TWI653123B - Method for adjusting a thickness of a carrier plate - Google Patents

Abstract

A method of adjusting the thickness of a bracket plate capable of reducing the amount of hole depression of the bracket plate is provided.

The method for adjusting the thickness of the stent plate according to the present invention is characterized in that the wafer holding hole 40 included in the stent plate 30 is filled with the dummy member 10 instead of the silicon wafer 20, and the dummy member 10 is filled. a step of polishing both sides of the holder plate 30 by a double-side polishing apparatus; in the holder plate 30, at least the inner peripheral surface portion 32 of the wafer holding hole 40 is made of a resin material, and the thickness of the dummy member 10 is smaller than the inner circumference The thickness of the face 32 is thicker.

Description

 Method for adjusting thickness of bracket plate  

The invention relates to a method for adjusting the thickness of a bracket plate.

In the fabrication of a wafer used for a substrate or the like of a semiconductor device, in order to obtain a semiconductor wafer having higher accuracy of flatness quality or surface roughness quality, the wafer is held by one of the polishing pads. The polishing slurry is supplied to the wafer while the upper surface and the lower surface are simultaneously subjected to chemical mechanical polishing. In order to improve the integration of large integrated circuits, the flatness of the wafer is one of the important factors.

Here, a conventional double-side polishing apparatus 1 using a conventional technique will be described using FIG. As shown in Fig. 1, the double-side polishing apparatus 1 includes a holder plate 30 having a wafer holding hole 40 for holding the silicon wafer 20, and a fixing plate 50a provided on the polishing pads 60a and 60b, respectively. The lower fixed plate 50b and the upper fixed plate 50a and the lower fixed plate 50b are respectively rotated to the motors 90a and 90b.

The upper fixed plate 50a and the lower fixed plate 50b are configured to be able to sandwich the silicon wafer 20 held by the wafer holding hole 40 with a desired load. The motors 90a and 90b are such that the upper fixed plate 50a and the lower fixed plate 50b are rotated in opposite directions from each other. Further, in general, the outer peripheral gear is disposed on the bracket plate 30 by the outer circumference of the sun gear 70 and the lower fixed plate 50b at the center portion of the lower fixed plate 50b. The internal gear 80 is engaged to cause the bracket plate 30 to rotate or revolve (referred to as "planetary rotation"). Further, the sun gear 70 and the internal gear 80 are individually driven by motors 90c and 90d different from the motors 90a and 90b. In the polishing apparatus 1, the upper surface and the lower surface of the semiconductor wafer 20 are pressed by the polishing of the polishing pads 60a and 60b and the dropping of the slurry (not shown) while the carrier plate 30 to be sandwiched is rotated by the planets. The surface is chemically mechanically ground simultaneously. Further, instead of rotating the holder plate 30 by the planets, it is also possible to chemically polish both sides of the crucible wafer 20 by being rotated only.

Further, in FIG. 1, although the holder plate 30 is illustrated as having one wafer holding hole 40, the holder plate 30 may have a plurality of wafer holding holes 40 as shown in FIG. 2(A). . In the second (B) diagram, the I-I cross-sectional view of the second (A) diagram is shown.

Here, Patent Document 1 discloses a method of manufacturing a stent plate. In other words, a method of manufacturing a wafer holder includes a method of manufacturing a wafer holder provided in a wafer double-side polishing apparatus for polishing a wafer on both sides of a wafer, and pre-processing the body constituting the wafer holder into In the processing step of setting the shape, a step of forming a preliminary hole and a slurry inflow hole for flowing the slurry is formed in the body of the wafer holder, and a DLC (Diamond-Like Carbon) is applied to the body on which the preliminary hole is formed. a coating step of diamond-like carbon), and a wafer holding hole forming step of expanding the preliminary holes after the application of the DLC to form a wafer holding hole for inserting a wafer.

[First technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-135424

However, unlike the wafer holder of Patent Document 1, as shown in FIG. 2(A), the inner circumferential surface portion 32 (referred to as "hole edge portion") of the wafer holding hole 40 is divided in the holder plate 30, It is generally formed of a resin material. This is because the inner peripheral surface portion 32 of the holder plate 30 that is in contact with the end surface of the crucible wafer 20 (in other words, the wafer edge portion), for example, SUS or the like, is formed by the edge portion of the hole when the crucible wafer 20 is polished. The inner circumferential surface portion 32 collides with the end surface of the silicon wafer 20, and the edge portion of the wafer is damaged. Therefore, in general, at least the edge portion of the 30-hole of the holder plate is made of a resin material as a cushioning material. Such a cushioning material is referred to as an insert. Further, the holder plate 30 may be entirely formed of a resin material.

In recent years, semiconductor technology has been advancing toward miniaturization, and the requirements for the grinding accuracy required for double-sided polished silicon wafers are very high. Therefore, in order to adjust the thickness of the holder plate 30, the thickness of the holder plate 30 is adjusted before the double-side polishing of the tantalum wafer 20. Even when the holder plate 30 is made of SUS or the like, when the resin material is included in the edge portion of the hole, it is necessary to adjust the thickness system in order to obtain high flatness. In particular, as shown in Fig. 1, in the batch type double-side polishing apparatus, in order to perform size-controlled polishing, it is important that the thickness of the holder plate 30 is the same in the submicron order. Further, the size control polishing system performs polishing while detecting the thickness of the finished product to which the polished silicon wafer is applied.

The dummy holding member 15 instead of the crucible wafer 20 is filled in the wafer holding hole 40 of the holder plate 30, and if the double-side polishing is performed by the double-side polishing apparatus 1, the thickness of the holder plate 30 can be adjusted. However, as shown in the pattern of FIG. 3, the inner peripheral surface portion 32 (the hole edge portion) of the holder plate 30 is formed by filling the dummy member 15 and adjusting the thickness of the holder plate 30 in the double-side polishing. The stress toward the polishing pads 60a, 60b is concentrated. As a result, a smooth R-shaped machining mark called a hole depression is inevitably generated on the inner peripheral surface 32. Hereinafter, referring to FIG. 3(B), in the present specification, the total thickness (H1+H2) of the recessed portion of the hole is defined as the amount of recessed hole.

The inventors of the present invention studied the relationship between the amount of hole depression and the edge roll-off of the tantalum wafer. Fig. 4 is a graph showing the relationship between the amount of hole depression of the stent plate and the average value of the ESFQD of the tantalum wafer in the case where the double-sided polishing of the tantalum wafer is performed under the same conditions. The larger the negative value of ESFQD, the more the 矽 wafer is rolled. Conversely, the larger the positive value of ESFQD, the more it is rolled-up. Further, in the graph of Fig. 4, ESFQD is described as an arbitrary unit (A.U.).

Further, the edge curling system refers to a phenomenon in which the edge portion of the wafer is recessed and the thickness of the edge portion is thinned. If the amount of the roll is large, the field of the device that can be manufactured becomes narrow, which is related to the deterioration of the manufacturing yield of the device. Further, in the ESFQD system, a fan-shaped sector is formed in the edge region, and the inner plane of the position in which the height data in the sector is calculated by the least square method is used as the reference plane, and the maximum displacement amount without the symbol from the plane is ESFQD. Have a value at each location. However, the representation contains symbols. The average value (except for any unit) of the ESFQD in the graph of Fig. 4 is the average value obtained when the ESFQD of the sector is acquired over the entire circumference, and the edge exclusion is set to 2 mm.

From the graph of Fig. 4, it can be confirmed that the smaller the amount of hole depression of the holder plate, the smaller the amount of the wafer to be wound after the double-side polishing. The reason is as presumed by the inventors of the present invention as described below. In other words, as shown in the fifth (A) and (B), the amount of hole depression in the inner peripheral surface portion 32 (that is, the edge portion of the hole) of the holder plate 30 is small (see Fig. 5(A)). When the size is controlled, that is, the holder effect (the holder plate 30 lifts the polishing pad 60a to alleviate the stress applied to the edge portion of the wafer), the amount of the wafer 20 is small. However, when the amount of hole depression of the holder plate 30 is large (refer to FIG. 5(B)), the effect of the holder at the time-controlled polishing is small, and the amount of the crucible of the crucible 20 is estimated to be changed. Bigger.

Thus, in order to reduce the amount of entanglement of the ruthenium wafer after double-side polishing, it is necessary to reduce the amount of hole sag of the stent plate. For this reason, when adjusting the thickness of the bracket plate, it is desirable to establish a method of adjusting the thickness of the bracket plate which can reduce the amount of hole depression of the bracket plate. Further, if the method of adjusting the thickness of the stent plate can be established in this way, it is also related to the improvement in the quality of the double-side polishing of the tantalum wafer.

Therefore, the present invention is directed to providing a method for adjusting the thickness of a stent plate which can reduce the amount of hole depression of the stent plate.

In order to achieve the above objectives, the inventors of the present case are constantly striving to study. Moreover, the inventors of the present invention have also focused on the thickness of the dummy member of the wafer holding hole filled in the holder plate. The inventors of the present invention have found that if the thickness of the dummy member is thicker than the thickness of the edge portion of the bracket plate, the amount of hole depression of the bracket plate can be reduced when the thickness of the bracket plate is adjusted, and the present invention has been completed.

The present invention completed based on the above findings has the following constitutional gist.

(1) A method for adjusting a thickness of a stent plate, characterized in that, in a silicon wafer to be held on a stent plate having a wafer holding hole, a fixing plate and a lower fixing plate are respectively placed on the polishing pad, and A double-side polishing apparatus that chemically grinds the upper surface and the lower surface of the tantalum wafer simultaneously by supplying the polishing slurry while rotating the holder plate, the upper stationary plate, and the lower stationary plate The method for adjusting the thickness of the bracket plate includes: a step of filling the dummy member in the wafer holding hole in place of the germanium wafer; and in a state where the dummy member is filled, by the double-side polishing device The step of polishing the both sides of the holder plate; wherein the inner peripheral surface of the holder holding plate includes at least a resin material; and the thickness of the dummy member is thicker than the thickness of the inner peripheral surface.

(2) The method for adjusting the thickness of a stent plate according to the above aspect, wherein at least the upper surface and the lower surface of the dummy member comprise a material having a lower polishing rate than a polishing rate of the resin material.

(3) The thickness adjustment method of the stent plate according to the above aspect, wherein the dummy member is coated with the coating material on the upper surface and the lower surface of the dummy silicon wafer, and the coating material is A material containing a lower polishing rate than the above-mentioned resin material.

(4) The method for adjusting the thickness of a stent plate according to the above (3), wherein the coating material includes a material that does not contaminate the tantalum wafer.

(5) The method for adjusting the thickness of a stent plate according to the above (3), wherein the coating material comprises diamond-like carbon.

(6) The method for adjusting the thickness of a stent plate according to any one of the above aspects, wherein the stent plate comprises a resin material.

According to the present invention, it is possible to provide a method for adjusting the thickness of a bracket plate which can reduce the amount of recessed holes in the bracket plate.

1‧‧‧ grinding device

10‧‧‧Virtual components

11‧‧‧Dummy wafers

12a‧‧‧ Coating material

12b‧‧‧ Coating material

15‧‧‧Virtual components

20‧‧‧矽 wafer

30‧‧‧ bracket plate

32‧‧‧ inner peripheral face (edge of the hole)

40‧‧‧ wafer holding hole

50a‧‧‧Upright

50b‧‧‧Fixed

60a‧‧‧ polishing pad

60b‧‧‧ polishing pad

70‧‧‧Sun Gear

80‧‧‧ internal gear

90a‧‧‧Motor

90b‧‧‧Motor

90c‧‧‧Motor

90d‧‧‧Motor

120‧‧‧Control Department

Fig. 1 is a schematic view showing a double-side polishing apparatus for a wafer of the prior art.

Fig. 2 is a schematic view of a conventional support plate, wherein Fig. 2(A) is a plan view, and Fig. 2(B) is a cross-sectional view taken along line I-I of Fig. 2(A).

Fig. 3(A) is a schematic view showing the thickness adjustment of the stent plate using the dummy member according to the study by the inventors of the present invention, and Fig. 3(B) is a schematic view showing the amount of the depression of the thickness after the thickness adjustment.

Fig. 4 is a graph showing the relationship between the amount of recessed holes and the amount of enthalpy of the wafer according to the study by the inventors of the present invention.

Fig. 5 is a schematic view showing the influence of the amount of hole depression on the edge curl of the wafer according to the study by the inventors of the present invention, wherein the fifth (A) diagram shows the case where the amount of the hole is small, and the fifth (B) The figure shows the case where the amount of hole depression is large.

Figure 6 is a schematic view showing the use of a dummy member in the thickness adjustment method of the stent plate according to an embodiment of the present invention, wherein the sixth (A) diagram is a mode for explaining the relationship with the thickness of the edge portion of the stent plate. Figure 6(B) is a schematic view showing a dummy member according to a preferred embodiment of the present invention.

Fig. 7 is a graph showing the relationship between the thickness of the dummy member and the amount of depression of the hole in the embodiment.

Hereinafter, a semiconductor wafer double-side polishing method using an embodiment of the present invention will be described with reference to the drawings. Moreover, the aspect ratio of each configuration in the drawing is exaggerated for convenience of explanation, and is different from the actual one.

One embodiment of the present invention is a method for adjusting the thickness of a stent plate in a double-side polishing apparatus. Further, as described above with reference to Fig. 1, a conventional double-sided polishing apparatus 1 is generally provided, and a silicon wafer 20 held by a holder plate 30 having a wafer holding hole 40 is provided with polishing pads, respectively. The upper fixed plate 50a and the lower fixed plate 50b of 60a and 60b are sandwiched, and the upper surface and the lower surface of the silicon wafer are supplied while the polishing slurry is supplied while the holder plate, the upper fixed plate, and the lower fixed plate are rotated. The surface is chemically mechanically ground simultaneously.

Then, the thickness adjustment method of the stent plate of the present embodiment is included in the step of filling the dummy member 10 in place of the silicon wafer 20 in the wafer holding hole 40, and in the state in which the dummy member 10 has been filled. The double-side polishing of the holder plate 30 is performed by the double-side polishing apparatus 1. Further, as shown in Fig. 6(A), it is important that at least the inner peripheral surface portion 32 of the wafer holding hole 40 is formed of a resin material in the holder plate 30, and the thickness of the dummy member 10 is smaller than the inner peripheral surface. The thickness of 32 is thicker.

First, the double-side polishing apparatus 1 which can be used in the present embodiment will be described again with reference to the first embodiment described above. The double-sided polishing apparatus 1 includes a holder plate 30 having a wafer holding hole 40 for holding the semiconductor wafer 20, a fixing plate 50a and a lower fixing plate 50b respectively provided with polishing pads 60a and 60b, and respectively The fixed plate 50a and the lower fixed plate 50b are rotated by one of the motors 90a and 90b.

The upper fixed plate 50a and the lower fixed plate 50b are configured such that the semiconductor wafer 20 held by the wafer holding hole 40 can be sandwiched by a desired load. The motors 90a and 90b generally rotate the upper fixed plate 50a and the lower fixed plate 50b in opposite directions from each other. Further, in general, the outer peripheral gear is provided on the bracket plate 30, and is engaged with the sun gear 70 at the center of the lower fixed plate 50b and the inner gear 80 at the outer periphery of the lower fixed plate 50b, so that the bracket plate 30 is rotated by the planet, but is double-sided ground. At the same time, the bracket plate can also be rotated only as described above. Double-sided grinding device In the first system, the semiconductor wafer is simultaneously pressed by the polishing of the polishing pads 60a and 60b and the polishing slurry (not shown) by rotating (or rotating) the clamped holder plate 30 by the planets. The upper surface and the lower surface of 20 are subjected to chemical mechanical polishing.

According to the CMP system of the double-side polishing apparatus 1, although the polishing of the ruthenium wafer 20 is mainly performed, the holder plate 30 is simultaneously polished. However, since chemical polishing acting on the holder plate 30 hardly contributes, the holder plate 30 is substantially mechanically polished only, and the polishing rate of the holder plate 30 is extremely small compared to the polishing rate of the tantalum wafer 20.

Therefore, in the double-side polishing apparatus 1, the dummy member 10 instead of the silicon wafer 20 is filled, and when the dummy member 10 is filled, the double-side polishing is performed, and the dummy member 10 can be chemically mechanically polished. The upper surface and the lower surface of the bracket plate 30 are mechanically ground.

Further, as described above, the present invention has an object of suppressing the depression of the edge portion of the hole when the thickness of the holder plate is adjusted. Therefore, as described above with reference to the second (A) and (B) drawings, in the present embodiment, the holder plate 30 including at least the resin material in the inner circumferential surface portion 32 of the wafer holding hole 40 is used. The number of the wafer holding holes 40 may be one or more. As the holder plate 30 called the insert holder, in the case where only the holder plate including the resin material is disposed on the inner peripheral surface portion 32 of the divided wafer holding hole 40, the inner peripheral surface portion 32 belongs to the insert. The insert part of the bracket.

On the other hand, the holder plate 30 may entirely contain a resin material. In this case, since it is difficult to occur in the vicinity of the insert in the case where only the inner peripheral surface portion 32 (i.e., the insert portion) is a resin material, the flatness of the bracket plate 30 is adjusted to be simple. . Further, when the ruthenium wafer 20 is polished using the thickness-adjusted holder plate 30, it is considered preferable to exclude the metal impurity contamination source. In this case, the inner peripheral surface portion 32 of the holder plate 30 is defined as a field in the diameter direction from the inner peripheral surface of the divided wafer holding hole 40 toward the outer diameter direction of the holder plate 30 by 5 mm. Moreover, when the inner circumferential surface portion 32 of the stent plate 30 is recessed before the thickness adjustment and the thickness of the inner circumferential surface portion 32 is not constant, the thickness of the end surface of the inner circumferential surface portion 32 is used.

Here, the "virtual member instead of the silicon wafer" as used in the present specification means that the shape of the wafer holding hole 40 that can be loaded on the holder plate 30 is obtained. Although the dummy member is preferably the same as the tantalum wafer 20 provided for polishing, it has a disk shape, but it may be an annular shape that can be loaded in the wafer holding hole 40. Therefore, the diameter or the outer diameter of the dummy member is only slightly smaller than the diameter of the wafer holding hole 40, but is a size that can be filled in the range of the wafer holding hole 40. Although it differs depending on the polishing conditions such as the material of the polishing pad, the processing load, the material of the holder plate, and the number of rotations of the plate, for example, the lower limit of the diameter or the outer diameter of the dummy member 10 may be [the wafer holding hole 40 The diameter] (mm) - 2 (mm), the lower limit system, may also be [the diameter of the wafer holding hole 40] (mm) - 1 (mm). For example, if the diameter of the wafer holding hole of the holder plate 30 is 301.0 mm, the diameter of the dummy member may be 300.5 mm.

Further, the thickness of the dummy member 10 is a thickness that can be filled in the wafer holding hole 40 of the holder plate 30 and can be polished according to the double-side polishing apparatus 1. The upper limit of the thickness of the dummy member 10 may be [the thickness of the holder plate 30] + [the amount of deformation of the polishing pad] in consideration of the sinking of the polishing pad 60a. In addition, the amount of deformation of the polishing pad varies depending on the material of the polishing pad, the processing load, the material of the holder plate, and the number of rotations of the disk, but it is in the range of 0 to 10 μm.

Next, in the present embodiment, the thickness of the dummy member 10 is thicker than the thickness of the inner peripheral surface portion 32 of the holder plate 30. Therefore, when the thickness of the holder plate is adjusted, the amount of depression of the holder plate 30 can be reduced. The inventors of the present invention believe that the reasons are as follows. In other words, in the case of the dummy member 15 of the third (A) diagram, the thickness thereof is thinner than the thickness of the inner peripheral surface portion 32 of the holder plate 30. Therefore, the load from the polishing pads 60a and 60b which are the elastic bodies is concentrated on the side of the dummy member 15 of the inner peripheral surface portion 32 of the holder plate 30. As a result, the depression of the inner peripheral surface portion 32 (the hole edge portion) becomes large. On the other hand, in the present embodiment, as shown in FIG. 6(A), the load from the polishing pads 60a and 60b is concentrated on the side of the dummy member 10 of the inner peripheral surface portion 32 of the holder plate 30, but The thickness of the dummy member 10 is such that the thickness is thicker than that of the inner peripheral surface portion 32 of the holder plate 30, and the stress is alleviated as compared with the case of the third (A) diagram. Therefore, it is considered that the amount of hole depression of the holder plate 30 can be reduced.

Here, in consideration of the fact that the dummy holding member 10 is filled in the wafer holding hole 40 of the holder plate 30, the shape of the dummy member 10 is preferably the same as or substantially the same as the thickness and diameter of the silicon wafer 20 provided for polishing. the same. As such a dummy member 10, it is preferable to use, for example, a dummy silicon wafer instead of the germanium wafer 20 provided for polishing. However, in the case where the dummy member 10 is a dummy wafer, the polishing is performed by chemical mechanical polishing as quickly as possible according to the polishing of the double-side polishing apparatus 1 as described above. This is because the grinding system contributing to the holder plate 30 is almost mechanically abrasive. For this reason, when the thickness of the stent plate is adjusted using the dummy wafer for the thickness condition according to the present embodiment, it is necessary to frequently replace the dummy wafer.

Therefore, at least the upper surface and the lower surface of the dummy member 10 are preferably materials having a lower polishing rate of the resin material than the inner peripheral surface portion 32. As the dummy member 10 using the material having such a low polishing rate, for example, SUS, Ti, Fe, SiC, sapphire, or the like can be used to form the shape of the dummy member 10, and the coating is satisfied on the upper surface and the lower surface. It doesn't matter the different materials of the grinding rate. In the case where the upper surface and the lower surface of the dummy member 10 are coated, a resin material having a lower polishing rate than the holder plate 30 may be used.

Further, as shown in Fig. 6(B), the upper surface and the lower surface of the dummy wafer 11 are coated with coating materials 12a and 12b, and the coating materials 12a and 12b are preferably used for A dummy member of a material having a polishing rate lower than that of the resin material of the inner peripheral surface portion 32 is included. The coating material can be applied to the dummy silicon wafer by a conventional method such as a sputtering method, a vacuum evaporation method, or a CVD method. Further, as the coating material, for example, diamond-like carbon (DLC), TiN, TiAlN, TiCN, CrN, or the like can be used. From the viewpoint of the shape adjustment of the diameter and thickness of the dummy member 10 at the μm level, it is preferable to coat the coating material. Further, although the coating materials 12a and 12b may be different materials from each other, it is preferable to use the same material in consideration of productivity. Further, the DLC system refers to an amorphous film which is made of carbon and has a property close to diamond.

Further, in the general manufacturing process of the wafer, contamination from the germanium wafer such as metal impurities is avoided. From this point of view, the dummy member 10 is preferably formed of a material that does not contaminate the germanium wafer. In the case where the dummy member 10 has a coating material, the coating material preferably also contains a material that does not contaminate the silicon wafer. Therefore, the coating material is particularly preferably a diamond-like carbon (DLC). According to the coating system of the diamond-like carbon, it is also preferable that the flatness of the dummy member after film formation is good. Further, as a coating material which does not contaminate the material of the tantalum wafer, polycrystalline silicon, ceramics, resin-based materials and the like are exemplified.

Hereinafter, the specific aspect that can be applied to the present embodiment will be described, but the present embodiment is not limited to the following aspects.

In order to explain the important portions of the double-side polishing apparatus 1, the sun gear 70 and the internal gear 80 are omitted, and the motors 90c and 90d different from the motors 90a and 90b are individually driven. Further, although not shown in the drawings for simplification of the first diagram, the bracket plate 30 is rotated by the outer peripheral gear of the bracket plate 30 engaging with the sun gear 70 and the internal gear 80. However, the engagement of the sun gear 70, the internal gear 80, and the outer peripheral gear of the bracket plate is not shown in order to simplify the schematic view of the double-side polishing apparatus 1. Further, the internal gear 80 is formed by driving a shaft pin in a plurality of rotating shafts in the circumferential direction, or an individual shaft pin or a gear in which a gear is disposed, by using an individual shaft pin or The gear engages the outer peripheral gear of the bracket plate 30 so that the bracket plate 30 can be rotated. However, the individual shaft pin systems are not shown in order to simplify the schematic view of the double-side polishing apparatus 1. Further, the control unit 120 of the double-side polishing apparatus 1 controls the above-described respective configurations, and performs double-side polishing on the wafer 20 to be polished, and if the dummy member 10 is loaded and polished, the thickness of the holder plate 30 can be performed. Adjustment.

Further, for the holder plate 30, for example, stainless steel (SUS: Steel special use Stainless), a resin material such as epoxy resin, phenol, or polyimide, or a resin material in which glass fiber, carbon fiber, or ruthenium is compounded may be used. Any material such as fiber-reinforced plastic of reinforcing fibers such as an amine fiber, and at least the inner peripheral surface portion 32 is also made of a resin material. Further, in the present specification, the above-mentioned fiber-reinforced plastic material contains a resin material.

Further, the diameter of the holding hole 40 of the holder plate 30 depends on the diameter of the wafer 20 to be polished. The wafer 20 has a diameter of 200 mm (±1 mm), a 300 mm (±1 mm) wafer, and a 450 mm (±1 mm) wafer without any limitation.

Further, any one of the polishing pads 60a and 60b or the slurry may be used. For example, as a polishing pad, a pad made of a polyester nonwoven fabric, a pad made of polyurethane, or the like may be used. As the polishing slurry, an alkaline aqueous solution containing free abrasive grains or the like can be used.

[Examples]

Next, in order to clarify the effects of the present invention, the following examples are given, but the present invention is not limited by the following examples.

The double-side polishing apparatus 1 having the same configuration as that shown in the above first embodiment is used. The double-sided polishing apparatus 1 has five support sheets 30, and one sheet of the wafers 20 is filled with one sheet of the wafer 30, and each of the batches can be subjected to double-side polishing of five wafers 20. Then, the dummy members 10 of the samples 1 to 5 are loaded into the wafer holding holes 40 of the holder plate 30 as shown in the following Table 1, and the thickness of the holder plate 30 is adjusted. Further, the holder plates 30 are all made of a resin material. Further, the diameter of the wafer holding hole 40 was 301.0 mm, the initial thickness of the inner peripheral surface portion 32 of the holder plate 30 was 779 μm, and the target thickness after the thickness adjustment was 778 μm. The thickness of the dummy member 10 of the samples 1 to 3 is thicker than the initial thickness of 779 μm, and the thickness of the dummy member 10 of the samples 4 and 5 is thinner than the initial thickness of 779 μm.

Further, in any of the samples 1 to 5, the dummy member 10 in which the DLC of 2 μm on one side was applied by the plasma CVD method was used on the upper surface and the lower surface of the dummy wafer. The diameter of the dummy members was all 300.5 mm, and the thickness was as described in Table 1 below.

The amount of hole depression after the thickness of the bracket plate was adjusted was measured using a laser displacement meter. The relationship between the thickness of the dummy member and the amount of depression of the hole is shown in the graph of Fig. 7.

From the graph of Fig. 7, it can be confirmed that as the dummy member, by using the dummy member having a thickness thicker than the inner peripheral surface portion of the holder plate, the amount of hole depression of the holder plate can be remarkably reduced. When the amount of the hole depression is reduced and the ruthenium wafer is polished using the stent plate having the adjusted thickness, the amount of entanglement of the ruthenium wafer can be reduced.

 [Industrial use possibilities]  

According to the thickness adjustment method of the bracket plate of the present invention, the amount of hole depression of the bracket plate can be reduced. When the double-sided polishing of the tantalum wafer is performed using the thus-adjusted stent plate, the polishing quality of the double-sided polishing of the tantalum wafer can be improved as compared with the conventional one, and is useful in the wafer manufacturing technology.

Claims (6)

A method for adjusting a thickness of a support plate, characterized in that, in a silicon wafer to be held on a support plate having a wafer holding hole, a fixed plate and a lower fixed plate are respectively placed on a polishing pad, and The bracket plate, the upper fixed plate, and the lower fixed plate are rotated while supplying the polishing slurry, and the double-side polishing device for chemically and mechanically polishing the upper surface and the lower surface of the silicon wafer simultaneously, the thickness of the support plate The adjusting method includes the steps of: filling the dummy holding member of the 矽 wafer in the wafer holding hole; and performing both sides of the bracket plate by the double-side polishing device in a state where the dummy member is filled In the above-described holder plate, at least the inner peripheral surface portion defining the wafer holding hole includes a resin material; and the thickness of the dummy member is thicker than the thickness of the inner peripheral surface portion. The method for adjusting the thickness of a stent plate according to claim 1, wherein at least the upper surface and the lower surface of the dummy member comprise a material having a lower polishing rate than the resin material. The thickness adjustment method of the stent plate according to the first aspect of the invention, wherein the dummy member is formed by coating a coating material on an upper surface and a lower surface of the dummy wafer; the coating material system includes A material having a lower polishing rate than the above-mentioned resin material. The method for adjusting the thickness of a stent plate according to claim 3, wherein the coating material comprises a material that does not contaminate the tantalum wafer. The method for adjusting the thickness of a stent plate according to claim 3, wherein the coating material comprises diamond-like carbon. The method for adjusting the thickness of a stent plate according to any one of claims 1 to 5, wherein the stent plate comprises a resin material.