WO2008082056A1

WO2008082056A1 - Diamond tool and method for manufacturing the same

Info

Publication number: WO2008082056A1
Application number: PCT/KR2007/004450
Authority: WO
Inventors: Sung Il Park; Jeong Bin Jeon; Dae Young Kim; Jeong Kim; Tae Soon Jung; Tae Jin Kim; Jin Ho Kim; Shin Kyung Kim; Kee Jeong Cheong
Original assignee: Shinhan Diamond Ind. Co., Ltd.
Priority date: 2007-01-02
Filing date: 2007-09-14
Publication date: 2008-07-10
Also published as: KR20080063588A

Abstract

The present invention relates to a diamond tool and a method of manufacturing the same. An object of the present invention is to provide a diamond tool and a method of manufacturing the same, in which diamond granules can be arranged in various form and in accurate positions, the bonding force of the diamond granules can be strengthened, and the manufacturing process can be more simplified. A method of manufacturing a diamond tool according to the present invention for achieving the object comprises the steps of forming a concave portion corresponding to a portion where a diamond granule is positioned on a surface of a shank; and attaching the diamond granule to the concave portion.

Description

DIAMOND TOOL AND METHOD FOR MANUFACTURING THE SAME

Technical field

The present invention relates to a diamond tool and a method of manufacturing the same, and more particularly, to a diamond tool and a method of manufacturing the same, in which the arrangement of diamond granules can be varied and the bonding force between the diamond granules and the shank can be improved.

Background Art In recent, semiconductor technologies have been significantly developed, together with development of other industries. As an example of the significant development, the circuit wiring in semiconductor chips becomes more highly integrated and multi-layered. In order to manufacture many chips per unit area, a method for manufacturing chips on a wafer basis has been proposed. In this way, in order to uniformly fabricate the chips to be manufactured on a wafer basis, it has been found out that the polishing work for global planarization of the wafer is of importance.

In general, a chemical mechanical polishing (CMP) process is used to polish an insulation layer, metallic wiring and circuit on a wafer. In this CMP process, a polishing pad and a wafer are compressed and relatively rotated while an abrasive for mechanical polishing and a slurry solution capable of chemical etching are interposed therebetween.

Fig. 1 is a view showing an apparatus used in a conventional CMP process, and Figs. 2 and 3 are views showing a conditioner of the apparatus used in the conventional CMP process. In the CMP process, a wafer is polished by means of a polishing device 20 for mechanical polishing and slurry 15 that is a chemical solvent for chemical polishing.

To this end, the wafer 10 is mounted on a carrier head 22 and then installed to a polishing pad 30.

At this state, the slurry 15 is supplied onto the polishing pad 30, which is then rotated. In addition, while the carrier head 22 rotates and wobbles at the same time, the wafer 10 is pressurized against the polishing pad 30 at a predetermined pressure thereby being polished.

The aforementioned wafer 10 is firmly mounted to the carrier head 22 by means of the surface tension or vacuum. A surface of the wafer 10 is brought into contact with a surface of the polishing pad 30 by means of the gravity of the carrier head 22 and an applied pressured. In this way, the wafer 10 contacts the polishing pad 30 and simultaneously the slurry 15 flows into a fine gap between the contact surfaces, so that the mechanical and chemical polishing is performed at the same time by means of abrasive particles contained in the slurry and pores (not shown) formed on the surface of the polishing pad 30. The surface of the wafer 10 can be effectively polished through simultaneous mechanical and chemical removal action.

Here, the polishing pad 30 is formed of a porous polyurethane material in order to prevent the wafer 10 from being damaged. Numerous pores are formed in the surface of the polishing pad 30. In the aforementioned process, the pressure applied between the polishing pad

30 and the wafer 10 is concentrated onto the contact surfaces therebetween to provide a relatively high surface-removal rate. Therefore, the abrasion residual is introduced into the pores on the polishing pad 30 to thereby cause a surface-pore blocking phenomenon, and thus, the polishing efficiency of the polishing pad 30 is rapidly degraded. Consequently, these problems lead to a degraded capacity of the polishing pad

30, thereby failing to achieve uniform polishing efficiency, global planarization over the entire area of the wafer 10, consistent planarization among the wafers 10 and the like.

In order to prevent the pores of the polishing pad 30 from being blocked and thus maintain a stable polishing process, the polishing pad 30 is re- worked through a separate processing means, so that the polishing capacity of the polishing pad 30 is re- activated.

A tool used for this work, which refers to a 'conditioner' or 'dresser', is generally a diamond tool, which may include a disk type conditioner 50 as shown in Fig.

2 or a rod type conditioner 60 as shown in Fig. 3. Such a conditioner 50 is configured to perform reciprocating translation and rotating motions on the surface of the polishing pad 30, so that the surface of the polishing pad 30 is finely cut off by means of a polishing plate having diamond granules fixed thereto to thereby form new pores.

The aforementioned disk type conditioner 50 has a shank 52 and a grinding portion 51 both of which have a circular shape. A fixing portion 51 formed in the shank

52 is fixed to a polishing machine (not shown) and rotates and wobbles to condition the surface of the polishing pad 30.

In addition, the aforementioned rod type conditioner 60 has a shank 62 and a grinding portion 65 both of which have a rod shape. A fixing portion 61 formed in the shank 62 is fixed in the polishing machine (not shown). The shank 62 and the grinding portion 65 are formed to have a length enough to cover the entire face of the polishing pad 30, so that the surface of the polishing pad 30 can be processed at a time. The rod type conditioner 60 can have an appropriate length depending on size or state of the polishing pad 30. The diamond grinding portion 55 or 65 includes diamond granules 56 or 66 and a bond 58 or 68 which causes the diamond granules 56 or 66 to be bonded to the shank

52 or 62.

In this way, the conditioner 50 or 60, which is a diamond tool, is used in grinding (hereinafter, referred to dressing) of the polishing pad 30, the dressed state of which causes the polishing rate of an oxide layer or metallic wiring on a wafer and a polishing rate over time to be determined. Further, in the dressing of the polishing pad

30, the polishing rate is significantly influenced by factors such as the arrangement of diamond granules and spaced distances between the diamond granules.

Meanwhile, in the aforementioned diamond tool 50 or 60, if the diamond granules 56 or 66 are irregularly arranged, the dressing of the polishing pad 30 may be irregularly performed. Further, the diamond granules weakly bonded to the bond 58 or 68 may be released off to thereby cause scratches on the wafer 10.

Therefore, the conventional diamond tool 50 or 60 is fabricated using a porous net screen so that diamond granules are arranged uniformly. Fig. 4 is a schematic view illustrating a process of manufacturing the conventional diamond tool. Referring to the figure, a net screen 70 of a nylon or polyester material is attached to the shank 52 or 62, which is to be coupled to a polishing machine.

Thereafter, diamond granules are arranged in openings of the net screen 70 and then bonded to the shank 52 or 62 through the bond 58 or 68. At this time, the net screen 70 has an opening area of about 100~300μm and an opening diameter of about

50~150μm. The particle size of the diamond granules 56 or 66 to be arranged in the openings of the net screen 70 is typically of 60-120.

In case of the conventional net screen 70, however, it is difficult to change design of the net screen, such as the opening area or the opening pattern. Accordingly, the spaced distance between the diamond granules 56 or 66 cannot be arbitrarily controlled. Furthermore, in a case where the net screen 70 is not in complete contact with the surface of the shank 52 or 62, the diamond granules 56 or 66 come to be attached to undesired portions, which causes irregular polishing or release (drop-off) of the diamond granules.

Disclosure of Invention

Technical Problem

The present invention has been made in order to solve the above problems in the art. An object of the present invention is to provide a diamond tool and a method of manufacturing the same, in which diamond granules can be arranged in various form and in accurate positions, the bonding force of the diamond granules can be strengthened,

and the manufacturing process can be more simplified.

Technical Solution

A method of manufacturing a diamond tool according to the present invention for achieving the object comprises the steps of forming a concave portion corresponding to a portion where a diamond granule is positioned on a surface of a shank; and attaching the diamond granule to the concave portion.

In addition, the concave portion may be formed through a mechanical process or an etching process. Further, the step of forming a concave portion may comprise the steps of forming a photosensitive layer on the surface of the shank; exposing the photosensitive layer to light in a desired pattern; removing an unexposed portion of the photosensitive layer; etching a portion of the shank, where the photosensitive layer is removed, to form the concave portion; and removing the photosensitive layer formed on the surface of the shank. The step of exposing may comprise the step of exposing the photosensitive layer to light using a film having an image inversed to the pattern. After the step of forming a concave portion, the method may further comprise the step of plating the concave portion. The surface of the shank may also be coated with the photosensitive layer of a thickness of 5 to 150 μm. In addition, the step of attaching a diamond granule may comprise the step of attaching the diamond granule to the shank by applying a paste thereto and performing a sintering, electrodeposition or fusion-bonding process. Further, the shank may be formed to have a diameter of 1 to 15 inches. Furthermore, the concave portion may be formed in a semi-circular, triangular, quadrangular or trapezoidal shape with an upper side opened, or in a combination thereof. The concave portion may be formed to have a depth of 10 to 200 μm. A diamond tool according to the present invention for achieving the object comprises a shank; a concave portion formed corresponding to a portion where a diamond granule is positioned on a surface of the shank; a diamond granule inserted in the concave portion; and a bonding portion formed between the concave portion and the diamond granule to attach the diamond granule to the shank. Here, the concave portion may be formed through a mechanical process or an etching process. The diamond tool may further comprise a plated layer formed by plating a surface of the concave portion. In addition, the bonding portion may be formed by being supplied in a paste form and performing a sintering process, an electrodeposition process, or a fusion-bonding process. Further, the shank may be formed to have a diameter of 1 to 15 inches. Furthermore, the concave portion may be formed in a semicircular, triangular, quadrangular or trapezoidal shape with an upper side opened, or in a combination thereof. The concave portion may also be formed to have a depth of 10 to 200 μm.

Advantageous Effects

According to a diamond tool of the present invention so configured, the pattern image formed in the film can be varied and thus the shape of concave portion formed in the surface of a shank and the arrangement of diamond granules can be arbitrarily controlled, thereby improving the grinding capacity. In addition, polished residuals and heat generated during the grinding can be discharged through a space defined between the diamond granules, thereby prevent thermal damages of products and degradation in the durability.

Further, the diamond granules are fixed to the shank with the diamond granules partially inserted into the concave portions, thereby strengthening bonding force between the shank and the diamond granules. In this way, as the bonding force between the diamond granules and the shank is increased, damages of a polishing pad caused by release of the diamond granules can be prevented. In addition, the concave portions for arranging the diamond granules are formed directly on the shank, thereby improving the product precision and also simplifying the manufacturing process to improve the productivity. It is possible to avoid defective products caused by screen prints, which may occur in a conventional method of manufacturing diamond tools using a screen.

Brief Description of the Drawings Fig. 1 is a view showing an apparatus used in a conventional CMP process.

Figs. 2 and 3 are views showing a conditioner of the apparatus used in the conventional CMP process.

Fig. 4 is a schematic view illustrating a process of manufacturing the conventional diamond tool. Fig. 5 is a plan view showing a diamond tool according to the present invention.

Fig. 6 is an enlarged sectional view of a part of the diamond tool according to the present invention.

Figs. 7 and 8 are enlarged views of concave portions formed in a shank of the diamond tool according to the present invention. Fig. 9 is an enlarged view of diamond granules in the diamond tool according to the present invention.

Fig. 10 is sectional views explaining a process of manufacturing the diamond tool according to the present invention.

Fig. 1 1 is a flow chart illustrating a method of manufacturing a diamond tool according to the present invention.

[Explanation of Reference Numerals for Major Portions Shown in Drawings]

110: Diamond tool 112: Shank

114: Concave portion 1 16: Diamond granule

1 18: Bonding portion 120: Photosensitive layer

130: Film 132: Image

Best Mode

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 5 is a plan view showing a diamond tool according to the present invention, and Fig. 6 is an enlarged sectional view of a part of the diamond tool according to the present invention. As shown in Figs. 5 and 6, in a diamond tool 110 according to the present invention, a segment containing a plurality of diamond granules 116 is attached to a surface of a shank 1 12. The shank 1 12 may be formed in the shape of a disk or lengthwise rod and rotatably coupled to a polishing machine.

As described above, the diamond tool 110 grinds the surface of a polishing member to remove foreign materials remaining in pores there of serves to form new pores, thereby re-activating the degraded polishing capacity and efficiency of the polishing member.

Here, the shank 112 is formed of a metallic material such as stainless steels or carbon steels. The diamond granule 116 generally includes an abrasion particle such as cubic boron nitride (c-BN) or silicon carbide (SiC). Further, the shank 1 12 is not particularly limited in size, but preferably has a diameter of 1 to 15 inches.

In the meantime, the diamond tool 1 10 is configured in such a way that the diamond granules 116 are attached directly to the surface of the shank 1 12.

Alternatively, the diamond tool 110 may be manufactured in such a way that after the diamond granules may be attached to a separate segment, the segment is attached to the surface of the shank 112.

To this end, concave portions 114 having predetermined size and depth are formed on the surface of the shank 1 12 at positions where the diamond granules are attached. Here, the shank 112 may be formed to have a diameter of 5 to 15 inches. In addition, the concave portion 1 14 may be formed through a mechanical machining using a cutting tool or a sand blaster, or through an etching process. Further, the concave portion is formed so as to have a depth of about 10 to 200 μm, considering the size and the like of the diamond granules to be attached. The diamond granules 1 16 are rested on the concave portions 114, respectively. In addition, a paste is supplied between the concave portions 1 14 and the diamond granules 1 16, and then a sintering, electrodeposition or fusion-bonding process is performed to form a bonding portion 118. Thus, the diamond granules 1 16 remain to be fixed to the concave portions 114 of the shank 1 12. Meanwhile, the concave portions 114 are formed in a predetermined pattern, which is previously programmed in a numerical controller or the like depending upon the positions where the diamond granules 1 16 are arranged. The programmed pattern in the numerical controller or the like can be changed to change the pattern of the concave portions 1 14. Therefore, it is possible to arrange the diamond granules 116 into any desired patterns.

Furthermore, a plated layer may be formed in the concave portions 114. The plated layer improves the bonding force with the paste, and thus the diamond granules can be more firmly bonded to the shank.

As shown in Figs. 7 and 8, which are enlarged views of the concave portions 1 14 formed in the shank 112 of the diamond tool 1 10 according to the present invention, the concave portions 114 may be formed in a regular lattice pattern, but not limited to the embodiment of the present invention. In addition, according to the aforementioned programmed pattern, the concave portions may be formed to have various pattern shapes, for example, so as to have a desired curvature or a gradually widened or narrowed spacing between the concave portions. Furthermore, the concave portion 114 may be configured in various forms so that the diamond granule 116 is easily rested, for example, a triangular, quadrangular, or trapezoidal form with an upper side opened as well as a semi-circular form with an upper side opened. Of course, a combination of such forms may be employed. Further, the diamond granule 1 16 may be of a typical shape. Alternatively, as shown in Fig. 9, a dedicated diamond granule 116 may be manufactured and used according to the shape of the shank 1 12.

Fig. 10 is sectional views explaining a process of manufacturing the diamond tool according to the present invention, and Fig. 1 1 is a flow chart illustrating a method of manufacturing a diamond tool according to the present invention. Referring to Figs. 10 and 11 , a method of manufacturing a diamond tool according to the present invention will be described.

First, a disk-type or rod type shank 112 is prepared and foreign materials stuck on the surface of the shank 112 are removed (Sl 1). The diameter of the shank 112 is not particularly limited, but in this embodiment, the shank 1 12 is preferably formed to have a diameter of 1 to 15 inches.

Thereafter, a photosensitive layer 120 is formed on the surface of the shank 112. At this time, the photosensitive layer 120 is formed of a light-curable resin, which is cured when exposed to light. The surface of the shank 112 is coated with the photosensitive layer 120 in the form of liquid or film. At this time, preferably, the photosensitive layer 120 is formed with a thickness of about 5 to 150 μm on the surface of the shank 112.

Next, a film 130 is disposed on top of the photosensitive layer 120 and exposed to a light source (S 13), wherein the film has an image inversed to a pattern by which diamond granules 116 are arranged. In this way, if the photosensitive layer 120 is exposed to a light source L, portions 122 of the photosensitive layer exposed to the light source are cured. In addition, the other portions 124 of the photosensitive layer not exposed to the light source remain soft. At this time, a white light, ultraviolet, X-ray, or laser source may be employed as light source. Light from the light source is incident on the film 130 in the form of scattered, semi-parallel or parallel light.

In the meantime, the portions 124 of the photosensitive layer 120 not exposed to the light source are removed through a development process (S 14). That is, the development process is carried out while the photosensitive layer 120 of the shank 112 is dipped in a developing solution such as 1~2 % Na₂CO₃ at about 30⁰C, whereby the soft portions not exposed to the light can be removed.

Thereafter, the shank 112 is cleansed to remove the developing solution and residuals of the photosensitive layer 124 that is removed, and an etching process is then performed (S 15). The etching process is carried out by spraying the shank 112 with an etching solution such as FeCl₃ at about 50⁰C through nozzles N. While the shank 112 passes through the etching solution sprayed through the nozzles N, the surface of the shank 1 12 exposed to the etching solution is etched to thereby form the concave portions 114. The size of the concave portion 114 can be controlled according to the size of an image 132 formed in the film 130. In addition, during the etching process, the size and depth of the concave portion 114 can be controlled by controlling the pressure, spraying time, spraying angle and the like of the etching solution being sprayed. That is, as described in this embodiment of the present invention, the concave portion 1 14 formed through the etching process can have various shapes depending on spraying characteristics of the etching solution, for example, an semi-circular, triangular, quadrangular, or trapezoidal shape with an upper side opened, or a combination thereof. Furthermore, the concave portion 114 is preferably formed to have a depth of about 10 to 200 μm considering the particle size of diamond granules 1 16.

Further, after the concave portions 114 are formed, it is preferable to further include the step of plating the surface of the concave portions 114. In this way, when a plated layer is formed on the concave portions 1 14, the bonding force can be further increased when being coupled with the paste. In addition, the plating step may be performed through both an electroplating processing and a chemical processing. Thus, even if the shank 1 12 is formed of a material having a low electrical conductivity, the plated layer can be easily formed. Accordingly, the diamond granules can be more firmly attached through an electrodeposition or fusion-bonding process. In the meantime, the concave portions 1 14 have been explained as being formed through an etching process, but may be formed through a machining process. For example, the concave portions 114 may be formed on the surface of the shank 112 using a machining tool such as a fine drill or the like.

In this way, after the concave portions 1 14 are formed in the surface of the shank 112, the photosensitive layer 120 cured and remained in the surface is removed (S16).

Meanwhile, the diamond granules 1 16 are inserted in and rested on the concave portions 114 formed in the surface of the shank 112 as described above. A paste is supplied between the concave portion 1 14 and the diamond granules 1 16. Through a high- temperature heating them, the paste, together with the concave portions 1 14 and the shank 1 12, is sintered, electrodeposited or fusion-bonded to thereby form a bonding portion 118 (Sl 7).

In the diamond tool 110 manufactured as described above, the spacing between the diamond granules 116 and the arrangement pattern thereof can be arbitrarily controlled and the positions at which the diamond granules are attached can be precisely established. Since the diamond granules 116 are firmly fixed to the shank 112, the diamond granules 116 can be prevented from being released.

Industrial Applicability Although a diamond tool and a method of manufacturing the same according to the present invention have been described in connection with the accompanying drawings, the present invention is not limited to the aforementioned embodiment and the drawings. It will be apparent that those skilled in the art can make various modifications and changes thereto within the scope of the claims.

Claims

1. A method of manufacturing a diamond tool, comprising the steps of: forming a concave portion corresponding to a portion where a diamond granule is positioned on a surface of a shank; and attaching the diamond granule to the concave portion.

2. The method as claimed in claim 1, wherein the concave portion is formed through a mechanical process or an etching process.

3. The method as claimed in claim 2, wherein the step of forming a concave portion comprises the steps of: forming a photosensitive layer on the surface of the shank; exposing the photosensitive layer to light in a desired pattern; removing an unexposed portion of the photosensitive layer; etching a portion of the shank, where the photosensitive layer is removed, to form the concave portion; and removing the photosensitive layer formed on the surface of the shank.

4. The method as claimed in claim 3, wherein the step of exposing comprises the step of exposing the photosensitive layer to light using a film having an image inversed to the pattern.

5. The method as claimed in claim 3, after the step of forming a concave portion, further comprising the step of plating the concave portion.

6. The method as claimed in claim 3, wherein the surface of the shank is coated with the photosensitive layer of a thickness of 5 to 150 μm.

7. The method as claimed in claim 1, wherein the step of attaching a diamond granule comprises the step of attaching the diamond granule to the shank by applying a paste thereto and performing a sintering, electrodeposition or fusion-bonding process.

8. The method as claimed in claim 1, wherein the shank is formed to have a diameter of 1 to 15 inches.

9. The method as claimed in claim 1, wherein the concave portion is formed in a semi-circular, triangular, quadrangular or trapezoidal shape with an upper side opened, or in a combination thereof.

10. The method as claimed in claim 1, wherein the concave portion is formed to have a depth of 10 to 200 μm.

11. A diamond tool, comprising: a shank; a concave portion formed corresponding to a portion where a diamond granule is positioned on a surface of the shank; a diamond granule inserted in the concave portion; and

a bonding portion formed between the concave portion and the diamond granule to attach the diamond granule to the shank.

12. The diamond tool as claimed in claim 11, wherein the concave portion is formed through a mechanical process or an etching process.

13. The diamond tool as claimed in claim 11, further comprising a plated layer formed by plating a surface of the concave portion.

14. The diamond tool as claimed in claim 1 1, wherein the bonding portion is formed by being supplied in a paste form and performing a sintering process, an electrodeposition process, or a fusion-bonding process.

15. The diamond tool as claimed in claim 11, wherein the shank is formed to have a diameter of 1 to 15 inches.

16. The diamond tool as claimed in claim 11, wherein the concave portion is formed in a semi-circular, triangular, quadrangular or trapezoidal shape with an upper side opened, or in a combination thereof.

17. The diamond tool as claimed in claim 11 , wherein the concave portion is formed to have a depth of 10 to 200 μm.