JPH09323255A - Polishing grit disk for polishing disk of chemical machine polisher - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix grit for polishing polishing disk on a flay base formed by a resin having resistance against chemical abrasive material firmly so as to prevent its peeling off by distributing the grit uniformly in a predetermined region on the base and bonding the grit by using adhesive having resistance against chemical abrasive material. SOLUTION: A grit disk 1 polishes a polishing pad attached on a surface of a polishing disk of a chemical machine polisher. A base 2 of the grit disk 1 has a shape like a disk of which surface of flat, is formed by a Duracon resin such as, fir example, backbite, and has excellent resistance against chemical abrasive material. Moreover, a diamond grit 3 polishes a surface of a polishing pad. The diamonds grit 3 is made into one layer and press-contact with the base 2 before it is bonded by using adhesive, and a part of it is embedded into the base 2. The diamond grit 3 is bonded on the base 2 by using bond 4 as adhesive which excels in resistance against chemical abrasive material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing plate polishing grit plate for polishing a polishing plate of a chemical machine polisher for polishing the surface of an object to be polished on a polishing plate, and in particular, grit does not fall off from a base. Technology to do.

[0002]

2. Description of the Related Art Conventionally, in the manufacture of semiconductors such as integrated circuits, when wiring each semiconductor element, for example, as shown in FIG. 9, trenches are formed on a silicon substrate 31 according to a wiring pattern.
32, and wiring metal 33 such as aluminum is formed in this groove 32.
The method of forming is generally used. Then, an integrated circuit is formed by stacking this in multiple layers.

In recent years, the degree of integration has been increasing in response to the demand for increasing the capacity of integrated circuits, but the insulating film between layers is also becoming thinner accordingly. However, in the above method, since the surface of the formed wiring metal 33 has irregularities, when the insulating film between layers is thinned, signals may interact with each other in a portion where the distance between layers is short. For this reason,
As shown in FIG. 3, a technique of forming a metal layer 34 of aluminum or the like on the entire surface of the silicon substrate 31 and polishing the metal layer 34 to form a flat wiring pattern is being adopted.

FIG. 11 shows a chemical machine polisher (hereinafter referred to as "CMP") used for polishing the metal layer 34.
Is described). As shown in this figure,
A flat polishing pad 36 is attached on the polishing platen 35. Then, for example, a fine abrasive is mixed with a chemical abrasive such as acid,
This is supplied to the surface of the polishing pad 36, and the polishing plate 35 is rotated to bring the metal layer 34 into contact with the surface of the polishing pad 36, whereby the metal layer 34 is polished with the chemical polishing agent and the polishing agent.

On the other hand, since the polishing pad 36 also wears during polishing of the metal layer 34 and the flatness of the polishing pad 36 cannot be maintained, the CMP apparatus is equipped with a polishing plate polishing apparatus for polishing the polishing pad 36. ing. Then, the polishing pad 36 is polished by the grit disc provided in this apparatus. Figure
As shown in FIG. 12, the conventional grit disk 37 is formed by uniformly distributing fine diamond grit 39 on a base 38 made of silicon and fixing the diamond grit 39 with nickel 40 which is a metal. Has been done.

Then, the grinding pad 37 is used to polish the polishing pad 36.
By polishing the surface of the pad, the flatness of the polishing pad 36 is maintained and the pad surface is also cleaned.

[0007]

By the way, in the chemical machine polisher, acid or the like is used as the chemical polishing agent, and since the diamond grit 39 of the grit disk is fixed with nickel 40 which is weak against acid, the acid on the pad surface is Nickel 40 on the grit board is corroded by the diamond grit
39 may come off the base 38. If the diamond grit 39 peels off and adheres to the pad surface, it adversely affects the silicon substrate 31 when polishing the metal layer 34 of the integrated circuit.

The present invention has been made in view of such conventional problems, and an object thereof is to provide a polishing machine polishing grit machine of a chemical machine polisher in which the grit is firmly fixed to the base and does not come off. And

[0009]

Therefore, the grit disk according to the invention of claim 1 supplies a chemical polishing agent to the disk surface of a flat and rotatable polishing disk, and the surface of the object to be polished on the polishing disk. In a grit plate for polishing the polishing plate of a chemical machine polisher for polishing, a flat base formed of a resin having resistance to the chemical polishing agent and the uniform distribution in a predetermined area on the base. A grit for polishing a polishing plate and an adhesive having resistance to a chemical polishing agent that adheres the grit to a base were provided.

According to this structure, since the base and the adhesive have resistance to the chemical polishing agent,
The grit is prevented from peeling off. In the grit board according to the invention of claim 2, the resin having resistance to the chemical polishing agent used for the base is a Duracon-based resin. With this configuration, the base is prevented from being attacked by the chemical polishing agent.

According to the third aspect of the invention,
The grit is pressure-bonded to the base so that part of the grit is embedded in the base. According to this configuration,
The grit is firmly fixed to the base. In the grit board according to the invention of claim 4, the grit is mixed with an adhesive and adhered to the base so as to form a multilayer.

According to this structure, even if the grit is worn, the new grit is exposed, so that the grit surface is regenerated and the life of the grit disc can be extended. In the grit disk according to the invention of claim 5, the grit is diamond grit. According to this structure, since it is strong and hard against a chemical polishing agent, it is most suitable for polishing a polishing plate.

In the grit machine according to the invention of claim 6,
The adhesive having resistance to the chemical polishing agent is glass bond. According to this structure, since the glass bond has excellent adhesion, the adhesion of the grit to the base is improved. In the grit board according to the invention of claim 7, the adhesive having resistance to the chemical polishing agent is a resin bond.

According to this structure, since the resin bond has excellent heat resistance, the grit does not peel off from the base even if the temperature rises due to friction during polishing.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
This will be described with reference to FIG. First, the first embodiment will be described. This is one in which a grit is pressure-bonded to a base so that a part of the grit is embedded in the base.

1 and 2 are a sectional view and a perspective view of the grit board 1 showing the first embodiment, respectively. The grit plate 1 is for polishing the polishing pad attached to the surface of the polishing plate of the CMP apparatus as described above. In these figures, the base 2 of the grit disc 1 has a disk-like shape with a flat surface, and is made of, for example, Duracon resin such as Bakelite. This Duracon resin has excellent resistance to chemical polishing agents.

The diamond grit 3 is a grit for polishing the surface of the polishing pad. Before the diamond grit 3 is bonded with an adhesive, the diamond grit 3 is made into one layer and pressure-bonded to the base 2, and a part of the diamond grit 3 is used as a base. It is embedded in the stand 2. Further, as shown in FIG. 1, the surface of the grit board 1 is formed in a checkered pattern, and the distribution area 2a on the convex side of the surface is formed.
The diamond grit 3 is evenly distributed on the surface. By distributing in a checkered pattern in this way, the polishing scraps and the like that have been polished can be evacuated to the non-distributed region 2b on the concave side, and the influence on the silicon substrate that is the object to be polished can be reduced as much as possible.

The diamond grit 3 is bonded to the base 2 with a bond 4 as an adhesive. As the material used for the bond 4, for example, a glass frit 49
%, Glass bond containing 49% of alumina (Al ₂ O ₃ ), resin bond containing 50% of phenol, 45% of cellulose, etc., both of which have excellent resistance to the chemical polishing agent. There is. When the two are compared, the resin bond has excellent heat resistance but poor adhesion, and the glass bond has excellent adhesion but weak heat. However, by installing a cooling device etc. on the polishing plate, the temperature rise can be reduced to 20
Since it can be suppressed to about 30 degrees, a glass bond having excellent adhesion is used in the present embodiment.

Next, a CMP apparatus using this grit board 1
The structure of 11 is shown in FIGS. In FIG. 3, the load station 12 is a place provided for mounting a wafer cassette (not shown). This wafer cassette has a metal layer 34 formed on a silicon substrate 31.
The unprocessed wafer as shown in 10 is stored.

The clean station 14 is a place provided to transfer the wafer 13 to the arm 15. Arm 15
Supports the wafer 13 by suction or the like at the clean station 14, and rotates in the direction of the arrow in the figure to convey the wafer 13 to each position.
The primary platen 16 is a polishing plate that polishes the metal layer of the integrated circuit.
The above-mentioned flat polishing pad is attached, and the above-mentioned cooling device or the like (not shown) for suppressing the temperature rise is arranged.

The pad conditioner 17 is for polishing the polishing pad of the primary platen 16, and the grit disc 1 is rotatably attached to the tip of the pad conditioner via a position adjusting tool 18 as shown in FIG. . And A-A '
It is designed to rotate in the direction of the arrow. The pad conditioner 17 may be configured to move the grit disc 1 in a right angle direction instead of rotating.

The slurry supply nozzle 19 is a nozzle for supplying a slurry prepared by mixing an abrasive with a chemical abrasive such as nitric acid having a high PH to the polishing pad on the primary platen 16. The final platen 20 is a rotatable flat platen and is provided to wash off the polishing agent and the like adhering to the wafer surface.

The pure water supply nozzle 21 is a nozzle for supplying pure water to the surface of the final platen 20. The unload station 22 is a place provided for mounting a wafer cassette that stores processed wafers 13. Next, the operation will be described.

The wafer 13 before polishing is set in the wafer cassette and placed on the load station 12. The wafers 13 are taken out one by one from the wafer cassette by a robot or the like and placed on the clean station 14. Then, it is adsorbed by the arm 15 and conveyed to the primary platen 16 in the arrow direction. The primary platen 16 is constantly rotated, and a slurry in which a polishing agent is mixed with a chemical polishing agent such as acid is supplied from the slurry supply nozzle 19 to the surface of the primary platen 16. Wafer 13 is arm
15 contacts the polishing pad attached to the surface of the primary platen 16 by 15, and the metal layer 34 on the surface of the wafer 13 is
It is polished by a chemical polishing agent and a fine polishing agent.

At the same time, the pad conditioner 17
Rotate in the direction of arrow AA 'on the polishing pad. Since the primary platen 16 is rotating, the grit board 1 attached to the tip of the pad conditioner 17 rotates as the primary platen 16 rotates. Further, since the base 2 and the bond 4 of the grit board 1 are resistant to a chemical polishing agent and the glass bond is used for the bond 4, the diamond grit 3 is peeled from the base 2. It is firmly fixed without falling and the polishing pad is uniformly polished by the grit disc 1. This maintains the flatness of the polishing pad and cleans its surface.

When the wafer 13 is polished to form a flat wiring pattern, the wafer 13 is carried to the final platen 20 by the arm 17. Final platen
The pure water is supplied to the surface of the final platen 20 from the pure water supply nozzle 21. Wafer 13
The surface of the wafer is cleaned on the final platen 20, and the polishing agent and the like adhering to the surface of the wafer 13 is cleaned off with pure water.

The cleaned wafer 13 is transferred to the unload station 22 by the arm 15 and stored in the wafer cassette placed on the unload station 22. According to this structure, the base 2 is formed of the Duracon resin having resistance to the chemical polishing agent, and the diamond grit 3 is bonded to the base 2 with a glass bond having excellent resistance to the chemical polishing agent and excellent adhesion. Therefore, the diamond grit 3 is firmly fixed to the base 2 and is not peeled off.

Since the diamond grit 3 is formed into a single layer and pressed, and a part of the diamond grit 3 is embedded in the base 2,
Further, the diamond grit 3 can be firmly fixed to the base 2. In the present embodiment, the diamond grit 3 is distributed on the base 2 in a checkered pattern, but the present invention is not limited to this, and any distribution may be used as long as it can be efficiently polished.

Next, a second embodiment will be described.
This one mixes diamond grit with glue,
It is configured so as to be adhered to the base so as to form a multi-layer. FIG. 5 is a sectional view showing the second embodiment. In this figure, the diamond grit is laminated in multiple layers and is adhered onto the base, and is exposed from the surface of the adhesive.

In this embodiment, as shown in FIG. 6, a donut-shaped grit disc 1 is formed by forming a hole in the central portion of the grit disc 1. As in the first embodiment, the grit disc 1 may be formed in a disc shape, but when the grit disc 1 rotates, the peripheral speeds of the central portion and the peripheral portion differ, so the grit disc 1 is formed in a donut shape. This is because the polishing pad can be more uniformly polished.

The grit disc 1 is formed by the following method. As shown in FIG. 7A, first, the base 2 is formed. That is, put the baking material 25 containing glass in the mold 26,
The bake material 25 is pressed from above. The base 2 is formed in this way in order to obtain the flatness of the base 2. Further, in order to form the doughnut-shaped grit disc 1, a mold having a concave portion formed around a central portion which becomes a hole is used as the mold 26.

Next, as shown in FIG. 7B, the diamond grit 3 and the bond 4 are put into the mold 26 from above and stirred to mix the diamond grit 3 and the bond 4. Then, pressurize and quench. By quenching, the diamond grit 3 mixes with the bond 4 and hardens. Once set, remove grit board 1 from the mold,
The grit surface of diamond grit 3 and bond 4
For example, it is polished with an abrasive such as green carbide. This green carbide is softer than diamond, so polish the bond 4 properly and use the diamond grit 3
Are uniformly exposed from the bond 4.

In this way, the grit disk 1 in which the diamond grit 3 is multi-layered is formed. As shown in FIG. 8, when diamond grit 3 is worn by using this grit disc 1, it is ground again with green carbide. As a result, the bond 4 is polished,
The diamond grit 3 on the worn surface is removed, and a new diamond grit 3'underneath is exposed to regenerate the grit surface.

As described above, according to the configuration of the second embodiment, even if the diamond grit 3 is worn, the grit surface of the grit disk 1 can be easily regenerated and the life of the grit disk 1 can be extended. be able to.

[0035]

As described above, according to the grit disk of the first aspect of the present invention, since the base and the adhesive have resistance to the chemical polishing agent, the grit peels off. Can be prevented. According to the grit disk of the invention of claim 2, the base is not attacked by the chemical polishing agent.

According to the grit disk of the third aspect of the present invention, the grit can be firmly fixed to the base. According to the grit disk of the fourth aspect, even if the grit is worn, the grit surface can be regenerated, and the life of the grit disk can be extended. The grit disk according to the invention of claim 5 is most suitable for polishing a polishing disk.

According to the grit disk of the sixth aspect of the present invention, the glass bond having excellent adhesion improves the adhesion of the grit to the base. According to the grit disk of the seventh aspect of the present invention, it is possible to prevent the grit from peeling off from the base due to a temperature rise during polishing with a resin bond having excellent heat resistance.

[Brief description of drawings]

FIG. 1 is a sectional view of a grit disk according to a first embodiment of this invention.

FIG. 2 is a perspective view of FIG. 1;

FIG. 3 is a plan view showing a CMP apparatus using the grit disk of FIG.

FIG. 4 is a perspective view of the same.

FIG. 5 is a sectional view showing a second embodiment of the present invention.

6 is a perspective view showing the shape of the grit disc of FIG.

FIG. 7 is a diagram showing a method for forming the grit disc of FIG.

FIG. 8 is a cross-sectional view for explaining the operation of FIG.

FIG. 9 is a sectional view of a wafer.

FIG. 10 is a cross-sectional view of a silicon substrate polished by a CMP apparatus.

FIG. 11 is a cross-sectional view of a main part of the CMP apparatus.

FIG. 12 is a cross-sectional view of a conventional grit board.

[Explanation of symbols]

 1 Grit board 2 Base 3 Diamond grit 4 Bond

Claims (7)

[Claims] 1. A grit plate for polishing a polishing plate of a chemical machine polisher for supplying a chemical polishing agent to a plate surface of a flat and rotatable polishing plate and polishing the surface of an object to be polished on the polishing plate. A flat base formed of a resin having resistance to a chemical polishing agent, grit for polishing the polishing plate uniformly distributed in a predetermined area on the base, and chemical polishing for adhering the grit to the base. A polishing machine polishing grit machine for a chemical machine polisher, which comprises an adhesive having resistance to the agent. 2. The polishing machine polishing grit machine for a chemical machine polisher according to claim 1, wherein the resin having resistance to a chemical polishing agent used for the base is a Duracon resin. 3. The polishing machine polishing of a chemical machine polisher according to claim 1, wherein the grit is pressure-bonded to a base so that a part of the grit is embedded in the base. Grit board. 4. A polishing plate polishing grit plate for a chemical machine polisher according to claim 1, wherein the grit is mixed with an adhesive and adhered to the base so as to form a multi-layer structure. 5. The grit is diamond grit, according to any one of claims 1 to 4.
Chemical machine Polisher polishing machine polishing grit machine described in 1. 6. The adhesive having resistance to the chemical polishing agent is a glass bond.
A polishing machine polishing grit board of the chemical machine polisher according to claim 5. 7. The adhesive having resistance to the chemical polishing agent is a resin bond.
A polishing machine polishing grit board of the chemical machine polisher according to claim 5.