JP2004315609A - Pressure-sensitive adhesive tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive tape which does not allow air bubbles to remain when stuck. <P>SOLUTION: The pressure-sensitive adhesive tape 1, being a double-faced one, comprises a pressure-sensitive adhesive material 2 and release materials 3, 4 stuck to both sides of the pressure-sensitive adhesive material 2. When the adhesive tape 1 is used, the release materials 3, 4 are peeled before the adhesive material 2 is stuck to a polishing pad or the like. A plurality of grooves 5 are formed on the pressure-sensitive adhesive surface 2a of the adhesive material 2 to be stuck to a surface plate. The grooves 5 are formed parallel with each other, as can be seen in the plan view. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an adhesive tape for fixing a polishing pad such as a silicon wafer, a glass for a flat panel display, and a hard disk that performs ultra-precision polishing.
[0002]
[Prior art]
In the field of semiconductor manufacturing, flattening technology for semiconductor layers and metal layers has become an important elemental technology as semiconductor devices become finer and multi-layered and highly integrated. When an integrated circuit is formed on a wafer, if layers are stacked without flattening unevenness due to electrode wiring or the like, a step is increased and flatness is extremely deteriorated. When the step is large, it is difficult to focus on both the concave portion and the convex portion in photolithography, and it is not possible to realize miniaturization. Therefore, it is necessary to perform a flattening process for removing irregularities on the wafer surface at an appropriate stage during the lamination. The flattening process includes an etch-back method of removing uneven portions by etching, a film forming method of forming a flat film by plasma CVD (Chemical Vapor Deposition), a fluidizing method of flattening by heat treatment, and a concave portion by selective CVD. And a selective growth method for embedding.
[0003]
The above methods have problems that they are appropriate depending on the type of film such as an insulating film and a metal film, and that the region that can be planarized is extremely narrow. As a planarization processing technique that can overcome such a problem, there is planarization by CMP.
[0004]
In the planarization process by CMP, a slurry in which fine particles (abrasive grains) are suspended is supplied to the polishing pad surface, and the surface is polished by relatively moving the pressed polishing pad and the silicon wafer to polish the surface. The wafer surface can be flattened with high precision.
[0005]
A CMP apparatus that performs planarization by CMP mainly includes a rotary platen section, a carrier section, a slurry supply section, and a dressing section. A polishing pad is attached to the upper surface of the rotary platen with an adhesive tape or the like, and the lower surface is connected to a rotary drive mechanism via a rotary shaft. The carrier section holds a silicon wafer as an object to be polished by a backing material and a retainer ring on a lower surface thereof, and presses a processed surface of the silicon wafer against a polishing pad. The upper surface is connected to a rotation drive mechanism via a rotation shaft.
[0006]
The slurry supply unit supplies a slurry in which particles such as silica, ceria, and alumina are suspended in a medium to the surface of the polishing pad. The dressing unit includes a plate on which industrial diamond particles are electrodeposited, and reclaims a surface of the polishing pad having reduced polishing characteristics by shaving off a portion to which polishing debris or the like has adhered.
[0007]
The CMP apparatus rotates the rotating platen section and the carrier section by a rotation drive mechanism, supplies slurry to a substantially central portion of the polishing pad, and relatively moves the silicon wafer and the polishing pad to polish a silicon wafer processing surface. I do.
[0008]
In such a CMP apparatus, when the polishing pad to which the adhesive tape is attached is attached to the surface plate, the area to be attached is wide, so that air bubbles are generated between the adhesive tape and the surface plate. The remaining bubbles cause poor flatness at the time of polishing and cause pad peeling due to insufficient adhesive area.
[0009]
In the planar polishing apparatus described in Patent Literature 1, lattice-shaped grooves are formed on the entire surface of the turntable (platen). When attaching the polishing pad (pad), air bubbles are eliminated through this groove.
[0010]
[Patent Document 1]
JP-A-10-315121
[Problems to be solved by the invention]
In the planar polishing apparatus described in Patent Literature 1, since grooves are formed in the turntable, there is a problem that processing is difficult and costs are increased. Further, there is a problem that slurry enters between the turntable and the adhesive tape through the groove, and the polishing pad is peeled off from the turntable.
[0012]
An object of the present invention is to provide a pressure-sensitive adhesive tape in which bubbles do not remain during application.
[0013]
[Means for Solving the Problems]
In the present invention, an adhesive and a release material are laminated, and at least one or a plurality of grooves having an end opening to an end surface of the adhesive are provided on at least an adhesive surface of the adhesive which is combined with the release material. It is an adhesive tape characterized by the above.
[0014]
In the present invention, a plurality of the grooves are provided,
Each groove is provided substantially in parallel.
[0015]
In the present invention, a plurality of the grooves are provided,
Each groove is provided in a lattice shape.
[0016]
In the present invention, a plurality of the grooves are provided,
Each groove is provided radially.
[0017]
According to the present invention, an adhesive and a release material are laminated. For example, in the case of a double-sided adhesive tape, the adhesive is laminated between two release materials. A groove is provided on the adhesive surface of the adhesive material that is to be combined with the release material, and the end of the groove is open to the end surface of the adhesive material. A plurality of grooves are provided, and each groove is provided in a substantially parallel, lattice, or radial shape.
[0018]
Thus, when the release material is peeled off and the adhesive is adhered to a predetermined member, the air bubbles generated between the adhesive and the member do not remain and pass through the groove provided on the adhesive surface. Can be easily discharged from the end face. When this adhesive tape is used, for example, for attaching a polishing pad of a CMP polishing apparatus to a surface plate, no air bubbles remain, so that the flatness can be improved.
[0019]
Further, in the present invention, the adhesive force of the adhesive is 4.0 N / 25 mm or more,
The width of the groove is 1 mm or less, and the depth is 1 mm or less.
[0020]
According to the present invention, the adhesive strength of the adhesive is 4.0 N / 25 mm or more (JIS Z1528: 90 ° peeling from stainless steel), the width of the groove is 1 mm or less, and the depth is 1 mm or less.
[0021]
Thereby, the adhesive is stuck to the predetermined member, and after the bubbles are discharged from the groove, the groove disappears due to the fluidity of the adhesive, thereby increasing the adhesive area and improving the adhesive strength. Particularly, in the case of a polishing apparatus such as a CMP apparatus, a slurry containing abrasive grains is often used. However, the disappearance of the groove can prevent the slurry from entering between the adhesive and the surface plate.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
An adhesive tape for bonding two or more members, a so-called double-sided adhesive tape, is formed by laminating two release materials and an adhesive material. When used in a CMP apparatus as described in the related art, one of the release materials is peeled off, an adhesive is attached to the polishing pad, and the other release material is peeled off and bonded to the surface plate, thereby obtaining a polishing pad and a surface plate. Are fixed via an adhesive. When the adhesive is attached to the polishing pad and when the adhesive is attached to the surface plate, since the area to be attached is large, air bubbles are generated between the adhesive and the polishing pad and between the adhesive and the surface plate.
[0023]
In the present invention, a groove is provided in the adhesive material, and the bubbles are removed to the outside through the groove at the time of sticking, whereby the bubbles can be removed. Thereby, the flatness and adhesive strength at the time of polishing are improved.
[0024]
FIG. 1 is a cross-sectional view and a plan view of a double-sided pressure-sensitive adhesive tape 1 according to an embodiment of the present invention. FIG. 1A is a cross-sectional view, and FIG. 1B is a plan view when the release material on the surface plate is peeled off. As can be seen from the cross-sectional view of FIG. 1A, the double-sided pressure-sensitive adhesive tape 1 has release materials 3 and 4 adhered to both surfaces of the adhesive material 2. wear. In the present embodiment, a plurality of grooves 5 having ends that are open to the end surfaces of the adhesive material are provided on the adhesive surface 2a to be bonded to the surface plate of the adhesive material 2. As can be seen from the plan view of FIG. 1B, the grooves 5 are provided substantially parallel to each other.
[0025]
The manufacturing process of the double-sided pressure-sensitive adhesive tape includes production of a release material and a pressure-sensitive adhesive, application of the pressure-sensitive adhesive to the release material, and attachment of the release material to the coated pressure-sensitive adhesive.
[0026]
The release material is made of, for example, paper, PET (Polyethylene Terephthalate), and the adhesive is made of natural rubber, synthetic rubber, acrylic resin, and ethylene-vinyl acetate-based, polyurethane-based, polyamide-based hot melt, and the like.
[0027]
There are two main methods of forming a groove in the adhesive, a method of forming a convex portion on the release material side on which the adhesive is coated, and a method of forming a concave portion (groove) after coating. First, a description will be given of a case where the process is performed before the application of the adhesive.
[0028]
In general, the following processes are performed on the release material before the application of the adhesive.
・ Thickening treatment of release material ・ Surface roughening treatment to enhance adhesive strength with adhesive ・ Antistatic treatment (application of antistatic agent)
[0029]
In addition to such processing, a projection is formed on the release material.
In particular,
-A load is applied to the release material only in one direction axis by a point contact load with a roller or the like to form a protrusion in the same direction.
・ Strip paper is moved in a certain direction during the surface roughening treatment to provide linear irregularities.
-Apply a load on which a convex portion has been formed in advance, and transfer the convex portion to the release material by a surface contact load.
And so on.
[0030]
An adhesive is applied to the release material having the projections formed in this manner. When the release material is peeled off at the time of sticking, a groove is formed in a portion of the adhesive material facing the convex portion of the release material.
[0031]
Next, the case of performing after the application of the adhesive will be described.
Specifically, like before coating,
A load is applied to the release material only in one direction, and a concave portion (groove) is formed in the adhesive material in the same direction.
Transfer a concave portion (groove) to the adhesive by applying a load in which a convex portion is formed in advance.
And so on.
[0032]
The arrangement of the grooves is, as shown in FIG. 1, in addition to a linear pattern composed of a plurality of substantially parallel linear grooves, a lattice pattern composed of a plurality of linear grooves orthogonal to each other, and radially extending from the center. There is a radiation pattern composed of a plurality of linear grooves, etc., but it may be curved, and it is sufficient that the ends of the grooves are open to the outside so that air bubbles can be removed when pasted.
[0033]
In the pressure-sensitive adhesive tape for use in precision polishing, flatness is also required for the pressure-sensitive adhesive material, and the surface of the pressure-sensitive adhesive material is coated so as to have a mirror surface or flatness equivalent thereto.
[0034]
When the polishing pad and the surface plate are bonded together using the double-sided pressure-sensitive adhesive tape prepared as described above, immediately after bonding, almost no difference is observed even when compared with the conventional pressure-sensitive adhesive tape having no groove, Many air bubbles are observed between the adhesive and the surface plate. However, as time elapses after the bonding, the bubbles gradually merge while passing through the groove and are finally discharged from the end face.
[0035]
The number of air bubbles that existed in large numbers decreases in the groove each time the curing time elapses. By the time the adhesive curing has been completed, no air bubbles are present.
[0036]
Further, the adhesive strength of the adhesive is increased. For example, the thickness is set to 4.0 N / 25 mm (JIS Z1528: 90 ° peeling from stainless steel) or more. Also, the dimensions of the grooves are made as small as possible. For example, the width is 1 mm or less, preferably about 0.5 mm, and the depth is 1 mm or less, preferably about 0.5 mm. Thus, after the bubbles are discharged, the adhesive flows and the grooves disappear.
[0037]
Further, if the gap between the grooves is too wide, it becomes difficult to discharge the bubbles. Therefore, the gap between the grooves is set to 5 mm or less, preferably about 1 mm.
[0038]
As described above, the adhesive area is large, the adhesive material and the surface plate are bonded uniformly and without unevenness, and the flatness and adhesive strength during polishing are improved.
[0039]
(Example)
The adhesive tape with the grooves formed therein is referred to as Example 1, and the conventional adhesive tape with no grooves formed is referred to as Comparative Example 1.
[0040]
In both Example 1 and Comparative Example 1, PET was used as the release material, and natural rubber was used as the adhesive.
[0041]
The groove of Example 1 was formed by applying a load only to the one-way axis to the release material. The grooves were arranged in a linear pattern as shown in FIG. 1, with a groove width of 0.5 mm and a groove depth of 0.5 mm.
[0042]
A polishing pad was prepared by laminating each of Example 1 and Comparative Example 1, and was laminated on a transparent plate made of polycarbonate (PC).
[0043]
After a lapse of a predetermined time from the pasting, the number and size of bubbles were measured from the back side of the laminated transparent plate. The measurement time was set to 10 minutes, 30 minutes, 1 hour, 3 hours, and 6 hours immediately after the application.
[0044]
FIG. 2 is a graph showing the change over time in the number of observed bubbles. The vertical axis indicates the number of bubbles, and the horizontal axis indicates the elapsed time after pasting. A curve 10 indicates Example 1, and a straight line 11 indicates Comparative Example 1. FIG. 3 is a graph showing the change with time of the observed bubble diameter. The vertical axis indicates the diameter of the bubble, and the horizontal axis indicates the elapsed time after the attachment. A curve 12 indicates Example 1, and a straight line 13 indicates Comparative Example 1.
[0045]
As can be seen from the graph, in Example 1, the number of air bubbles decreased and the diameter of the air bubbles increased in Example 1 as time passed after the application. This is due to the phenomenon that bubbles are gathered because the adhesive material of Example 1 has grooves. In Example 1, around 250 minutes, the diameter of the bubble became small, and the number of bubbles became almost zero. This is because bubbles were discharged from the end face through the groove. Further, as time passed, the grooves disappeared due to the fluidity of the adhesive, and the polishing pad and the transparent plate were uniformly bonded without unevenness.
[0046]
In Comparative Example 1, the generated air bubbles could not move because there was no groove, and neither the number nor the diameter of the air bubbles changed over time.
[0047]
INDUSTRIAL APPLICABILITY The present invention is useful for bonding various members, but is particularly useful for a polishing apparatus. At the time of polishing, a slurry in which abrasive grains are dispersed is often used, and in the case of the planar polishing apparatus described in the related art, bubbles can be discharged by the grooves, but since the grooves are formed on the surface plate, Slurry permeates from this groove, and the adhesive material comes off from the surface plate. On the other hand, in the present invention, since the groove disappears after the bubble is discharged, the slurry does not enter.
[0048]
As described above, air bubbles generated between the adhesive material of the adhesive tape and the surface plate can be discharged. As a result, the adhesive surfaces are all uniform, and the flatness and adhesive strength during polishing can be improved. Further, by preventing the slurry from penetrating, even if the adhesive material has a low adhesive strength, it does not peel off during polishing. Surface plates to be used in the future will tend to increase in number with improved prevention of slurry sticking and improved chemical resistance. A Teflon (registered trademark) platen or a platen that has been subjected to a corrosion-resistant treatment generally has poor compatibility with an adhesive tape, and the adhesive material is easily peeled off as compared with a normal platen. However, by using the present invention, the peelability can be reduced.
[0049]
In addition, in order to prevent air bubbles from remaining, the work of laminating to the surface plate often depended on the skill of the worker, but by using the present invention, it is possible to reduce individual differences in workability. It can be easily bonded.
[0050]
The cross-sectional shape of the groove is not limited to a rectangle, but may be a semicircular shape, a semicylindrical shape, a triangular shape, or the like. In the above description, the case where the groove is formed only on one side of the adhesive tape has been described. However, in the case of the double-sided adhesive tape, it is preferable to form the groove on both sides. By forming grooves on both surfaces, bubbles generated between the adhesive and the polishing pad and between the adhesive and the surface plate can be discharged, and the flatness and adhesive strength during polishing can be further improved.
[0051]
【The invention's effect】
As described above, according to the present invention, when the release material is peeled off and the adhesive is adhered to a predetermined member, bubbles generated between the adhesive and the member are provided on the adhesive surface without remaining. It can be easily discharged from the end face of the adhesive through the groove. When this adhesive tape is used, for example, for attaching a polishing pad of a CMP polishing apparatus to a surface plate, no air bubbles remain, so that the flatness can be improved.
[0052]
According to the present invention, the adhesive is attached to the predetermined member, and after the bubbles are discharged from the groove, the groove disappears due to the fluidity of the adhesive, thereby increasing the adhesive area and improving the adhesive strength. I do. Particularly, in the case of a polishing apparatus such as a CMP apparatus, a slurry containing abrasive grains is often used. However, the disappearance of the groove can prevent the slurry from entering between the adhesive and the surface plate.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view and a plan view of a double-sided pressure-sensitive adhesive tape 1 according to an embodiment of the present invention.
FIG. 2 is a graph showing the change over time in the number of observed bubbles.
FIG. 3 is a graph showing the change with time of the observed diameter of bubbles.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Double-sided adhesive tape 2 Adhesive material 3, 4 Release material 5 Groove

Claims (5)

An adhesive material and a release material are laminated, and at least one or a plurality of grooves having an end opening to an end surface of the adhesive material are provided on at least an adhesive surface of the adhesive material to be combined with the release material. Adhesive tape. The groove is provided in plurality,
2. The adhesive tape according to claim 1, wherein each groove is provided substantially in parallel. The groove is provided in plurality,
The pressure-sensitive adhesive tape according to claim 1, wherein each groove is provided in a lattice shape. The groove is provided in plurality,
The pressure-sensitive adhesive tape according to claim 1, wherein each groove is provided radially. The adhesive strength of the adhesive is 4.0 N / 25 mm or more,
The pressure-sensitive adhesive tape according to any one of claims 1 to 4, wherein the groove has a width of 1 mm or less and a depth of 1 mm or less.

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