KR20200135175A - Carrier for double-side polishing apparatus and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a carrier for a both-sided polishing apparatus capable of preventing dislocation or detachment due to high coupling strength in a vertical direction of an insert member, and suppressing the dislocation of an insert member with respect to a carrier body when the insert member is formed, and a manufacturing method thereof. In regard to a both-sided polishing apparatus polishing both sides of a semiconductor wafer, the carrier for a both-sided polishing apparatus, which is placed between upper and lower plates with abrasive fabrics attached thereon respectively and maintains the semiconductor wafer inserted between the upper and lower plates during a polishing procedure, includes: a metal carrier body having a maintenance hole formed therein to maintain the semiconductor wafer; and a resin insert member placed adjacently to an inner circumference surface of the maintenance hole. The surface roughness Ra of the inner circumference surface of the maintenance hole adjacent to the insert member is no less than 1.0 μm.

Description

Carrier for double-sided polishing device and its manufacturing method {CARRIER FOR DOUBLE-SIDE POLISHING APPARATUS AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a carrier for a double-sided polishing apparatus for a semiconductor wafer (hereinafter, also simply referred to as a wafer) and a method for manufacturing the same.

The double-sided polishing device is usually equipped with an upper platen and a lower platen on which a polishing cloth made of non-woven fabric or urethane foam is attached, and has a planetary gear structure in which a sun gear is placed in the center and an internal gear is placed in the outer circumference. It is being used. In the case of polishing the wafer, the wafer is inserted and held inside the wafer holding hole (hereinafter, also referred to as simply holding hole) formed in the carrier. The polishing slurry is supplied to the wafer from the upper and lower platens, and the upper and lower platens are rotated, pressing the polishing cloths facing the upper and lower platens on both sides of the wafer, and rotating the carrier between the sun gear and the internal gear, thereby making each wafer Both sides can be polished at the same time.

The carrier body for a double-sided polishing apparatus having a holding hole for holding a wafer is mainly made of metal such as SK steel, stainless steel, and titanium. When the outer circumference of the wafer and the metal carrier are directly contacted, there is a possibility that cracks or scratches may occur in the wafer. Accordingly, in order to protect the outer peripheral portion of the wafer, a resin ring called an insert member is provided in the inner peripheral portion of the wafer holding hole of the carrier. The resin of this insert member is formed by adhesion processing or injection molding. Since the insert member is in contact with the outer periphery of the wafer, it becomes important when making the edge shape of the wafer.

Regarding this insert member, in order to prevent the insert member from shifting or falling off during the formation of the insert member, wafer processing, and carrier transport, the outer periphery of the insert member and the inner periphery of the retaining hole of the carrier are snow-shaped (楔狀). There is something fitting with ). In the prior art, there is a document that prevents shifting or dropping in the vertical direction by performing groove processing, protrusion processing, or oblique processing on the carrier cross-section (inner peripheral surface of the holding hole) (refer to Patent Document 1-5).

Japanese Patent Publication No. 2002-18708 Japanese Patent Publication No. 2009-012086 Japanese Patent Laid-Open No. 2003-109925 Japanese Patent No. 4605564 Japanese Patent Laid-Open No. 2010-179375

In order to prevent misalignment or dropping of the insert, the fact that the joint part of the insert member and the carrier body is fitted in a snowy manner has little effect on the misalignment or dropping of the insert member in the upper and lower directions, and it is required to improve the adhesive strength in the vertical direction. . In addition, in the case of a tapered shape such that the angle of the inner peripheral surface of the holding hole of the carrier body is inclined with respect to the main surface of the carrier body, the insert member is shifted along the tapered shape during use, or when the insert member is formed. In some cases, the member is formed to be shifted vertically with respect to the carrier body.

Here, the problem of the carrier for a conventional double-sided polishing apparatus will be described with reference to the cross-sectional view of FIG. 4. In this example, the conventional carrier 101 has a tapered shape in which the angle of the inner peripheral surface 104 of the holding hole 103 is slightly inclined with respect to the principal surface 106 of the carrier body 102. In the conventional product, as shown in FIG. 4, the insert member 105 may be formed to be shifted vertically when the insert member 105 is formed, or polished in a state that is shifted vertically during use.

The present invention has been made in view of the above-described problems, and the coupling strength of the insert member in the vertical direction is high, so it is possible to prevent misalignment or dropping, and the misalignment of the insert member with respect to the carrier body when the insert member is formed. An object of the present invention is to provide a carrier for a suppressed double-sided polishing apparatus and a method of manufacturing the same.

In order to achieve the above object, the present invention is a double-sided polishing apparatus for double-sided polishing of a semiconductor wafer, wherein the polishing cloth is disposed between the upper and lower platens to which each is affixed, and the semiconductor wafer is sandwiched between the upper and lower platens during polishing. As a carrier for a double-sided polishing device that holds,

A metal carrier body having a holding hole for holding the semiconductor wafer, and a resin insert member disposed in contact with an inner peripheral surface of the holding hole,

It provides a carrier for a double-sided polishing apparatus, characterized in that the surface roughness Ra of the inner circumferential surface of the holding hole in contact with the insert member is 1.0 μm or more.

As described above, the surface roughness of the inner circumferential surface of the holding hole of the carrier body is rough, and the surface roughness Ra (the arithmetic mean roughness of JIS standard) is 1.0 μm or more, so that the bonding strength between the carrier body and the insert member can be improved. During formation, wafer polishing, etc., it is possible to suppress the vertical shift of the insert member.

Further, the surface roughness Rz of the inner circumferential surface of the holding hole in contact with the insert member may be 5.0 μm or more.

In this way, further, if the surface roughness Rz (maximum height roughness in the JIS standard) is 5.0 μm or more, the shift in the vertical direction of the insert member can be further suppressed.

Further, the inner circumferential surface of the holding hole in contact with the insert member may be perpendicular to the main surface of the carrier body.

If the angle of the inner circumferential surface of the holding hole is vertical with respect to the main surface of the carrier body as described above, it is possible to further prevent the position of the insert member from shifting or shifting to either the top or bottom of the carrier body compared to a tapered case.

In addition, the insert member,

Consisting of inserts by injection molding,

Alternatively, it may be made of an insert material and an adhesive layer between the insert material and the inner peripheral surface of the holding hole.

As described above, the double-sided polishing apparatus of the present invention can be adapted to either one of the insert member by injection molding of the insert material, or the insert material and the adhesive layer, and it is possible to suppress the displacement of the insert member.

In addition, the present invention is a double-sided polishing apparatus for double-sided polishing a semiconductor wafer, wherein a polishing cloth is disposed between the upper and lower platens each affixed, and the double-sided polishing apparatus for holding the semiconductor wafer sandwiched between the upper and lower platens during polishing. As a method of manufacturing a carrier for,

When a holding hole for holding the semiconductor wafer is formed in a metal carrier body, and the insert member is formed by contacting the inner peripheral surface of the holding hole,

There is provided a method for manufacturing a carrier for a double-sided polishing apparatus, comprising forming the insert member after making the surface roughness Ra of the inner circumferential surface of the holding hole in contact with the insert member equal to or greater than 1.0 μm.

In this way, it is possible to obtain a carrier for a double-sided polishing apparatus capable of improving the bonding strength between the carrier body and the insert member and suppressing the shift in the vertical direction of the insert member during formation of the insert member or wafer polishing.

At this time, the insert member may be formed after the surface roughness Rz of the inner circumferential surface of the holding hole that comes into contact with the insert member is set to 5.0 μm or more.

In this way, it is possible to further suppress the shift in the vertical direction of the insert member.

Further, the insert member can be formed after the inner peripheral surface of the holding hole that comes into contact with the insert member is made perpendicular to the main surface of the carrier body.

In this way, it is possible to further prevent displacement of the insert member in either the upper or lower side of the carrier body compared to the case of the tapered shape.

Further, the insert member may be formed by injection molding of the insert material, or may be formed by bonding the insert material using an adhesive.

As described above, the method of manufacturing a carrier for a double-sided polishing apparatus according to the present invention relates to the formation of an insert member, and can be adapted to both injection molding and bonding of the insert material, and it is possible to suppress the displacement of the insert member.

According to the carrier for a double-sided polishing apparatus of the present invention and its manufacturing method, it is possible to improve the bonding strength between the carrier body and the insert member, and when the insert member is formed or wafer is polished, shift in the vertical direction of the insert member occurs. It is possible to suppress that.

1 is a top view showing an example of a carrier for a double-sided polishing apparatus of the present invention.
2 is a cross-sectional view showing an example of a carrier for a double-sided polishing apparatus of the present invention.
3 is a top view showing another example of the carrier for the double-sided polishing apparatus of the present invention.
4 is a cross-sectional view showing an example of a carrier for a conventional double-sided polishing apparatus.
5 is a longitudinal sectional view showing an example of a double-sided polishing apparatus.
6 is an internal structure diagram of a double-sided polishing apparatus in plan view.
7 shows the measurement results of the peel strength in the case of injection molding in Examples 1-3 and 7, Comparative Example 1.
8 shows the measurement results of the displacement amount of the insert material in the case of injection molding in Examples 1-3 and 7, Comparative Example 1. FIG.
9 shows the measurement results of the peel strength in the case of adhesion processing in Examples 4-6 and 8 and Comparative Example 2.
Fig. 10 shows the measurement results of the displacement amount of the insert material in the case of adhesion processing in Examples 4-6 and 8 and Comparative Example 2.

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

1 is a top view of a carrier for a double-sided polishing apparatus (hereinafter, referred to simply as a carrier) of the present invention. Further, Fig. 2 shows a cross-sectional view of this carrier.

The carrier 1 of the present invention is disposed in contact with a metal carrier body 2 having a holding hole 3 for holding a wafer and an inner circumferential surface 4 of the holding hole 3 as shown in FIG. It has a resin insert member (5).

Here, as a material of the carrier body 2, SK steel, stainless steel, titanium, etc. are mentioned, for example.

In addition, the resin (insert material 7) of the insert member 5 includes epoxy, vinyl, polystyrene, acrylic, polyamide (nylon), polyimide, polyacetal, polycarbonate, polyethylene terephthalate, and cycloolefin. A resin composed of, for example, fluorine-based (Teflon (registered trademark)) can be used.

In addition, in the carrier 1 of the present invention, the surface roughness Ra of the inner peripheral surface 4 of the holding hole 3 is 1.0 μm or more. With such an inner circumferential surface 4, the bonding strength between the carrier body 2 and the insert member 5 is higher than that of the conventional product. Since their bonding strength is high, the vertical direction of the insert member 5 with respect to the inner circumferential surface 4 of the retaining hole 3 in various cases including the formation of the insert member, wafer polishing, and carrier transport. The shift in (direction perpendicular to the main surface 6 of the carrier body 2) can be suppressed. Since the insert member 5 comes into contact with the wafer during wafer polishing, it is important to suppress the shift in forming the edge shape of the wafer. Therefore, the carrier 1 of the present invention capable of effectively suppressing this shift is very significant.

On the other hand, the upper limit of Ra of the inner peripheral surface 4 is not particularly limited. The rougher it is, the higher the bonding strength with the insert member 5 can be, but only 5 μm is sufficient.

In addition, it is preferable that Ra satisfies the above conditions, and that the surface roughness Rz of the inner peripheral surface 4 is 5.0 μm or more. If this is the case, it is possible to further suppress the shift in the vertical direction of the insert member 5.

On the other hand, the upper limit of Rz of the inner peripheral surface 4 is not particularly limited. The rougher it is, the higher the bonding strength with the insert member 5 can be, but only 20 μm is sufficient.

In addition, it is preferable that the angle of the inner circumferential surface 4 with respect to the main surface 6 of the carrier body 2 is vertical. As described above, if the surface roughness Ra of the inner circumferential surface 4 is at least 1.0 μm or more, even if the inner circumferential surface 4 is tapered, it is possible to sufficiently suppress the displacement of the insert member 5 compared to the conventional one. However, when it is perpendicular to the main surface 6 of the carrier main body 2, it is possible to more effectively suppress the shift compared to the tapered case.

On the other hand, the insert member 5 can be made of the insert material 7 by injection molding, for example. The resin of the same type as described above can be molded by direct injection to the inner circumferential surface 4 of the holding hole 3 of the carrier body 2. On the other hand, Fig. 1 shows an example by this injection molding.

Further, another example of the insert member 5 is shown in FIG. 3. 3 is a top view of another example of the carrier for the double-sided polishing apparatus of the present invention. As shown in the carrier 1A of this example, the insert member 5 is made of an insert material 7 and an adhesive layer 8. The adhesive layer 8 is located between the inner circumferential surface 4 and the insert material 7 and combines the two. The type of the adhesive is not particularly limited, but examples thereof include an epoxy adhesive.

The present invention is applicable to any of the inner circumferential surface 4 of the retaining hole 3 and the insert 7 bonded by injection molding, or bonded through the adhesive layer 8, and the insert member 5 ) (Insert material 7) can be prevented from shifting in the vertical direction.

Next, a description will be given of a double-sided polishing apparatus provided with the carrier 1 for a double-sided polishing apparatus of the present invention.

FIG. 5 is a longitudinal sectional view of an example of a double-sided polishing apparatus provided with a carrier for a double-sided polishing apparatus of the present invention, and FIG. 6 is an internal structure diagram of a double-sided polishing apparatus in plan view.

As shown in Figs. 5 and 6, the double-sided polishing apparatus 11 provided with one or more carriers 1 (three in this case) includes a lower platen 12 and an upper platen 13 provided vertically facing each other. It is provided, and the polishing cloth 14 is affixed to the opposite surface side of each base plate 12, 13, respectively.

Further, a slurry hole 15 for supplying a slurry is provided between the upper plate 13 and the lower plate 12 on the upper part of the upper plate 13.

On the other hand, as shown in Figs. 5 and 6, a sun gear 16 is provided in the center between the upper platen 13 and the lower platen 12, and an internal gear 17 is provided at the periphery. Device.

In addition, the outer circumferential teeth (not shown) of the carrier 1 are meshed with each of the teeth (not shown) of the sun gear 16 and the internal gear 17, and the upper plate 13 and the lower plate 12 are not As it is rotated by a driving source in the city, the carrier 1 revolves around the sun gear 16 while rotating.

On the other hand, when the semiconductor wafer (W) is double-sided, the wafer (W) is held by the holding hole (3) of the carrier (1), and the wafer (W) is held by rotation of the upper and lower platens (12, 13). One carrier 1 self-revolves, and both surfaces of the wafer W are simultaneously polished by the upper and lower polishing cloths 14. On the other hand, during polishing, the slurry is supplied from the slurry hole 15.

Next, a method of manufacturing the carrier 1 for a double-sided polishing apparatus according to the present invention will be described.

First, a holding hole 3 is formed in a metal plate prepared for the carrier body 2 by processing. The processing method is not particularly limited, but may be processed by, for example, laser processing, machining processing, router processing, price processing, wire discharge processing, and the like.

At this time, it is processed so that the surface roughness Ra of the inner peripheral surface 4 of the holding hole 3 is 1.0 μm or more. The method of roughening the surface roughness of the inner circumferential surface 4 is also not limited, but it may be roughened by additional processing in addition to adjustment by the above processing conditions. For example, after the holding hole 3 is once formed by wire discharge processing, a router processing is performed as an additional processing to adjust the surface roughness of the inner peripheral surface 4 of the holding hole 3. More preferably, it is processed so that the surface roughness Rz of the inner circumferential surface 4 is 5.0 μm or more.

Further, when processing the retaining hole 3, the inner peripheral surface 4 may be processed so that it is obliquely inclined (taper shape) with respect to the main surface 6 of the carrier body 2, but it is more preferable to process it to be vertical. Do.

In this way, after processing so that at least the surface roughness Ra of the inner circumferential surface 4 of the holding hole 3 falls within the above numerical range, the insert member 5 is formed in contact with the rough inner circumferential surface 4. In the manufacturing method of the present invention, since the insert member 5 is formed on the roughly formed inner circumferential surface 4, the bonding strength between the inner circumferential surface 4 and the insert member 5 can be increased. As a result, deviation of the insert member 5 in the vertical direction can be suppressed. In addition to the adjustment of Ra, by performing the adjustment of Rz and the formation angle of the main surface 6 of the carrier body 2 as described above, the shift can be more effectively suppressed.

The method of forming the insert member 5 itself is not particularly limited, and for example, the insert material 7 can be directly injection molded on the rough inner circumferential surface 4. Alternatively, it is also possible to form an insert material 7 fitted to the holding hole 3 by adhesive processing on the inner circumferential surface 4 using an adhesive.

Even when formed by any method, the shift can be suppressed.

Example

Hereinafter, the present invention will be described in more detail by showing examples and comparative examples of the present invention, but the present invention is not limited thereto.

(Example 1-8, Comparative Example 1-2)

As Comparative Examples 1 and 2, a carrier body having a tapered inner peripheral surface of the holding hole and a small surface roughness (all Ra is less than 1.0 μm) was prepared by laser processing.

In Examples 1-6 and 8, by wire discharge processing, the inner peripheral surface of the holding hole was vertically processed, and additional processing by router processing to prepare a carrier body having a large level of surface roughness (all Ra is 1.0 μm or more). I did. Further, in Example 7, a carrier body was prepared in the same manner as in Example 1, except that the inner peripheral surface of the holding hole was tapered.

The material of these carrier bodies is titanium.

Insert members were formed on these carrier bodies by injection molding or adhesion processing. In injection molding, a cycloolefin copolymer was used as an insert material. In addition, in the bonding process, the insert material made of a glass epoxy resin was bonded with an epoxy-based adhesive.

The surface roughness measurement of the inner circumferential surface of the holding hole and the check of the misalignment of the insert member were carried out by a surface roughness measuring instrument surf test manufactured by Mitsutoyo.

In addition, as for the strength of adhesion of the insert material after the insert member was formed, the peel strength was measured with a force gauge made by Imada.

Table 1 (in the case of injection molding) and Table 2 (in the case of adhesive processing) show the surface roughness Ra and Rz at each level, the vertical/taper classification, peel strength, and the amount of displacement of the insert material. On the other hand, in injection molding, the value of Comparative Example 1 and the value of Comparative Example 2 in the bonding process were normalized with the peel strength and the amount of displacement of the insert material.

On the other hand, Figs. 7 and 8 show graphs of the peel strength and the amount of displacement of the insert material in the case of injection molding. In addition, in Figs. 9 and 10, graphs of the peel strength and the amount of displacement of the insert material in the case of adhesion processing are shown.

[Table 1]

[Table 2]

In the insert member formation by injection molding, as shown in Table 1, Figs. 7, 8, the peel strength of the insert material is improved by about 1.5 to 2.3 times compared to the comparative example of the conventional product, and the amount of displacement of the insert material is also suppressed by about 50 to 80%. Could.

Similarly in the formation of the insert member by adhesion processing, as shown in Tables 2 and 9 and 10, the peel strength was improved by about 1.8 to 2.2 times, and the amount of displacement of the insert material was also suppressed by about 50 to 70%.

In addition, as can be seen by comparing the examples, basically, it can be seen that the larger the surface roughness, the larger the peel strength and the smaller the amount of displacement. Furthermore, as can be seen by comparing Examples 3 and 7 in which the surface roughness is almost the same, it can be seen that it is more difficult to shift the inner circumferential surface of the retaining hole perpendicular to the tapered shape.

From the above, according to the present invention, it is possible to prevent the insert material from falling off and to suppress the deviation from the carrier body.

In addition, this invention is not limited to the said embodiment. The above-described embodiment is an illustration, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same operation and effect is included in the technical scope of the present invention.

1, 1A: carrier for the double-sided polishing apparatus of the present invention, 2: carrier body, 3: holding hole,
4: inner circumferential surface of the retaining hole, 5: insert member, 6: main surface of the carrier body,
7: insert material, 8: adhesive layer,
11: double-sided polishing device, 12: lower platen, 13: upper platen, 14: polishing cloth,
15: slurry hole, 16: sun gear, 17: internal gear,
W: semiconductor wafer

Claims (10)

A double-sided polishing apparatus for double-sided polishing a semiconductor wafer, comprising: a carrier for a double-sided polishing apparatus which is disposed between upper and lower platens each of which a polishing cloth is attached, and holds the semiconductor wafer sandwiched between the upper and lower platens during polishing,
A metal carrier body having a holding hole for holding the semiconductor wafer, and a resin insert member disposed in contact with the inner circumferential surface of the holding hole,
A carrier for a double-sided polishing apparatus, characterized in that the surface roughness Ra of the inner circumferential surface of the holding hole in contact with the insert member is 1.0 μm or more. The method of claim 1,
A carrier for a double-sided polishing apparatus, wherein the surface roughness Rz of the inner circumferential surface of the holding hole in contact with the insert member is 5.0 μm or more. The method of claim 1,
A carrier for a double-sided polishing apparatus, wherein an inner circumferential surface of the holding hole in contact with the insert member is perpendicular to a main surface of the carrier body. The method of claim 2,
A carrier for a double-sided polishing apparatus, wherein an inner circumferential surface of the holding hole in contact with the insert member is perpendicular to a main surface of the carrier body. The method according to any one of claims 1 to 4,
The insert member,
Consisting of inserts by injection molding,
Or an insert material and an adhesive layer between the insert material and the inner peripheral surface of the holding hole. In a double-sided polishing apparatus for double-sided polishing a semiconductor wafer, a carrier for a double-sided polishing apparatus which is disposed between the upper and lower platens to which polishing cloths are attached, and which holds the semiconductor wafer sandwiched between the upper and lower platens during polishing As a method,
When a holding hole for holding the semiconductor wafer is formed in a metal carrier body, and the insert member is formed by contacting the inner peripheral surface of the holding hole,
A method of manufacturing a carrier for a double-sided polishing apparatus, wherein the insert member is formed after making the surface roughness Ra of the inner circumferential surface of the holding hole in contact with the insert member equal to or greater than 1.0 μm. The method of claim 6,
A method of manufacturing a carrier for a double-sided polishing apparatus, wherein the insert member is formed after making the surface roughness Rz of the inner circumferential surface of the holding hole in contact with the insert member to be 5.0 μm or more. The method of claim 6,
A method of manufacturing a carrier for a double-sided polishing apparatus, wherein the insert member is formed after making the inner peripheral surface of the holding hole in contact with the insert member perpendicular to the main surface of the carrier body. The method of claim 7,
A method of manufacturing a carrier for a double-sided polishing apparatus, wherein the insert member is formed after making the inner peripheral surface of the holding hole in contact with the insert member perpendicular to the main surface of the carrier body. The method according to any one of claims 6 to 9,
The method of manufacturing a carrier for a double-sided polishing apparatus, wherein the insert member is formed by injection molding of the insert material or by bonding the insert material using an adhesive.

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