JP2003133277A - Apparatus for cleaning polishing surface of polishing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for cleaning the polishing surface of a polishing apparatus which prevents foreign particles removed from the polishing surface of a polishing table from being deposited and adhered to the inner wall of a cover that is attached in such a manner to surround injection nozzles of the polishing surface cleaning apparatus of atomizer system. SOLUTION: The apparatus for cleaning the polishing surface of the polishing apparatus in which mixed fluids 14 comprising cleaning liquid and gas are injected from the injection nozzles 7-1 to 7-4 to the polishing surface of the polishing apparatus which presses an object to be polished to the polishing surface of the polishing table (top surface of a polishing cloth 2) to polish the object to be polished by relative motions of the polishing surface and the object to be polished, wherein a cover 12 is provided that surrounds a predetermined outer region ranging from front ends the injection nozzles to the polishing surface where the mixed fluids are injected, and a space adjustment mechanism 13 is provided for adjusting a space between the front end of the cover and the polishing surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing surface of a polishing apparatus for pressing a polishing object such as a semiconductor wafer against a polishing surface of a polishing table and polishing the polishing object by relative movement of the polishing surface and the polishing object. The present invention relates to a polishing surface cleaning device of a polishing device for cleaning.

[0002]

2. Description of the Related Art Conventionally, as a polishing surface cleaning apparatus of this type of polishing apparatus, a mixed fluid of a gas such as N ₂ gas and a cleaning liquid such as pure water is sprayed from an injection nozzle onto a polishing surface (eg, a polishing cloth surface) of a polishing table. There is a so-called atomizer type polishing surface cleaning device whose main purpose is to remove foreign matters (polishing cloth slag, abrasive liquid adhered matter, etc.) on the polishing surface by jetting vigorously.
By removing the foreign matter on the polishing surface in this way, it is possible to reduce the damage (microcracks) on the surface to be polished when polishing an object to be polished such as a semiconductor wafer.

However, in the above-mentioned atomizer-type polishing surface cleaning apparatus, foreign matter removed from the polishing surface by spraying the mixed fluid scatters into the polishing chamber (polisher room). In particular, in order to prevent the sprayed mixed fluid from scattering, it adheres and accumulates on the inner wall surface of the cover that surrounds the spray nozzle, sticks, peels off during polishing over time, and falls onto the polishing surface of the polishing table. As a result, there is a concern that the surface to be polished of a polishing object such as a semiconductor wafer may be damaged (microcracks). In order to prevent the occurrence of such a defect, the cover must be regularly cleaned, but this cleaning work is troublesome and troublesome.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is provided on an inner wall surface of a cover mounted so as to surround an injection nozzle of an atomizer type polishing surface cleaning device from a polishing surface of a polishing table. An object of the present invention is to provide a polishing surface cleaning device for a polishing device in which the removed foreign matter does not adhere and accumulate and are not fixed.

[0005]

In order to solve the above problems, the invention according to claim 1 presses an object to be polished against a polishing surface of a polishing table, and the object to be polished is moved by relative movement of the polishing surface and the object to be polished. In a polishing surface cleaning device of a polishing device for injecting a mixed fluid of a cleaning liquid and a gas from the injection nozzle to the polishing surface of a polishing device for polishing an object, the injection nozzle mixes the tip to the polishing surface. The present invention is characterized in that a cover is provided to enclose a predetermined range outer circumference of the fluid ejection region, and a gap adjusting mechanism is provided to adjust a gap between the tip of the cover and the polishing surface.

As described above, the injection nozzle is provided with the cover surrounding the predetermined range outer periphery of the mixed fluid injection area from the tip to the polishing surface, and the interval adjusting mechanism capable of adjusting the interval between the tip of the cover and the polishing surface. By providing the cover, the distance between the tip of the cover and the polishing surface can be adjusted, and the mist of the mixed fluid that has rebounded on the polishing surface can be almost completely prevented from jumping out of the cover, and the polishing surface can be prevented. Most of the mixed fluid of the cleaning liquid and the gas that has rebounded in step 3 can be vigorously brought into contact with the inner wall surface of the cover, and the inner wall surface can be washed away, so that no foreign matter is attached and deposited.

According to a second aspect of the present invention, the polishing surface of a polishing apparatus for pressing the polishing object against the polishing surface of the polishing table and polishing the polishing object by relative movement of the polishing surface and the polishing object. In a polishing surface cleaning device of a polishing device for cleaning a polishing surface by injecting a mixed fluid of a cleaning liquid and a gas from an injection nozzle, a cover surrounding a predetermined range outer periphery of a mixed fluid injection area from a tip of the injection nozzle to a polishing surface. And the width between the inner wall surfaces of the cover that face each other is large on the downstream side of the mixed fluid injection and small toward the tip of the injection nozzle.

As described above, the injection nozzle is provided with a cover surrounding the outer periphery of a predetermined area of the mixed fluid injection area from the tip to the polishing surface, and the width between the inner wall surfaces of the cover facing each other is increased on the downstream side of the mixed fluid injection. Since the small size is formed toward the tip of the jet nozzle, the mixed fluid of the cleaning liquid and the gas that bounces off the polishing surface of the polishing table vigorously abuts the inner wall surface of the cover, and the inner wall surface is washed away.
No foreign matter is attached and deposited.

The invention described in claim 3 is the same as claim 1
Alternatively, in the polishing surface cleaning device of the polishing device described in the item 2, at least the inner surface of the cover is formed of a Teflon material.

Since the inner surface of the cover is made of the Teflon material as described above, the water repellency of the Teflon material can prevent foreign substances from adhering to and depositing on the inner wall surface of the cover.

The invention described in claim 4 is the same as claim 1.
The polishing surface cleaning apparatus for a polishing apparatus according to any one of items 1 to 3, wherein one or a plurality of cleaning nozzles for cleaning the inner wall surface of the cover and / or the spray nozzles are provided.

By providing the cleaning nozzle for cleaning the inner wall surface of the cover and the injection nozzle as described above, foreign matters adhering to the inner wall surface of the cover and the outer peripheral surface of the injection nozzle are positively washed and removed. It is possible to prevent adhesion and deposition on the wall surface.

The invention according to claim 5 is the same as claim 4
In the polishing surface cleaning apparatus of the polishing apparatus described in (1), there is provided control means for performing the mixed fluid injection from the injection nozzle and the cleaning liquid injection from the cleaning nozzle at different timings.

As described above, since the control means for performing the mixed fluid jetting from the jetting nozzle and the washing liquid jetting from the washing nozzle at different timings is provided, the mixed fluid jetted from the jetting nozzle and the washing nozzle are jetted. The interference of the cleaning liquid can be prevented.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a polishing apparatus having a polishing surface cleaning apparatus according to the present invention. As shown in the figure, the present polishing apparatus presses the semiconductor wafer Wf (object to be polished) held on the lower surface of the top ring 3 against the upper surface (polishing surface) of the polishing cloth 2 attached to the upper surface of the polishing table 1 to polish the polishing cloth. The semiconductor wafer Wf is polished by the relative movement of the semiconductor wafer Wf and the semiconductor wafer Wf (the relative movement of the polishing table 1 and the top ring 3).

Reference numerals 7-1 to 7-4 are for mixing the nitrogen (N ₂ ) gas from the nitrogen gas supply source 4 and the pure water from the pure water supply source 8,
An injection nozzle for injecting the mixed fluid 14 onto the polishing surface of the polishing table 1. After the polishing of one semiconductor wafer Wf is completed, the top ring 3 is retracted to a predetermined position, and the injection nozzle 7 is applied to the polishing surface of the polishing table 1 (the upper surface of the polishing cloth 2).
The mixed fluid 14 of nitrogen gas and pure water is jetted from -1 to 7-4 to clean the polishing surface. In addition, 5 is a regulator,
6 is an air operator valve, 9 is a regulator, and 10 is an air operator valve.

A plurality of injection nozzles 7-1 to 7-4 are provided.
(4 in the figure) are arranged in series in the radial direction of the polishing table 1.
Are lined up. From the injection nozzles 7-1 to 7-4,
Sea urchin N ₂The mixed fluid 14 of gas and pure water is added to the polishing table 1.
The foreign matter on the polishing surface (polishing cloth
Slag, abrasive fluid adherents, etc.) are removed. The jet of this mixed fluid 14
Since foreign matter removed from the polishing surface by scattering will scatter,
In order to prevent the mixed fluid 14 from scattering, the injection nozzle 7
A cover is attached so as to surround -1 to 7-4.

FIG. 2 is a view showing an example of the structure of the spray nozzle and the cover surrounding the spray nozzle of the polishing surface cleaning apparatus according to the present invention.
9A is a side sectional view (a sectional view taken along the line AA of FIG. 9B), and FIG. As shown in the figure, the individual injection nozzles 7-1 to 7-4 are attached to the housing 11 so as to correspond to the radial direction of the polishing table 1. As shown in the drawing, the cover 12 surrounding the spray nozzles 7-1 to 7-4 is provided on the casing 11 of the spray nozzles 7-1 to 7-4 from the tip thereof to the polishing surface of the polishing table 1 (the upper surface of the polishing cloth 2). Up to a predetermined range of the injection area of the mixed fluid 14 up to. In addition, the cover 12 is a movable part 12-
1, the movable portion 12-1 is vertically adjustable by a gap adjusting mechanism 13 capable of adjusting the gap between the tip of the movable portion 12-1 and the polishing surface of the polishing table 1 (the upper surface of the polishing cloth 2). .

As the structure of the space adjusting mechanism 13, the movable part 12-1 is moved in the vertical direction and the cover 1 is moved at a predetermined position.
Any configuration can be used as long as it can be fixed to 2.
Here, the tip has a screw 13a that is screwed into the movable portion 12-1, and the screw 13a is loosened to move the movable portion 12-1 up and down along a slit 12a provided in the side wall of the governor 12 and tighten it at a predetermined position. It can be fixed.

As described above, the gap adjusting mechanism 13 is provided, and the movable portion 12-1 of the cover 12 is attached to the tip of the movable portion 12-1 and the polishing table 1.
Since the gap with the polishing surface (upper surface of the polishing cloth 2) can be adjusted, the gap can be adjusted depending on the state of the mist of the mixed fluid 14 that has rebounded on the polishing surface (rebound speed or scattering state). Mist of the mixed fluid 14 that jumps out can be almost completely prevented, and most of the mixed fluid 14 that has rebounded on the polishing surface is vigorously brought into contact with the inner wall surface of the cover 12 (including the movable portion 12-1). Since the inner wall surface can be washed away (self-cleaning), foreign matters such as abrasive grains and shavings removed from the polishing surface do not adhere and accumulate.

FIG. 3 is a view showing another example of the structure of the spray nozzle and the cover surrounding the spray nozzle of the polishing surface cleaning apparatus according to the present invention. FIG. 3 (a) is a side sectional view (arrow BB) of FIG. (View cross section) and FIG. 6B are front cross-sectional views. As shown,
Housing 11 with individual injection nozzles 7-1 to 7-4 attached
Further, a Teflon cover 15 is provided so as to surround the mixed fluid 14 jetted from the jet nozzles 7-1 to 7-4. The width between the opposing inner wall surfaces of the cover 15 is large on the downstream side of the injection of the mixed fluid 14, and the injection nozzles 7-1 to 7-
4 is formed smaller toward the tip.

As described above, the cover 15 is formed such that the width between the inner wall surfaces facing each other is large on the downstream side of the mixed fluid jet and is small toward the tips of the jet nozzles 7-1 to 7-4. Polishing surface (upper surface of polishing cloth 2)
The mixed fluid 14 bounced off from the inner surface of the cover 15 vigorously abuts against the inner wall surface of the cover 15 to wash away the inner wall surface, so that the foreign matter removed from the polishing surface (polishing cloth slag, abrasive liquid adhered matter, etc.)
Will never be deposited.

Further, since the cover 15 is made of the Teflon material here, the water repellency of the Teflon material makes it difficult for the foreign matter to adhere to the inner wall surface of the cover 15, so that the adhesion and accumulation of the foreign matter can be prevented. Although the cover 15 is made of Teflon here, the same effect can be obtained even if only the inner wall surface of the cover 15 is made of Teflon or coated with Teflon material.

FIG. 4 is a view showing another example of the structure of the spray nozzle and the cover surrounding the spray nozzle of the polishing surface cleaning apparatus according to the present invention. FIG. 4 (a) is a side sectional view (C- of FIG. 4 (b)). (C arrow cross section), the same figure (b) is a right sectional view. As shown,
Housing 11 with individual injection nozzles 7-1 to 7-4 attached
Further, a cover 16 is provided so as to surround the mixed fluid 14 jetted from the jet nozzles 7-1 to 7-4. The cover 1
The width dimension between the facing inner wall surfaces of the portion 16-1 surrounding the mixed fluid 14 of No. 6 is large on the downstream side of injection of the mixed fluid 14 and is small toward the tips of the injection nozzles 7-1 to 7-4. There is.

Further, in FIG. 4B, 17 is a cleaning nozzle, and by spraying the cleaning liquid 18 from the cleaning nozzle 17, the spray nozzles 7-1 to 7-4 and the cover 1 are provided.
The inner wall surface of the portion 16-1 surrounding the mixed fluid 14 of No. 6 can be washed. The cleaning nozzle 1
The cleaning liquid sprayed from 7 may be a cleaning liquid such as pure water, or a cleaning liquid such as pure water and a nitrogen (N ₂ ) gas such as the mixed fluid 14 sprayed from the spray nozzles 7-1 to 7-4. A mixed fluid of gas may be used. The cleaning nozzles 17 are provided in an appropriate number for cleaning the outer peripheral surfaces of the injection nozzles 7-1 to 7-4 and the inner wall surface of the portion 16-1 of the cover 16 surrounding the mixed fluid 14.

The cleaning nozzle 17 is provided with an angle adjusting mechanism (not shown) for freely adjusting the injection angle of the cleaning liquid 18 in the vertical plane and in the horizontal plane on the base portion 17-1 and performs the above cleaning at an optimum position. Can be set to Also, the base 17-1
Is fixed to a holder 19, and the holder 19 is fixed to the outside of the cover 16 via a packing 20.

By providing the cleaning nozzles 17 for cleaning the inner wall surfaces of the injection nozzles 7-1 to 7-4 and the portion 16-1 of the cover 16 surrounding the mixed fluid 14 as described above, the injection nozzles 7-1 to 7-7 are provided. The foreign matter adhering to the outer peripheral surface of -4 or the inner wall surface of the cover 16 can be positively washed and removed.

Further, in order to prevent the mixed fluid 14 jetted from the jet nozzles 7-1 to 7-4 and the washing liquid 18 jetted from the washing nozzle 17 from interfering with each other, control means for jetting at different timings (not shown). No) is provided.

By providing the control means for performing the mixed fluid injection from the injection nozzles 7-1 to 7-4 and the cleaning liquid injection from the cleaning nozzle 17 at different timings as described above, the injection nozzles 7-1 to 7-1 are provided. It is possible to prevent interference between the mixed fluid 14 ejected from -4 and the cleaning liquid 18 ejected from the cleaning nozzle 17, and it is possible to prevent the cleaning efficiency from decreasing due to the interference.

FIG. 5 is a diagram showing the operation timing when the polishing surface cleaning device shown in FIG. 4 is attached to the polishing device shown in FIG. As shown, Top Ring (T / R) 3
The semiconductor wafer Wf to be polished is loaded on the
Load ”) and polish the semiconductor wafer Wf (“ W
f polishing ”). After polishing, the top ring (T / R) 3 is cleaned (“T / R cleaning”), and the semiconductor wafer Wf is removed from the top ring (T / R) 3 (“release”).
The top ring (T / R) 3 is in a standby state.

At the same time as the cleaning of the top ring (T / R) 3 ("T / R cleaning"), the cleaning liquid 18 is sprayed from the cleaning nozzle 17 to clean the outer peripheral surfaces of the spray nozzles 7-1 to 7-4. At the same time, the inner wall surface of the portion 16-1 of the cover 16 surrounding the mixed fluid 14 is washed (“nozzle washing”). Then, the mixed fluid 14 is sprayed from the spray nozzles 7-1 to 7-4 to clean the polishing surface, that is, the cleaning surface of the polishing table 1 (the upper surface of the polishing cloth 2) (“polishing surface cleaning”). This polishing surface cleaning time tx is arbitrarily set.

After completion of polishing of the semiconductor wafer Wf for one polishing cycle period T as described above, the top ring (T / R)
"T / R cleaning" for cleaning No. 3 and spray nozzles 7-1 to 7-1
-4 around the outer peripheral surface of the cover 16 and the mixed fluid 14 of the cover 16
"Nozzle cleaning" for cleaning the inner wall surface of 6-1 is performed in synchronization. Further, the "nozzle cleaning" and the "polishing surface cleaning" for cleaning the polishing surface of the polishing table 1 are performed at different timings. By thus performing the "nozzle cleaning" and the "polishing surface cleaning" at different timings, the injection nozzle 7-
The mixed fluid 14 jetted from 1 to 7-4 and the cleaning nozzle 1
It is possible to prevent the interference of the cleaning liquid 18 sprayed from 7.

In the above embodiment, the polishing apparatus for polishing the semiconductor wafer Wf as the polishing object has been described as an example, but the polishing apparatus for polishing the polishing object other than the semiconductor wafer Wf also has the polishing according to the present invention. Of course, the surface cleaning device can be applied.

Although the polishing cloth has been described as an example of the material forming the polishing surface, a so-called fixed abrasive, that is, abrasive particles (such as CeO ₂ ) is used as a binder (thermoplastic or thermal) as the material forming the polishing surface. Of course, it may be integrated with a curable resin).

[0035]

As described above, according to the invention described in each claim, the following excellent effects can be obtained.

According to the first aspect of the present invention, the injection nozzle is provided with a cover for enclosing a predetermined range outer periphery of the mixed fluid injection region from the tip to the polishing surface, and the gap between the tip of the cover and the polishing surface. The gap between the tip of the cover and the polishing surface can be adjusted by providing a gap adjusting mechanism that can completely prevent the mist of the mixed fluid rebounding from the polishing surface from jumping out of the cover. Since most of the mixed fluid of the cleaning liquid and the gas that bounces off on the polishing surface can be vigorously brought into contact with the inner wall surface of the cover and the inner wall surface can be washed away, no foreign matter is attached and deposited.

According to the second aspect of the present invention, the injection nozzle is provided with a cover surrounding the outer periphery of a predetermined area of the mixed fluid injection area from the tip to the polishing surface, and the width dimension between the inner wall surfaces facing each other of the cover. Since the mixed fluid jetting downstream side is formed to be large toward the tip of the jet nozzle, the mixed fluid of the cleaning liquid and the gas that bounces off the polishing surface of the polishing table vigorously contacts the inner wall surface of the cover, Since it is washed away, no foreign matter is deposited and deposited.

According to the third aspect of the present invention, since the inner surface of the cover is made of the Teflon material, the water repellency of the Teflon material can prevent foreign substances from adhering and depositing on the inner wall surface of the cover.

According to the fourth aspect of the present invention, by providing the cleaning nozzle for cleaning the inner wall surface of the cover and the injection nozzle, foreign matters attached to the inner wall surface of the cover and the outer peripheral surface of the injection nozzle are positively cleaned and removed. Therefore, it is possible to prevent foreign matter from adhering and accumulating on the inner wall surface of the cover.

According to the fifth aspect of the present invention, since the control means for performing the mixed fluid jetting from the jet nozzle and the cleaning liquid from the washing nozzle at different timings is provided, the mixture jetted from the jetting nozzle is mixed. It is possible to prevent interference between the fluid and the cleaning liquid sprayed from the cleaning nozzle.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a polishing apparatus equipped with a polishing surface cleaning apparatus according to the present invention.

FIG. 2 is a diagram showing a configuration example of a spray nozzle and a cover surrounding the spray nozzle of the polishing surface cleaning apparatus according to the present invention, FIG.
Is a side sectional view (a sectional view taken along the line AA of (b)), and FIG.

FIG. 3 is a diagram showing another configuration example of the spray nozzle and the cover surrounding the spray nozzle of the polishing surface cleaning apparatus according to the present invention, in which FIG. 3 (a) is a side sectional view (cross section taken along the line BB of FIG. 3 (b)). ), The same figure (b) is a front sectional view.

FIG. 4 is a view showing another configuration example of the spray nozzle and the cover surrounding the spray nozzle of the polishing surface cleaning apparatus according to the present invention, FIG.
Is a side sectional view (a sectional view taken along the line C-C of (b)), and FIG.

5 is a diagram showing an operation timing when the polishing surface cleaning device shown in FIG. 4 is attached to the polishing device shown in FIG.

[Explanation of symbols]

1 polishing table 2 polishing cloth 3 top rings 4 Nitrogen gas supply source 5 regulator 6 Air operator valve 7-1 to 7-4 injection nozzle 8 Pure water supply source 9 regulator 10 Air operator valve 11 housing 12 covers 13 Interval adjustment mechanism 14 Mixed fluid 15 cover 16 covers 17 Washing nozzle 18 Cleaning solution 19 holder 20 packing

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoshi Okamura             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION F-term (reference) 3C047 FF08 FF19                 3C058 AA09 AC05 DA17

Claims (5)

[Claims] 1. A mixture of a cleaning liquid and a gas from an injection nozzle to the polishing surface of a polishing apparatus that presses an object to be polished against the polishing surface of a polishing table and polishes the object to be polished by relative motion of the polishing surface and the object to be polished. In a polishing surface cleaning device of a polishing device for injecting a fluid and cleaning the polishing surface, the injection nozzle is provided with a cover surrounding a predetermined range outer periphery of a mixed fluid injection region from the tip to the polishing surface,
A polishing surface cleaning apparatus for a polishing apparatus, which is provided with a space adjusting mechanism capable of adjusting a space between the tip of the cover and the polishing surface. 2. A mixture of a cleaning liquid and a gas from an injection nozzle to the polishing surface of a polishing apparatus that presses the polishing object against the polishing surface of the polishing table and polishes the polishing object by the relative movement of the polishing surface and the polishing object. In a polishing surface cleaning device of a polishing device for injecting a fluid and cleaning the polishing surface, the injection nozzle is provided with a cover surrounding a predetermined range outer periphery of a mixed fluid injection region from the tip to the polishing surface,
A polishing surface cleaning apparatus for a polishing apparatus, wherein a width dimension between opposed inner wall surfaces of the cover is formed so that a downstream side of the mixed fluid is large and small toward a tip of the injection nozzle. 3. The polishing surface cleaning apparatus for a polishing apparatus according to claim 1, wherein at least an inner surface of the cover is made of a Teflon (registered trademark) material. 4. The polishing surface cleaning apparatus of the polishing apparatus according to claim 1, wherein one or a plurality of cleaning nozzles for cleaning the inner wall surface of the cover and / or the injection nozzle are provided. A polishing surface cleaning device for a polishing device. 5. The polishing surface cleaning apparatus of the polishing apparatus according to claim 4, further comprising a control means for performing the mixed fluid injection from the injection nozzle and the cleaning liquid injection from the cleaning nozzle at different timings. A polishing surface cleaning device for a polishing device.