JPH0929633A - Dressing tool for polishing cloth - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dressing tool for polishing, which can effectively dress a polishing cloth without falling the diamond abrasive grains. SOLUTION: A dressing tool 10 has a circular board 12 and diamond pellets 14 formed into a disk-shape smaller than this board 12. The diamond pellets 14 are respectively formed by filling the mixture of the diamond powder and the resin in a die and compressing it. The surface of this diamond pellet 14 is formed with the file-like fine projecting and recessed parts. The diamond pellets 14 are arranged with an equal space, and adhered to the base board 12 by an adhesive agent. When this dressing tool 10 is used for dressing a polishing cloth, the polishing cloth is evenly dressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dressing tool for dressing a polishing cloth used, for example, in a polishing process in a semiconductor device manufacturing process.

[0002]

2. Description of the Related Art In recent years, chemical mechanical polishing (hereinafter referred to as CMP) is generally used as a planarization technique for semiconductor devices.
The so-called polishing technique has been put to practical use. This CMP
Is an application of the polishing technique used for mirror processing of a silicon substrate, and is a technique for flattening various films formed on a silicon substrate.

In a semiconductor wafer, since a film is formed in multiple layers on a silicon substrate, the surface of the film has irregularities. In order to polish this wafer flat, a polishing cloth is pressed against the surface having irregularities while injecting a polishing liquid called slurry to process the wafer. At this time, if a relatively soft polishing cloth is used for polishing, the surface tends to be processed according to the unevenness of the surface. Recently, for example, a polishing cloth made of a hard polyurethane resin has been used, and it is possible to flatten the entire surface of the wafer regardless of the unevenness of the surface.

However, since a hard polishing cloth has a poor effect of retaining a polishing liquid and cannot be uniformly processed even when used as it is, a dressing step of lightly processing the surface of the polishing cloth with a dressing tool is required. Further, as the polishing step using such a hard polishing cloth is repeated, clogging of the polishing cloth by the polishing liquid or the polished particles occurs, and the processing uniformity is lowered. The dressing process is performed.

An example of a dressing tool used in this dressing process is shown in FIG. FIG. 9A is a plan view of the processed surface of the dressing tool 100, and FIG.
[Fig. 4] is a sectional view of the dressing tool shown in (a) taken along the line AA. As shown in FIG. 9, the dressing tool 100 has a circular metal plate 102 and a layer 104 of diamond powder, and the layer 104 of diamond powder is electrodeposited in a ring shape on one surface of the metal plate 102. .

However, when this dressing tool is used, there is a possibility that the electrodeposited diamond powder may be lost. This missing diamond powder mixes into the polishing cloth,
When a wafer is polished using this polishing cloth, there arises a problem that the coating surface of the wafer is damaged. In addition, the substrate needs to be a metal in order to electrodeposit the diamond powder, which causes a problem of metal contamination on the wafer surface.

To solve this problem, a dressing tool as shown in FIG. 10 has been proposed. 10A is a plan view of the processed surface of the dressing tool 110, and FIG. 10B is a plan view of the dressing tool shown in FIG.
It is sectional drawing cut | disconnected by the -B line. Dressing tool 11
0 is a circular substrate 112 and a diamond pellet 1 obtained by solidifying a resin containing diamond powder into a disk shape.
It has 14. The diamond pellet 114 is bonded to one surface of the substrate 112 with an adhesive. FIG.
The dressing tool 110 shown in FIG. 1 is manufactured by bonding diamond pellets to the substrate 112.
The 12 materials are not specified. Generally, the substrate 112 is made of plastic or ceramics. Therefore, metal contamination of the wafer surface by the metal substrate is prevented. However, the dressing tool 112 has an improved ability to retain a polishing liquid for a soft polishing cloth and can be effectively processed, but has a drawback that it is less effective for a hard polishing cloth.

[0008]

As described above, in a semiconductor wafer in which a coating is formed over multiple layers on a silicon substrate, a polishing process using a hard polishing cloth is performed in order to flatten the unevenness of the wafer surface. Will be needed. In order to improve the processing uniformity of this hard polishing cloth, a dressing step of lightly processing the surface of the polishing cloth to make it sharp is necessary. In this dressing step, a dressing tool containing diamond powder on the processed surface is used, but this diamond powder may be missing during dressing. For this reason, the diamond powder that has been omitted mixes into the polishing cloth, and polishing the wafer using this polishing cloth causes a problem of damaging the wafer surface.

There is also a problem that the hard polishing cloth cannot be effectively noticed. Therefore, an object of the present invention is to provide a dressing tool for a polishing abrasive cloth, which has been made in view of the above-mentioned circumstances and has no diamond powder loss and a high dressing effect.

[0010]

SUMMARY OF THE INVENTION The present invention has been made based on the above problems, and in a dressing tool for dressing a polishing abrasive cloth, it has a substrate and a filed processed end surface, and the processed end surface is exposed. A dressing tool for polishing abrasive cloth is provided, which includes a processed member adhered onto the substrate as described above.

Further, according to the present invention, in a dressing tool for dressing a polishing abrasive cloth, it has a substrate and a processed end surface in which at least one surface is formed by solidifying and molding diamond powder with a resin. There is provided a dressing tool for polishing abrasive cloth, comprising: a diamond pellet adhered onto the substrate so as to expose the processed surface.

According to this invention, the processed member having the file-shaped processed end surface is adhered onto the substrate so that the processed end surface is exposed. Therefore, there is provided a dressing tool for polishing abrasive cloth, which can effectively sharpen even a hard abrasive cloth. Therefore, by polishing the semiconductor wafer using the polishing cloth dressed with this dressing tool, the wafer surface is uniformly flattened.

Further, according to the present invention, the diamond pellets formed by solidifying diamond powder with a resin are adhered onto the substrate so as to expose the processed end face formed in a file shape. Therefore, the diamond powder does not drop when the polishing pad is sharpened, and the diamond powder that has been dropped does not mix into the polishing pad. Therefore, when a semiconductor wafer is polished using this polishing polishing cloth, the wafer film surface is not damaged by the missing diamond powder.

Further, according to the present invention, even a hard polishing polishing cloth can be efficiently dressed, so that the polishing liquid holding ability of the polishing cloth is improved. Therefore, in the polishing step, the polishing liquid is sufficiently and uniformly held between the polishing cloth and the semiconductor wafer. Therefore,
The semiconductor wafer is uniformly polished in this polishing step.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a dressing tool for polishing abrasive cloth of the present invention will be described in detail below with reference to the drawings. FIG. 4 is a view showing a dressing tool of the present invention, (a) is a plan view showing a processed surface,
(B) is sectional drawing cut | disconnected by the CC line shown in (a). As shown in FIG. 4, the dressing tool 10 has a circular substrate 12 and a diamond pellet 14 formed into a disk shape smaller than the substrate 12. The circular substrate 12 is made of, for example, plastic or ceramics, but is not particularly limited as long as it is a material other than metal. The diamond pellet 14 is formed by injecting a mixture of diamond powder and resin into a mold and compressing the mixture. The diamond pellets 14 are adhered to the substrate 12 with an adhesive at equal intervals, for example, as shown in FIG. Therefore, when the dressing tool 10 is used to dress the polishing cloth, the polishing cloth is evenly dressed.

FIG. 1 is a perspective view schematically showing a disk-shaped diamond pellet attached to the dressing tool of the present invention. Surface 1 of diamond pellet 14
No. 5 has file-like fine irregularities. The diamond pellet 14 has a diameter of about 10 to 20 m.
It is a disc having a thickness of m and a thickness of about 3 mm. The mesh size of the irregularities on the surface 15 is about 0.1 to 0.5 mm. The surface 15 having the file-like irregularities serves as a processed surface. As shown in FIG. 4, the back surface of such a diamond pellet 14 is bonded to the substrate 12 so that the processed surface is exposed in a predetermined arrangement.

FIG. 2 is an enlarged view in which a part of the file-shaped convex portion of the diamond pellet shown in FIG. 1 is enlarged. The shape of the convex portion is formed, for example, in a triangular pyramid shape as shown in FIG. Further, the convex portion of the diamond pellet 14 may have a shape as shown in FIG.

As described above, by dressing the polishing cloth with the dressing tool in which the diamond pellets having the surface of file-like irregularities are adhered on the substrate, even if the polishing cloth is hard, it can be efficiently dressed. Of course, even a soft polishing cloth can be efficiently dressed. As described above, the dressing tool according to this embodiment can provide a higher dressing effect than the conventional dressing tool regardless of the softness of the polishing pad. Therefore, the effect of holding the polishing liquid on the polishing cloth is improved, and the processing uniformity of the member to be processed such as a semiconductor wafer by the polishing cloth is improved.

Further, the diamond pellets adhered on the substrate of the dressing tool do not necessarily have to be arranged as shown in FIG. 5 to 8 are diagrams showing other arrangement examples of diamond pellets attached to the substrate.

In the dressing tool 20 shown in FIG. 5, the disc-shaped diamond pellets 14 are arranged and bonded only on the periphery of the circular substrate 12. In the dressing tool 30 shown in FIG. 6, rectangular diamond pellets 32 are radially arranged from the center of the circular substrate 12 and bonded.

In the dressing tool 40 shown in FIG. 7, the polygonal, in this embodiment, hexagonal shaped diamond pellets 42 are arranged and adhered on the circular substrate 12 in the arrangement as shown.

In the dressing tool 50 shown in FIG. 8, the entire surface of the circular substrate is covered with diamond pellets 52. Dressing tools 20, 3 shown in FIGS.
Like No. 0, 40, and 50, like the dressing tool 10 shown in FIG. 4, the surface of the diamond pellet is formed into a file-like concavo-convex shape as shown in FIGS. Therefore, these dressing tools 20, 3
Nos. 0, 40, and 50 can be efficiently dressed not only on a soft polishing cloth but also on a hard polishing cloth.

Next, the dressing process of the polishing cloth using this dressing tool will be described. This dressing step is appropriately performed when the polishing cloth before use is sharpened to improve the effect of retaining the slurry (polishing liquid), and when clogging due to adhesion of slurry particles to the polishing cloth in use occurs. Is executed.

First, the dressing tool shown in any one of FIGS. 4 to 8 is pressed against the polishing cloth attached to the surface plate. Next, at least one of the surface plate and the dressing tool is rotated to sharpen the polishing cloth. At this time, the pressing pressure of the dressing tool is 80 g per unit contact area with the polishing cloth when dressing a soft polishing cloth.
It is noticeable at low pressure. On the other hand, when dressing a hard polishing cloth, it is dressed at a high pressure of about 200 g / cm ² .

As described above, in this dressing step, the pressing force of the dressing tool pressed against the polishing cloth is set according to the hardness of the polishing cloth. Therefore, the polishing cloth is efficiently dressed according to its hardness.

[0026]

As described above, according to the present invention, the diamond pellet having the filed processed end surface is bonded onto the substrate so that the processed end surface is exposed. Therefore, there is provided a dressing tool for polishing abrasive cloth, which can effectively sharpen even a hard abrasive cloth. Therefore, by polishing the semiconductor wafer using the polishing cloth dressed with this dressing tool, the wafer surface is uniformly flattened.

Further, according to the present invention, the diamond pellets formed by hardening the diamond powder with the resin are adhered onto the substrate so that the processed end face formed in a file shape is exposed. Therefore, the diamond powder does not drop when the polishing pad is sharpened, and the diamond powder that has been dropped does not mix into the polishing pad. Therefore, when a semiconductor wafer is polished using this polishing polishing cloth, the wafer film surface is not damaged by the missing diamond powder.

Furthermore, according to the present invention, even a hard polishing polishing cloth can be dressed uniformly and efficiently, so that the polishing liquid holding ability of the polishing cloth is improved. Therefore, in the polishing step, the polishing liquid is sufficiently and uniformly held between the polishing cloth and the semiconductor wafer.
Therefore, the semiconductor wafer is uniformly polished in this polishing step.

[Brief description of drawings]

FIG. 1 is a perspective view of a diamond pellet attached to a dressing tool of the present invention.

FIG. 2 is an enlarged view of a convex portion of the diamond pellet shown in FIG.

FIG. 3 is an enlarged view of another convex portion of the diamond pellet.

FIG. 4 is a view showing a dressing tool of the present invention, (a) is a plan view showing a processed surface, and (b) is a sectional view.

FIG. 5 is a diagram showing another arrangement example of diamond pellets attached to a substrate.

FIG. 6 is a diagram showing another arrangement example of diamond pellets attached to a substrate.

FIG. 7 is a diagram showing another arrangement example of diamond pellets attached to a substrate.

FIG. 8 is a diagram showing another arrangement example of diamond pellets attached to a substrate.

9A and 9B are views showing a conventional dressing tool, wherein FIG. 9A is a plan view of a processed surface, and FIG. 9B is a sectional view.

FIG. 10 is a view showing a conventional dressing tool, (a) is a plan view of a processed surface, and (b) is a sectional view.

[Explanation of symbols]

10 ... Dressing tool 12 ... Substrate 14 ... Diamond pellet 20 ... Dressing tool 30 ... Dressing tool 32 ... Diamond pellet 40 ... Dressing tool 42 ... Diamond pellet 50 ... Dressing tool 52 ... Diamond pellet 100 ... Dressing tool 102 ... Metal substrate 104 ... Diamond Powder layer 110 ... Dressing tool 112 ... Substrate 114 ... Diamond pellet

Claims (4)

[Claims] 1. A dressing tool for dressing a polishing abrasive cloth, comprising: a substrate; and a processing member having a processed end face in the shape of a file and being bonded to the substrate so as to expose the processed end face. A dressing tool for polishing polishing cloth. 2. A dressing tool for dressing a polishing abrasive cloth, which has a substrate and a processed end surface in which at least one surface is formed into a file shape by solidifying diamond powder with a resin and exposes the processed surface. And a diamond pellet adhered onto the substrate as described above, and a dressing tool for a polishing abrasive cloth. 3. The dressing tool for a polishing abrasive cloth according to claim 2, wherein the diamond pellets are formed in a flat plate shape smaller than the substrate, and are arranged on the substrate at equal intervals. 4. The dressing tool for polishing abrasive cloth according to claim 2, wherein the diamond pellets are formed in a flat plate shape smaller than the substrate, and are arranged radially from a central portion of the substrate.