JP2000246618A - Dresser for polishing pad - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the stability of polishing rate of a member to be polished by a polishing pad by holding plural abrasive grains so that tips of the plural abrasive grains at a polishing pad side are unevenly positioned and while embed ding ratio of all the abrasive grains are set at a specific value or more. SOLUTION: A polishing pad dresser 78 is installed on a wafer holding part 34, and an electrodeposition layer surface 78a is arranged opposite to a polishing pad. The dresser 78 is formed of a pedestal 84 and an electrodeposition layer 86 arranged on the pedestal 84 and holding plural diamond abrasive grains 88 in relation to the pedestal 84. The diamond abrasive grains 88 include plural kinds of abrasive gains having a different grain diameter so that all the abrasive grains work at a different time. The diamond abrasive grains 88 are arranged so that bottom parts of all the diamond abrasive grains 88 contact with the top surface of the pedestal 84, and the only tip of a part of the abrasive grains is projected outside of the electrodeposition layer 86. In order to prevent a removal of the diamond abrasive grains 88, embedding ratio of all the diamond abrasive grains 88 is set at 60% or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dressing apparatus for dressing a polishing pad used for polishing a surface of a semiconductor substrate.
About.

[0002]

2. Description of the Related Art Like a CMP (chemical mechanical polishing) apparatus,
In an apparatus for polishing the surface of a semiconductor wafer using a polishing slurry, a semiconductor wafer set on a disk-shaped surface plate,
The surface of the semiconductor wafer is polished by relatively contacting and rotating a polishing pad (polishing pad). When such a polishing operation is repeated, shavings and polishing slurry of the member to be polished enter the fine holes of the polishing pad to cause clogging, and the surface (working surface) of the polishing pad is smoothed. As a result, the polishing rate gradually decreases.

[0003] For this reason, dressing of the polishing pad is performed regularly or constantly. Generally, a dresser for a polishing pad includes a plurality of diamond abrasive grains and a fixed layer that holds the abrasive grains. The diamond abrasive grains are held by the fixed layer with only the tip portions protruding toward the polishing pad.

In a conventional dresser for a polishing pad, as shown in Japanese Patent Application Laid-Open No. 9-225827, the projections of diamond abrasive grains are arranged so as to be on the same plane.

[0005]

However, in the conventional dresser for a polishing pad as described above, the dressing ability of a new dresser and a dresser after repeated dressing are significantly different. That is, since the protruding portions (tip portions) of the abrasive grains are aligned on the same surface, all the abrasive grains act simultaneously, and wear of the tip portions of all the abrasive grains progresses simultaneously. Therefore, abrasive grains having sufficient capacity for dressing the pad, that is, abrasive grains having a sufficient amount of protrusion and a sharp tip end are simultaneously eliminated.

Since the wear of all the abrasive grains proceeds simultaneously,
The dressing efficiency (the amount of pad removal) immediately after the start of using a new dresser and thereafter is greatly different. As a result, there is a disadvantage that the polishing rate by the polishing pad is not stable. Generally, in polishing such as CMP, the polishing amount (film thickness) of a wafer is controlled by the polishing time. Therefore, it is preferable that the polishing rate is stable for a long time rather than high in the initial stage.

Accordingly, it is an object of the present invention to provide a dresser for a polishing pad which contributes to stabilization of a polishing rate of a member to be polished by the polishing pad.

[0008]

In the dresser for a polishing pad according to the first aspect of the present invention, the tip positions of a plurality of abrasive grains on the polishing pad side become non-uniform, and the embedding rate of all the abrasive grains is reduced. Is held so as to be 60% or more.

In the above dresser for a polishing pad,
A plurality of types of abrasive grains having different particle sizes can be employed.
In this case, only a part of the abrasive grains is projected from the abrasive grain holding member toward the polishing pad.

In the present invention configured as described above, in the initial stage of dressing of the polishing pad, only the abrasive grains whose tip positions are located on the outermost side (polishing pad side) act. Thereafter, when the tips of the abrasive grains located on the outside thereof wear and become dull, the next abrasive grains having a sharp tip will act on the dressing. In this way, the tip position is from the outer abrasive grains to the inner tip position (the abrasive grain support surface side).
Since the abrasive grains acting on the dressing change in the order of the abrasive grains, new abrasive grains having a sharp tip can always be used. For this reason, the dressing rate of the polishing pad is stabilized, and as a result, the stability of the polishing rate of the polishing pad can be improved. Another advantage is that the life of the dresser is longer than in the conventional case.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail with reference to the following examples. In this embodiment, the present invention is applied to a CMP (chemical mechanical polishing) system.

[0012]

FIG. 1 shows an overall configuration of a CMP system including a CMP apparatus main body 12 and a wafer transfer mechanism arranged around the CMP apparatus main body 12 according to a first embodiment of the present invention. On the left side of the front surface (lower side of the paper) of the CMP apparatus main body 12, cassette ports 42a and 42b for mounting a product wafer cassette for loading and storing product wafers and a monitor wafer cassette for loading and storing monitor wafers are provided, respectively. ing.

On the right side of the front (lower side of the paper) of the CMP apparatus main body 12, a cassette port 42c for mounting a dummy wafer cassette for loading and storing dummy wafers is provided. These cassette ports 42a, 42b, 4
2c, the cassette transport device 5
8, a wafer cassette is automatically transferred, and any of the cassette ports (42a, 42b, 42
c).

A transfer robot 54 is disposed on the cassette port 42a, 42b on the CMP apparatus main body 12 side, and a transfer robot 56 is disposed on the cassette port 42c on the CMP apparatus main body 12 side. The transfer robot 54
A stage 60 for temporarily placing a wafer is disposed between the stage 60 and the stage 56. CM of transfer robot 54
A stage 48 for temporarily mounting a wafer is also arranged on the side of the P device main body 12.

A transfer robot 44 is arranged between the main body 12 of the CMP apparatus and the stage 48. Stage 4
A monitor wafer storage port (cassette) 46 capable of storing 25 wafers is arranged in the direction of measurement by the transfer robot 8 and the transfer robot 44. CMP apparatus main body 12 of transfer robot 56
On the side, a carry-out standby port (cassette) 50 is arranged. A transfer robot 52 is disposed between the carry-out standby port 50 and the CMP apparatus main body 12.

The main body 12 of the CMP apparatus has a wafer table 32 on which five wafer holders 34 are mounted. Above the wafer table 32, a polishing platen (62) to which a polishing pad (68) is attached is arranged so that five wafers can be polished simultaneously. The detailed configuration of the CMP apparatus main body 12 will be described later.

A load-side transfer arm 36a and a wafer load lift 36 are provided between the transfer robot 44 and the wafer table 32. Then, the wafer placed on the wafer load lift 36 is transferred to the transfer arm 36a.
Is loaded on the wafer holder 34. An unload-side transfer arm 40a and a wafer load lift 40 are provided between the transfer robot 52 and the wafer table 32. Then, the polished wafer on the wafer holding unit 34 is unloaded onto the wafer load lift 40 by the transfer arm 40a. Wafer load lift 4
The unloaded wafer placed on the transfer robot 5
2 to be sequentially carried into the carry-out standby port 50.

FIG. 2 shows a detailed configuration of the CMP apparatus main body 12. The CMP apparatus main body 12 includes a polishing platen 62, a polishing pad 68 attached to the lower surface of the polishing platen 62, an elastic member 66 arranged between the polishing platen 62 and the polishing pad 68, and the above-described wafer. The table 32 includes a table 32, a wafer holder 34, and a dresser 78 for a polishing pad 68. The dresser 78 also serves as a retainer for fixing the wafer 80 on the wafer holding unit 34. FIG.
Is a wafer holding unit 3 arranged on the wafer table 32.
4 shows the installation state of the dresser 78 and the dresser 78. The details of the dresser 78 will be described later.

The elastic member 66 is formed in a ring shape and is fixed to the polishing platen 62 with a double-sided tape or the like. The polishing pad 68 is similarly formed into a ring shape, and the inner peripheral ring 70 is formed.
, The outer ring 74 and the bolts 72 and 76 are pulled up and fixed to the bottom surface of the polishing platen 62. Wafer holder 3
4 is rotatably mounted on the wafer table 32.

The polishing table 62, the wafer table 32,
The wafer holding unit 34 includes rotation axes AA ′, BB ′,
It is configured to rotate around CC ′. A slurry supply hole 64 is formed in the central axis of the polishing platen 62, and the polishing slurry is supplied between the polishing pad 68 and the wafer 80 through the slurry supply hole 64.

FIG. 4A shows a dresser 78 for a polishing pad.
FIG. 4B shows an internal structure of a dresser 78 for a polishing pad. As shown in FIG. 4 (A), the polishing pad dresser 78 is provided on the wafer holder 34 so that the electrodeposition layer surface (working surface) 78a faces the polishing pad 68 (see FIG. 2). Are located in
As shown in FIG. 4B, a dresser 78 for a polishing pad.
Is a pedestal 84 (base material), a plurality of diamond abrasive grains 88 arranged on the pedestal 84, and an electrodeposition layer (plating layer) 8 for holding the diamond abrasive grains 88 with respect to the pedestal 84.
6 is comprised. The pedestal 84 and the electrodeposition layer 86 form an abrasive grain holding member.

The diamond abrasive grains 88 include a plurality of types of abrasive grains having different particle sizes, and are designed so that all the abrasive grains do not act simultaneously. That is, all the diamond abrasive grains 88 are arranged so that the bottoms thereof are in contact with the upper surface (abrasive support surface) of the pedestal 84, and only the tips of some abrasive grains protrude outside the electrodeposition layer 86. It has become.

When forming the electrodeposition layer 86,
The embedding rate of the diamond abrasive grains 88. That is,
In order to prevent detachment of the diamond abrasive grains 88, the embedding rate of all the diamond abrasive grains 88 is set to 60% or more. Here, the embedding rate is calculated as shown in FIG. That is, the embedding rate is determined by dividing the value obtained by subtracting the protrusion amount from the particle diameter of the diamond abrasive grains 88 by the particle diameter.

FIG. 6 shows the change in the number of scratches on the wafer 80 with respect to the average filling ratio of the diamond abrasive grains 88. As can be seen from the graph of FIG.
When the average filling rate of No. 8 is 60% or more, the number of scratches remaining on the wafer sharply decreases. It is considered that the scratches remaining on the wafer are caused by the diamond abrasive grains dropped from the dresser falling on the wafer. That is, by setting the embedding rate of all the diamond abrasive grains to 60% or more, the polishing can be favorably performed without the diamond abrasive grains 88 coming off (dropping).

FIG. 7A shows an example of the particle size distribution of the diamond abrasive grains 88 in this embodiment. In the figure,
The ratio of abrasive grains having a particle size of # 90 (220 to 240 μm) is set to 1
In this case, the ratio of the abrasive grains of each particle size is shown. As another example, # 60 abrasive grains are 20% and # 70 abrasive grains are 3%.
It is also possible to adopt a ratio of 0% and # 80 abrasive particles of 50%. Further, a ratio of 10% of abrasive grains of # 60, 30% of abrasive grains of # 70, and 60% of abrasive grains of # 80 can be adopted. When determining the ratio of abrasive grains of each particle size,
Care should be taken to reduce the number of large abrasive grains and increase the number of small abrasive grains.

By increasing the number of small-diameter diamond abrasive grains, the small-diameter abrasive grains can sufficiently function for dressing. In other words, when a large number of large-diameter diamond grains are present around small-diameter diamond abrasive grains, even if the tips of the large-diameter diamond grains are blunted, only the large-diameter diamond grains are applied to the polishing pad. A small-grain abrasive having a sharp tip that comes into contact cannot contribute to the dressing. If the abrasive grains having a small particle diameter and the abrasive grains having a large particle diameter are arranged at a certain distance from each other, the abrasive grains having a small particle diameter can come into contact with the polishing pad 68 by the elastic force of the polishing pad 68.

Also, care is taken so that the minimum particle size of the diamond abrasive grains 88 is about 70% or more of the maximum particle size. As a result, even when the larger abrasive particles are worn and the abrasive particles having the minimum particle diameter start to act (when they protrude to the outside of about 20 μm), the embedding rate of the abrasive particles having the maximum particle diameter is 60%. be able to. As a result, it is possible to effectively prevent the diamond abrasive grains from coming off during the long polishing operation.

FIG. 7B shows a change in the polishing rate of the wafer 80 when the diamond abrasive grains 88 having the ratio shown in FIG. 7A are used. In this experiment, the slurry was C
abot SS25, flow rate of 500 c
c / min and the temperature was 20 ° C. The polishing pad 6
As No. 8, IC 1400 manufactured by Rodale was used. The rotation speed of the polishing table 62 is set to 60 rpm, the rotation speed of the wafer table 32 is set to 50 rpm, and the polishing pad 68 is rotated.
Was polished against the wafer 80 with a load of 400 gf / cm ² . As a comparative example, data obtained by a conventional polishing apparatus using diamond abrasive grains having a uniform protrusion height was employed.

As can be seen from the graph of FIG. 7B, according to the conventional method, a high polishing rate can be obtained in the initial stage of polishing, but if the polishing is continued for a long time, the polishing rate rapidly decreases. In contrast, in the case of the present embodiment, the initial polishing rate is lower than the conventional one, but the polishing rate hardly changes even if polishing is continued for a long time.

FIGS. 8A to 8F show a part of the manufacturing process of the polishing pad dresser 78 of this embodiment. When manufacturing the dresser 78 for a polishing pad, first, as shown in FIG. 1A, diamond abrasive grains 88 having different particle diameters are arranged on the abrasive grain support surface of the pedestal 84. Next, as shown in (B), initial electrodeposition by Ni-based plating is performed, and about 5% of the maximum particle size is fixed by electrodeposition. afterwards,
As shown in (C), floating abrasive grains not fixed (electrodeposited) on the base are removed. The removal of the floating abrasive grains can be performed by a method such as physically rubbing a diamond whetstone.

Next, as shown in (D), the entire diamond abrasive grains 88 are coated with an electrodeposited layer 86 using a Ni-based plating material.
Embed in Thereafter, as shown in FIG.
Then, the tip of diamond abrasive grains 88 having a large particle diameter is projected above electrodeposition layer 86 as shown in FIG. At this time, the protrusion amount of the large-diameter diamond abrasive grains is about 20 μm.

Thereafter, the electrodeposited layer surface 78a of the dresser 78 is mirror-finished by a polishing pad (90) for mirror-finish treatment shown in FIG. As the pad 90, for example, SUBA400 manufactured by Rodale is used. As the slurry, for example, alumina-based WA # 400 abrasive grains are added to 20
Dissolve 0 g and supply 2 ml per minute. Also, the polishing load (pressure) is set to 500 gf / cm ² , and the polishing rotation speed is set to 40 rpm (diameter 55 cm platen). The electrodeposited layer surface 78a is preferably finished to a mirror surface having a Rms of 1 μm or less, for example.

FIG. 10A shows the surface condition (irregularities) of the electrodeposition layer surface 78a before the mirror surface treatment, and FIG. 10B shows the surface condition of the electrodeposition layer surface 78a after the mirror surface treatment. Is shown. For measuring the surface roughness of the electrodeposition layer surface 78a, for example,
Taristep manufactured by Rank Taylor Hobson, or the like can be used. As shown in (A), it is extremely difficult to detect the amount of protrusion of the diamond abrasive grains 88 on the electrodeposition layer surface 78a that has not been subjected to mirror finishing. That is, it cannot be distinguished which is the tip of the diamond abrasive grains 88 or the unevenness of the electrodeposited layer surface.

On the other hand, as shown in (B), in the case of this embodiment, the protruding portions of the diamond abrasive grains 88 from the electrodeposition layer surface 78a can be clearly identified. As a result, it is possible to accurately inspect whether the polishing pad dresser 78 is defective. Also, when the protrusion amount of the diamond abrasive grains 88 is adjusted while performing the inspection, the protrusion amount at that time can be accurately grasped.

FIG. 11A shows a state before using the dresser 78 for a polishing pad according to this embodiment. In the dresser 78 before use, the large-diameter diamond abrasive particles 8
8a only protrudes above the electrodeposition layer 86,
The abrasive grains 88c having a small particle diameter and the abrasive grains 88b having an intermediate particle diameter are embedded in the electrodeposition layer 86. CMP
When the polishing of the wafer 80 is started by the apparatus 12 (see FIG. 2), the polishing pad dresser 78 arranged on the outer peripheral portion of the wafer 80 acts to sharpen the polishing pad 68 in parallel with the polishing operation of the wafer 80. Dressing) is performed.

When the polishing operation is repeated, the tip of the large-diameter diamond abrasive grains 88a of the polishing pad dresser 78 becomes dull due to abrasion, as shown in FIG. At this time, the electrodeposited layer 86 also wears out at the same time, so that the sharp tip of the abrasive grains 88 b having an intermediate particle diameter starts to protrude above the electrodeposited layer 86. Further, when the polishing operation is repeated, the tips of the diamond abrasive grains 88b of the intermediate grain diameter become dull due to wear, and the sharp tips of the abrasive grains 88c of the small grain diameter project above the electrodeposition layer 86.

As described above, in this embodiment, the diamond abrasive grains 88 (88a, 88b, 88) having different particle diameters are used.
By using c), since the tip positions of the abrasive grains on the polishing pad side are made non-uniform and are sequentially projected from the electrodeposition layer surface 78a, the working abrasive grains change with the lapse of the cumulative polishing time. To go. That is, even if the polishing operation is repeatedly performed, the abrasive grains having a sharp tip sequentially projecting from the electrodeposition layer 86 act on the dressing, and the dressing ability can be kept substantially constant. Therefore, the polishing pad 6
8, the amount of sharpening (sharpening rate) becomes constant, and the polishing rate of the wafer 80 by the polishing pad 68 becomes stable.

FIGS. 12A and 12B show the change in the amount of polishing of the polishing pad 68 and the change in the polishing rate with respect to the cumulative polishing time. As is clear from the figure, even if the accumulated polishing time becomes longer, the amount of shaving of the pad and further the polishing rate do not show a large change. In the above-described example, the case where the electrodeposition layer 86 is naturally cut along with the diamond abrasive grains 88 is shown. However, the setting may be such that the electrodeposition layer 86 is forcibly cut every predetermined time. good.

FIG. 13A shows a conventional polishing pad dresser using diamond abrasive grains 100 having a uniform particle size before use. In the dresser before use, the sharp tip of the diamond abrasive grain 100 protrudes above the electrodeposition layer 102. When the polishing operation of the wafer is repeated by the CMP apparatus or the like, the tip of the diamond abrasive grain 100 becomes dull due to wear as shown in FIG. In such a state, the dressing effect of the polishing pad is significantly reduced, and it is necessary to replace the dresser itself.

FIGS. 14A and 14B show the change in the amount of polishing pad polishing and the change in polishing rate with respect to the cumulative polishing time when a conventional dresser is used. As is clear from the figure, as the cumulative polishing time becomes longer, the amount of pad shaving and further the polishing rate decrease significantly. That is, since the positions of the tips of the abrasive grains 100 are aligned, all the abrasive grains act at once, and the wear of the tips of the abrasive grains simultaneously proceeds. For this reason, the shaving amount (sharpening rate) of the polishing pad decreases with the polishing time. Since there is a correlation between the polishing rate and the shaving amount of the polishing pad, over time,
The polishing rate also decreases in accordance with the decrease in the amount of polishing of the polishing pad.

FIG. 15 is a circuit diagram of a C-type semiconductor device according to a second embodiment of the present invention.
1 shows a configuration of a main part of an MP system. Note that, in the present embodiment, the same reference numerals are given to the same or corresponding components as those in the first embodiment, and redundant description is omitted. In this CMP system, an external dresser 230 is provided on the side of the wafer table 32. The external dresser 230 includes a dressing wheel 232 having a surface facing the polishing surface side of the polishing pad 68, and a wheel guide 23 that guides the dressing wheel 232.
1 is provided. As in the first embodiment, high hardness abrasive grains such as diamond abrasive grains are embedded in the upper surface of the dressing wheel 232 (the surface facing the polishing surface).

When it is determined that sharpening of the polishing pad 68 is necessary, the polishing pad 68 (indicated by a two-dot chain line in FIG. 15)
Is horizontally moved above the wafer table 32 and is disposed above the wheel guide 231. In this state, the dressing wheel 232 is guided by the wheel guide 231 and slides while being pressed against the polishing surface (lower surface) of the polishing pad 68. At this time, the dressing wheel 232 is rotating. Thus, dressing of the polishing pad 68 is performed.

In the first embodiment, a dresser 78 for a polishing pad is arranged on the outer periphery of a wafer 80, and dressing is performed in parallel with the polishing of the wafer. On the other hand, in the second embodiment, the dresser 23 for the polishing pad is used.
0 is arranged at a position away from the wafer table 32, and the polishing pad 68 is dressed as necessary.

FIG. 16 shows another embodiment of the dresser for a polishing pad of the present invention. That is, the dressers 78 and 232 of the first and second embodiments are annular and circular, but the present invention is not limited to this, and FIGS.
As shown in the figure, a drum shape (300) or a rectangular plate shape (4
00) can also be used.

In each of the above embodiments, diamond abrasive grains having different particle diameters are employed. However, diamond abrasive grains having the same particle diameter can be used. That is, the present invention is characterized in that the positions of the tips of the abrasive grains on the polishing pad side are not uniform, whereby the tips of the abrasive grains sequentially project from the electrodeposition layer. If detachment (dropping) can be sufficiently prevented, diamond abrasive grains having a uniform particle diameter can be used. For example, the embedding depth of the abrasive grains in the electrodeposition layer can be adjusted.

For example, as shown in FIG. 17, if a step is formed on the abrasive grain supporting surface of the dresser pedestal 584, the electrodeposition layer 5 can be formed even when diamond abrasive grains 588 having the same particle diameter are used.
The position of the tip of the diamond abrasive grains 588 projecting from the surface of 86 becomes uneven. Therefore, the same effects as those of the other embodiments described above can be obtained.

[0047]

As described above, according to the present invention, the tip positions of a plurality of abrasive grains on the polishing pad side are unevenly arranged,
Since only the abrasive grains whose outer ends are located outside the abrasive grain holding member, only the projecting abrasive grains act in the initial stage of dressing the polishing pad. Thereafter, when the tip of the abrasive grain is worn and dulled, the next abrasive grain having a sharp tip portion protrudes from the abrasive grain holding member and acts on the dressing. In this way, since the abrasive grains acting on the dressing change in the order of the abrasive grains whose tip is located on the outside to the abrasive grains whose tip is located on the inside, a new abrasive grain that always has a sharp tip Can be used. For this reason, the dressing rate of the polishing pad is stabilized, and as a result, the stability of the polishing rate of the polishing pad can be improved. Also, there is an effect that the life of the dresser itself is longer than in the conventional case.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram (plan view) illustrating a configuration of a CMP system according to a first embodiment of the present invention.

FIG. 2 is a side view (partial cross section) showing a configuration of the CMP apparatus of the first embodiment.

FIG. 3 is a plan view showing a configuration of a main part of the first embodiment.

FIG. 4A is a perspective view showing a configuration of a main part of the first embodiment. FIG. 4B is a cross-sectional view showing the structure of the dresser for a polishing pad.

FIG. 5 is an explanatory diagram used for explaining the first embodiment, and shows a method of calculating an embedding rate of abrasive grains.

FIG. 6 is a graph used to explain the first embodiment, and shows a change in the number of scratches on a wafer with respect to an average burying rate of abrasive grains.

FIGS. 7A and 7B are graphs used for explaining the first embodiment. FIGS. (A) shows the ratio of diamond abrasive grains for each abrasive grain size, and (B) shows the change in the polishing rate with respect to the cumulative polishing time.

FIG. 8 is a cross-sectional view illustrating a manufacturing process of the dresser for a polishing pad of the first embodiment.

FIG. 9 is a schematic perspective view showing an apparatus used for manufacturing a dresser for a polishing pad of the first embodiment.

FIGS. 10A and 10B are graphs showing the operation of the first embodiment. (A) shows the roughness of the electrodeposited layer (plated layer) that has not been mirror-finished, and (B) shows the surface roughness of the electrodeposited layer (plated layer) that has been mirror-finished.

FIGS. 11A and 11B are cross-sectional views showing the operation of the first embodiment.

FIGS. 12A and 12B are graphs showing the operation of the first embodiment.

FIGS. 13A and 13B are cross-sectional views showing the operation of a conventional dresser.

FIGS. 14A and 14B are graphs showing the operation of a conventional dresser.

FIG. 15 is a diagram showing a CMP according to a second embodiment of the present invention;
It is a top view showing composition of an important section of a system.

FIGS. 16A and 16B are perspective views showing a shape of a dresser for a polishing pad according to another embodiment of the present invention.

FIG. 17 is a sectional view showing a structure of a dresser for a polishing pad according to still another embodiment of the present invention.

[Explanation of symbols]

 12 CMP apparatus main body 68 Polishing pad 78 Dresser for polishing pad 78a Electrodeposited layer surface 80 Wafer 86, 586 Electrodeposited layer 88, 588 Diamond abrasive grain 88a Large grain abrasive grain 88b Intermediate grain abrasive grain 88c Small grain abrasive grain 230 Dresser for polishing pad 231 Wheel guide 232 Dressing wheel

Claims (6)

[Claims] 1. A polishing pad dresser for dressing a polishing pad, comprising: a plurality of abrasive grains in contact with the polishing pad; and a tip position of the plurality of abrasive grains on the polishing pad side becomes non-uniform. A dresser for a polishing pad, comprising: an abrasive holding member that holds the plurality of abrasives so that an embedding rate of the abrasives is 60% or more. 2. The method according to claim 1, wherein the plurality of abrasive grains include a plurality of types of abrasive grains having different particle diameters, and the abrasive grain holding member has a substantially flat abrasive grain supporting surface that supports all of the abrasive grains. Thereby, the tip position of the abrasive grains on the polishing pad side is made non-uniform, and the abrasive grains are held so that only some abrasive grains protrude toward the polishing pad side. The dresser for a polishing pad according to claim 1, wherein: 3. A method according to claim 1, wherein said plurality of abrasive grains have a minimum grain size of 7
The dresser for a polishing pad according to claim 2, wherein the setting is made to be 0% or more. 4. The abrasive grains all have substantially the same particle diameter, and the abrasive grain holding member has an uneven abrasive grain support surface, whereby the polishing pad of the abrasive grains is formed. 2. The abrasive grain according to claim 1, wherein the tip is arranged to be non-uniform, and the abrasive grains are held so that only a part of the abrasive grains protrudes toward the polishing pad. Dresser for polishing pad. 5. A dresser for a polishing pad for polishing a surface of a semiconductor wafer, wherein the dresser for a polishing pad sharpens the polishing pad by relative friction with the polishing pad. And an abrasive holding member for holding the plurality of diamond abrasives, wherein the abrasive holding member has an embedding rate of all diamond abrasives of 60% or more and the polishing of the diamond abrasives. The tip position on the pad side becomes uneven,
A dresser for a polishing pad, wherein the diamond abrasive is held so that only a part of the diamond abrasive is projected toward the polishing pad. 6. The polishing pad according to claim 1, wherein a surface of said abrasive grain holding member on a side of said polishing pad is mirror-finished.
6. The dresser for a polishing pad according to 3, 4, or 5.