditioning plate is sharpened, and the polishing action of the polishing pad is restored.

[0006]

In the above polishing apparatus, the drive source for rotating the conditioning plate is monitored in order to monitor whether the conditioning apparatus is operating normally. However, even if the drive source operates, the conditioning device may not operate due to a failure of the power transmission system, and the polishing pad may not be conditioned. This state cannot be detected by monitoring the drive source. If the object to be polished is polished in this state, the object to be polished is not sufficiently polished, resulting in a problem that overall work efficiency is reduced and material loss is increased. The present invention has been made to solve the above-mentioned problems, and when an abnormality occurs in the conditioning of the polishing pad, a polishing pad conditioning device capable of reliably detecting the abnormality and a polishing device using the same The purpose is to provide a device.

[0007]

In order to achieve the above object, a polishing pad conditioning apparatus of the present invention comprises:
It is provided with rotatable conditioning means for conditioning the surface of the polishing pad, a drive source for rotating the conditioning means, and rotation detection means for detecting the rotation of the conditioning means. Further, the polishing apparatus of the present invention holds a polishing pad for polishing an object to be polished, a rotatable platen for holding the polishing pad, and the object to be polished so as to bring them into contact with the polishing pad. It comprises a rotatable polishing head and a conditioning device for the polishing pad.

According to the present invention, the operating condition of the conditioning device is detected by detecting the rotation of the conditioning section for conditioning the polishing pad. As a result, not only when the drive source fails,
Even if a problem occurs in the power transmission unit that transmits the power of the drive source to the conditioning unit, this can be detected. Therefore, according to the present invention, it is possible to detect the operating state of the conditioning device more accurately, and therefore, when an abnormality occurs in the conditioning, it is possible to stop the polishing or conditioning work and inspect or repair the device. become.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show the first embodiment of the present invention.
1 shows a polishing apparatus 10 using a polishing pad conditioning apparatus according to an embodiment. This polishing apparatus 10 includes a polishing platen 20 having a polishing pad 24 provided on the surface thereof, a polishing head 30 for holding a wafer W as an object to be polished so as to face the polishing pad 24, and a polishing material for the polishing pad 24. A nozzle 40 for supplying the polishing pad and a conditioning device 50 for conditioning the polishing pad 24 are provided.

An elastic mat 22 made of foamed urethane or the like is attached to the surface of the polishing platen 20. A polishing pad 24 for polishing the wafer W is attached to the surface of the elastic mat. As the polishing pad 24, for example, a foamed polyurethane sheet in which bubbles are continuously formed or a polyurethane sheet in which a large number of grooves are formed on the surface can be used. A rotating shaft 20a is provided at the center of the lower surface of the polishing platen 20, and the polishing platen 20 is rotatable about this rotating shaft 20a.

Above the polishing platen 20, the polishing head 3 is provided.
0 is provided. A holding ring 32 for removably holding the wafer W is provided on the lower surface of the polishing head 30. Further, a rotary shaft 30a is provided at the center of the upper surface of the polishing head 30, and the polishing head 30 is rotatable around the rotary shaft 30a.

A conditioning device 50 is provided on the side of the polishing platen 20. The conditioning device 50 includes an end effector 52 as a conditioning unit that contacts the polishing pad 24 and restores the polishing action of the polishing pad 24, and an end effector 52.
A base portion 60 that houses a drive source that rotationally drives the arm 60 and an arm portion 70 that connects the base portion 60 and the end effector 52.
It has and.

The end effector 52 is disposed above the polishing pad 24 provided on the polishing platen 20, as shown in FIGS. 1 and 2. The end effector 52 includes a disc-shaped holder 54 made of a metal material or the like. A conditioning plate 56, on the surface of which the particles such as diamond particles are electrodeposited, is held on the lower surface of the holder 54. Further, the end effector 52 is provided at the center of the upper surface of the holder 54.
Is provided with a rotary shaft 54a for horizontally rotating the end effector 52, and the end effector 52 is connected to the distal end portion of the arm portion 70 via the rotary shaft 54a.

As shown in FIGS. 3 to 5, the base 60 is provided with a first motor 61 as a drive source for rotating the end effector 52, and, if necessary, a first motor 61. An encoder 62 that detects the rotation of the motor 61 as an electric signal is provided. This first motor 6
The first rotary shaft 61a is provided with a first gear 63.
Further, a drive shaft 64 for transmitting the rotation of the first motor 61 to the arm portion 70 is vertically provided at a substantially central portion of the base portion 60, and the drive shaft 64 engages with the first gear 63. A second gear 65 is provided. As a result, the rotation of the first motor 61 is regarded as the rotation of the drive shaft 64, and the arm portion 70
Can be transmitted to.

Further, the base 60 is provided with a second motor 66 for horizontally reciprocatingly rotating the arm 70. The rotating shaft 66a of the second motor 66 is provided with an arm portion 70.
The arm portion 70 is connected to the rear end portion of the second motor 66 and can reciprocate about the rotation shaft 66a of the second motor 66. As a result, the end effector 52 provided at the tip of the arm 70 can be moved horizontally on the polishing pad 24.

A first pulley 7 is provided at the rear end of the arm 70.
1 is provided, and the first pulley 71 is a drive shaft 64.
Is connected to the upper end of the. A second pulley 72 is provided at the tip of the arm portion 70, and the second pulley 72 is connected to the rotary shaft 54 a of the end effector 52. A drive belt 73 is stretched around the first pulley 71 and the second pulley 72.

Gear-shaped concavo-convex portions 71a and 72a are continuously formed on the outer peripheral surfaces of the first pulley 71 and the second pulley 72, respectively.
On the inner peripheral surface of the drive belt 73 that engages with the outer peripheral surface of the pulley 72, the uneven portion 71 of the first pulley 71 and the second pulley 72 is formed.
An uneven portion 73a corresponding to a and 72a is formed.
As a result, when the first pulley 71 is rotated, the drive belt 73 travels and the second pulley 72 is rotated. Therefore, according to the conditioning device 50 of the present embodiment, by driving the first motor 61,
The rotation of the rotary shaft 61a of the first motor 61 is transmitted to the second pulley 72 via the drive shaft 64 and the first pulley 71,
Eventually, the end effector 52 connected to the second pulley 72 will rotate.

A photoelectric sensor 80 for detecting the rotation of the second pulley 72 is provided inside the arm portion 70. The photoelectric sensor 80 detects the rotation of the second pulley 72 based on the reflected light of the light emitted to the uneven portion 72a formed on the outer peripheral surface of the second pulley 72. This photoelectric sensor 80
Is a light emitting diode (LED), as shown in FIG.
Alternatively, a light guide fiber 81 for guiding light emitted from a light emitting body (not shown) such as a laser diode (LD), and a second pulley 7 of the light emitted from the light guide fiber 81.
Reflection path fiber 82 for guiding the light reflected by the outer peripheral surface of
And an optical system 83 such as a lens for collecting the light emitted from the light guide fiber 81 and the light reflected by the outer peripheral surface of the second pulley 72. The optical system of the photoelectric sensor 80 is arranged near the outer peripheral surface of the second pulley 72, irradiates the outer peripheral surface of the second pulley 72 with the light from the light guide fiber 81, and The reflected light is guided to the reflection path fiber 82. The rotation of the second pulley 72 is detected by analyzing the light guided by the reflection path fiber 82 and detecting the difference in the intensity of the reflected light reflected by the convex portion and the reflected light reflected by the concave portion of the outer peripheral surface. Can be detected.

The operation of the polishing apparatus 10 will be described below. When polishing is performed by the polishing apparatus 10, the wafer W held by the polishing head 30 is pressed against the polishing pad 24 on the polishing platen 20 as shown in FIG.
Along with this, the polishing platen 20 and the polishing head 24 are horizontally rotated. At this time, the polishing pad 24 is supplied with a polishing agent containing an alkaline component such as potassium hydroxide and fine particles such as silica particles from the nozzle 40, and the wafer W is polished by the chemical action of the alkaline component and the mechanical action of the fine particles. To be done.

When such polishing continues for a certain period of time, the polishing surface of the surface of the polishing pad 24 is scraped off and becomes flat, and the polishing ability of the polishing pad 24 decreases. Therefore, after polishing is performed for a certain period of time or simultaneously with polishing, the polishing pad 2
4 conditioning is performed. When conditioning the polishing pad 24, the end effector 52
The conditioning plate 56 held by
As shown in FIG. 1, it is pressed against the rotating polishing pad 24. In this state, the first motor 61 is driven and the end effector 52 is rotated. At the same time, in order to condition the entire surface of the polishing pad 24, the second
The motor 66 is driven and the end effector 52 is reciprocated on the polishing pad 24. As a result, the diamond particles electrodeposited on the surface of the conditioning plate 56 serve to sharpen the polishing pad 24 and recover the polishing ability of the entire surface of the polishing pad 24.

In the polishing apparatus of this embodiment, the operating state of the conditioning apparatus detects the rotation of the second pulley 72 together with or in place of the encoder 62 for detecting the drive of the first motor 61. It is detected by the photoelectric sensor 80. Therefore, the first motor 61
If a failure occurs in the power transmission system such as the drive shaft 64, the first pulley 71 and the drive belt 73, the failure can be detected and the polishing and conditioning work can be stopped to inspect and repair the device. become. Therefore, according to the polishing apparatus 10 of the present embodiment, the conditioning device 5
Even when an abnormality occurs in 0, it is possible to reduce the work efficiency and minimize the loss of material.

Next, another embodiment of the present invention will be described. In the following description, description of the same components as those of the above-described first embodiment will be omitted, and only different components will be described. The same members as those described above are designated by the same reference numerals. 7 and 8 show a polishing pad conditioning device 50 of a polishing device according to a second embodiment of the present invention. As shown in FIG. 7, the conditioning device 50 is provided with a photoelectric sensor 80 that detects the rotation of the end effector 52 that holds the conditioning plate 56. The optical system 83 of the photoelectric sensor 80 is provided so as to face the upper surface of the end effector 52, and the photoelectric sensor 80 detects the rotation of the end effector 52 by the reflected light of the light with which the upper surface of the end effector 52 is irradiated. .

On the upper surface of the end effector 52, as shown in FIG. 8, markings 54b extending radially from the center are formed. This marking 54
b is formed in a color that allows the marking 54b to be identified even when a liquid such as an abrasive supplied to the polishing pad 24 reaches the upper surface of the end effector 42, for example, red. This photoelectric sensor 80 includes a light guide fiber 81.
Is emitted to the upper surface of the end effector 52, and reflected light from the upper surface of the end effector 52 is guided by the reflection path fiber 82 for analysis. The reflected light reflected by the portion where the marking 54b is formed and the marking 54b
The rotation of the end effector 52 is detected based on the difference in the intensity, color, etc. of the reflected light reflected by the portion where the end effector 52 is not formed.

According to the polishing apparatus of this embodiment, the end effector 5 that holds the conditioning plate 56.
The rotation of 2 can be detected directly. Therefore, even if there is a problem in the connecting portion between the second pulley 72 and the end effector 52, this can be detected. FIG. 9 shows a polishing pad conditioning device of a polishing device according to a third embodiment of the present invention. The polishing apparatus of this embodiment has the same configuration as that of the second embodiment described above except for the structure of the upper surface of the end effector.

On the upper surface of the end effector 52, as shown in FIG. 9, a projection 54c extending radially from the center is formed. The photoelectric sensor 80 is
The light from the light guide fiber 81 is applied to the upper surface of the end effector 52, and the reflected light from the upper surface of the end effector 52 is guided by the reflection fiber 82 for analysis. Then, the rotation of the end effector 52 is detected based on the difference in the intensity of the reflected light reflected by the protruding portion 54c and the reflected light reflected by the portion other than the protruding portion 54c.

According to the polishing apparatus of this embodiment, the end effector 5 that holds the conditioning plate 56.
The rotation of 2 can be detected directly. Therefore, even if a problem occurs in the connecting portion between the second pulley 72 and the end effector 52, this problem can be detected.

FIG. 10 shows a polishing pad conditioning device 50 of a polishing device according to a fourth embodiment of the present invention. An encoder 76 that converts the rotation of the second pulley 72 into an electric signal and detects the rotation is provided at the tip of the arm portion 70 of the conditioning device 50. According to the present embodiment, even if an abnormality occurs not only in the first motor 61 but also in the drive shaft 64, the first pulley 71, and the drive belt 73, this trouble can be detected. Further, since the rotation of the second pulley 72 is directly converted into an electric signal and detected, it is possible to easily and surely confirm the abnormality. It should be noted that the present invention is not limited to the above-described embodiments, and can be implemented with appropriate modifications without departing from the spirit of the invention. For example,
The present invention is not limited to the chemical mechanical polishing apparatus and can be used for other types of polishing apparatuses.

[0028]

As is apparent from the above description, according to the present invention, the operating state of the conditioning device can be detected more accurately. Therefore, if a problem occurs in the conditioning of the polishing pad, this problem is detected, polishing and conditioning work is stopped, and the equipment is inspected and repaired to reduce work efficiency and minimize material loss. The effect is that it can be suppressed to the limit.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of a polishing apparatus that is a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an outline of a polishing apparatus that is a first embodiment of the present invention.

FIG. 3 is a perspective view schematically showing a conditioning device of the polishing apparatus according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view schematically showing the conditioning device of the polishing device according to the first embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view schematically showing the conditioning device of the polishing device according to the first embodiment of the present invention.

FIG. 6 is a sectional view showing an outline of a photoelectric sensor.

FIG. 7 is a vertical cross-sectional view showing an outline of a conditioning device of a polishing device according to a second embodiment of the present invention.

FIG. 8 is a plan view showing an upper surface of an end effector of a conditioning device of a polishing device according to a second embodiment of the present invention.

FIG. 9 is a plan view showing an upper surface of an end effector of a conditioning device of a polishing apparatus which is a third embodiment of the present invention.

FIG. 10 is a vertical cross-sectional view showing an outline of a conditioning device of a polishing device according to a fourth embodiment of the present invention.

[Explanation of symbols]

10 Polishing equipment 20 Polishing platen 24 polishing pad 30 polishing head 50 conditioning equipment 52 End Effector 61 First motor 63 1st gear 64 drive shaft 65 Second Gear 71 first pulley 72 Second pulley 76 encoder 80 Photoelectric sensor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hidenori Matsumoto             14-3 Shinizumi, Narita City, Chiba Prefecture Nogedaira Industrial Park             Uchi Applied Materials Japan             Within the corporation F-term (reference) 3C047 AA34 FF08 FF11                 3C058 AA07 AA09 AA16 AA19 AC03                       BA09 CB06 DA12 DA17

Claims (6)

[Claims] 1. A polishing pad comprising rotatable conditioning means for conditioning the surface of the polishing pad, a drive source for rotating the conditioning means, and rotation detection means for detecting rotation of the conditioning means. Conditioning equipment. 2. A power transmission means for transmitting the power of the drive source to the conditioning means, wherein the rotation detecting means detects the rotation of the conditioning means by detecting the movement of the power transmitting means. Item 2. A polishing pad conditioning device according to item 1. 3. The conditioning means includes a conditioning plate that contacts the surface of the polishing pad to condition the surface of the polishing pad, and a holder that holds the conditioning plate, and the rotation detecting means includes a holder of the holder. The polishing pad conditioning apparatus according to claim 1, wherein rotation of the conditioning means is detected by detecting rotation. 4. The polishing pad conditioning apparatus according to claim 1, wherein the rotation detecting means optically detects rotation of the conditioning means. 5. The polishing pad conditioning device according to claim 1, wherein the rotation detecting means detects the rotation of the conditioning means by converting the rotation into an electric signal. 6. A polishing pad for polishing an object to be polished, a rotatable platen for holding the polishing pad, and a rotatable polishing plate for holding the object to be polished and contacting the polishing pad. A polishing apparatus comprising a head and the polishing pad conditioning apparatus according to claim 1.