JP2000288908A - Device and method for polishing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for polishing, capable of preventing the damage to the polished surface of an article to be polished caused by falling abrasive grains. SOLUTION: A polishing device is provided with a pad 32 fixed to the upper surface of a surface plate 30 rotary-driven around an axis, a polishing head 36 disposed above the pad 32 in a position eccentric from the axis of the surface plate 30 and holding an article 12 to be polished by an abrasive material 16 with a pad surface 32a on the lower surface side, a polishing head rotating lifting means 46 for rotating/lifting the polishing head 36 to press the article 12 to be polished to the pad surface 32a, and a pad surface smoothing means 50 made eccentric from the axis of the surface plate 30, disposed above the pad surface 32a in a position different from the polishing head 36, and capable of smoothing the roughness of the pad surface 32a using very super-acoustic wave vibration in a non-contact state.

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 for polishing a surface to be polished of various objects to be polished, for example, a thin plate-like object to be polished such as a semiconductor wafer or a glass plate for an LCD (liquid crystal). It is about.

[0002]

2. Description of the Related Art As a conventional polishing apparatus provided for the above polishing, for example, there is one as shown in FIG. As shown in the figure, an axis C is rotated by a platen rotating mechanism (not shown).
A pad 74 for polishing a polished surface (a lower surface in the figure) of an object to be polished 78 described later via an abrasive 88 is fixed on a surface plate 72 rotated around the surface 1 using a double-sided tape or the like. I have. Above the pad 74 and at a position eccentric from the axis C1, a polishing head 80 having an object to be polished 78 such as a semiconductor wafer attached via a suction film 76 having suction and cushioning properties is disposed below. Has been established.

The polishing head 80 is rotatable about an axis C2 perpendicular to the pad surface 74a of the pad 74, and is fixed to the lower end of a polishing head mounting shaft 84 that can move up and down along the axis C2. . On the other hand, the upper end of the polishing head mounting shaft 84 is connected to a first rotary elevating mechanism 86 so as to rotate and drive up and down.

As shown in FIG. 7, an abrasive supply hose for supplying an abrasive 88 in a slurry state (liquid mixture of fine solids) to a pad surface 74a of the pad 74 is provided above the pad 74. 90 are provided. The tip end of the abrasive supply hose 90 is arranged so as to face the pad surface 74a, and the base end thereof is connected so as to communicate with an abrasive supply part of an abrasive supply unit (not shown).

Further, above the pad 74 and at a position separated by a predetermined circumferential angle from the axis C2 of the polishing head 80 around the axis C1, a pad surface 7 roughened by polishing is provided.
A pad conditioner 92 for leveling 4a is provided. Like the polishing head 80, the pad conditioner 92 can rotate around an axis C3 perpendicular to the pad surface 74a of the pad 74, and can move up and down along the axis C3 at the lower end of a pad conditioner mounting shaft 96. It is fixed to the part. On the other hand, the upper end of the pad conditioner mounting shaft 96 is connected to the second rotary elevating mechanism 98 so as to rotate and drive up and down.

In the polishing apparatus shown in FIG. 7, an object 78 to be polished is
The retainer ring 100 is attached so that the retainer ring 100 does not come off from the lower side of the zero. As shown in FIGS. 8 and 9, the pad conditioner 92 is configured by attaching an annular diamond dresser 104 to the lower side of a disk-shaped stainless steel substrate 102. And this diamond dresser 1
Reference numeral 04 denotes an annular base metal 106 and diamond abrasive grains 108 deposited on the lower surface thereof.

With the conventional polishing apparatus having the above-described configuration,
At the time of polishing, the platen rotating mechanism and the first rotary elevating mechanism 86 are operated to lower the polishing head 80 while driving the rotation of the platen 72 and the polishing head 80. After the object to be polished 78 is brought into contact with the pad surface 74a of the pad 74, the object to be polished 78 is polished by further pressing the object to be polished 78. At the time of this polishing, the slurry-like abrasive 88 is supplied from the abrasive supply hose 90 to the pad surface 74a.
Supply on top.

When the polishing operation is repeated, and the pad surface 74a of the pad 74 is roughened and the polishing function is deteriorated, the platen is rotated at the time of polishing by the polishing head 80 or at the time of non-polishing. By operating the mechanism and the second rotary elevating mechanism 98, the pad conditioner 92 is lowered while driving the rotation of the surface plate 72 and the pad conditioner 92. Then, after the pad conditioner 92 is brought into contact with the pad surface 74a of the pad 74, conditioning (dressing) is performed in which the roughened pad surface 74a of the pad 74 is leveled by the diamond abrasive particles 108 by further pressing. ing.

[0009]

However, the above-described polishing method using the conventional polishing apparatus has the following problems to be solved.

First, in the polishing method using the polishing apparatus described above, the pad surface 74 is polished while the object 78 is being polished.
When the abrasive particles 108 are peeled off from the base metal 106 of the diamond dresser 104 performing the conditioning a, the abrasive particles 108 damage the polished surface of the polished object 78, and the polishing process of the polished object 78 The yield will be reduced.

As shown in FIG. 7, the pad surface 74a
The object to be polished 78 is polished by directly pressing the object to be polished 78 against the surface, and at this time, the axis C1 of the surface plate 72 is polished.
The precision of the parallelism of the axis C2 of the polishing head mounting shaft 84 with respect to the above has a great influence on the polishing uniformity (in-plane uniformity) in the polished surface of the polished work 78 after polishing.

For example, the axis C2 of the polishing head mounting shaft 84
And the accuracy error of the parallelism between the axes C1 of the platen 72, as shown in FIG.
8 and the pad surface 74a have a relative angle θ of t
When anθ is about 1/2000, when the polishing head 80 is brought into contact with the pad 74 and pressurized during polishing, the processing surface of the workpiece 78 is unevenly pressurized due to this accuracy error. Become. Then, when the object to be polished 78 is polished in this state, the amount of polishing increases when the surface of the object to be polished is strongly pressed, and the amount of processing decreases when the pressure is weak. As a result, The in-plane uniformity of the polished state of the polished object 78 deteriorates.

Further, in order to improve the in-plane uniformity of the polished state of the object 78 to be polished on the side of the polishing head 80 despite the state shown in FIG.
Since the polishing plate cannot be polished by rotating the surface plate 4 on the side of the pad 4 and the pad 74 at high speed, and the surface to be processed must be polished at low speed rotation, the polishing time becomes longer and the processing efficiency becomes worse.

Further, since the in-plane uniformity of the polished state of the polished object 78 is poor, the pad 74 must be replaced frequently, which increases the cost of parts and increases the time and labor required for replacing the pad 74. Will do.

In view of the above problems, the present invention can prevent the polished surface of the object to be polished from being damaged by the dropped abrasive grains, and / or prevent the polished state of the object to be polished in-plane from being uniform. It is an object of the present invention to provide a polishing apparatus and a polishing method capable of improving workability and improving processing efficiency.

[0016]

In order to solve the above-mentioned problems, a polishing apparatus and a polishing method according to the present invention have the following configurations.

(1) A pad fixed to an upper surface of a surface plate which is driven to rotate around an axis and having a pad surface, and a pad arranged above the pad at a position eccentric from the rotation axis of the surface plate and having a pad surface on a lower surface side. A polishing head for holding an object to be polished via an abrasive in between, a polishing head rotating / lowering means for rotating / elevating the polishing head and pressing the object to be polished against a pad surface, and a rotating axis of the platen. Eccentric and arranged on a pad surface at a position different from the polishing head, and a pad surface leveling means capable of leveling the roughness of the pad surface by using ultrasonic vibration in a non-contact state. Polishing equipment.

(2) A pad fixed to an upper surface of a surface plate that is driven to rotate about an axis and having a pad surface, and a pad disposed above the pad at a position eccentric from the rotation axis of the surface plate and having a pad surface on a lower surface side. A polishing head for holding an object to be polished through an abrasive in between, a polishing head rotating and lowering means for rotating and raising and lowering the polishing head to press the object to be polished against a pad surface, and a polishing surface of the object to be polished Parallelism adjusting means capable of adjusting the parallelism between the polishing pad and the pad surface, and a pad eccentric from the rotation axis of the surface plate and arranged on the pad surface at a position different from the polishing head and capable of leveling the roughness of the pad surface A polishing apparatus comprising a leveling means.

(3) A pad fixed to an upper surface of a surface plate that is driven to rotate around an axis and having a pad surface, and a pad that is disposed above the pad at a position eccentric from the rotation axis of the surface plate and that is closer to the lower surface. A polishing head for holding an object to be polished through an abrasive in between, a polishing head rotating and lowering means for rotating and raising and lowering the polishing head to press the object to be polished against a pad surface, and a polishing surface of the object to be polished And a parallelism adjusting means capable of adjusting the parallelism between the pad surface and the pad surface, eccentric from the rotation axis of the surface plate and arranged on the pad surface at a position different from the polishing head, using ultrasonic vibration in a non-contact state A polishing apparatus comprising: a pad surface leveling means capable of leveling the roughness of a pad surface.

(4) A pad fixed to an upper surface of a surface plate which is driven to rotate around an axis and having a pad surface, and a pad surface disposed above the pad at a position eccentric from the rotation axis of the surface plate and having a pad surface on a lower surface side. A polishing head for holding an object to be polished through an abrasive in between, a polishing head rotating and lowering means for rotating and raising and lowering the polishing head to press the object to be polished against a pad surface, and a polishing surface of the object to be polished And a parallelism adjusting means capable of adjusting the parallelism between the pad surface and the pad surface, eccentric from the rotation axis of the surface plate and arranged on the pad surface at a position different from the polishing head, using ultrasonic vibration in a non-contact state Using a polishing apparatus provided with a pad surface leveling means capable of leveling the roughness of the pad surface, the polishing surface of the object to be polished and the pad surface of the pad are adjusted in parallel by the parallelism adjusting means, and the polishing head is adjusted. Retained on the polishing head by means of rotary elevating The polished surface of the polished object is pressed against the rotating pad surface via an abrasive to polish, and during or before and after polishing, the roughness of the pad surface is super-thin in a non-contact state by the pad surface leveling means. A polishing method characterized in that the polishing is performed using sonic vibration.

According to the polishing apparatus having the above-mentioned configuration (1), the pad surface can be leveled by using the ultrasonic vibration in a non-contact state by the pad surface leveling means. Damage to the polished surface of the object to be polished by the dropped abrasive grains can be prevented.

Further, according to the polishing apparatus having the above configuration (2), the parallelism between the polished surface and the pad surface of the workpiece can be adjusted by the parallelism adjusting means. The in-plane uniformity of the polished state can be improved, and the processing efficiency can be improved.

Further, according to the polishing apparatus having the structure as described in the above item (3) and the polishing method having the characteristics as described in the above item (4), the pad surface leveling means uses ultrasonic vibration in a non-contact state. Since the roughness of the pad surface can be leveled, it is possible to prevent the polished surface of the polished object from being damaged by the abrasive particles that have fallen off as in the conventional case, and to adjust the polished surface of the polished object by the parallelism adjusting means. Since the parallelism with the pad surface can be adjusted, the in-plane uniformity of the polished state of the object to be polished can be improved, and the processing efficiency can be improved.

[0024]

Embodiments of the present invention will be specifically described below with reference to the drawings. 1 to 6
FIG. 1 is a diagram referred to for describing a polishing apparatus and a polishing method according to a first embodiment of the present invention.

First, the overall configuration of a polishing apparatus 10 according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a plan view of the polishing apparatus 10. As shown in the figure, a polishing apparatus 10 according to the present embodiment includes a semiconductor wafer 12 (see FIG.
A polishing unit 14 for performing polishing (see FIG. 2); a polishing agent supply unit 18 for supplying a slurry 16 (see FIG. 2) in the form of a slurry (liquid mixture of fine solids) used for polishing in the polishing unit 14; Cleaning unit 20 for cleaning and drying semiconductor wafer 12 after polishing of wafer 12
A chemical supply unit 22 for supplying a cleaning chemical such as HF or NH3 used in the cleaning unit 20, a transport unit 26 for transporting the semiconductor wafer 12 from the cassette 24A to the polishing unit 14, and a transport from the polishing unit 14 to the cassette 24B. Consists of

Next, the configuration of the polishing unit 14 in the polishing apparatus 10 having the above configuration will be described in detail with reference to FIG. As shown, the platen 30 is rotated around an axis C1 by a drive shaft 29 of the platen rotating mechanism.
A pad 32 having a pad surface 32a for polishing the polished surface (lower surface in the figure) of the semiconductor wafer 12 in cooperation with the abrasive 16 is fixed on the upper side using a double-sided tape or the like.

Above the pad 32 and eccentric from the axis C1, there is provided a polishing head 36 to which the semiconductor wafer 12 is attached below via a suction film 34 having suction and cushioning properties. ing. Polishing head 36
A retainer ring 37 is attached so as to surround the semiconductor wafer 12 so that the semiconductor wafer 12 does not come off from the lower side of the polishing head 36 and jump out.

The polishing head 36 is rotatable about an axis C2 perpendicular to the pad surface 32a of the pad 32, and is fixed to the lower end of a polishing head mounting shaft 44 that can move up and down along the axis C2. I have. On the other hand, the upper end of the polishing head mounting shaft 44 is
The polishing head rotation mechanism 46 is connected to a polishing head rotating / elevating means so as to be driven to rotate and elevate. Is fixed to the tip of a polishing head support arm 51 extending horizontally upward.

As shown in FIG. 2, above the pad 32, a slurry-like abrasive 16 is applied to the pad surface 32a.
A polishing agent supply hose 48 for supplying the polishing agent is provided.
2, and the base end thereof is connected to communicate with the abrasive supply unit of the abrasive supply unit 18 as shown in FIG.

Further, at a position above the pad 32 and separated by a predetermined circumferential angle from the axis C2 of the polishing head 36 around the axis C1, a pad surface 32a which has been roughened by polishing and has a reduced polishing function is provided. A megasonic portion 50 (pad surface leveling means) for leveling (dressing) is provided. Like the polishing head 36, the megasonic portion 50 is also fixed to the lower end of a megasonic portion elevating shaft 54 that can move up and down along an axis C3 perpendicular to the pad surface 32a of the pad 32.

On the other hand, the upper end of the megasonic unit elevating shaft 54 is connected to the megasonic unit elevating mechanism 56 so as to be driven up and down.
Extends horizontally from the upper part of the megasonic unit turning unit 58 erected on the floor surface 47 toward the upper side of the surface plate 30.
It is fixed to the tip of the megasonic support arm 60.

As shown in FIGS. 3 and 4, the megasonic portions 50 are arranged in a staggered manner in two rows on the lower surface of the holder 62 fixed to the megasonic portion elevating shaft 54 and the holder 62 in two rows. It is composed of a plurality of megasonic oscillators 64 mounted in an upright state. Here, the megasonic oscillator 64 is a device that can generate megahertz-order ultrasonic vibrations, and causes the ultrasonic vibrations to act on the pad surface 32a via the abrasive 16 during processing of the semiconductor wafer 12. In addition, it is possible to perform conditioning by leveling the pad surface 32a roughened by the ultrasonic vibration of the polishing agent 16.

The output of the megasonic (ultrasonic vibration) from the megasonic oscillator 64 is supplied to the pad surface 3 of the pad 32.
The adjustment can be made based on the rough condition of 2a.
In the megasonic unit 50, by changing the arrangement pattern of the megasonic oscillator 64, such as a staggered pattern, or increasing or decreasing the number, the polishing processing of semiconductor wafers of various film types becomes possible.

As shown in FIG. 2, the megasonic portion 50 does not directly contact the pad surface 32a of the pad 32. Therefore, the ultrasonic vibration output from the megasonic oscillator 64 of the megasonic unit 50 is transmitted through the slurry-like abrasive 16 interposed between the megasonic unit 50 and the pad surface 32a of the pad 32, and the ultrasonic vibration is applied to the pad. It will act on the surface 32a. Therefore, it is possible to polish the pad surface 32a that has been adjusted to an optimum state.

As shown in FIG. 2, in the present embodiment, a measuring device 66 for measuring the roughness of the pad surface 32a of the pad 32 is attached to the polishing head 36. Before and after polishing, pad surface 3
The shape of the radial roughness 2a can be measured by rotating the polishing head 36. This measuring instrument 6
6, the output of the megasonic unit 50 and the arrangement or number of the megasonic oscillators 64 are determined, and conditioning can be performed to equalize the roughness of the pad surface 32a under optimal processing conditions.

The measurement by the measuring device 66 gives
The parallelism between the pad surface 32a of the pad 32 and the polishing surface of the semiconductor wafer 12 on the polishing head 36 side can also be measured. Therefore, the pad surface 32a of the pad 32 and the axis C2 of the polishing head mounting shaft 44 are adjusted by the polishing head turning unit 49 (parallelism adjusting means) having a function of finely adjusting the angle of the polishing head support arm 51 of the polishing head 36. Is perpendicular to the pad surface 32a of the pad 32 and the polished surface of the semiconductor wafer 12 on the polishing head 36 side. Incidentally, the angle adjustment range of the polishing head support arm 51 by the polishing head turning unit 49 can be set to about ± several degrees.

Next, the polishing apparatus 10 having the above-described configuration will be described.
A method of polishing the semiconductor wafer 12 using the method will be described below. At the time of polishing, the platen rotating mechanism and the polishing head rotation elevating mechanism 46 are driven so that the polishing head 36 and the platen 30 are rotated.
The polishing head 36 is lowered while rotating, and
After the semiconductor wafer 12 is brought into contact with the pad surface 32a of the pad 32, the semiconductor wafer 12 is polished by further applying pressure. At the time of this polishing, the slurry-like abrasive 16 is supplied from the abrasive supply hose 48 to the pad surface 32.
Supply on a.

Then, as described above, the semiconductor wafer 1
2 is repeated to obtain the pad surface 3 of the pad 32.
When the surface 2a becomes rough, the platen rotating mechanism and the megasonic unit 50 are driven during polishing by the above-mentioned polishing head 36 or during non-polishing, and the megasonic unit 50 generates ultrasonic vibrations of the order of megahertz from the megasonic unit 50. By applying the non-contact voltage to the pad surface 32a, the polishing agent 16 is vibrated, whereby the pad surface 32a of the pad 32 can be conditioned.

According to the polishing apparatus 14 having such a configuration,
The polishing surface of the semiconductor wafer 12 and the pad surface 32a are adjusted in parallel by adjusting the angle of the polishing head support arm 51 by the polishing head turning unit 49, and the semiconductor wafer 12 held by the polishing head 36 by the polishing head rotating / lowering mechanism 46. The polishing surface can be polished by pressing the rotating pad surface 32a with the abrasive 16 interposed therebetween, and conditioning can be performed during or before and after polishing so that the roughness of the pad surface 32a is leveled by the megasonic unit 50.

Further, since the megasonic portion 50 can equalize the roughness of the pad surface 32a by the ultrasonic vibration in the non-contact state, it is possible to prevent the polished surface of the semiconductor wafer 12 from being damaged by the dropped abrasive grains as in the conventional case. Can be prevented.

The polishing head turning unit 49 can adjust the degree of parallelism between the polishing surface of the semiconductor wafer 12 and the pad surface 32a by adjusting the angle of the polishing head supporting arm 51.
a can be uniformly pressed to improve in-plane uniformity. In addition, since the force is uniformly applied to the entire processing surface, good in-plane uniformity can be obtained even when the polishing head mounting shaft 44 and the pad 32 are rotated at a high speed.

Therefore, the polishing unit 14 according to the present embodiment has the following effects. (1) Providing an optimal pad condition by using megasonic, improving the accuracy of the parallelism between the pad surface of the pad and the polishing surface of the object to be polished, and improving the in-plane uniformity by performing polishing. be able to. (2) Damage to the object to be polished (scratch etc.) due to the drop of abrasive grains (diamond), which has been a problem in the conventional pad conditioner, is eliminated, and the yield is improved. (3) Polishing by high-speed rotation of the polishing head becomes possible,
Productivity is improved. (4) Since the in-plane uniformity of the object to be polished is improved and the state of the pad shape can be ascertained for each process, the life of the pad can be extended and the cost of consumables can be reduced.

Next, a polishing apparatus according to a second embodiment of the present invention will be described with reference to FIG. As shown in the figure, in the polishing unit 14A of the polishing apparatus according to the second embodiment, the polishing head support arm 51 is fixed to the polishing head turning unit 49, and the angle of the polishing head turning unit 49 itself is fine. By finely adjusting the angle of the polishing head mounting shaft 44 by adjusting, the semiconductor wafer 12 is held parallel to the polishing surface of the semiconductor wafer 12 on the polishing head 36 side with respect to the pad surface 32a of the pad 32. Can be polished.

The other configuration of the polishing unit 14A of the polishing apparatus according to the present embodiment is substantially the same as the configuration of the polishing unit 14 of the polishing apparatus 10 according to the first embodiment. The same components are denoted by the same reference numerals, and detailed description is omitted. Such a second
According to the third embodiment, the same effect as that of the first embodiment can be obtained.

[0045]

EXAMPLE A result of a polishing experiment performed using the polishing apparatus according to the first embodiment shown in FIG. 1 will be described with reference to the table in FIG. As the conditions in this experiment, the condition at low speed (polishing head rotation speed / pad rotation speed) was 21 /
20, the same condition at medium speed was 42/40, and the same condition at high speed was 93/90. The polishing rate is 224 nm / min under low speed conditions and 366 nm / mi under medium speed conditions.
n, high-speed conditions were 550 nm / min.

The in-plane uniformity of the polished surface of the semiconductor wafer 12 was measured by measuring 49 points on the polished surface and calculated by the following formula. In-plane uniformity = ｛(MAX−MIN) / (MAX + MI)
N)｝ × 100 (%)

In the table of FIG. 6, a circle plot indicates data in the polishing apparatus according to the present embodiment, and a square plot indicates data in the conventional polishing apparatus. As is clear from the table of FIG. 6, the polishing apparatus according to the present embodiment has improved in-plane uniformity as compared with the conventional polishing apparatus. In particular, in-plane uniformity is dramatically improved at high-speed rotation, and the in-plane uniformity of the polishing apparatus according to the present invention under high-speed conditions (high-speed rotation) is lower than that under the conventional low-speed conditions (low-speed rotation). Good uniformity allows polishing under high speed conditions. Furthermore, the polishing rate can be improved under high-speed conditions, and the processing efficiency can be improved as compared with the case under low-speed conditions.

Although the embodiment has been described with reference to the case where the object to be polished is a semiconductor wafer, the object to be polished in the present invention is other than a semiconductor wafer, for example, a semiconductor wafer such as a glass plate for an LCD (liquid crystal). Any other than these may be used.

In the above embodiment, the polishing head swivel unit 49 finely adjusts the angle of the polishing head support arm 51 to thereby adjust the pad surface 32 of the pad 32.
The error in the degree of parallelism between the a and the polishing surface of the semiconductor wafer 12 on the polishing head 36 side is corrected. 32 pad surfaces 3
The parallelism between 2a and the lower surface of the megasonic unit 50 may be improved.

Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments, and various other modifications may be made based on the technical concept of the present invention. Can be changed.

[0051]

As described above, according to the polishing apparatus of the first aspect of the present invention, it is possible to equalize the roughness of the pad surface by using ultrasonic vibration in a non-contact state by the pad surface equalizing means. Therefore, it is possible to prevent the polished surface of the object to be polished from being damaged by the abrasive grains which have fallen as in the related art.

According to the polishing apparatus of the second aspect of the present invention, the parallelism between the polished surface of the object to be polished and the pad surface can be adjusted by the parallelism adjusting means. The in-plane uniformity of the state can be improved, and the processing efficiency can be improved.

Further, according to the polishing apparatus of the present invention according to claim 3 and the polishing method of the present invention according to claim 7, the pad surface leveling means uses ultrasonic vibration in a non-contact state by the pad surface leveling means. Since the roughness can be leveled, it is possible to prevent the polished surface of the polished object from being damaged by the abrasive grains that have fallen off as in the related art, and to adjust the polished surface and the pad surface of the polished object by the parallelism adjusting means. Can be adjusted, so that the in-plane uniformity of the polished state of the object to be polished can be improved and the processing efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view of a polishing apparatus according to a first embodiment of the present invention.

FIG. 2 is a front view of a polishing unit in the polishing apparatus of FIG.

FIG. 3 is an enlarged front view of a megasonic portion of the polishing apparatus of FIG.

FIG. 4 is a bottom view of the megasonic unit shown in FIG. 3;

FIG. 5 is a front view of a polishing unit of a polishing apparatus according to a second embodiment of the present invention.

FIG. 6 is a graph showing experimental results of an embodiment of the present invention relating to in-plane uniformity of an object to be polished and a conventional polishing apparatus.

FIG. 7 is a front view of a conventional polishing apparatus.

FIG. 8 is a side view and a partially enlarged view of a pad conditioner of a conventional polishing apparatus.

9 is a bottom view of the pad conditioner of FIG.

FIG. 10 is a main part side view of a polishing apparatus for explaining a conventional problem.

[Explanation of symbols]

10: polishing apparatus, 12: object to be polished, 14, 14A: polishing unit, 16: abrasive, 18: abrasive supply unit,
20: Cleaning unit, 22: Chemical supply unit, 24
A, 24B: cassette, 26: transport unit, 29: drive shaft, 30: surface plate, 32: pad, 32a: pad surface,
34 ... adsorption film, 36 ... polishing head, 37 ... retainer ring, 44 ... polishing head mounting shaft, 46 ... polishing head rotating / lowering means, 47 ... floor surface, 49 ... polishing head rotating unit, 50 ... megasonic part, 51 ... Polishing head support arm, 54: Megasonic unit elevating shaft, 56: Megasonic unit elevating mechanism, 58: Megasonic unit swivel unit, 6
0: Megasonic support arm, 62: Holder, 64
... Megasonic oscillator, 66 ... Measuring instrument, 74 ... Stripper mounting rod, 74 ... Pad, 74a ... Pad surface, 7
5: Spring, 76: Spring, 77: Punch plate, 78: Polished object, 79: Base plate, 80: Polishing head, 84: Polishing head mounting shaft, 86: First rotary elevating mechanism, 88: Polishing agent, Reference numeral 90: abrasive supply hose, 92: pad conditioner, 96: pad conditioner mounting shaft, 98: second rotary elevating mechanism, 100: retainer ring, 102: stainless steel substrate, 104: diamond dresser, 106: annular Base metal, 108: diamond abrasive grains, C1, C2, C3: axis,

Claims (7)

[Claims] A pad fixed to an upper surface of a surface plate that is driven to rotate around an axis, the pad surface having a pad surface; and a pad surface disposed above the pad at a position eccentric from a rotation axis of the surface plate and disposed on a lower surface side. A polishing head for holding an object to be polished via an abrasive between the polishing head; a polishing head rotating and lowering means for rotating and raising and lowering the polishing head to press the object to be polished against the pad surface; Pad surface leveling means eccentric from the rotation axis of the surface plate and arranged on the pad surface at a position different from the polishing head, and capable of leveling the roughness of the pad surface using ultrasonic vibration in a non-contact state A polishing apparatus comprising: 2. A pad fixed to an upper surface of a surface plate that is driven to rotate around an axis and having a pad surface; and a pad surface disposed above the pad at a position eccentric from the rotation axis of the surface plate and disposed on the lower surface side. A polishing head for holding an object to be polished via an abrasive between the polishing head; a polishing head rotating and lowering means for rotating and raising and lowering the polishing head to press the object to be polished against the pad surface; A parallelism adjusting means capable of adjusting the parallelism between the polishing surface of the object to be polished and the pad surface; and a pad arranged eccentrically from the rotation axis of the platen and arranged on the pad surface at a position different from the polishing head. A polishing apparatus comprising: a pad surface leveling means capable of leveling surface roughness. 3. A pad fixed to an upper surface of a surface plate that is driven to rotate around an axis and having a pad surface; and a pad surface disposed above the pad at a position eccentric from the rotation axis of the surface plate and disposed on the lower surface side. A polishing head for holding an object to be polished via an abrasive between the polishing head; a polishing head rotating and lowering means for rotating and raising and lowering the polishing head to press the object to be polished against the pad surface; Parallelism adjusting means capable of adjusting the parallelism between the polishing surface of the object to be polished and the pad surface, and eccentric from the rotation axis of the surface plate and arranged on the pad surface at a position different from the polishing head, A polishing apparatus comprising: pad surface leveling means capable of leveling the roughness of a pad surface by using ultrasonic vibration in a non-contact state. 4. The apparatus according to claim 1, wherein said pad surface leveling means includes a megasonic oscillator, and said megasonic oscillator applies ultrasonic vibration toward said pad surface via an abrasive. Polishing equipment. 5. A measuring device for measuring the rough shape of the pad surface is attached to the polishing head, and the polishing head is rotated by the measuring device to change the rough shape of the pad surface in the radial direction before and after polishing. The polishing apparatus according to claim 1, wherein the measurement is performed by: 6. The parallelism adjusting means can adjust the parallelism between the polishing surface of the object to be polished and the pad surface held by the polishing head by making the polishing head rotating / elevating means tiltable. The polishing apparatus according to claim 2, wherein the polishing is performed. 7. A pad fixed to an upper surface of a surface plate driven to rotate around an axis and having a pad surface; and a pad surface disposed above the pad at a position eccentric from the rotation axis of the surface plate and disposed on the lower surface side. A polishing head for holding an object to be polished via an abrasive between the polishing head; a polishing head rotating and lowering means for rotating and raising and lowering the polishing head to press the object to be polished against the pad surface; Parallelism adjusting means capable of adjusting the parallelism between the polishing surface of the object to be polished and the pad surface, and eccentric from the rotation axis of the surface plate and arranged on the pad surface at a position different from the polishing head, Using a polishing apparatus provided with a pad surface leveling means capable of leveling the roughness of the pad surface using ultrasonic vibration in a non-contact state, the polishing surface of the object to be polished by the parallelism adjusting means and the Parallel to the pad surface of the pad Adjusting the polishing head by rotating the polishing surface of the object to be polished held by the polishing head by the polishing head rotating elevating means, and pressing the pad surface through a polishing agent to polish, and during the polishing or during the polishing. A polishing method characterized in that roughness of the pad surface is leveled back and forth using ultrasonic vibration in a non-contact state by the pad surface leveling means.