JP2022060241A - Manufacturing method of dresser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing pad dresser excellent in high productivity, and to provide a manufacturing method of the same.

SOLUTION: A manufacturing method of a dresser includes: preparing chip parts obtained by singulating an Si substrate having a plurality of projections on the surface; forming diamond membrane layers on the projections of the chip parts; and providing the chip parts formed with the diamond membrane layers on a base metal. The diamond membrane layers are formed by heating the chip parts in a reduced pressure, making the mixture gas of methane and hydrogen flow in the reduced pressure, and performing abnormal glow discharge.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

Embodiments of the present invention relate to a method of manufacturing a dresser.

Chemical mechanical polishing (CMP) is known as a technique for flattening an insulating film, a metal film, a polycrystalline silicon film, or the like embedded in a groove in a manufacturing process of a semiconductor device. In CMP, the surface of the polishing pad is deformed with repeated polishing and the polishing ability is lowered. Therefore, in order to suppress this deterioration, the polishing pad is dressed with a dresser at regular intervals.

Japanese Unexamined Patent Publication No. 10-71559 Japanese Patent Publication No. 2014-522739

The problem to be solved by this embodiment is to provide a method for manufacturing a dresser having excellent high productivity.

In the method for manufacturing a dresser of the embodiment, a chip portion in which a Si substrate having a plurality of protrusions on the surface is individualized is prepared, a diamond thin film layer is formed on the protrusions of the chip portion, and the above-mentioned is performed on a base metal. The chip portion on which the diamond thin film layer is formed is provided. The diamond thin film layer is formed by heating the chip portion under reduced pressure and then flowing a mixed gas of methane and hydrogen under the reduced pressure to perform an abnormal glow discharge.

The figure explaining the dresser which concerns on 1st Embodiment. The figure explaining the details of the chip part of FIG. The figure explaining the manufacturing method of the chip part of 1st and 2nd Embodiment. The figure explaining the manufacturing method of the chip part of 1st and 2nd Embodiment. Top view of the mask. The figure explaining the manufacturing method of the dresser which concerns on 1st Embodiment. The figure which shows the specific example using the dresser 1. The figure explaining the dresser which concerns on the 2nd Embodiment. The figure explaining the manufacturing method of the dresser which concerns on 2nd Embodiment.

Hereinafter, embodiments for carrying out the invention will be described.

(First Embodiment)
The dresser according to the first embodiment will be described with reference to FIGS. 1 to 7. In the description of the following drawings, the same parts are represented by the same reference numerals. However, in the drawings, the relationship between the thickness and the plane dimensions, the ratio, etc. are different from the actual ones and are schematic.

The configuration of the dresser 1 according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic plan view showing the working surface of the dresser 1 of the present embodiment. The working surface is a surface facing a dressing object such as a polishing pad.

As shown in FIG. 1, the working surface of the dresser 1 has a plurality of chip portions 20 on the base metal 10. The base metal 10 includes, for example, stainless steel (SUS) and iron, but the material thereof is not particularly limited. The chip portion 20 is formed of, for example, a Si wafer (Si substrate). The size of the chip portion 20 is, for example, 1 mm to 50 mm, but the size of the chip portion 20 is not particularly limited in the present embodiment. Further, the number of chip portions 20 of the dresser 1 of the present embodiment is not particularly limited, but the presence of a plurality of chip portions 20 facilitates uniform dressing.

Next, the details of the chip portion 20 will be described. 2A is a schematic plan view of the chip portion 20, and FIG. 2B is a schematic cross-sectional view showing a cross section taken along the line AA'of FIG. 2A.

As shown in FIGS. 2A and 2B, the chip portion 20 has a substrate 21 and a plurality of protrusions 22 on the substrate 21. The protrusion 22 has, for example, a conical shape having a radius of about 0.15 mm. In the chip portion 20, the projections 22 are arranged in a honeycomb shape, for example, in order to form as many projections 22 as possible in one chip portion 20. The protrusion 22 contains, for example, Si and is integrated with the substrate 21. As shown in FIG. 2B, a diamond thin film layer 23 is formed on the protrusion 22. The diamond thin film layer 23 is formed over the entire surface of the chip portion 20 including the protrusions 22 and the substrate 21 exposed from the protrusions 22. Further, the thickness of the diamond thin film layer 23 is formed to be substantially uniform. The arrangement of the protrusions 22 on the tip portion 20 is not limited as shown in FIG.

Next, a method of manufacturing the chip portion and the dresser of the present embodiment will be described with reference to FIGS. 3 to 6.

3 and 4 are schematic cross-sectional views showing a part of a region of a Si wafer. In the following manufacturing method, there is no bias due to the position in the Si wafer, and the structure is formed to be substantially uniform over the entire surface of the wafer.

As shown in FIG. 3A, first, a Si wafer is prepared. A base film 30 is formed on a Si wafer by using a CVD (Chemical Vapor Deposition) method. The undercoat film 30 is, for example, a TEOS film having a size of about 500 nm. In this embodiment, the Si wafer is generally used in the semiconductor manufacturing process, and is suitable because it has a constant hardness at a low price. In particular, a Si wafer having a (111) plane orientation (Si (111)) has a high Vickers hardness (Gpa) (for example, 10.6 Gpa or more) because the crystal plane orientations are uniform, and is more suitable. Furthermore, it is suitable because it has a coefficient of thermal expansion comparable to that of diamond (for example, 2.56 × 10-6 / K or less) as compared with other high-hardness materials. Note that Si (111) refers to a structure having an atomic arrangement such that the distances between Sis are equal in the crystal.

Next, the resist film 40 is formed on the undercoat film 30 as shown in FIG. 3 (b). The resist film 40 is, for example, an i-line resist film. Then, for example, the resist film is exposed by, for example, i-line through a mask as shown in FIG. However, the wavelength and the like are not particularly limited.

Next, as shown in FIG. 3C, after developing the exposed resist film 40, the undercoat film 30 is etched substantially vertically with the resist film 40 as a mask by dry etching. At this time, for example, CF4 gas or the like is used.

Next, as shown in FIG. 3D, the Si wafer is etched. For example, etching is performed using a mixed gas of SF6 = 70 secm, C4F8 = 200 sccm, and O2 = 500 sccm. When the etching is further advanced under the same conditions, the upper end of the Si wafer approaches the conical shape of the corner as shown in FIG. 4 (a). At the same time, the sizes of the resist film 40 and the undercoat film 30 are also reduced. Finally, a plurality of conical protrusions 22 are formed on the Si wafer (FIG. 4 (b)). The reduced resist film 40 and the base film 30 fall between the protrusions 22.

Next, the resist film 40 and the undercoat film 30 that have been reduced by asher or NH4OH cleaning are removed. By the above steps, a Si wafer having protrusions having a desired shape such as a conical shape can be obtained.

Next, in order to individualize the Si wafer on which the above-mentioned plurality of conical protrusions 22 are formed, dicing to a desired size is performed to obtain a chip portion 20 to be a base plate (FIG. 6A). For example, the chip portion 20 can acquire 160 chips or more in the case of a 300 mm wafer and 70 chips or more in the case of a 200 mm wafer, but the number of chips is not particularly limited.

Next, the diamond thin film layer 23 is formed on the chip portion 20. The diamond thin film layer 23 is heated to 800 degrees by placing the chip portion 20 on a grounded anode provided in a vacuum vessel, for example, by using a plasma CVD method. After that, a mixed gas of methane and hydrogen is made to flow under reduced pressure, a direct current of about 1000 V is applied to the cathode, and an abnormal glow discharge is performed to form the cathode. The above forming method is an example. As described above, the chip portion 20 having the protrusions 22 on which the diamond thin film layer 23 is formed is obtained.

Next, as shown in FIG. 6B, a resin is applied to the back surface of the projection 22 forming surface of the chip portion 20 and attached to a base metal 10 containing, for example, stainless steel (SUS) or the like. As the resin, for example, a mixture of an epoxy resin and an amine-based adhesive or a mixture of an epoxy resin and a polyamide amine-based adhesive is used. The base metal 10 has, for example, a ring-shaped structure, but is not particularly limited.

As described above, the dresser 1 of the present embodiment is completed.

Next, a specific example using the dresser 1 according to the present embodiment will be described.

FIG. 7 is a schematic diagram showing the configuration of the polishing apparatus 100, which is a specific example using the dresser 1. As shown in FIG. 7, the polishing apparatus 100 includes a dressing mechanism 2, a polishing head 3, a nozzle 4, a polishing pad 5, and a rotary table 6. In addition, there may be a configuration (partially not shown).

The rotary table 6 is supported from below by a rotary shaft (not shown), and the rotary shaft is rotationally driven by an external drive device to rotate at a predetermined speed.

A semiconductor wafer is located below the polishing head 3. The wafer is installed so that the surface to be polished faces the polishing pad 5, and is held by the polishing head 3. The polishing head 3 is provided with a mechanism that can press the wafer against the rotary table 6.

A nozzle 4 for discharging the slurry is arranged above the rotary table 6. The slurry is, for example, cerium dioxide as abrasive grains.

During the polishing process, the slurry is supplied from the nozzle 4 onto the polishing pad 5, and the polishing head 3 is lowered to bring the wafer into contact with the polishing pad 5. Then, the rotary table 6 and the polishing head 3 are rotated in the same direction. In this way, a semiconductor device is manufactured by polishing a predetermined material to be polished provided on the wafer.

Further, the dressing mechanism 2 is provided with a dresser 1 on the polishing pad 5 side. The dresser 1 is arranged so that a plurality of protrusions 22 of the chip portion 20 are located on a surface (working surface) facing the polishing pad 5. The dressing mechanism 2 rotates the dresser 1 during or before and after polishing the wafer, and sharpens the polishing pad 5 while swinging the dresser 1. By providing the dressing mechanism 2, it is possible to evenly sharpen the surface of the passing region of the wafer.

As described above, according to the dresser 1 according to the present embodiment, since the diamond thin film layer is formed on the Si substrate, a dresser resistant to a high temperature environment is formed as compared with the case where the diamond thin film layer is formed on the metal-based substrate. It will be possible to do. For example, it is possible to avoid the problem that the metal elutes when the diamond thin film layer is exposed to a high temperature environment of 800 ° C., and the carbon in the metal grows and becomes soot-like. Further, since the coefficient of thermal expansion of the Si substrate and that of diamond are about the same, it is possible to avoid the possibility that cracks occur in the diamond thin film layer due to the large difference in the coefficient of thermal expansion from that of diamond in a high temperature environment.

Furthermore, since the Si substrate is processed into a conical shape to form protrusions, it is possible to dress the polishing pad more efficiently, and compared to quadrangular pyramids and other protrusion shapes, the polishing pad between the protrusions can be dressed. It becomes difficult for waste to collect.

According to the method for manufacturing a dresser 1 according to the present embodiment, after forming protrusions on a Si wafer, dicing is performed into a plurality of chips by a dicing step, and the obtained chip portions are attached to a base metal. Therefore, the number of dressers that can be manufactured from one wafer increases, and the cost can be reduced.

(Second embodiment)
Hereinafter, the dresser according to the second embodiment will be described with reference to FIG. The dresser according to the second embodiment is different from the first embodiment in that a chip holding table is used between the base metal and the chip portion.

FIG. 8 shows the configuration of the dresser 1 according to the second embodiment. Since the structure of the chip portion 20 is the same as that of the first embodiment, the description thereof will be omitted. As shown in FIG. 8, the dresser 1 of the present embodiment has a base metal 10 and a plurality of chip holding bases 50 provided on the base metal 10, and each chip portion 20 is provided on each chip holding base 50. Have.

The chip holding table 50 includes, for example, stainless steel (SUS) and the like, but the material thereof is not particularly limited. It may be made of the same material as the base metal 10 and integrated as a part of the base metal 10. Further, the number of the chip holding tables 50 is not particularly limited, and at least one may be sufficient. In this embodiment, the chip holding table 50 may be included as a part of the base metal 10.

Next, the manufacturing method of the dresser 1 of the present embodiment will be described with reference to FIG.

First, the chip portion 20 is manufactured. Since the method of forming the chip portion 20 is the same as that of the first embodiment, the description thereof will be omitted (see FIGS. 3, 4 and 6 (a)).

Next, the chip portion 20 on which the diamond thin film layer 23 obtained by the above method is formed is coated with a resin on the back surface of the projection 22 forming surface, and the chip portion 20 is attached onto the chip holding table 50 (FIG. 9 (FIG. 9). a)). As the resin, for example, a mixture of an epoxy resin and an amine-based adhesive is used.

Finally, the chip holding table 50 to which the chip portion 20 is attached is fixed to the base metal 10 using, for example, a screw or the like. As described above, the dresser 1 of the second embodiment is completed. The fixing method is not particularly limited.

According to the dresser 1 according to the present embodiment, the dresser 1 has the same effect as that of the first embodiment, and by having the chip holding table between the chip portion and the base metal, only the chip portion acts on the polishing pad. It will be easier to make. Specifically, when the polishing pad is soft and the amount of protrusion of the tip portion from the base metal is small, the polishing pad also comes into contact with the base metal, and the pressure from the tip portion on the polishing pad can escape to the base metal. There is sex. In order to avoid the above, there is a method of increasing the thickness of the chip portion by using a thick Si wafer, but in this embodiment, since a metal chip holder is used, the cost can be reduced.

Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 Dresser 2 Dressing mechanism 3 Polishing head 4 Nozzle 5 Polishing pad 6 Rotating table 10 Base metal 20 Chip part 21 Substrate 22 Projection 23 Diamond thin film layer 30 Base film 40 Resist film 50 Chip holding table 100 Polishing device

Claims (5)

Prepare a chip part in which a Si substrate with multiple protrusions on the surface is separated into individual pieces.
A diamond thin film layer is formed on the protrusions of the chip portion to form a diamond thin film layer.
It is a method of manufacturing a dresser in which the chip portion in which the diamond thin film layer is formed is provided on a base metal.
A method for producing a dresser, wherein the diamond thin film layer is formed by heating the chip portion under reduced pressure and then flowing a mixed gas of methane and hydrogen under the reduced pressure to perform an abnormal glow discharge. A plurality of the individualized chip portions are prepared, and after forming a diamond thin film layer on the protrusions of the plurality of chip portions, the plurality of chip portions are provided on the base metal. Item 1. The method for manufacturing a dresser according to Item 1. The method for manufacturing a dresser according to claim 1 or 2, wherein the Si substrate is a Si wafer having a (111) plane orientation. The heating of the chip portion is performed by placing the chip portion on a grounded anode provided in a decompression container.
The method for manufacturing a dresser according to any one of claims 1 to 3, wherein the abnormal glow discharge is performed by applying a direct current to the cathode. The method for manufacturing a dresser according to any one of claims 1 to 4, wherein the diamond thin film layer is formed over the entire surface of the chip portion including the protrusion and the Si substrate exposed from the protrusion.

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