KR19980703331A - A wafer retainer that protects and holds the wafer for polishing, and a method of adhering the wafer retainer to a substrate of the polishing machine and detaching from the substrate of the polishing machine - Google Patents

Abstract

No summary.

Description

A wafer retainer that protects and holds the wafer for polishing, and a method of adhering the wafer retainer to a substrate of the polishing machine and detaching from the substrate of the polishing machine

1 is a cross-sectional view of a wafer retainer according to the present invention.

2A is a cross-sectional view showing a state of a foam layer formed on a substrate for forming a backing film. 2B is a cross-sectional view showing the adhesive film.

3 is a cross-sectional view showing a state where the surface portion of the foam layer of the backing film shown in FIG. 2A is buffed.

4 is a cross-sectional view showing a state in which a template is placed on the top surface of the backing film shown in FIG.

5 is a cross-sectional view showing a state in which the wafer retainer of the present invention is adhered to a substrate.

[Best way to carry out the invention]

A wafer retainer for protecting and holding a wafer to be polished according to the present invention includes at least the following: a foam layer capable of absorbing the wafer onto the foam layer surface so as to be detachable; A pressure-sensitive adhesive layer for adhering the foam layer to the substrate of the polishing machine; The release sheet wafer retainer, which can be attached to and detached from the pressure-sensitive adhesive layer, may consist of the above three layers or may include additional layers. For example, a base sheet may additionally be formed between the foam layer and the adhesive layer to obtain a four-layer wafer retainer.

As the base sheet, a sheet made of synthetic resin such as polyethylene terephthalate, polyetherimide, polyurethane can be used. For example, polyesters (lumirrors manufactured by Toray Industries) can be used.

Foam compositions comprising, for example, vinyl polymers such as vinyl chloride polymers, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-vinyl alcohol terpolymers and urethane polymers, and suitable foam solvents such as dimethylformaldehyde in the substrate sheet. The foamed layer is formed by coagulating and coagulating the foam composition by wet coagulation. The surface area of the foam layer, especially the shell layer formed on the surface, is well buffed so that the wafer is easily absorbed thereon.

An adhesive layer is formed on the back surface of the substrate (the surface facing the substrate of the polishing machine) when the surface layer of the foam layer or the wafer retainer comprises the substrate.

The adhesive layer is made of an adhesive composition comprising a polymer in which the first solution transition occurs in a temperature range narrower than 15 ° C. The adhesive composition is a polymer composition having a first solution transition between about 5 ° C and 50 ° C. This transition preferably occurs at a temperature narrower than 15 ° C., more preferably at a temperature narrower than 10 ° C.

The primary solution transition of the polymer can be measured by a viscoelasticity meter.

As shown in Japanese Patent Application Laid-open No. Hei 4-507425, the adhesive composition is such that the resulting adhesive layer is substantially non-adhesive to the substrate at a temperature of about 20 ° C. or lower and substantially to the substrate at a temperature of about 20 ° C. or higher. It sufficiently contains a side-chain determinable polymer.

During polishing of the wafer, the temperature T1 of the wafer retainer is preferably 20 ° C or higher, more preferably between 25 and 35 ° C, most preferably between 25 and 30 ° C. When the wafer retainer is detached from the substrate, the temperature T1 of the wafer retainer is 20 ° C. or less, more preferably between about 10 ° C. and 20 ° C.

As side-chain determinable polymers, side-chain determinable and / or main-chain determinable polymers are preferred. These polymers include polymers exhibiting temperature dependent adhesion properties. The determinable polymer to be used in the adhesive composition may include both side-chain determinable polymers and main-chain determinable polymers. While the main-chain determinable polymer is determinable by their backbone structure, the side-chain determinable polymer comprises a determinable side-chain portion. Examples of such polymers include those selected from single stereoregular polyolefin alkyl acrylates and alkylmethacrylates.

Side-chain determinable polymers used in the present invention can be prepared to contain a mixture of two or a plurality of different polymers.

Generally these polymers comprise a monomer unit X of the formula

In the above formula

M is a divalent group capable of forming the main-chain (or skeletal atoms) of the polymer,

S is spacer unit

C is a determinable group.

These polymers generally have a heat of fusion (ΔHf) of at least about 20 Joules / g and preferably at least about Joules / g.

The polymer contains about 50-100% by weight of monomer units represented by X. If the polymer contains less than or equal to 1005 X, it additionally contains monomer units represented by Y or Z or both Y and Z. Wherein Y is polymerizable with X or Z as any polar or nonpolar monomer or a mixture of polar, nonpolar monomers, and Z is a mixture of polar or nonpolar monomers.

Examples of such polar monomers include polyoxyalkylenes, hydroxyethyl acrylates, acrylates including acrylamide and methacrylamide. These monomers increase the adhesion to most substrates.

The backbone of the polymer (defined as M) may be an organic structure (aliphatic or aromatic hydrocarbon, ether, ester, amide, etc.) or an inorganic structure (sulfide, phosphazine, silicone, etc.), and the spacer bond may be, for example, ester, amide , A combination of suitable organic or inorganic units, such as hydrocarbons, phenyl, ethers or ionic salts (for example carboxyl-alkylammonium or sulfonium or phosphonium, ion pairs or other known ion pairs).

The side chains defined by S and C can be aliphatic or aromatic or a combination of aliphatic and aromatic. However, it should be possible to enter the crystallization state. Typical examples include linear aliphatic side chains of 10 carbon atoms, for example C14 to C22 acrylates or methacrylates, acrylamides or methacrylamides, vinylethers or esters, siloxanes or alphaolefins; Fluorinated aliphatic side chains having at least six carbon atoms; And p-alkyl styrene side chains wherein the alkyl group has from 8 to 24 carbon atoms.

The length of the moiety of the side chain is generally at least 5 times longer than the distance between the side chains in the case of acrylates, methacrylates, vinyl esters, acrylamide methacrylates, vinyl ethers and α-olefins.

The amount of side chain units is at least 50% of the polymer volume, preferably at least 65%.

In addition to one or more of the aforementioned polymer types, the adhesive composition may be a conventional additive such as tegiurized (eg rosin, polyester), antioxidants, fibrous or non-fiber fillers and colorants. It includes. The additional adhesive may also contain the adhesive composition as long as it does not significantly affect the thermal sensitivity of the adhesive composition. The amount of determinable polymer contained in the adhesive composition is preferably in the range of about 40% to about 100% by weight.

Examples of the polymer contained in the gum adhesive composition are as follows.

(1) Copolymer of 90-97 parts by weight tetradecyl acrylate and 3-10 parts by weight acrylic acid

(2) a copolymer of 10-60 parts by weight of lauryl acrylate, 40-90 parts by weight of tetradecyl acrylate and 3-10 parts by weight of acrylic acid

(3) a copolymer of 70-90 parts by weight of tetradecyl acrylate, 5-20 parts by weight of butyl acrylate and 3-10 parts by weight of acrylic acid

(4) a copolymer of 70-90 parts by weight of hexadecyl acrylate, 5-10 parts by weight of butyl acrylate and 3-10 parts by weight of acrylic acid

The suitable temperature used for the adhesive composition containing the copolymer of said (1)-(4) is as follows.

(1) about 20 ° C. Abrupt drop in adhesive force temperature at about 15 ° C or below

(2) about 10 to about 20 ° C. The abrupt drop in adhesion at about 10 ° C is about 5 ° C or less, and the abrupt drop in adhesion at about 20 ° C is about 15 ° C or less

(3) about 0 to about 15 ° C. At about 0 ° C, the abrupt drop in adhesion is about -5 ° C or less, and at about 15 ° C, the abrupt drop in adhesion is about 10 ° C or less.

(4) about 15 to about 35 ° C. The abrupt drop in adhesion at about 15 ° C is about 10 ° C or less, and the abrupt drop in adhesion at about 35 ° C is about 30 ° C or below

Particularly suitable are copolymers of (meth) acrylates with 10 to 14 carbons, acrylic acid and / or (meth) acrylates with 1 to 4 carbons and require a well-balanced temperature with sensitivity and viscosity. The copolymer is 40% or more, preferably 45 to 95% by weight of (meth) acrylate having 10 to 14 carbons, 1 to 10% by weight, preferably 2 to 5% by weight of acrylic acid and And / or 5 to 40% by weight, preferably 10 to 35% by weight of (meth) acrylate.

An adhesive composition comprising a polymer exhibiting the above temperature-dependent adhesive properties may be directly applied to a foam layer or a base sheet to form an adhesive layer having a uniform thickness. Optionally, after the adhesive composition is thinly and uniformly applied to the thin substrate sheet, the substrate having the adhesive layer may be thinned with the foam layer, or may be thinned with the substrate sheet including the foam layer formed thereon.

The adhesive composition may be applied in its original state or in a latex state with an emulsion or a suitable solvent. Suitable monomers capable of forming polymers and additives can be applied directly to the foam layer or substrate sheet and dried by heating, radiation, or any other suitable method known to those skilled in the art. .

The release sheet (or release film) is adhered to the exposed surface of the adhesive layer to ensure that the adhesive layer is protected by the release sheet until the wafer retainer is substantially used.

The release sheet is, for example, a soft, thin film such as paper, a plastic film such as polypropylene film, or a metal foil whose surface is treated with a release agent if necessary to facilitate releasing. It consists of. In particular, siliconized Paulerster films are preferred in terms of dusting properties and softness.

The wafer retainer having the above structure is bonded to the substrate of the polishing machine in the following manner. First, the mounting surface is mounted so that the substrate is removed from the polishing machine and wiped and the surface to which the wafer retainer is to be bonded is exposed to room temperature (typically about 25 ° C). The wafer retainer is taken out of the package to remove the release sheet from the adhesive face of the wafer retainer and then placed on the substrate such that the adhesive face is in contact with the exposed face of the substrate. The wafer retainer is then preferably bent slightly before adhering to the substrate such that the center of the retainer adheres first to the substrate and gradually adheres toward the perimeter of the retainer. The pressure is then evenly applied from above to the entire upper surface of the wafer retainer by any suitable method. The pressure is preferably 1 kg / cm 2 or less. As an example of pressure application, the wafer retainer may be pressed into a sufficiently thick elastic plate. Most preferably the retainer is covered with a plastic sheet. The air under the plastic sheet is aspirated to achieve a reduced pressure and in this way pressurizes the wafer retainer.

Through this process, the adhesive layer on the back surface of the wafer retainer substrate is in close contact with the substrate. The adhesive strength of the wafer retainer in close contact with the substrate at this time is in the range of about 2-3 kg / inch as seen when the retainer is generally detached from the substrate.

The wafer retainer is attached to the polishing machine by the above method and after a series of wafer processing procedures, the wafer retainer is detached from the substrate in the following manner. The adhesiveness of the temperature-activated pressure-sensitive adhesive formed on the back side of the wafer retainer is rapidly lowered by cooling the substrate to about 5 ° C. at a normal temperature, that is, 20 ° C. Adhesion strength drops in the range of about 0.2-0.5 kg / inch, allowing the wafer retainer to be easily detached from the substrate. The substrate may be cooled by immersing the substrate in water or cold water, soaking it, or exposing it to cold air.

The adhesive composition thus forming the adhesive layer in vinyl chloride according to the invention comprises a polymer in which the first solution transition occurs in a narrower range than 15 ° C. With such an adhesive composition comprising a thermoactive pressure sensitive adhesive, the adhesive strength of the adhesive layer to the substrate can be even lowered by cooling the substrate and wafer retainer. In this way, the wafer retainer can be easily detached from the substrate when the used retainer is replaced with a new one.

The first solution transition is a temperature phenomenon that occurs at an intermediate temperature between the glass transition point and the melting point, as observed when the polymer's viscoelasticity is measured by gradually increasing the temperature. By varying the temperature to a predetermined temperature (eg 2-5 ° C.), the polymer becomes crystalline or vice versa, resulting in a drastic change in the viscoelasticity of the polymer relative to the substrate described above.

Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to this embodiment.

[Technical Aspects]

The present invention relates to a retainer used to protect and retain a workpiece such as a semiconductor when the workpiece is placed on a base plate of the polishing machine for polishing purposes, and to retain the retainer to the substrate of the polishing machine. And desorption from a substrate.

[Prior technology]

In the recent semiconductor industry, the integration of ICs has increased dramatically. It increased from 4M to 16M and is currently in the 64M level.

Under the above circumstances, there is a high demand for wafers having high quality surfaces. In order to increase the density of ICs, the improvement of the chemical and electrical properties of the wafer is occupied, and the reduction of the minimum width allocated to configure the mechanism on the wafer is increasingly required. Compared with 0.5 microns of the past, 0.35 microns is required now.

In order to achieve such a high precision treatment, flatness of the wafer surface, uniformity and accuracy of the wafer thickness are demanded more strictly. To be precise, after final mirror finishing and polishing, the Total Thickness Variation (TTV) is less than 1 micron and the Local Thickness Variation (LTV) for a 20 mm square, the size of an IC chip. It should be less than 0.2 micron.

In order to meet these precision requirements during the polishing process, the wafer must be placed on the substrate of the polishing machine in an exact parallel with the plane of the substrate. In general, the following two methods have been used to install a wafer on a polishing machine substrate.

One method is to apply the molten wax onto a heated substrate. The wafer is fixed to the substrate via wax.

According to this method, the wafer fixed to the substrate is polished. After polishing, the substrate is heated again to melt the wax and the wafer is detached from the substrate. The wafer is then washed with an organic solvent to remove the wax deposits on the wafer.

This method is advantageous in that the thickness variation of the polished wafer is small. However, heating and cooling the substrate are required before and after every polishing. This undesirably requires the heating and melting of the wax and the use of harmful organic solvents used to clean the wafer to remove the wax deposits.

Another method is to use the wafer retainer described in the present invention. First the retainer is fixed on the substrate and the wafer is absorbed onto the surface of the retainer through a solution such as water. According to this method, the wafer can be easily installed and detached from the substrate during polishing, thereby increasing efficiency and facilitating automation. The wafer retainer is generally fixed to the substrate by a strong pressure-sensitive adhesive (PSA) with high adhesive strength.

However, in this method, the adhesive layer formed on the outer surface of the wafer retainer is strongly adhered to the substrate, and the adhesive strength of about 2-3 kg / inch width is required when the wafer retainer is detached from the substrate in a general manner. To be precise, a force of up to 57 kg is required to detach the wafer retainer from the 485 mm diameter polisher substrate. Therefore, a considerable amount of effort is required to replace the used wafer retainer with a new one.

It is therefore an object of the present invention to provide a wafer retainer which (1) strongly and stably holds onto a substrate of a polishing machine when the wafer is polished, and protects and supports a wafer that easily escapes from the substrate when detaching, and (2) the wafer retainer is Providing a method of adhering to and detaching from a substrate, (3) providing a wafer retainer that easily escapes from the substrate of the polishing machine by simply cooling the adhesive layer of the substrate and the wafer retainer upon exchange or replacement of the wafer retainer, and (4) It is to provide a method of adhering a wafer retainer to a substrate of a polishing machine and detaching from the substrate.

[Initiation of invention]

According to the present invention, a wafer retainer for protecting and supporting a polished wafer includes the following: a foam layer capable of absorbing the wafer onto the foam layer surface so as to be detachable; A pressure-sensitive adhesive layer for adhering the foam layer to the substrate of the polishing machine; Release sheet that can be adhered to and separated from the pressure-sensitive adhesive layer (release sheet) wherein the pressure-sensitive adhesive layer has an adhesive component comprising a polymer (polymer) in which the first solution transition occurs in a temperature range narrower than 15 ℃.

In an embodiment of the present invention, the adhesive composition has a side chain (by an amount such that the pressure-sensitive adhesive layer is substantially non-adhesive to the substrate of the polishing machine at 20 ° C. or less, and substantially adheres to the substrate of the polishing machine at a temperature of at least 0 ° C.). side chain) contains a determinable polymer.

As an embodiment of the present invention, the side chain determinable polymer comprises an acrylic ester as the main component and / or a methacrylic ester having a straight-chain alkyl group comprising 10 or more carbons as the side chain. .

As an embodiment of the present invention, the side chain determinable polymer is selected from the group consisting of acrylate (methacrylate) having 10 to 14 carbons and acrylate (methacrylate) having acrylic acid and 1 to 4 carbons. Copolymers of at least one monomer selected.

As another embodiment of the invention, the copolymer comprises the following components: 40-95% by weight of acrylate (methacrylate) having 10-14 carbons; 1-10% by weight acrylic acid; And / or 5-40% by weight of acrylate (methacrylate) having 1-4 carbons.

The method of adhering a wafer retainer to a substrate of a polishing machine and detaching from the substrate according to the present invention includes the following steps; By removing the release sheet of the wafer retainer from the pressure-sensitive adhesive layer, the wafer retainer is adhered to the substrate of the polishing machine, the substrate is allowed to adhere to the substrate of the polishing machine of the pressure-sensitive adhesive layer of the wafer retainer while maintaining the substrate at T1 temperature, and the substrate after use of the wafer retainer The wafer retainer is detached from the substrate of the substrate of the polishing machine while the temperature of is cooled from the temperature T1 to the temperature T2 so that the temperature T2 is lower than the temperature T1.

In an embodiment of the present invention, the temperature of T1 is 20 ° C or higher and the temperature of T1 is 20 ° C or lower.

In another embodiment of the present invention, the temperature of T1 is 25 ° C or higher and the temperature of T2 is 20 ° C or lower.

Example 1

As shown in Figure 2A, Composition I (having the composition shown in the first diagram) was coated to a thickness of 700 microns on Polyester Film 1 (Lumirror made by Toray Corporation: 188 microns thick). Composition I was wet solidified to form next foam layer 2. This composite was washed and dried to obtain a backing film. The outermost 100 microns of the backing film (denoted 2a in FIG. 2A) were thinned by buffing where the backing film shown in FIG. 3 was obtained.

The temperature-activated pressure-sensitive adhesive (manufactured by Landex) was coated with a thickness of 20 microns on one side of the polyester film 3C (Lumir made by Toray Corporation: 25 microns thick) to form an adhesive layer 3a. On the other side of this polyester film, a conventional adhesive composition (AR-798: acrylic adhesive manufactured by Sankyo Chemical Co., Ltd.) was coated to have a thickness of 20 microns to form an adhesive layer 3b. Each adhesive layer was then covered with release sheet 4. Thus a double coated adhesive film A with release sheet 4 was obtained as shown in FIG. 2B.

The release sheet 4 on the adhesive layer 3b of the adhesive film A is peeled off and the adhesive layer 3b of the adhesive film A is bonded to the polyester film 1 of the backing film to produce a backing film 5 provided with a temperature-activated pressure-sensitive adhesive thereon. done. In FIG. 1, reference numeral 3 (including 3a, 3b and 3c) denotes an adhesive layer and reference numeral 4 denotes a release sheet.

Backing film 5 was cut into circles of 485 mm diameter. A template 6 (consisting of glass epoxy resin) having recesses for installing, protecting and supporting the wafer was attached to the backing film 5 by a press. Thus, a template having a backing film was obtained (FIG. 4).

Template 6 with double-coated adhesive tape on top has an outer diameter of 485 mm and seven six-inch pockets (concave). Template 6 includes an adhesive layer provided on one side thereof with a release sheet adhered to the adhesive layer. The release sheet was peeled off from the adhesive layer and the template 6 was bonded onto the backing film 5. This completes the wafer retainer.

Next, as shown in FIG. 5, the release sheet 4 of the wafer retainer was peeled off from the wafer retainer and the wafer retainer was lightly adhered to the upper ceramic substrate 7 of the polishing machine. After that, a plate made of quartz (weight 10 kg, outer diameter 485 mm) was uniformly placed on the template 6 and left for 30 minutes so that the adhesive was intimate with the upper substrate 7. Adhesion temperature was 25 degreeC.

The wafer was measured by using a single side polisher (SPM-18, manufactured by Fujikoshi Kikai Co., Ltd.). The wafer of silicon monocrystal P (100) was polished under the conditions described in the second diagram. 50 polishings, each taking 30 minutes, were continued. After this wafer retainer was used, the upper ceramic substrate with the wafer retainer, which was not reusable, was immersed in clean water at 20 ° C. The wafer retainer with the temperature-activated pressure-sensitive adhesive easily fell off the upper substrate with only 7 kg of separation force.

Example 2

The temperature-activated pressure sensitive adhesive was directly coated to a thickness of 20 microns to form an adhesive layer 3 on the back side (eg, polyester film 1 side) of the backing film prepared in the same manner as described in Example 1. Release sheet 4 was in close contact with this adhesive layer to produce a backing film 5 having the structure shown in FIG.

A template (consisting of glass epoxy resin sheet) with seven 6 inch pockets (concave portions) with a diameter of 485 mm was adhered to the upper ceramic substrate by using the same coated adhesive film A used in Example 1. To be precise, the adhesive layer 3a of the double coated adhesive film A was bonded to the upper ceramic substrate. Adhesion was carried out at 25 ° C. for 2 minutes with a 1.5 kg / cm 2 load applied to the template. Moreover, the backing film was cut into circles with a diameter of 6 inches. After release sheet 4 was peeled off, each circular backing film was inserted into a pocket (concave) of the template. The backing film was thus mounted on the upper ceramic substrate to obtain a wafer retainer.

The wafer retainer was measured by using a one-side polisher (SPM-18, manufactured by Fujikoshi Gigai Co., Ltd.). Wafers of silicon monocrystal P (100) (6 inches in diameter) were polished under the conditions described in the second diagram. 50 polishings, each taking 30 minutes, were continued. After this wafer retainer was used, the upper ceramic substrate with the wafer retainer, which was not reusable, was immersed in clean water at 20 ° C. Situation also fell easily from the upper substrate with only 2.8 kg of separation force.

Comparative Example 1

Composition I was coated to a thickness of 700 microns on polyester film 1 (Lumirror made by Toray Corporation: 188 microns in diameter). Composition I was then wet solidified. This composite was washed and dried to obtain a backing film having the structure shown in FIG. The outermost 100 microns of the backing film (denoted 2a in FIG. 2) were thinned by buffing where the backing film shown in FIG. 3 was obtained.

A commercially available double-coated adhesive tape (ST-442, manufactured by Sumitomo 3M) was bonded to the polyester film 1 of the backing film, and a backing film having a conventional pressure-sensitive adhesive was produced.

This backing film was cut into circles of 485 mm diameter. As in Example 1, a template 6 (consisting of glass epoxy resin) with recesses for installing, protecting and supporting the wafer was adhered to the backing film 5 by a press. This obtained the steel plate with a backing film (FIG. 4).

Template 6 with double coated adhesive tape has an outer diameter of 485 mm and a 6-inch pocket (concave) of 7. As described above, template 6 includes an adhesive layer provided on one side thereof with a release sheet adhered to the adhesive layer. This completes the wafer retainer.

Next, as shown in FIG. 5, the release sheet of the wafer retainer was peeled off and the wafer retainer was lightly adhered to the upper ceramic substrate of the polishing machine. After that, a plate made of quartz (weight 10 kg, outer diameter 485 mm) was uniformly installed on the template and left for 30 minutes to be intimate with the upper substrate. Adhesion temperature was 25 degreeC.

The wafer was measured by using a single side polisher (SPM-18, manufactured by Fujikoshi Kikai Co., Ltd.). The wafer of silicon monocrystal P (100) was polished under the conditions described in the second diagram. 50 polishings, each taking 30 minutes, were continued. After this wafer retainer was used, the upper ceramic substrate with the wafer retainer, which was not reusable, fell easily with only 34 kg of separation force. The template of the wafer retainer of Comparative Example 1 could not fall as easily as the template of the wafer retainers of Examples 1 and 2.

[Figure 1]

[Table 2]

Example 3

(Herein, parts represent parts by weight)

A. Polymer Manufacturing

45 parts of tetradecyl acrylate, 50 parts of dodecyl acrylate, 5 parts of acrylic acid, 0.3 parts of azobis isobutyronitrile (AIBN) were mixed with 200 parts of toluene and stirred at 60 ° C. for 20 hours to polymerize this monomer. . The resulting polymer had a melting point of 10 ° C. at a molecular weight of 500,000.

The polymer solution was prepared using a solvent (heptane: ethyl acetate = 90 parts: 10 parts) so that the solid part of the polymer solution was 30% by weight. A temperature-sensitive pressure-sensitive adhesive was obtained by adding 0.1 part of a crosslinking agent (Kemitaito PZ-33) to 100 parts of this polymer solution.

B. Fabrication of Wafer Retainers and Their Measurements

Double-coated adhesive film B with a release sheet is the double-coated adhesive film A of Example 1 except that the temperature-activated pressure-sensitive adhesive was used in place of the temperature-activated pressure-sensitive adhesive (manufactured by Landex) of the double-coated adhesive film A This was obtained in the same manner as that prepared.

The wafer retainer was obtained in the same manner as the wafer retainer of Example 1 was obtained except that a double coated adhesive film B with a release sheet was used. The resulting wafer retainer was measured in the same manner as in Example 1 except that the upper ceramic substrate with the wafer retainer was immersed in clean water at about 0 ° C.

The wafer retainer with the temperature-activated pressure sensitive adhesive was separated from the upper substrate with only 6 kg of separation force.

Example 4

A. Preparation of Polymer

45 parts of tetradecyl acrylate, 5 parts of acrylic acid and 0.3 parts of azobis isobutyronitrile (AIBN) were mixed with 200 parts of toluene and stirred at 60 ° C. for 20 hours to polymerize this monomer. The resulting polymer had a melting point of 21C at a molecular weight of 500,000.

The polymer solution was prepared using a solvent (heptane: ethyl acetate = 90 parts: 10 parts) so that the solid part of the polymer solution was 30% by weight. A temperature-sensitive pressure-sensitive adhesive was obtained by adding 0.1 part of a crosslinking agent (Kemitaito PZ-33) to 100 parts of this polymer solution.

B. Fabrication of Wafer Retainers and Their Measurements

The double-coated adhesive film C provided with the release sheet thereon is the double-coated adhesive film of Example 1 except that the above-described pressure-activated pressure-sensitive adhesive was used in place of the temperature-activated pressure-sensitive adhesive (made by Landex) of the double-coated adhesive film A. A was obtained in the same way as it was prepared.

The wafer retainer was obtained in the same manner as the wafer retainer of Example 1 was obtained except that a double coated adhesive film C with a release sheet was used. The resulting wafer retainer was measured in the same manner as in Example 1 except that the upper ceramic substrate with the wafer retainer was immersed in clean water at about 10 ° C.

The wafer retainer with the temperature-activated pressure sensitive adhesive was separated from the upper substrate with only 5 kg of separation force.

Example 5

A. Preparation of Polymer

50 parts of hexadecylacrylate, 45 parts of dodecylacrylate, 5 parts of acrylic acid, 0.3 parts of azobis isobutyronitrile (AIBN) were mixed with 200 parts of toluene and stirred at 60 ° C. for 20 hours to polymerize this monomer. . The resulting polymer had a melting point of 20 ° C. at a molecular weight of 500,000.

The polymer solution was prepared using a solvent (heptane: ethyl acetate = 90 parts: 10 parts) so that the solid part of the polymer solution was 30% by weight. A temperature-sensitive pressure-sensitive adhesive was obtained by adding 0.1 part of a crosslinking agent (Kemitaito PZ-33) to 100 parts of this polymer solution.

B. Fabrication of Wafer Retainers and Their Measurements

Double-coated adhesive film D with a release sheet is the double-coated adhesive film A of Example 1 except that the above-described pressure-activated pressure-sensitive adhesive was used instead of the temperature-activated pressure-sensitive adhesive (made by Landex) of the double-coated adhesive film A This was obtained in the same manner as that prepared.

The wafer retainer was obtained in the same manner as the wafer retainer of Example 1 was obtained except that a double coated adhesive film D with a release sheet was used. The resulting wafer retainer was measured in the same manner as in Example 1 except that the upper ceramic substrate with the wafer retainer was immersed in clean water at about 10 ° C.

The wafer retainer with the temperature-activated pressure sensitive adhesive was separated from the upper substrate with only 4 kg of separation force.

Example 6

A. Preparation of Polymer

75 parts of hexadecylacrylate, 20 parts of butylacrylate, 5 parts of acrylic acid, 0.3 parts of azobis isobutyronitrile (AIBN) were mixed with 200 parts of toluene and stirred at 60 ° C. for 20 hours to polymerize this monomer. The resulting polymer had a melting point of 20 ° C. at a molecular weight of 500,000.

The polymer solution was prepared using a solvent (heptane: ethyl acetate = 90 parts: 10 parts) so that the solid part of the polymer solution was 30% by weight. A temperature-sensitive pressure-sensitive adhesive was obtained by adding 0.1 part of a crosslinking agent (Kemitaito PZ-33) to 100 parts of this polymer solution.

B. Fabrication of Wafer Retainers and Their Measurements

The double coated adhesive film E provided with the release sheet thereon was the double coated adhesive film of Example 1 except that the temperature activated pressure sensitive adhesive was used in place of the temperature activated pressure sensitive adhesive (manufactured by Landex) of the double coated adhesive film A. A was obtained in the same way as it was prepared.

The wafer retainer was obtained in the same manner as the wafer retainer of Example 1 was obtained except that a double coated adhesive film E with a release sheet was used. The resulting wafer retainer was measured in the same manner as in Example 1 except that the upper ceramic substrate with the wafer retainer was immersed in clean water at about 120 ° C.

The wafer retainer with the temperature-activated pressure sensitive adhesive was separated from the upper substrate with only 7 kg of separation force.

Comparative Example 2

An adhesive consisting of 100 parts of butyl acrylate, 5 parts of acrylonitrile and 5 parts of acrylic acid was prepared.

The double-coated adhesive film provided with the release sheet above was the double-coated adhesive film A of Example 1 except that the above-mentioned pressure-activated pressure-sensitive adhesive was used instead of the temperature-activated pressure-sensitive adhesive (made by Landex) of the double-coated adhesive film A. This was obtained in the same manner as that prepared.

The wafer retainer was obtained in the same manner as the retainer of Example 1 was obtained except that the above double coated adhesive film with a release sheet was used. The resulting wafer retainer was measured in the same manner as 1.

The wafer retainer with the temperature activated pressure sensitive adhesive was separated from the upper substrate with only 28 kg of separation force.

According to the present invention, the replacement or replacement of the wafer retainer for protecting and holding the wafer to be polished is carried out after each polishing process, since the wafer retainer is easily separated from the substrate by simply cooling the substrate and the adhesive layer of the wafer retainer. , Replacement is substantially easy.

Claims (8)

A foam layer capable of detachable absorbing the wafer onto the foam layer surface; A pressure-sensitive adhesive layer for adhering the foam layer to the substrate of the polishing machine; It consists of a release sheet that can be adhered to and separated from the pressure-sensitive adhesive layer (pressure release adhesive layer), wherein the pressure-sensitive adhesive layer comprises an adhesive component comprising a polymer (polymer) in which the first solution transition occurs in a temperature range narrower than 15 ℃ A wafer retainer for supporting a polished wafer, characterized in that it comprises an adhesive composition with The adhesive composition of claim 1, wherein the adhesive composition has a side chain (by an amount such that the pressure-sensitive adhesive layer is substantially non-adhesive to the substrate of the polishing machine at 20 ° C. or less and substantially adhesive to the substrate of the polishing machine at a temperature of 20 ° C. or more). side chain) wafer retainer characterized by comprising a determinable polymer 3. The side chain determinable polymer of claim 2 comprises a acrylic acid ester as the main component and / or a methacrylic acid ester having a straight-chain alkyl group comprising 10 or more carbons as the side chain. Featured Wafer Retainer 3. The side chain determinable polymer of claim 2 is selected from the group consisting of acrylates (methacrylates) with 10 to 14 carbons and acrylates (methacrylates) with acrylic acid and 1 to 4 carbons. A wafer retainer characterized by a copolymer of at least one monomer The method according to claim 4, wherein 40 to 95% by weight of the acrylate (methacrylate) having 10 to 14 carbons; 1-10% by weight acrylic acid; And / or an acrylate (methacrylate) component having from 5 to 40% by weight of 1 to 4 carbons. The wafer retainer is adhered to the substrate of the polishing machine by removing the release sheet of the wafer retainer from the pressure-sensitive adhesive layer by using the wafer retainer according to claim 1, and while the substrate is held at T1 temperature, Adhering to the substrate of the polishing machine and detaching the wafer retainer from the substrate of the substrate of the polishing machine while cooling the temperature of the substrate after use of the wafer retainer from the temperature T1 to the temperature T2 so that the temperature T2 is lower than the temperature T1. Method of Bonding / Removing Wafer Retainers from Substrate The method of claim 6, wherein the temperature of T1 is 20 ° C. or higher and the temperature of T1 is 20 ° C. or less. The method of claim 6, wherein the temperature of T1 is 25 ° C or more, and the temperature of T2 is 20 ° C or less.