JP6935635B2 - Carrier for holding objects to be polished for double-sided polishing equipment - Google Patents

Description

In the present invention, at least one of the upper and lower platens and the object to be polished is rotated while the object to be polished is sandwiched between the upper and lower platens to which the polishing cloth is attached and pressure-welded, and both sides of the object to be polished are polished at the same time. The present invention relates to a carrier for holding an object to be polished, which is used in a double-sided polishing apparatus to be processed, and which is provided with small holes for passing a polishing agent around the holes for holding the object to be polished.

In double-sided polishing of an object to be polished made of silicon wafer, compound semiconductor wafer, aluminum magnetic disk substrate, glass magnetic disk substrate or photomask glass, crystal oscillator, ceramics, etc., the object to be polished is adapted to its shape. The internal gear is held in the holding hole of the carrier for holding the object to be polished, which is molded so as to have a holding hole and an outer peripheral tooth that meshes with the internal gear and the sun gear of the double-sided polishing device at the outer peripheral edge thereof. And the sun gear is rotated to make a planetary motion, and at the same time, the upper and lower plates are rotationally driven to polish both the upper and lower surfaces of the object to be polished at the same time. This carrier for holding the object to be polished is used as a member of a polishing device for simultaneously lapping or mirror polishing the object to be polished on both sides.

Conventionally, a carrier for holding an object to be polished uses a metal material such as steel or stainless steel, a fiber reinforced plastic (FRP), or the like as a material, and is processed so as to have a holding hole large enough to hold the object to be polished. Further, it is generally manufactured by a method of processing the outer periphery thereof so as to have outer peripheral teeth that mesh with the gear shapes of the internal gear and the sun gear.

In the above-mentioned polishing process, the slurry is supplied to the processed portion from the slurry supply hole formed in the upper surface plate during the polishing process, enters the lower surface plate side through the gap of the holding hole, and simultaneously polishes both the upper and lower surfaces of the object to be polished. It is to be processed. However, when a carrier for holding an object to be polished is used such that the holes drilled in the carrier for holding the object to be polished are only the holes for holding the object to be polished, the carrier for holding the object to be polished and the object to be polished are almost the same as the lower platen. Since the shape covers the entire surface, the slurry does not wrap around to the lower platen side sufficiently, and uniform processing becomes difficult. Therefore, the shape of the object to be polished after processing becomes tapered, the outer circumference sags, the finished surface roughness varies, or the surface roughness of the upper and lower surfaces differs, which is an unfavorable phenomenon. The outbreak was pointed out. Further, it has been pointed out that the slurry is wasted a lot because it is easily discharged to the outside of the system before it sufficiently contributes to the polishing process due to the centrifugal force accompanying the rotation.

In particular, in recent years, as the manufacturing technology of the object to be polished has advanced, the above-mentioned problem regarding the carrier for holding the object to be polished has become more prominent, and its solution is strongly demanded.

In order to avoid the above-mentioned phenomenon, a method of drilling a discard hole (also referred to as a discard hole) in a place other than the holding hole and using it as a slurry passage hole to facilitate the wraparound of the slurry to the lower platen side. However, it has been conventionally proposed (Patent Document 1 or Patent Document 2).

Further, in Patent Document 3, a mesh-like void portion is provided in a region other than the holding hole of the carrier for holding the object to be polished to improve the wraparound of the slurry to the lower platen side, and the wave of the object to be polished after processing is improved. A method for preventing the phenomenon is disclosed.

In Patent Document 4, by defining the diameter of the slurry passing holes and the distance between the slurry passing holes, the carrier for holding the object to be polished suppresses the displacement amount of the carrier for holding the object to be polished so that distortion does not occur. Proposed.

Japanese Unexamined Patent Publication No. 11-170164 Japanese Unexamined Patent Publication No. 2004-291115 Japanese Unexamined Patent Publication No. 2000-84835 Japanese Unexamined Patent Publication No. 2016-22542

However, even with these methods, the supply (wraparound) of the slurry to the back surface of the object to be polished (lower surface plate side) is not always sufficient, and the homogenization of the supply amount of the slurry to the upper and lower surface plates is not sufficient. That is, it has never been easy to obtain an object to be polished having a fine upper and lower surface roughness, excellent parallelism, and excellent flatness.

The present inventors have carried out diligent research on a carrier for holding an object to be polished used for double-sided polishing of an object to be polished such as a silicon wafer, and have completed the present invention. An object of the present invention is to provide a carrier for holding an object to be polished, which solves the above-mentioned problems. That is, the present inventors arrange small holes having a constant pore size at regular intervals in the region of the carrier base material for holding the object to be polished other than the holding holes for the object to be polished, and the pore diameters of the small holes are the base material. By arranging the slurry with a gradient so that it increases from the inside to the outside, the flow of the slurry is homogenized, the surface roughness on both the upper and lower sides is uniform, there is no unevenness, and it has high parallelism and high flatness. It was found that an object to be polished can be obtained.

The above-mentioned problem is a carrier for holding an object to be polished having one or more holding holes for holding the object to be polished, which has the same center as the holding hole and has a radius larger than the radius thereof. Both sides of which a plurality of small holes are perforated in the carrier base material inside the virtual concentric circles drawn as described above, and a plurality of small holes having a diameter larger than the small holes are perforated in the carrier base material outside the virtual concentric circles. Oite the workpiece holding carrier for the polishing apparatus that the diameter of the plurality of small holes drilled in the inner side of the carrier substrate from the virtual concentric circles, the radius of more than 3% of the object to be polished, 15% or less It is manually achieved workpiece holding carrier according to claim. Further, the above-mentioned problem is a carrier for holding an object to be polished having one or more holding holes for holding the object to be polished, which has the same center as the holding hole and has a radius larger than the radius thereof. A plurality of small holes are drilled in the carrier base material inside the virtual concentric circles, and a plurality of small holes having a diameter larger than the small holes are drilled in the carrier base material outside the virtual concentric circles. In the carrier for holding the object to be polished for the double-sided polishing device, the diameters of the plurality of small holes drilled in the carrier base material outside the virtual concentric circles are 6% or more and 30% or less of the radius of the object to be polished. This is achieved with a carrier for holding an object to be polished.

In the carrier for holding an object to be polished of the present invention, it is preferable that the difference between the radius of the object to be polished (work) and the radius of the above-mentioned virtual concentric circles is equal to or less than the radius of the holding hole. When the difference in radii of the two circles this exceeds the radius of the holding hole, the area to drill small holes from the virtual concentric circle inside the carrier base is wider than the small holes from the virtual concentric to the outside of the carrier base Since the region for perforating the small holes having a large diameter is narrowed, the homogenization of the slurry flow due to the gradient of the size of each small hole becomes insufficient. Specifically, it is set in the range of 10% to 70% of the radius of the object to be polished.

In the carrier for holding an object to be polished of the present invention, the diameter of a plurality of small holes drilled in the carrier base material inside the above-mentioned virtual concentric circles may be 3% to 15% of the radius of the object to be polished (work). It is necessary . If it is less than 3%, even if the surface tension of the slurry acts on the small holes, the action as a slurry passage hole for wrapping the slurry toward the lower platen side is reduced. If it exceeds 15%, the ability to hold the slurry supplied from the small holes drilled in the carrier base material outside the virtual concentric circles decreases, and the slurry is supplied to the polished surface of both the upper and lower surface plates and the object to be polished. The balance deteriorates and uniform polishing becomes impossible. Specifically, it is set in the range of φ3 mm to φ15 mm.

In the carrier for holding an object to be polished of the present invention, the diameter of a plurality of small holes, that is, the larger small holes, which are formed in the carrier base material outside the above-mentioned virtual concentric circles is 6% of the radius of the object to be polished (work). Or need to be 30%. If it is smaller than 6%, the difference in diameter from the smaller pores, that is, the pores drilled in the carrier substrate inside the virtual concentric circles, becomes smaller, and the slurry flow is uniform due to the gradient of the pore size. Insufficient conversion. On the other hand, if it exceeds 30%, the ability to hold the slurry of the small holes drilled in the carrier base material outside the virtual concentric circles decreases, and the slurry is supplied to the small holes punched in the carrier base material inside the virtual concentric circles. Is insufficient, and the balance of the slurry supply to the polished surface of both the upper and lower surface plates and the object to be polished is deteriorated, and uniform polishing cannot be performed. Specifically, it is set in the range of φ10 mm to φ30 mm.

Further, in the carrier for holding the object to be polished, in the case of the small holes inside the virtual concentric circles described above, the distance between the plurality of small holes other than the holes for holding the object to be polished is the small holes. It is preferably less than or equal to the diameter. If the arrangement is made at intervals larger than the diameter, the arrangement of the holes becomes too sparse, and the effect intended by the present invention cannot be obtained. Specifically, it is set in the range of 30% to 100% with respect to the small hole diameter.

Further, in the carrier for holding the object to be polished, in the case of the small holes outside the above-mentioned virtual concentric circles, the distance between the plurality of small holes other than the holes for holding the object to be polished and the adjacent small holes is the small holes. It is preferably less than or equal to the diameter. If the arrangement is made at intervals larger than the diameter, the arrangement of the holes becomes too sparse, and the effect intended by the present invention cannot be obtained. Specifically, it is set in the range of 30% to 100% with respect to the small hole diameter.

A feature of the present invention is that a plurality of small holes are provided in a region other than the object holding holes of the carrier for holding the object to be polished, and a gradient is formed so that the pore diameters of the small holes increase from the inside to the outside of the carrier base material. By attaching and arranging the slurry, the slurry can be smoothly diffused to the polished surface of both the upper and lower surface plates, and the distribution of the slurry becomes uniform. In the following description of the present invention, an example in which the distribution regions of the small holes are doubled is taken up, but the present invention is not particularly limited, and this may be triple or more.

By the carrier for holding the object to be polished of the present invention, the supply of the slurry, which is an abrasive in double-sided polishing, to the polishing surfaces of both the upper and lower surface plates is equalized, and at the same time, the distribution of the slurry on the surface plate polishing surface is also uniform. Was made. As a result, it has become possible to obtain an object to be polished having fine surface roughness on both the upper and lower surfaces of the object to be polished, a surface without spots, and an excellent flatness. In addition, the consumption of slurry is reduced, and the cost of polishing can be reduced.

It is a top view of the carrier for holding an object to be polished of this invention. It is a plane enlarged view of the main part of the carrier for holding an object to be polished of this invention. It is a top view of an example of the carrier for holding an object to be polished by the prior art. It is a top view of another example of the carrier for holding an object to be polished by the prior art. It is a top view of another example of the carrier for holding an object to be polished by the prior art. It is a graph which shows the result of the thickness distribution (Y axis) measurement in the diameter direction (X axis) of the silicon wafer of φ300 mm polished by using the carrier for holding the object to be polished of this invention. It is a graph which shows the result of the thickness distribution (Y axis) measurement in the diameter direction (X axis) of the silicon wafer of φ300 mm polished by using the conventional carrier for holding the object to be polished shown in FIG. It is a graph which shows the result of the thickness distribution (Y axis) measurement in the diameter direction (X axis) of the silicon wafer of φ300 mm polished by using the conventional carrier for holding the object to be polished shown in FIG. It is a graph which shows the result of the thickness distribution (Y axis) measurement in the diameter direction (X axis) of the silicon wafer of φ300 mm polished by using the conventional carrier for holding the object to be polished shown in FIG.

Next, the contents of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a carrier for holding an object to be polished, which is one of the embodiments of the present invention, and FIG. 2 is an enlarged view of a main part thereof. A plurality of holding holes 1 (three in this embodiment) for holding an object to be polished having a diameter of 300 mm are perforated. In each of the three holding holes for holding the object to be polished, a virtual concentric circle 2 having the same center point as each holding hole and having a radius of 210 mm is drawn, and from the peripheral edge of the holding hole 1 for holding the object to be polished to the inner peripheral edge of the virtual concentric circle 2. Let the region A be the region A and the region outside it be the region B. Then, a small hole 3 for passing a slurry having a diameter of 10 mm is drilled in the A region so that the distance from the adjacent small hole for passing the slurry is 7.5 mm, and a small hole for passing a slurry having a diameter of 15 mm is formed in the region B. The holes 4 were drilled so that the distance from the adjacent small holes for passing the slurry was 10 mm.

In the case of the carrier for holding the object to be polished shown in FIGS. 1 and 2, the radius of the three holding holes 1 is 150 mm, and the radius of the virtual concentric circles 2 having the same center point is 210 mm. Is 60 mm, and the value is smaller than the radius of the holding hole for holding the object to be polished, 150 mm. Since the diameter of the small holes for passing the plurality of slurries drilled in the A region is φ10 mm, it is 6.67% of the radius of 150 mm of the silicon wafer to be polished. Further, since the diameter of the small holes for passing the plurality of slurries drilled in the B region is φ15 mm, it is 10.0% of the radius of 150 mm of the silicon wafer to be polished.

The object to be polished (work) referred to in the present invention refers to a silicon wafer, a compound semiconductor wafer, an aluminum magnetic disk substrate, a glass magnetic disk substrate, photomask glass, a crystal oscillator, ceramics, or the like, and is particularly limited. Although not, it is mainly intended for silicon wafers. The shape is almost circular, but the size (diameter) and shape are not particularly limited. For example, a large-diameter object to be polished such as a silicon wafer having a diameter of 300 mm can be mentioned, and those objects to be polished can be mentioned. The effect of the present invention on an object is remarkable. Further, the double-sided polishing referred to in the present invention refers to polishing, pre-polishing, wrapping, etc., and is not particularly limited.

The material used for the carrier for holding the object to be polished of the present invention is a metal such as stainless steel, carbon tool steel (SK steel), high carbon chrome bearing steel, high speed tool steel, alloy tool steel, high tension steel or titanium. Composite resin such as ceramics, polyamide, polyacetal, polyvinyl chloride, polycarbonate, polyimide, polyamideimide, epoxy or fiber material such as glass fiber, carbon fiber, aramid fiber, cloth bake and epoxy resin, polyamide resin, phenol resin, etc. Fiber reinforced plastic (FRP) can be used, but is not particularly limited. The surface of the carrier for holding the object to be polished may be coated with a resin such as polypropylene or diamond-like carbon. The carrier for holding the object to be polished of the present invention is provided with a resin frame such as an aramid resin at the inner peripheral edge of the hole for holding the object to be polished in order to prevent damage to the outer edge of the object to be polished.

FIG. 3 is an explanatory view of a carrier for holding an object to be polished according to the prior art. An amorphous slurry passage hole is formed in addition to the holding hole 1 for holding the object to be polished. The shape of passage holes have substantially rhombic, substantially triangular or the like amorphous form.

FIG. 4 is also an explanatory view of a carrier for holding an object to be polished according to the prior art. A plurality (3) holding holes for holding an object to be polished having a diameter of 300 mm are perforated. Slurry passage holes of different sizes are formed in regions other than the respective holding holes. Small holes for Luz rally passes put in this prior art and three small holes 5 for φ100mm slurry passes, is formed by small holes 6 for six φ50mm slurry pass. These small holes for passing the slurry are composed of those having a small hole diameter and those having a large hole diameter. No array is done.

FIG. 5 is also an explanatory view of a carrier for holding an object to be polished according to the prior art. A plurality (three) holding holes 1 for holding an object to be polished having a diameter of 300 mm are perforated. A plurality of small holes 7 for passing a slurry having a diameter of 30 mm are formed in regions other than the respective holding holes so that the distance from the adjacent small holes is 22 mm. There is only one type of small hole diameter for passing the slurry, and it is not a mixture of small holes having different hole diameters as in the present invention.

In FIGS. 1 and 2, as one of the embodiments of the carrier for holding an object to be polished of the present invention, a carrier for holding an object to be polished having three holding holes for holding an object to be polished having a diameter of φ300 mm is formed on one sheet. Shown. In this case, since the area of the region other than the holding holes is relatively small, in this embodiment, the region for drilling the small holes is divided by a single virtual concentric circle (single virtual concentric circle). If it is singular, it is possible to make the area for perforating small holes for passing slurry separated by a plurality of virtual concentric circles having different radii larger than that. Assuming a carrier for holding an object to be polished with only one holding hole for holding a silicon wafer of φ300 mm, the area formed by the virtual concentric circles is divided into A by a plurality of virtual concentric circles (here, double virtual concentric circles) having different radii. It is possible to triple the region, the B region, and the C region. In this case, for example, the A region is φ5 mm (ratio to the radius of the object to be polished 3.33%), the B region is φ10 mm (ratio to the radius of the object to be polished 6.67%), and the C region is φ15 mm (ratio to the radius of the object to be polished). It is possible to perforate small holes for passing slurry (ratio of 10.00% to the radius of the object), and a higher effect can be expected. When drilling small holes for slurry passage in a region separated by multiple virtual concentric circles, drill a small hole for slurry passage with the smallest diameter in the region closest to the holding hole, and the outer region adjacent to that region. In the region closest to the retention hole, a small hole for slurry passage having a diameter larger than that of the small hole for slurry passage is drilled, and in the region adjacent to the outer region thereof, the pore is closest to the retention hole. It is possible to drill small holes for passing slurry having a diameter larger than the small holes for passing slurry which are drilled in the outer region adjacent to the region. That is, when there are three or more regions separated by a plurality of virtual concentric circles, the diameter of the small holes for passing the slurry is based on the diameter of the small holes for passing the slurry in the region closest to the holding hole. It is possible to make a hole so that the diameter of the small hole for passing the slurry increases as the area becomes larger.

Example 1
A carrier for holding an object to be polished having the same shape as the carrier for holding an object to be polished shown in FIG. 1 was prepared. The material of the prepared carrier for holding the object to be polished was stainless steel, and the thickness thereof was 774 μm. The carrier for holding the object to be polished is provided with a resin frame made of aramid resin on the inner peripheral edge of the hole for holding the object to be polished in order to prevent damage to the outer edge of the object to be polished.

Using the above-mentioned carrier for holding an object to be polished, a polishing test of a silicon wafer having a diameter of 300 mm was performed. The polishing machine and polishing processing conditions are as follows.
Polishing machine: Speedfam double-sided polishing machine Polishing cloth: Nitta Haas MH (registered trademark) series Polishing agent: Fujimi Incorporated GLANZOX (registered trademark) series Upper surface plate rotation: Counterclockwise Lower surface plate rotation: Clockwise internal gear rotation: Clockwise sun gear rotation: Clockwise load (upper surface plate load): Surface pressure 10 kPa
Processing time: 30 minutes

The thickness distribution in the diameter direction of the silicon wafer polished under the above conditions was measured. A known thickness measuring device (manufactured by Hamamatsu Photonics Co., Ltd.) was used as the measuring device. The measurement results are shown in FIG. The PV (Peak to Valley) value indicating the thickness distribution in the radial direction, that is, the value indicating the difference between the maximum measured value and the minimum measured value of the work was 0.048 μm. As is clear from the graph of FIG. 6, there is almost no variation in the diameter direction of the silicon wafer polished by using the carrier for holding the object to be polished of the present invention, and no phenomenon such as surface sagging is observed. The PV value of 0.048 μm is an extremely excellent value.

Comparative Example 1
Using the conventional carrier for holding the object to be polished shown in FIG. 3, a polishing experiment was performed under exactly the same conditions as in Example 1. The specifications of the carrier for holding the object to be polished used in this comparative example are the same as the carrier for holding the object to be polished used in Example 1 except for the shape and arrangement of the slurry passage holes.

Using this carrier for holding the object to be polished, the thickness distribution in the diameter direction of the polished silicon wafer was measured. The measurement results are shown in FIG. The obtained PV value was 0.524 μm. As is clear from the graph of FIG. 7, the outer peripheral portion tends to be thinner than the central portion. The so-called surface sagging phenomenon is prominent. The PV value is 0.524 μm, which is 10 times or more worse than that of Example 1. Further, it is recognized that the variation in thickness in the radial direction is larger than that in Example 1 as a whole.

Comparative Example 2
Using the conventional carrier for holding the object to be polished shown in FIG. 4, a polishing experiment was performed under exactly the same conditions as in Example 1. The specifications of the carrier for holding the object to be polished used in this comparative example are the same as the carrier for holding the object to be polished used in Example 1 except for the diameter and arrangement of the slurry passage holes.

When a virtual concentric circle 2 having the same center point as each holding hole is drawn in the holding hole 1 for holding the object to be polished of this conventional carrier for holding the object to be polished, a slurry of φ50 mm passes through the inner circumference of the virtual concentric circle. Small holes 6 for passing a slurry of φ50 mm are arranged on the inner circumference of a virtual concentric circle, and small holes 5 for passing a slurry of φ100 mm are arranged in a virtual concentric circle. No matter what radius the virtual concentric circles are set to, such as being arranged so as to overlap on the circumference, or the small holes for passing slurry of φ50 mm and φ100 mm are arranged so as to overlap on the circumference of the virtual concentric circles. The arrangement does not satisfy the constituent requirements of the invention.

In the case of the carrier for holding the object to be polished shown in FIG. 4, the radius of the plurality of holding holes 1 is 150 mm, and the radius of the virtual concentric circles 2 having the same center point is 210 mm as in the present invention. The region from the peripheral edge of the holding hole to the inner peripheral edge of the virtual concentric circle was designated as the A region, and the region outside the peripheral region was designated as the B region. Then, when the small holes 6 for passing the slurry of φ50 mm and the small holes 5 for passing the slurry of φ100 mm are drilled in the regions other than the holding holes, the small holes for passing the slurry of φ50 mm and φ100 mm overlap on the circumference of the virtual concentric circles. That is, small holes for passing slurry of φ50 mm and φ100 mm are perforated so as to straddle the A region and the B region.

A small hole 6 for passing a slurry of φ50 mm and a small hole for passing a slurry of φ100 mm are drilled so as to straddle the A region and the B region, which is a reference value. It will be 33.33%. Further, the slurry passage hole of φ100 mm is 66.67% of the radius of 150 mm of the silicon wafer.

Using this carrier for holding the object to be polished, the thickness distribution in the diameter direction of the polished silicon wafer was measured. The measurement results are shown in FIG. The obtained PV value was 0.206 μm. As is clear from the graph of FIG. 8, the outer peripheral portion of the silicon wafer has a convex shape thinner than the central portion. In addition, the phenomenon of surface sagging appears on the outer peripheral portion. The PV value is 0.206 μm, which is four times or more worse than that of Example 1. Further, it is recognized that the variation in thickness in the radial direction is larger than that in Example 1 as a whole.

Comparative Example 3
Using the conventional carrier for holding the object to be polished shown in FIG. 5, a polishing experiment was performed under exactly the same conditions as in Example 1. The specifications of the carrier for holding the object to be polished used in this comparative example are also the same as the carrier for holding the object to be polished used in Example 1 except for the diameter and arrangement of the slurry passage holes.

When a virtual concentric circle 2 having the same center point as each holding hole is drawn in the holding hole 1 for holding the object to be polished of this conventional carrier for holding the object to be polished, both the inner and outer regions of the virtual concentric circle are formed. , Φ30 mm slurry passage holes are arranged, and even if the virtual concentric circles are set with any radius, the arrangement does not satisfy the constituent requirements of the present invention.

In the case of the carrier for holding the object to be polished shown in FIG. 5, the radii of the three holding holes are 150 mm as in FIG. 4, and the radius of the virtual concentric circles 2 having the same center point is 210 mm as in the present invention. .. The region from the peripheral edge of the holding hole to the inner peripheral edge of the virtual concentric circle is defined as the region A, and the region outside the region is defined as the region B. Then, a small hole 7 for passing a slurry having a diameter of 30 mm was drilled so that the distance between the small holes adjacent to the A region and the B region, which are regions other than the holding holes, was 22 mm.

Since the diameters of the small holes for passing the plurality of slurries drilled in the A region and the B region are both φ30 mm, they are 20% of the radius of 150 mm of the silicon wafer to be polished.

Using this carrier for holding the object to be polished, the thickness distribution in the diameter direction of the polished silicon wafer was measured. The measurement results are shown in FIG. The obtained PV value was 0.231 μm. As is clear from the graph of FIG. 9, the outer peripheral portion of the silicon wafer has a convex shape thinner than the central portion. In addition, the phenomenon of surface sagging appears on the outer peripheral portion. The PV value is 0.231 μm, which is about 5 times worse than that of Example 1. Further, it is recognized that the variation in thickness in the radial direction is larger than that in Example 1 as a whole.

As described above, the difference in quality is clear when the results of Example 1 and Comparative Examples 1 to 3 are compared. The fact that the result of the thickness measurement of Comparative Example 1 is inferior to the result of the thickness measurement of Example 1 is that in the carrier for holding the object to be polished used in Comparative Example 1, the polishing slurry is diffused on both the upper and lower platen surfaces, particularly. It is proved that the wraparound to the lower platen side is not smooth and the distribution of the slurry is not uniform. That is, the carrier for holding an object to be polished according to the present invention is one in which the shape accuracy of the object to be polished after polishing, specifically, the variation in thickness is remarkably improved, and the conventional carrier for holding an object to be polished has. It solves the problem.

According to the present invention, the carrier for holding an object to be polished of the present invention has a problem of the conventional carrier for holding an object to be polished, that is, the supply of the slurry to both the upper and lower platen surfaces is not uniform, and the polishing slurry is covered. The wraparound to the back surface of the polished object (lower platen side) is not sufficient, and therefore the shape of the object to be polished after processing According to the carrier for holding the object to be polished of the present invention, both the upper and lower sides of the object to be polished such as a silicon wafer Both of them have a delicate and uneven surface, and an object to be polished with excellent flatness can be obtained, which greatly contributes to the improvement of the quality and the yield of the object to be polished. Furthermore, it also has the effect of reducing the consumption of slurry, which greatly contributes to the industrial world.

1: Holding hole for holding the object to be polished 2: Virtual concentric circle having the same center point as the holding hole 3: Small hole for passing a slurry of φ10 mm 4: Small hole for passing a slurry of φ15 mm 5: For passing a slurry of φ100 mm Small hole 6: Small hole for passing a slurry of φ50 mm 7: Small hole for passing a slurry of φ30 mm

Claims (5)

A virtual carrier for holding an object to be polished having one or more holding holes for holding the object to be polished, having the same center as the holding holes and having a radius larger than the radius thereof. A cover for a double-sided polishing machine in which a plurality of small holes are perforated in a carrier base material inside the concentric circles, and a plurality of small holes having a diameter larger than the small holes are perforated in a carrier base material outside the virtual concentric circles. The polished object holding carrier is characterized in that the diameters of a plurality of small holes drilled in the carrier base material inside the virtual concentric circles are 3% or more and 15% or less of the radius of the polished object. Holding carrier . A virtual carrier for holding an object to be polished having one or more holding holes for holding the object to be polished, having the same center as the holding holes and having a radius larger than the radius thereof. A cover for a double-sided polishing machine in which a plurality of small holes are perforated in a carrier base material inside the concentric circles, and a plurality of small holes having a diameter larger than the small holes are perforated in a carrier base material outside the virtual concentric circles. The polished object holding carrier is characterized in that the diameters of a plurality of small holes drilled in the carrier base material outside the virtual concentric circles are 6% or more and 30% or less of the radius of the polished object. Holding carrier. The carrier for holding an object to be polished according to claim 1 or 2 , wherein the difference between the radius of the object to be polished and the radius of the virtual concentric circle is equal to or less than the radius of the holding hole. The small hole formed in the carrier substrate of the inner side of the virtual concentric circle, any gap between the adjacent small holes as in claim 1, wherein through the third term, characterized in that said at most the diameter of the stoma A carrier for holding an object to be polished described in Crab. The small holes drilled from the virtual concentric outer side of the carrier substrate, either the interval between the adjacent small holes as in claim 1, wherein through the third term, characterized in that said at most the diameter of the stoma A carrier for holding an object to be polished described in Crab.

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