JP2005335016A - Dressing plate for abrasive cloth, dressing method for abrasive cloth, and workpiece polishing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dressing plate performing uniform dressing to a double-sided polishing device without being influenced by a polishing table shape and performing uniform grinding by eliminating the influence of upper and lower polishing table shapes even when using particularly high hardness abrasive cloth. <P>SOLUTION: The dressing plate 1 for the abrasive cloth for dressing the abrasive cloth of an upper polishing table and the abrasive cloth of a lower polishing table simultaneously in the double-sided polishing device provided with the upper polishing table and lower polishing table each with the abrasive cloth attached thereto, comprises at least two plate bodies 2 and an elastic body layer 3 provided between the plate bodies. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a dressing for a polishing cloth of a double-side polishing apparatus used when polishing a workpiece such as a silicon wafer, and more particularly to a dressing plate suitable for dressing a high-hardness polishing cloth.

  Conventionally, in the manufacture of a silicon wafer, after a silicon wafer is manufactured by slicing a single crystal silicon ingot, 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 step, a double-side polishing apparatus that simultaneously polishes both sides of the wafer may be used in addition to a single-side polishing apparatus that polishes one side of the wafer.

  The double-side polishing apparatus usually includes an upper surface plate and a lower surface plate to which a polishing cloth made of nonwoven fabric or the like is attached. As shown in FIG. 13, the sun gear 101 is at the center and the internal gear is at the outer periphery. A so-called 4-way system having a planetary gear structure in which 102 is arranged is used. When polishing a silicon wafer, the wafer is inserted and held in a plurality of wafer holding holes 104 formed in the carrier plate 103, and polishing slurry is supplied to the wafer from above, while rotating the upper and lower surface plates. The opposite polishing surfaces of the upper surface plate and the lower surface plate are pressed against both front and back surfaces of the wafer, and both surfaces of each wafer can be simultaneously polished by rotating and revolving the carrier plate 103 between the sun gear 101 and the internal gear 102. it can.

  In addition, as another type of double-side polishing apparatus, there is also known an apparatus that performs double-side polishing by making a circular motion so as to draw a small circle without rotating the carrier plate sandwiched between upper and lower surface plates. (For example, refer to Patent Document 1) With the increase in wafer diameter, a double-side polishing apparatus having such a configuration has come to be used.

  While the double-side polishing apparatus can simultaneously polish both surfaces 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 and clogging. As the frequency of use increases, the wafer shape changes. So that the so-called peripheral sag is likely to occur. Therefore, in order to prevent such a change in wafer shape, dressing of the surface of the polishing pad is regularly or constantly performed.

  For dressing, as shown in FIG. 9, generally, a dressing plate 10 is set on a carrier plate 9 dedicated to dressing having a plurality of holding holes 11 or the same carrier plate used for polishing a wafer. By sandwiching this between the upper surface plate 5 and the lower surface plate 6 and operating the apparatus in the same manner as normal polishing, both the upper and lower polishing cloths 7 and 8 are simultaneously dressed.

  As shown in FIG. 7, a conventionally used dressing plate is generally a disk-shaped dressing plate 41, and a surface 44 (hereinafter referred to as a “dressing surface”) on which both front and back surfaces are in contact with upper and lower polishing cloths. ”). As the material, for example, a hard material such as ceramics is used, and a material having minute irregularities on the dress surface is generally used. For example, as shown in FIG. 8, the dressing plate has various shapes other than the donut-shaped dressing plate 51 in which grooves 53 are formed radially on the dress surface 54 and a hole 52 is formed in the center. Things are used.

In order to polish the wafer, the surface condition of the polishing cloth is particularly important. To obtain a high flatness wafer stably over a long period of time, and to improve the life of the polishing cloth, dress the polishing cloth uniformly. is important.
However, when dressing both upper and lower polishing cloths simultaneously, as schematically shown in FIG. 10, a part of the dressing plate 10 (the center of each surface plate in FIG. The portion close to) acts strongly on the polishing cloths 7 and 8, while the other portions (portions close to the outside of each surface plate in FIG. 10) are weakly touched with the polishing cloths 7 and 8 and are not sufficiently dressed. Variations sometimes occurred. Further, when dressing plates are sandwiched between the upper and lower surface plates 5 and 6 in order to simultaneously dress the polishing cloths 7 and 8 attached to the upper and lower surface plates 5 and 6, the surface plates 5 and 6 face each other. The surface plate shape was transmitted, and the action of the dress surface varied. In particular, the influence is great in a polishing apparatus or the like in which the carrier plate itself does not rotate as disclosed in Patent Document 1 described above.

  Furthermore, as a polishing cloth for double-side polishing, conventionally, a non-woven cloth type (Asker C hardness of about 60 to 90) is used, and the purpose of dressing such a non-woven cloth is a non-woven fiber. It was to crush by applying pressure with a dressing plate so as to reduce the elastic deformation. Therefore, even if the action of the dressing plate varies to some extent as described above, it is absorbed by the deformation of the polishing cloth, and the shape between the upper and lower surface plates does not affect each other so much, and if it is sufficiently compressed, the variation in dressing is so much. It didn't matter.

However, in recent years, high-hardness polishing cloths, for example, polishing cloths having a Shore D hardness of about 40 to 100, are being used for the purpose of further increasing the flatness of the wafer and correcting minute irregularities on the wafer surface. The Shore D hardness is a value measured according to ASTM D 2240. The above Asker C hardness is a value measured with an analog hardness meter (Asker rubber hardness meter C type) commercially available from Kobunshi Keiki Co., Ltd., and is a hardness according to SRIS (Japan Rubber Association Standard) 0101. .
In such a high-hardness polishing cloth, in order to stably and improve the polishing ability, as schematically shown in FIG. 6 rather than the dressing effect for the purpose of compression as in the case of the nonwoven cloth type polishing cloth. It is important to make a sharpening (generally called “raising”).

In order to sufficiently perform such sharpening, a dressing plate with diamond pellets or the like attached on both sides may be used. However, when dressing a high-hardness polishing cloth using such a dressing plate, the polishing cloth of the upper surface plate is affected by the shape of the lower surface plate, and the polishing cloth of the lower surface plate has the shape of the upper surface plate. As a result of the influence, the diamond pellet portion is strongly hit and scraped, and the polishing cloth tends to vary in thickness, and the portion where the thickness of the polishing cloth is thin and the portion where the contact is weak and the surface layer portion is insufficiently sharpened. In addition, when there are variations in the thickness and sharpness of the polishing cloth, there is a problem that it is difficult to polish the wafer uniformly.
Thus, when using a high-hardness polishing cloth for a double-side polishing apparatus, uniform dressing by a dressing plate is difficult, and therefore double-side polishing of a silicon wafer using a high-hardness polishing cloth has not been easily performed.

JP-A-10-202511

  The present invention has been made in view of the above problems, and even when a dressing plate that can perform uniform dressing without being affected by the surface plate shape, particularly a high-hardness polishing cloth, is used for a double-side polishing apparatus. The main object is to provide a dressing plate that can eliminate the influence of the surface plate shape and perform uniform sharpening.

  In order to achieve the above object, according to the present invention, for a double-side polishing apparatus comprising an upper surface plate and a lower surface plate to which an abrasive cloth is attached, for simultaneously dressing the upper surface plate and the lower surface plate. A dressing plate for abrasive cloth, comprising: at least two plate bodies and an elastic body layer provided between the plate bodies, is provided. (Claim 1).

  If the dressing plate is provided with an elastic layer in this way, even if the surface plate of the double-side polishing apparatus is deformed, the elastic layer absorbs changes in the surface plate shape, so the dress surfaces on the front and back of the plate body Can uniformly act on both the upper and lower polishing cloths. Therefore, by using such a dressing plate, uniform dressing of the polishing cloth can be performed, and in particular, even for high-hardness polishing cloth, uniform dressing can be performed without being affected by the shape of the upper and lower surface plates. Can do.

The elastic layer is preferably made of rubber (claim 2).
The material of the elastic layer is not particularly limited, but rubber is excellent in shock absorption and can easily absorb the shape change of the surface plate.

The elastic layer preferably has a rubber hardness of 40 to 90 (claim 3).
Here, the rubber hardness is a hardness according to JIS-K-6301, and is a value measured by a spring type hardness test (C type).
If the elastic layer has a hardness within the above range, the change in shape of the surface plate can be reliably absorbed, and the surface of the polishing pad can be stably dressed because it is not compressed too much.

The thickness of the elastic body layer is preferably 2 to 10 mm.
If the elastic layer has such a thickness, the shape change of the surface plate can be absorbed sufficiently, and the dressing plate will not be too thick, ensuring uniform dressing. It can be carried out.

The plate body may be made of ceramics (Claim 5), and dressing auxiliary members having a higher dressing action than the plate body may be provided on both surfaces of the dressing plate with respect to the polishing cloth (Claim 6). As such a dressing auxiliary member, diamond pellets are preferred (claim 7).
If the plate body is made of ceramics in this way, the dress surface is made of ceramics, and dressing such as clogging of the polishing cloth can be removed and uniform dressing can be achieved, especially dressing such as diamond pellets on both sides of the dressing plate. If a dressing auxiliary member having a high action is provided, the dressing can be made uniformly with respect to the high-hardness abrasive cloth.

  Furthermore, according to the present invention, for a dressing method using the dressing plate, that is, a double-side polishing apparatus comprising an upper surface plate and a lower surface plate to which a polishing cloth is attached, between the upper surface plate and the lower surface plate. A method of simultaneously dressing both upper and lower polishing cloths with a dressing plate interposed therebetween, wherein the dressing plate comprises the at least two plate bodies and an elastic layer provided between the plate bodies. A dressing method for an abrasive cloth, characterized in that dressing is performed using a plate (claim 8).

  If a dressing plate having an elastic layer is used in this way, the elastic layer absorbs the change in the shape of the surface plate, the dress surface acts uniformly on the polishing cloth, and as a result, the upper and lower polishing cloths are mutually connected. A uniform dressing can be achieved without any influence.

  In this case, the polishing cloth affixed to the upper surface plate and the lower surface plate can be a high hardness polishing cloth having a Shore D hardness of 40 or more.

  When polishing a wafer with a double-side polishing machine, it is difficult to make a high-hardness polishing cloth with a conventional dressing plate, which causes problems such as polishing ability, life of the polishing cloth, and uniformity of the polished wafer. Is generally used, but if a dressing plate provided with an elastic layer of the present invention is used, uniform dressing can be performed even for a high-hardness abrasive cloth as described above. Wafer polishing with a double-side polishing apparatus using a high-hardness polishing cloth becomes easy.

  Furthermore, according to the present invention, using a double-side polishing apparatus comprising an upper surface plate and a lower surface plate to which a polishing cloth is attached, both sides of the work are sandwiched between the upper surface plate and the lower surface plate. A polishing method for a workpiece to be polished simultaneously, comprising: a dressing plate comprising the at least two plate bodies between an upper surface plate and a lower surface plate, and an elastic layer provided between the plate bodies. A method for polishing a workpiece is provided, in which both the upper and lower polishing cloths are dressed at the same time and then the workpiece is polished between the upper surface plate and the lower surface plate (Claim 10). .

  As described above, if the dressing plate of the present invention is used, uniform dressing can be performed on the polishing cloth of the double-side polishing apparatus. After dressing the polishing cloth using the dressing plate, a workpiece such as a wafer is attached. If polished, uniform double-sided polishing can be performed stably. Accordingly, if the dressing plate according to the present invention is used to polish the wafer by performing dressing of the polishing cloth regularly or constantly, a high flatness wafer having almost no peripheral sag can be stably obtained for a long period of time. Can be obtained.

  The dressing plate according to the present invention comprises at least two plate bodies and an elastic layer provided between the plate bodies, and the elastic layer absorbs a change in the shape of the upper and lower surface plates of the double-side polishing apparatus. Therefore, the dress surfaces on the front and back of the plate body act uniformly on both the upper and lower polishing cloths. Therefore, in particular, if the dressing plate of the present invention is used for a double-side polishing apparatus in which a high-hardness polishing cloth is attached to the upper and lower surface plates, and the dressing plate of the present invention is used for regular or regular dressing, the shape will affect the upper and lower surface plates. The thickness and sharpness of the polishing cloth does not vary, the surface state can be made uniform, and as a result, a high flatness wafer having almost no outer peripheral sag can be stably obtained over a long period of time. it can.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. However, the present invention is not limited to these embodiments.
FIG. 1 shows an outline of an example of a dressing plate for polishing cloth according to the present invention. The dressing plate 1 is composed of two plate bodies 2 and an elastic layer 3 provided between the plate bodies 2. The plate body 2 is made of ceramics, and minute irregularities are formed on the dress surface 4.
The kind of ceramics which comprises the plate main body 2 is not specifically limited, For example, an alumina, a zirconia, a silicon carbide, a cermet, a sapphire etc. can be used.

  On the other hand, the elastic body layer 3 is made of rubber excellent in shock absorption, and is bonded between two plate bodies. In addition, pure water is usually used during dressing, but an alkaline polishing slurry is used during polishing and remains even during dressing, or dressing can be performed while supplying such an alkaline polishing slurry. For this reason, the elastic layer 3 is preferably made of, for example, fluorine-based rubber having excellent alkali resistance.

Moreover, if the hardness of the elastic body layer 3 is set to rubber hardness 40-90, it will not be compressed too much and it can absorb the shape change of a surface plate and can perform uniform dressing reliably. The thickness of the elastic body layer is preferably about 2 to 10 mm. If the thickness of the elastic layer 3 is less than 2 mm, the change in shape of the surface plate may not be sufficiently absorbed. On the other hand, if the thickness exceeds 10 mm, it is too thick and it is difficult to perform dressing in the holding hole in the carrier. Therefore, it is preferable to set the thickness as described above.
The method for joining the plate main body 2 made of ceramics and the elastic body layer 3 made of rubber is not particularly limited. For example, the plate body 2 can be firmly joined by using an epoxy resin adhesive. be able to.

FIG. 2 shows an outline of another form of the dressing plate according to the present invention. The dressing plate 21 is provided with an elastic layer 23 between two plate bodies 22, and further, a diamond pellet 25 is provided as a dressing auxiliary member around both sides to form a dress surface 24. The diamond pellet 25 is obtained by forming diamond abrasive grains into a pellet by nickel electrodeposition or the like, and diamond abrasive grains having a count of 60 to 200 are preferable. By providing such a diamond pellet 25, the dressing action can be made higher, and a high-hardness polishing cloth can be suitably dressed. In addition, in the dressing plate 21 of FIG. 2, the diamond pellet 25 is provided only in the peripheral part of both surfaces, but you may provide in the whole surface.
In addition, the dressing auxiliary member is not limited to the diamond pellet as described above, and a member having a higher dressing action than the plate body 22 can be used. For example, the dressing auxiliary member is bonded to the plate body 22 via an epoxy resin adhesive. Just do it.

  FIG. 3 shows an outline of a dressing plate according to still another embodiment of the present invention. In the dressing plate 31, an elastic layer 33 is provided between two ring-shaped ceramic body plates 32. Annular grooves 36 are formed on both surfaces of the dressing plate 31, and a number of diamond pellets 35 are provided in the grooves 36 to form a dress surface 34.

  As mentioned above, although three forms were illustrated about the dressing plate which concerns on this invention, the shape of a dressing plate, the shape of a dress surface, etc. are not restricted to the above, A various thing can be used. Further, the diameter, thickness, etc. of the dressing plate may be appropriately set according to the size of the double-side polishing apparatus, and are not limited.

  Next, the case where a polishing cloth is dressed using the dressing plate according to the present invention will be described for a double-side polishing apparatus. If the dressing plate according to the present invention is a double-side polishing apparatus that performs polishing with a workpiece sandwiched between an upper surface plate and a lower surface plate to which the polishing cloth is attached, the form of the apparatus and the type of the polishing cloth are particularly Although it can apply without limitation, the case where dressing is performed using the above-described dressing plate 21 will be described while explaining a double-side polishing apparatus using a high-hardness polishing cloth as an example.

  FIGS. 11A and 11B show an example of a double-side polishing apparatus. The double-side polishing apparatus 61 includes an upper surface plate 5 and a lower surface plate 6. The upper surface plate 5 has a cylinder rod 12 a that rotates while applying a polishing load to the upper surface plate 5, and the load is applied to the upper surface plate 5. A housing 13 or the like is attached. A cooling means for controlling temperature and a slurry supply pipe 14 for supplying slurry are provided in the surface plate 5. Further, when the silicon wafer or the dressing plate is supplied to or discharged from the carrier plate 9, the upper surface plate 5 can be moved up and down in the vertical direction by an elevating device (not shown).

On the other hand, in addition to the rotating rod 12b, a thrust bearing 15 for supporting the load of the surface plate 6 is attached to the lower surface plate 6, and cooling means for controlling the temperature is provided in the surface plate 6. Yes.
At the time of wafer polishing or dressing, the upper and lower surface plates 5 and 6 are rotated in a horizontal plane by a motor or a speed reducer (not shown) so that the rotation speed and the like can be controlled.

  Polishing cloths 7 and 8 are attached to the surface plates 5 and 6, respectively. In addition, as mentioned above, the dressing plate of the present invention can be applied without being limited to the material of the polishing cloth, etc., and the nonwoven fabric that has been used conventionally, and further, the nonwoven fabric impregnated with urethane resin and cured However, there is an advantage that a hard polishing cloth other than a nonwoven fabric, preferably a high-hardness polishing cloth having a Shore D hardness of 40 or more can be uniformly dressed.

  As such a high hardness abrasive cloth, for example, in a hard water-insoluble thermoplastic polymer or a crosslinked elastomer as disclosed in JP 2000-34416 A or JP 2002-134445 A, an average is used. An abrasive cloth formed by dispersing a water-soluble substance having a small particle size can be used. With such a polishing cloth, the particulate water-soluble substance exposed on the surface of the polishing cloth elutes to form fine pores on the surface, and the water-soluble substance remains inside to form pores. Therefore, the polishing pad has a high hardness. In addition, a polishing cloth having an independent foam structure, for example, a polishing cloth based on a foamed polyurethane sheet having independent fine bubbles may be used. Such an abrasive cloth is preferably an extremely hard abrasive cloth and has a micropore on the polishing surface, so that the polishing ability is relatively high and preferable. Note that the higher the hardness of the polishing cloth, the greater the effect of improving fine irregularities. However, considering the polishing ability and the like, an upper limit of about 100 Shore D hardness is appropriate.

As other polishing cloth forms, a multilayer polishing cloth having two or more layers in which polishing cloths made of a plurality of materials are laminated may be used. Also in such a case, it is preferable that the hardness of the polishing cloth on the surface layer serving as the polishing surface is high.
If a polishing cloth having a high hardness as described above is used, minute irregularities on the wafer surface can be improved.

The carrier plate 9 is held by a carrier holder 16, and four bearing portions 17 protruding outward are provided at equal intervals on the outer peripheral portion of the holder 16. An eccentric arm 18 is rotatably inserted in each bearing portion 17, and a rotating shaft 19 is attached to the center portion of the lower surface of each eccentric arm 18. Then, by rotating the sprocket provided on the rotation shaft 19 of each eccentric arm 18 by the timing chain 20, all the eccentric arms 18 are synchronously rotated within the horizontal plane around the rotation shaft 19. Thereby, the carrier plate 9 held by the carrier holder 16 can perform a circular motion so as to draw a small circle in a horizontal plane without rotating.
The material of the carrier plate 9 and the number of holding holes are not particularly limited. For example, the carrier plate 9 is made of glass epoxy or vinyl chloride, and the number of holding holes is, for example, five holding holes 64 as shown in FIG. Double-side polishing can be performed by using the carrier plate 63 having the wafer W in each holding hole 64.

In such a double-side polishing apparatus 61, all points on the carrier plate 9 draw a locus of a small circle of the same size as indicated by C in FIG. 11B due to the circular motion without rotation. There is an advantage that the wafer W can be uniformly polished.
On the other hand, when dressing the polishing cloths 7 and 8, if a conventional dressing plate is inserted in the holding hole 64 of the carrier plate 9 instead of the wafer W and dressing is performed, uneven contact of the dressing plate (dressing unevenness) is likely to occur. Also, there is a drawback that it is easily affected by the shape of the upper and lower surface plates. Therefore, it is necessary to perform uniform dressing on such a double-side polishing apparatus 61 by using the dressing plate of the present invention without affecting the shape of the upper and lower surface plates.

  Since the dressing can be performed in the same manner as the polishing of the wafer, the same carrier plate 63 as the polishing of the wafer W may be used. However, it is preferable that the dressing is performed wider than the area where the wafer W is polished. Accordingly, for the dressing, for example, as shown in FIG. 12B, a dedicated carrier plate 73 having a holding hole 74 larger than that for the wafer is prepared, and the dressing plate 10 is also dressed by using a larger one than the wafer W. It is preferable to carry out.

  When performing dressing, the dressing plate 21 of the present invention is sandwiched between the upper surface plate 5 and the lower surface plate 6 with respect to the double-side polishing device 61 as shown in FIG. 4, and the device 61 is operated in the same manner as the wafer polishing. Then, the upper and lower polishing cloths 7 and 8 are simultaneously dressed. At this time, even if the upper and lower surface plates 5 and 6 are deformed as shown in FIG. It acts and uniform dressing of the polishing cloths 7 and 8 can be performed. With such dressing, dressing as schematically shown in FIG. 6 can be performed.

  When performing dressing, it is preferable to supply a dressing solution such as pure water or an alkaline polishing slurry used during polishing from the slurry supply pipe 14 or a dedicated supply pipe. In particular, if the dressing liquid is pure water, it is cheaper than the polishing slurry, and it is easy to remove debris and the like present in the polishing cloth. The supply amount of the dressing liquid varies depending on the size of the polishing apparatus (carrier plate) and the like, but is usually about 5 to 15 liters / minute. However, the kind and the supply amount of the dressing liquid are not limited to the above.

Also, the rotational speed and direction of each surface plate are not limited, and the pressing force on the wafer or dressing plate is not particularly limited. However, when polishing the wafer, the rotational speed is usually 5 to 30 rpm, the pressing force (load) on the wafer. ) Is about 100 to 350 g / cm ^2, when performing dressing of a high-hardness polishing cloth (for example, Shore D hardness of 40 or more), it is preferable to perform at a lower rotational speed and lower load than the polishing conditions. For example, the rotation speed is 5 to 20 rpm and the load is about 10 to 300 g / cm ² . In addition, when dressing with respect to the nonwoven fabric type abrasive cloth (Asker C hardness of about 60-90) used conventionally, since it is necessary to compress an abrasive cloth, it carries out with a load higher than polishing conditions. Is preferred.

  By performing dressing using the dressing plate 21 according to the present invention as described above, it is possible to uniformly set both the upper and lower polishing cloths 7 and 8 without being affected by the upper and lower surface plates. Therefore, after performing dressing in this way, both sides of the wafer can be polished extremely uniformly by sandwiching the wafer between the upper surface plate and the lower surface plate, and high flatness with no peripheral sag The wafer of the degree can be obtained.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to these.
(Example)
A polishing cloth made of a closed foam polyurethane sheet (Shore D hardness 98: Example 1) as a polishing cloth in a double-side polishing apparatus as shown in FIG. 11 and a polishing cloth (Shore D hardness) in which a water-soluble substance is added to a crosslinked elastomer. 45: Each of the two types of polishing cloths of Example 2) was used for polishing.
First, dressing of the polishing cloth was performed. The dressing plate is of the form shown in FIG. 3 and is made of alumina ceramics and the elastic layer is made of fluoro rubber (rubber hardness 80) and has a thickness of 5 mm. 200 diamond pellets provided concentrically were used.

For dressing, the above dressing plate was set on a carrier plate having four holding holes, and the upper and lower surface plates were each set to have a rotational speed of 10 rpm and a load of 200 g / cm ² . During dressing, dressing was performed while supplying pure water at a flow rate of 10 liters / minute.

After dressing, double-side polishing of a silicon wafer having a diameter of 300 mm was performed. For polishing, five etched silicon wafers are set on a carrier plate having five holding holes, the upper and lower surface plates each have a rotation speed of 20 rpm, a load of 250 g / cm ^2, and contain colloidal silica as an abrasive. An alkaline solution was used.
As a result, in both Example 1 and Example 2, a wafer with a high flatness (GBIR = 0.5 μm or less) having a polishing allowance (removal allowance) of 5 μm or more on one side was obtained.

Dressing was repeated in the same manner and polishing was repeated.
As a result, both Example 1 and Example 2 were able to perform double-sided polishing with the same level of high flatness and 20 batches or more of batch variation with the same level of high flatness.

(Comparative example)
Except for using a conventional dressing plate as shown in FIG. 7, dressing was performed in the same manner as in the example, and then the silicon wafer was polished.
Depending on the method for correcting pad clogging, a wafer with a poor flatness may be obtained suddenly, resulting in large variations in wafer quality between batches. Moreover, even if dressing was performed in about 5 to 10 batches, the wafer shape deteriorated, and the polishing cloth had to be replaced.

The present invention is not limited to the above embodiment. The above embodiment is merely an example, and the present invention has the same configuration as that of the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.
For example, the dressing plate of the present invention is not limited to the above-described double-side polishing apparatus, but can be similarly applied to other forms of double-side polishing apparatuses such as a conventional 4-way double-side polishing apparatus.
Moreover, although the case where the silicon wafer is polished has been described in the above-described embodiments, the object to be polished is not particularly limited, and the present invention is preferably applied to polishing a compound semiconductor substrate, a quartz glass substrate, or the like. Can do.

It is a figure which shows the outline of an example of the dressing plate which concerns on invention. (A) Plan view (B) Cross section It is a schematic sectional drawing which shows another example of the dressing plate which concerns on this invention. It is a figure which shows the outline of another example of the dressing plate which concerns on this invention. (A) Plan view (B) Cross section It is the schematic which shows the state which set the dressing plate shown in FIG. 2 to the double-side polish apparatus. It is a schematic diagram at the time of performing dressing in FIG. It is explanatory drawing which shows the surface state before and after dressing of a high-hardness abrasive cloth. It is the schematic which shows an example of the conventional dressing plate. (A) Plan view (B) Cross section It is the schematic which shows another example of the conventional dressing plate. (A) Plan view (B) Cross section It is the schematic which shows the state which set the conventional dressing plate to the double-side polish apparatus. It is a schematic diagram which shows the contact nonuniformity at the time of dressing using the conventional dressing plate. It is a figure which shows the outline of an example of a double-side polish apparatus. (A) Side view (B) Plan view It is a schematic plan view of a carrier plate. (A) Five holding holes (B) Three holding holes It is the schematic which shows the planetary gear structure of a 4 way system of a double-side polish apparatus.

Explanation of symbols

1, 21, 31 ... Dressing plate, 2, 22, 32 ... Plate body,
3, 23, 33 ... elastic layer, 4, 24, 34 ... dress surface, 5 ... upper surface plate,
6 ... lower surface plate, 7, 8 ... polishing cloth, 9 ... carrier plate,
10 ... Dressing plate, 11 ... Holding hole,
12a, 12b ... cylinder rod, 13 ... housing, 14 ... slurry supply pipe,
15 ... Thrust bearing, 16 ... Carrier holder, 17 ... Bearing part,
18 ... Eccentric arm, 19 ... Rotating shaft, 20 ... Timing chain,
25, 35 ... Diamond pellet, 36 ... Groove, 41 ... Dressing plate,
44 ... Dress surface 51 ... Dressing plate 52 ... Hole 53 ... Groove
54 ... Dress surface, 61 ... Double-side polishing machine, 63, 73 ... Carrier plate,
64, 74 ... holding holes, 101 ... sun gear, 102 ... internal gear,
103: Carrier plate 104: Holding hole W: Workpiece (wafer)

Claims (10)

  A polishing cloth dressing plate for simultaneously dressing the polishing cloth of the upper surface plate and the lower surface plate with respect to a double-side polishing apparatus comprising an upper surface plate and a lower surface plate to which an abrasive cloth is attached, comprising at least two sheets A dressing plate for polishing cloth, comprising a plate body and an elastic layer provided between the plate bodies.   The dressing plate for an abrasive cloth according to claim 1, wherein the elastic layer is made of rubber.   The dressing plate for an abrasive cloth according to claim 1 or 2, wherein the elastic body layer has a rubber hardness of 40 to 90.   The dressing plate for an abrasive cloth according to any one of claims 1 to 3, wherein the elastic layer has a thickness of 2 to 10 mm.   The dressing plate for an abrasive cloth according to any one of claims 1 to 4, wherein the plate body is made of ceramics.   The dressing auxiliary member having a dressing action higher than that of the plate body with respect to the polishing cloth is provided on both surfaces of the dressing plate, according to any one of claims 1 to 5. Dressing plate for polishing cloth.   The dressing plate for polishing cloth according to claim 6, wherein the dressing auxiliary member is a diamond pellet.   A method of simultaneously dressing both upper and lower polishing cloths with a dressing plate sandwiched between the upper and lower surface plates for a double-side polishing apparatus comprising an upper surface plate and a lower surface plate to which an abrasive cloth is attached. A dressing method for an abrasive cloth, wherein dressing is performed using the dressing plate according to claim 1 as the dressing plate.   The polishing cloth dressing method according to claim 8, wherein the polishing cloth affixed to the upper surface plate and the lower surface plate is a high hardness polishing cloth having a Shore D hardness of 40 or more.   Using a double-side polishing apparatus comprising an upper surface plate and a lower surface plate to which a polishing cloth is attached, a work polishing method for simultaneously polishing both surfaces of the work by sandwiching a plate-like work between the upper surface plate and the lower surface plate The dressing plate according to any one of claims 1 to 7 is sandwiched between the upper surface plate and the lower surface plate, and the upper and lower polishing cloths are simultaneously dressed, and then the workpiece is A method for polishing a workpiece, wherein polishing is performed between the upper surface plate and the lower surface plate.

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