WO2018043054A1

WO2018043054A1 - Dresser

Info

Publication number: WO2018043054A1
Application number: PCT/JP2017/028633
Authority: WO
Inventors: 一将浅井; 智史 ▲高▼野
Original assignee: 信越半導体株式会社
Priority date: 2016-08-31
Filing date: 2017-08-07
Publication date: 2018-03-08
Also published as: TW201811507A; JP2018034257A

Abstract

The present invention provides a dresser provided with a diamond plate on which diamond abrasive grains, for dressing upper and lower polishing cloths of a double-side polishing machine, are fixed, the dresser being characterized by being provided with: an inner ring (2); an outer ring (3) having a larger diameter than the inner ring, disposed to be concentric with the inner ring and outside the inner ring, and having a connection part connected to the inner ring; and a diamond plate (5) disposed between the inner ring and the outer ring, having a side surface retained by an outer peripheral portion of the inner ring and an inner peripheral portion of the outer ring, and having a greater thickness than the inner ring and the outer ring, wherein the diamond plate is retained in a non-fixed manner in the thickness direction of the diamond plate by the outer peripheral portion of the inner ring and the inner peripheral portion of the outer ring and can float in the thickness direction of the diamond plate. Thus, there is provided a dresser having a high thickness precision, enabling uniform dressing to be efficiently performed, and having a lighter weight than conventional dressers.

Description

dresser

The present invention relates to a dresser for a polishing cloth of a double-side polishing apparatus.

Conventionally, in the manufacture of a silicon wafer, after a silicon single crystal ingot is sliced to produce a silicon wafer, each process such as chamfering, lapping, and etching is sequentially performed on the wafer, and then at least one main surface of the wafer is mirror-finished. Polishing is performed. In this polishing process, a single-side polishing apparatus that polishes one side of a wafer and a double-side polishing apparatus that simultaneously polishes both sides of the wafer may be used.

The double-side polishing apparatus usually includes an upper surface plate and a lower surface plate to which polishing cloth made of urethane pad or the like is attached, and a sun gear 101 is provided at the center of the double-side polishing device 100 as shown in FIG. The outer peripheral portion has a planetary gear structure in which internal gears 102 are respectively arranged. When polishing the semiconductor wafer W, the semiconductor wafer W is inserted and held in the wafer holding hole 104 formed in the carrier 103, and the polishing slurry is supplied to the semiconductor wafer W from above, and the upper and lower surface plates are moved. While rotating, the opposing polishing cloths of the upper surface plate and the lower surface plate are pressed against both the front and back surfaces of the semiconductor wafer W, and the carrier 103 is rotated and revolved between the sun gear 101 and the internal gear 102 so that both surfaces of each semiconductor wafer W are rotated. Can be polished simultaneously.

While the double-side polishing apparatus can simultaneously polish both sides of the wafer, there is a problem that the wafer shape gradually changes if polishing is continued using the same polishing cloth. This is mainly due to the life of the polishing cloth, which is affected by changes in the compressibility of the polishing cloth, clogging, etc., and the wafer shape becomes different as the use frequency increases. Therefore, in order to prevent such a change in the shape of the wafer, dressing on the surface of the polishing pad is performed regularly or constantly.

As the dresser, for example, as in Patent Document 1, a diamond electrodeposition plate made of a plurality of fan-shaped members in which diamond is electrodeposited on a stainless steel plate is used on the outer periphery of a disk-shaped base portion. it can. A plurality of fan-shaped members of the diamond electrodeposition plate are detachably installed on the surface of the outer peripheral portion of the base portion with screws, and the diamond electrodeposition plate is thus installed in a ring shape on the outer peripheral portion of the base portion Can be used. By bringing the diamond abrasive grains of the diamond electrodeposition plate into sliding contact with the polishing cloth, the surface of the polishing cloth can be roughened and clogging can be removed.

In addition, as shown in FIG. 7, the base portion 201 is formed in a ring shape, and diamond is electrodeposited directly on the upper surface of the base portion (diamond electrodeposition portion 202), and the diamond electrodeposition portion 202 is arranged in a ring shape. A dresser 200 or the like can also be used.

JP 2014-147993 A

For example, in a conventional dresser such as Patent Document 1, when the diamond electrodeposition plate is fixed to the surface of the outer peripheral portion of the base portion with screws, the surface accuracy of the base portion and the accuracy of attaching to the base portion with screws are high. It was necessary. That is, if these precisions are poor, the dresser's dressing surface precision will deteriorate, and some of the diamond abrasive grains will not come into contact with the surface of the polishing cloth, resulting in poor dressing efficiency or even uniform dressing. There was a problem to do.

In addition, the dresser with diamond electrodeposited on the surface of the base part was distorted during the electrodeposition of diamond as described below, and the surface accuracy deteriorated. That is, in the diamond electrodeposition operation, blasting or the like is performed as a pretreatment for diamond electrodeposition, and then diamond abrasive grains are electrodeposited on the base portion 201. However, when diamond electrodeposition is performed by such a method, stress is applied to the base portion 201 other than the electrodeposition portion in the electrodeposition pretreatment and electrodeposition as shown in FIGS. 8B and 8C. As a result, the overall distortion of the dresser has increased.

Furthermore, in such a conventional dresser, in order to suppress deterioration of surface accuracy due to electrodeposition work or the like, the base portion was thickened so as to reduce the distortion of the base portion, but this increases the dresser weight, There was also a problem that it was difficult to handle the dresser.

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a dresser with high thickness accuracy, capable of efficient and uniform dressing, and lighter than conventional ones.

In order to achieve the above object, the present invention provides a dresser comprising a diamond plate to which diamond abrasive grains are fixed for dressing a polishing cloth attached to an upper surface plate and a lower surface plate of a double-side polishing apparatus. An inner ring, an outer ring having a diameter larger than that of the inner ring, concentrically arranged on the outer side of the inner ring and connected to the inner ring, and the inner ring and the outer ring. A diamond plate disposed between the outer ring and the outer ring, and the outer ring and the inner ring. The diamond plate is held non-fixed in the thickness direction of the diamond plate on the outer peripheral part of the inner ring and the inner peripheral part of the outer ring, Providing a dresser, characterized in that the bets in the thickness direction is capable floating.

In such a dresser, since the side surface of the diamond plate is held by the inner ring and the outer ring, the diamond plate is hardly affected by the thickness accuracy of the inner ring and the outer ring, and the surface accuracy of the dress surface is hardly deteriorated. . In addition, since the diamond plate can float in the thickness direction, the followability to the surface shape (surface plate shape) of the polishing cloth is improved. Therefore, the dresser of the present invention can perform uniform dressing with high efficiency. In addition, the dresser of the present invention has a configuration in which the diamond plate is mainly held from the side surface by an annular, hollow inner and outer ring, and the inner and outer rings can be thinned with such a configuration. The thickness itself can be designed to be thin, lighter than conventional dressers, and easy to handle.

At this time, the outer peripheral portion of the inner ring, the side surface of the diamond plate facing the outer peripheral portion of the inner ring, the inner peripheral portion of the outer ring, and the side surface of the diamond plate facing the inner peripheral portion of the outer ring Has a concave shape or a convex shape, and the convex shape is meshed with the concave shape so as to have play in the thickness direction of the diamond plate. It is preferable that the diamond plate is held so as to be floatable in the thickness direction by the inner periphery of the outer ring and the outer ring.

In this way, the diamond plate can be held unfixed in the thickness direction and can float in the thickness direction of the diamond plate.

Further, the diamond plate is composed of a plurality of fan-shaped members electrodeposited with diamond on a stainless steel plate, and each of the plurality of fan-shaped members is installed between the inner ring and the outer ring to form a ring shape. It is preferable that it is arrange | positioned.

A dresser equipped with such a diamond plate can perform dressing more efficiently and more uniformly.

The flatness and parallelism of the diamond plate are preferably 0.02 mm or less.

If the flatness and parallelism of the diamond plate are 0.02 mm or less, uniform dressing can be performed more reliably and efficiently.

Moreover, it is preferable that the inner ring and the outer ring are made of stainless steel (SUS) or resin.

If the inner ring and outer ring are made of SUS, the strength of the dresser can be further improved. In addition, if the inner ring and the outer ring are made of resin, the dresser becomes lighter at a lower cost.

Further, the double-side polishing apparatus is a planetary motion type double-side polishing that simultaneously polishes both the front and back surfaces of the semiconductor wafer by revolving the carrier holding the semiconductor wafer in the holding hole between the sun gear and the internal gear. It is a device, and it is preferable that the outer ring is one in which outer teeth are provided around an outer peripheral surface, and the outer teeth can mesh with the sun gear and the internal gear.

With such a dresser, the entire surface of the surface plate can be dressed efficiently and uniformly by meshing the external teeth with the sun gear and the internal gear of the double-side polishing machine and revolving.

The dresser of the present invention is capable of highly efficient and uniform dressing. The dresser of the present invention is lighter than the conventional dresser, is easy to handle, and can improve workability.

It is the top view which showed an example of the dresser of this invention. FIG. 2 is a cross-sectional view of the dresser of the present invention taken along line A-A ′ in FIG. 1. It is an exploded top view of the dresser of the present invention. It is a partial exploded perspective view of the dresser of the present invention. FIG. 2 is a diagram illustrating an example of a method for manufacturing a dresser according to the present invention with a cross section taken along line A-A ′ in FIG. 1. It is the schematic which shows a general double-side polish apparatus. It is the schematic of the conventional dresser. It is a figure explaining the flatness change at the time of preparation of the conventional dresser. It is a measurement result of the thickness variation | change_quantity of the polishing cloth in an Example and a comparative example. It is a measurement result of Si content in an Example and a comparative example. It is a measurement result of GBIR in an Example and a comparative example. It is a measurement result of ROA in an Example and a comparative example.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited thereto.

First, the dresser of the present invention will be described with reference to FIGS. As shown in FIG. 1, the dresser 1 of the present invention has an inner ring 2, a diameter larger than that of the inner ring 2, a concentric arrangement with the inner ring 2 on the outer side of the inner ring 2, and connection to the inner ring And an outer ring 3 having a portion 4. As shown in FIG. 2, the inner ring 2 may be one in which an upper inner ring 2a and a lower inner ring 2b are overlapped and fixed vertically. For example, as shown in FIG. 3, the outer ring 3, the connecting portion 4 that is located on the inner peripheral portion of the outer ring 3 and is connected to the lower inner ring 2 b, and the lower inner ring 2 b that constitutes a part of the inner ring 2 A base ring in which the outer ring 3 and the inner ring 2 are formed by fixing the upper inner ring 2a with a bolt or the like on the lower inner ring 2b of the base ring as shown in FIG. There may be. Although FIG. 4 illustrates the base ring including the lower inner ring 2b, the base ring may include the upper inner ring 2a, and the lower inner ring 2b may be fixed to the base ring with a bolt.

As shown in FIG. 2, the dresser 1 includes a diamond plate 5 to which diamond abrasive grains 6 for dressing a polishing cloth attached to an upper surface plate and a lower surface plate of a double-side polishing apparatus are fixed. The diamond plate 5 is disposed between the inner ring 2 and the outer ring 3. The side surface of the diamond plate 5 is held by the outer peripheral portion of the inner ring 2 and the inner peripheral portion of the outer ring 3, and the thickness is larger than that of the inner ring 2 and the outer ring 3.

When a plurality of diamond plates 5 are installed as shown in FIG. 1, the diamond plates 5 may be arranged so that the surfaces (upper surfaces in FIG. 2) to which the diamond abrasive grains 6 are fixed are all in the same direction. The diamond plate 5 whose upper surface is the surface to which the abrasive grains 6 are fixed and the diamond plate 5 whose lower surface is the surface to which the diamond abrasive grains 6 are fixed may be arranged alternately. In FIG. 2, the diamond abrasive grains 6 are fixed only on the upper surface of the diamond plate 5. However, in the dresser 1 of the present invention, the diamond abrasive grains 6 are fixed on both the upper and lower surfaces of the diamond plate 5. Also good.

Furthermore, in the dresser 1 of the present invention, the diamond plate 5 is held in the outer peripheral portion of the inner ring 2 and the inner peripheral portion of the outer ring 3 in an unfixed manner in the thickness direction of the diamond plate 5. Can float in the thickness direction.

More specifically, such a configuration includes the outer periphery of the inner ring 2, the side surface of the diamond plate 5 facing the outer periphery of the inner ring 2, the inner periphery of the outer ring 3, and the inner periphery of the outer ring 3. The side surface of the diamond plate 5 facing the portion has either a concave shape or a convex shape, and the convex shape meshes with the concave shape so that there is play in the thickness direction of the diamond plate 5. Thus, the diamond plate 5 can be held by the outer peripheral portion of the inner ring 2 and the inner peripheral portion of the outer ring 3 so as to float in the thickness direction. An example of such a configuration will be described more specifically with reference to FIG.

In the case of FIG. 2, the outer peripheral portion of the inner ring 2 that is thinner than the diamond plate 5 has a concave shape, and the side surface of the diamond plate 5 that faces the outer peripheral portion of the inner ring 2 has a convex shape. These irregularities mesh with each other so as to have play in the thickness direction of the diamond plate 5. Similarly, the inner peripheral portion of the outer ring 3 that is thinner than the diamond plate 5 has a convex shape, and the side surface of the diamond plate 5 facing the inner peripheral portion of the outer ring 3 has a concave shape. The plates 5 are engaged so as to have play in the thickness direction. With these configurations, the diamond plate 5 can float in the thickness direction. In the present invention, any one of the outer peripheral portion of the inner ring 2 and the side surface of the diamond plate 5 facing the inner ring 2 may be a concave shape, and the other may be a convex shape, and is limited to the embodiment shown in FIG. There is no. The same applies to the relationship between the inner peripheral portion of the outer ring 3 and the side surface of the diamond plate 5 facing the inner ring portion. For example, the outer peripheral portion of the inner ring 2 may have a convex shape, and the side surface of the diamond plate 5 facing this may be concave, and the inner peripheral portion of the outer ring 3 may have a concave shape, and the diamond plate 5 facing this. The side surface may be convex.

In this way, if the dresser 1 is such that the side face of the diamond plate 5 is held by the inner and

outer rings

2 and 3, the dress surface to which the diamond abrasive grains 6 of the diamond plate 5 are fixed is the thickness of the inner and

outer rings

2 and 3. Since it is not affected by accuracy, the surface accuracy of the dress surface is not deteriorated by the support member (base portion or the like) of the diamond plate as in the prior art. Further, the floatable diamond plate 5 can move following the shape of the polishing cloth surface of the double-side polishing apparatus during dressing. Therefore, dressing can be performed with improved dressing efficiency (improvement in the thickness variation of the polishing cloth) and uniform roughness. Further, since the diamond plate is not pasted on the support member as in the prior art, it is not necessary to increase the thickness of the inner and

outer rings

2 and 3 in order to suppress distortion. Therefore, the dresser 1 becomes light and easy to handle.

Further, in the dresser 1 of the present invention, the diamond plate 5 is preferably composed of a plurality of fan-shaped members as shown in FIG. 1 in which diamond is electrodeposited on a stainless steel plate. It is preferable that the ring is disposed between the outer ring 3 and the outer ring 3. Here, the “fan shape” in the present invention means a shape obtained by dividing the ring-shaped diamond plate 5 in the outer peripheral direction as shown in FIG. That is, the ring-shaped diamond plate 5 can be formed by combining a plurality of fan-shaped members. If the diamond plate 5 is divided into a plurality of sector members, the area of each sector member can be reduced. The fan-shaped member having a small area also has a small amount of stress change of the stainless steel plate due to the electrodeposition treatment of the diamond abrasive grains, and has a high flatness, so that the dresser 1 has high surface accuracy of the dress surface. In addition, since the dresser 1 of the present invention has a structure in which the diamond plate can be easily exchanged, for example, when a defect is found in the diamond abrasive grains of the sector member, only the problematic sector member can be removed and easily replaced. It is.

In particular, the flatness and parallelism of the diamond plate 5 are preferably 0.02 mm or less. As a result, the dresser 1 is capable of further improving dressing efficiency and more uniform dressing.

Further, the inner ring 2 and the outer ring 3 may be made of stainless steel or resin. If the inner ring and the outer ring are made of SUS, the strength of the dresser will be higher. In addition, if the inner ring and the outer ring are made of resin, the cost is lower and there is no metal contamination, and the dresser is lighter.

Further, in the dresser 1 of the present invention, it is preferable that the outer ring 3 has outer teeth 7 around the outer peripheral surface, and the outer teeth 7 can mesh with the sun gear and the internal gear. For example, the planetary motion type double-side polishing apparatus 100 as shown in FIG. 6 causes the carrier 103 holding the semiconductor wafer W in the holding hole to revolve between the sun gear 101 and the internal gear 102, thereby causing the semiconductor wafer W to rotate. The front and back surfaces can be polished simultaneously. If the outer teeth 7 of the outer ring 3 of the dresser 1 can mesh with the sun gear 101 and the internal gear 102, the entire surface of the polishing cloth can be easily dressed by revolving with the sun gear 101 and the internal gear 102. Become a dresser.

The dresser 1 of the present invention as shown in FIGS. 1 and 2 can be manufactured as follows, for example. FIG. 5 is a cross-sectional view taken along line A-A ′ of FIG. First, when manufacturing the dresser 1 as shown in FIGS. 1 and 2, as shown in FIGS. 3 and 4, the base ring in which the outer ring 3, the connecting portion 4, and the lower inner ring 2b are integrated, and the upper inner ring 2a The diamond plate 5 may be prepared. Moreover, as the diamond plate 5, a plurality of sector members in which diamond abrasive grains are electrodeposited on a sector plate can be prepared. In addition, if the fan-shaped member electrodeposited with diamond abrasive grains is selected according to the thickness in advance so that the variation in thickness among the plurality of fan-shaped members is reduced, a more accurate dresser can be produced. it can.

Next, as shown in FIG. 5A, the outer end of the diamond plate 5 is engaged with the inner peripheral portion of the outer ring. At this time, the meshing portion has play in the thickness direction of the diamond plate 5.

Next, as shown in FIG. 5B, the upper inner ring 2a is attached so that the inner end of the diamond plate 5 is sandwiched from above and below by the upper inner ring 2a and the lower inner ring 2b. The portion is engaged with the inner end of the diamond plate 5. At this time, the meshing portion has play in the thickness direction of the diamond plate 5.

Next, as shown in FIG. 5C, the upper inner ring 2a and the lower inner ring 2b are fixed with bolts.

As described above, the diamond plate 5 is held non-fixed in the thickness direction on the outer peripheral portion of the inner ring 2 and the inner peripheral portion of the outer ring 3 so that the diamond plate 5 can float in the thickness direction. The dresser 1 can be manufactured.

Next, a method of dressing the upper and lower polishing cloths of the double-side polishing apparatus using the dresser 1 as described above will be described. In order to perform dressing, if the dresser 1 is sandwiched between the upper surface plate and the lower surface plate of the double-side polishing apparatus and the apparatus is operated in the same manner as normal polishing, the upper and lower polishing cloths can be dressed simultaneously. At this time, if the external teeth 7 of the outer ring 3 are engaged with the sun gear and the internal gear as described above, the dresser 1 rotates and revolves by these gears, and the entire surfaces of the upper and lower polishing cloths are moved. Can be dressed.

In addition, as shown in FIG. 2, when using the dresser 1 in which the diamond abrasive grains 6 are fixed to only one side of the diamond plate 5 and the surfaces to which the diamond abrasive grains 6 are fixed are all in the same direction, 1 is arranged on a plurality of lower surface plates, some of the dressers 1 are installed so that the diamond abrasive grains 6 face the lower surface plate, and the rest are placed so that the diamond abrasive grains 6 face the upper surface plate direction. The upper and lower polishing cloths can be dressed simultaneously by sandwiching the dresser 1 between the upper and lower surface plates.

Alternatively, the upper and lower polishing cloths may be dressed simultaneously using the dresser 1 in which the surface on which the diamond abrasive grains 6 are fixed is in two directions. In this case, a plurality of diamond plates 5 each having diamond abrasive grains 6 fixed on only one side thereof are installed, diamond plates 6 with diamond abrasive grains 6 facing the lower surface plate, and diamond plates 5 with diamond abrasive grains 6 facing the upper surface plate direction. Or a dresser 1 in which diamond abrasive grains 6 are fixed to both upper and lower surfaces of the diamond plate 5 may be used.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples of the present invention, but the present invention is not limited to the examples.

(Example)
A silicon wafer was polished using a double-side polishing apparatus as shown in FIG. 6, and dressing of upper and lower polishing cloths was performed between polishing batches with the dresser of the present invention as shown in FIGS. And the thickness change amount of the polishing cloth of dressing, the surface shape measurement of the polishing cloth after dressing, and Si content measurement of the polishing cloth after dressing were performed. Furthermore, the change in flatness of the polished wafer was evaluated before and after dressing.

The dresser of the example was manufactured by the following procedure. That is, first, diamond abrasive grains are fixed to one surface of a stainless steel base ring, a stainless steel upper inner ring, and a stainless steel plate, in which a lower inner ring and an outer ring are integrated via a connecting portion. A diamond plate was prepared. For the diamond plate, a ring-shaped stainless steel plate having a thickness of 1 cm was cut into eight fan shapes, and diamond abrasive grains were electrodeposited on the respective surfaces to prepare eight fan-shaped members. And these members were assembled in the procedure shown in FIG. 5, and the dresser of this invention like FIG. 1 was produced.

The inner ring of this dresser has a thickness of 0.3 cm, an inner diameter of 62 cm, and an outer diameter of 65 cm. The outer ring has a thickness of 0.6 cm, an outer diameter of 74 cm, and a gear tooth bottom of 73 cm. The weight of this dresser was about 5 kg, which was about 1/3 the weight of the conventional dresser used in the comparative example described later. In this procedure, four dressers were produced and used for dressing.

Moreover, as a double-side polishing apparatus, a double-side polishing machine 30B manufactured by Fujikoshi Machine Industry Co., Ltd. was used.

When dressing, the external gear of the dresser was installed so as to mesh with the sun gear and the internal gear. At this time, the two dressers were installed so that the diamond abrasive grains face upward, and the remaining two dressers were placed so that the diamond abrasive grains face downward. Then, while rotating the upper and lower surface plates, press the polishing cloths facing the upper and lower surface plates against the dresser and simultaneously rotate the dresser between the sun gear and the internal gear to simultaneously dress the upper and lower polishing cloths. did. As the polishing cloth, a urethane polishing pad was used.

In dressing, the upper and lower surface plates and the dresser were revolved so that the relative rotational speed of the upper and lower surface plates was 1: 1 with respect to the revolution of the dresser. The load on the dresser was the same as the load during polishing, and the dressing time was 60 minutes.

As for polishing conditions for a silicon wafer having a diameter of 300 mm, the load is 150 gf / cm ² , the rotation speed of the upper and lower surface plates, the sun gear and the internal gear is the difference between the carrier revolution number and the upper surface plate rotation number, and the lower surface plate rotation number and the carrier. Processing was performed so that the carrier rotation speed was set to 2.5 rpm so that the difference in revolution number was 10 rpm.

After dressing between polishing batches, the amount of change in thickness of the upper and lower polishing cloths, measurement of the surface shape of the polishing cloth, and measurement of the Si content of the polishing cloth after dressing were performed. The amount of change in the thickness of the polishing pad was calculated from the thickness of the polishing pad before and after dressing. The surface shape of the polishing cloth was measured using a straightness measuring machine. Moreover, Si content of polishing cloth was measured by SEM.

As a result, as shown in FIG. 9, the amount of change in the thickness of the polishing cloth is larger in the example than in the comparative example described later, and the amount of change in the thickness of the polishing cloth is 10% higher than the comparative example described later. And found that effective dressing was done. In FIG. 9, a relative value with the amount of change in the thickness of the polishing cloth of the comparative example as 1 is shown as the amount of change in the thickness of the polishing cloth. In addition, as shown in FIG. 10, in the example, the Si content of the polishing cloth was 10% less than that of the comparative example, and it was found that clogging due to polishing scraps of the silicon wafer was sufficiently removed as compared with the comparative example. It was. In addition, in FIG. 10, the relative value which set Si content of the comparative example to 1 is described as Si content.

Further, as the flatness of the silicon wafer, GBIR (Global Backsurface-referenced ideal plane / Range) and ROA (Roll Off Amount) were measured with Nanometer. As a result, as shown in FIGS. 11 and 12, in the example, a flatness equivalent to that of a comparative example described later was obtained.

(Comparative example)
Except for using the conventional dresser as shown in FIG. 7, double-side polishing and batch-to-batch dressing are performed under the same conditions as in the example. went. The dresser in the comparative example was configured such that eight diamond plates made of a plurality of fan-shaped members electrodeposited with diamond on a stainless steel plate were arranged in a ring shape on a ring-shaped base portion. The weight of such a dresser was about 15 kg, which was heavier than the dresser of the example.

As a result of the dressing evaluation, as shown in FIG. 9, the thickness change amount of the polishing cloth was smaller than that of the example, and the dressing effect was low. Furthermore, as shown in FIG. 10, the Si content of the polishing cloth is larger than that in the example, and the clogging due to the polishing scraps of the silicon wafer remains more than in the example, and the dressing effect more effective than the comparative example is achieved. It was confirmed that it was obtained.

Further, as in the example, when the flatness of the silicon wafer after double-side polishing was examined, it was the same flatness as in the example as shown in FIGS.

Note that the present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

Claims

A dresser comprising a diamond plate to which diamond abrasive grains are fixed for dressing a polishing cloth affixed to an upper surface plate and a lower surface plate of a double-side polishing apparatus,
An inner ring,
An outer ring having a diameter larger than the inner ring, concentrically arranged on the outer side of the inner ring and connected to the inner ring;
The diamond plate that is disposed between the inner ring and the outer ring, has a side surface held by the outer peripheral portion of the inner ring and the inner peripheral portion of the outer ring, and is thicker than the inner ring and the outer ring. When,
Comprising
The diamond plate is held in the outer peripheral portion of the inner ring and the inner peripheral portion of the outer ring in an unfixed manner in the thickness direction of the diamond plate, so that it floats in the thickness direction of the diamond plate. A dresser characterized by being capable.
The outer peripheral portion of the inner ring, the side surface of the diamond plate facing the outer peripheral portion of the inner ring, the inner peripheral portion of the outer ring, and the side surface of the diamond plate facing the inner peripheral portion of the outer ring are concave. Or a convex shape, and the convex shape meshes with the concave shape so as to have play in the thickness direction of the diamond plate, and the outer peripheral portion of the inner ring and the The dresser according to claim 1, wherein the diamond plate is held by an inner peripheral portion of an outer ring so as to be floatable in a thickness direction.
The diamond plate is composed of a plurality of fan-shaped members electrodeposited with diamond on a stainless steel plate, and each of the plurality of fan-shaped members is disposed between the inner ring and the outer ring to be arranged in a ring shape. The dresser according to claim 1 or 2, wherein
The dresser according to any one of claims 1 to 3, wherein the diamond plate has a flatness and parallelism of 0.02 mm or less.
The dresser according to any one of claims 1 to 4, wherein the inner ring and the outer ring are made of stainless steel or resin.
The double-side polishing apparatus is a planetary motion type double-side polishing apparatus that simultaneously polishes both the front and back surfaces of the semiconductor wafer by revolving the carrier holding the semiconductor wafer in the holding hole between the sun gear and the internal gear. Yes,
6. The outer ring according to claim 1, wherein outer teeth are provided around an outer peripheral surface, and the outer teeth can mesh with the sun gear and the internal gear. The dresser of any one of Claims.