KR101467718B1 - Semiconductor device manufacturing method and film used therein for protecting surface of semiconductor - Google Patents

Abstract

Provided is a film for protecting a surface of a semiconductor wafer which is capable of grinding even a hard and brittle semiconductor wafer without damaging it. More specifically, the present invention relates to a base layer (A) having a storage modulus G _A (150) of at least 1 MPa at 150 ° C and a storage modulus G _B (120 to 180) at a temperature of 120 to 180 캜 of 0.05 MPa , And a softening layer (B) having a storage modulus G _B (40) of 10 MPa or more at 40 캜.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for manufacturing a semiconductor device, and a film for protecting a surface of a semiconductor wafer used in the method. [0002]

The present invention relates to a method of manufacturing a semiconductor device and a semiconductor wafer surface protective film used in the method.

Thinning of a semiconductor wafer in a manufacturing process of a semiconductor device is usually performed by grinding the circuit non-formation surface (back surface) of the semiconductor wafer. Protection of the circuit formation surface of the semiconductor wafer during back side grinding is performed by various methods.

For example, the circuit formation surface of a semiconductor wafer made of a sapphire substrate is protected by the following method (for example, Patent Document 1 and Non-Patent Document 1). That is, a ceramic plate provided with a wax resin layer on its surface is prepared. Next, the wax resin layer is heated and melted to embed (embed) the circuit forming surface of the sapphire substrate into the molten wax resin layer. Then, the wax resin layer is cooled to solidify. Thereby, the entire circuit formation surface of the sapphire substrate is protected by the wax resin layer. The wax resin is usually composed of rosin wax (wax containing rosin, montan wax, phenol resin, etc., melting point of about 50 캜).

International Publication No. 2005/099057

 Disco Press Release Co., Ltd. November 5, 2009 Internet (URL: http://www.disco.co.jp/jp/news/press/20091105.html)

However, in the above method, it is necessary to heat-melt the wax resin layer in order to peel the sapphire substrate after the back grinding from the wax resin layer. Further, it is necessary to clean and remove the wax resin remaining on the surface of the sapphire substrate with a solvent, which complicates the process. Further, the sapphire substrate after the back side grinding has a problem that it is fragile in these steps because the sapphire substrate is very thin and easily bent.

Therefore, the present inventors have studied a method for protecting the circuit formation surface of a sapphire substrate by a semiconductor wafer protective film which is relatively easy to peel off. Conventional semiconductor wafer protective films have a base layer and an adhesive layer. Then, the adhesive layer of the semiconductor wafer protective film is attached to the circuit formation surface of the semiconductor wafer, and then the semiconductor wafer is ground. Thereafter, the semiconductor wafer protective film is peeled off by a tape peeling machine or the like.

However, in the conventional method using the semiconductor wafer protective film, there is a problem that the end portion of the sapphire substrate tends to be broken at the time of back grinding. That is, as shown in Fig. 3, in the wax method, since the entire end of the sapphire substrate 1 is embedded in the wax resin layer 2, the end portion of the sapphire substrate 1 tends to be stably maintained. 4, since the end portion of the sapphire substrate 1 is not embedded in the semiconductor wafer protective film 4 in the conventional method using the semiconductor wafer protective film, It is difficult for the end portion to be stably maintained. Therefore, it is considered that the end portion of the sapphire substrate 1 is liable to be damaged when it is brought into contact with the grindstone 3 or the like during back grinding.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a semiconductor device manufacturing method capable of grinding a back surface without being damaged even in a hard and brittle semiconductor wafer such as a sapphire substrate, And to provide the above objects.

The inventors of the present invention have found that the breakage of the end portion of the semiconductor wafer can be suppressed by holding the vicinity of the end portion of the semiconductor wafer at the ridge portion during back grinding. The inventors of the present invention have found that the structure of a film capable of relatively easily forming a ridge portion by thermocompression bonding and capable of maintaining a shape of a ridge portion even at the time of back grinding .

That is, the first aspect of the present invention relates to the following semiconductor wafer surface protection film.

[1] _A pressure-sensitive adhesive composition comprising a base layer (A) having a storage elastic modulus at 150 ° C (150) of 1 MPa or more and a storage modulus G _B (120 to 180) at a temperature of 120 to 180 ° C of 0.05 MPa or less, And a softening layer (B) having a storage elastic modulus G _B (40) of 10 MPa or more at 40 占 폚.

[2] The semiconductor wafer surface protection film according to [1], wherein the softening layer (B) has a storage modulus G _B (100) at 100 ° C of 1 MPa or more.

(3) The tensile modulus E _B (60) of the softening layer (B) at 60 ° C and the tensile modulus E _B (25) at 25 ° C satisfy 1> E _B (60) / E _B The semiconductor wafer surface protective film according to [1] or [2]

[4] The adhesive layer (C) further comprises an adhesive layer (C) disposed on the side opposite to the base layer (A) through the softened layer (B) and the adhesive strength measured in accordance with JIS Z0237 of the adhesive layer The film for surface protection of a semiconductor wafer according to any one of [1] to [3], wherein the film has a thickness of 0.1 to 10 N / 25 mm.

[5] The semiconductor wafer surface protection film according to any one of [1] to [4], wherein the base layer (A) is disposed on the outermost surface.

[6] The semiconductor wafer surface protection film according to [4] or [5], wherein the adhesive layer (C) is disposed on the outermost surface opposite to the base layer (A) through the softened layer (B).

[7] The semiconductor wafer surface protection film according to any one of [1] to [6], wherein the softened layer (B) comprises a homopolymer of hydrocarbon olefin, a copolymer of hydrocarbon olefin, or a mixture thereof.

[8] The semiconductor wafer surface protection film according to any one of [1] to [7], wherein the resin constituting the softened layer (B) has a density of 880 to 960 kg / m ³ .

[9] The semiconductor wafer surface protection film according to any one of [1] to [8], wherein the base layer (A) is a polyolefin layer, a polyester layer or a laminate of a polyolefin layer and a polyester layer.

A second aspect of the present invention relates to the following method of manufacturing a semiconductor device.

A step of disposing a semiconductor wafer on a semiconductor wafer surface protective film such that the circuit forming surface of the semiconductor wafer is in contact with the semiconductor wafer surface protective film;

Forming a ridge portion of the semiconductor wafer surface protection film for holding the semiconductor wafer on an outer periphery of the semiconductor wafer;

A step of grinding a circuit non-formation surface of the semiconductor wafer held by the raised portion,

And peeling the semiconductor wafer surface protection film from the circuit formation surface of the semiconductor wafer,

Wherein the storage elastic modulus G (100) of the ridge portion at 100 占 폚 is 1 MPa or more.

[11] The semiconductor wafer surface protection film according to any one of [1] to [9]

Wherein the protruding portion is formed by thermocompression bonding the semiconductor wafer surface protective film and the semiconductor wafer at a temperature of 120 to 180 DEG C and a pressure of 1 to 10 MPa.

[12] A method for manufacturing a semiconductor device according to [11]

The temperature TM of the film in the step of disposing the semiconductor wafer on the semiconductor wafer surface protective film so that the circuit forming surface of the semiconductor wafer is in contact with the semiconductor wafer surface protective film and the temperature rise TM of the semiconductor wafer surface protective film And the softening point temperature TmB of the softening layer (B) satisfies a relationship expressed by the following general formula.

[Formula 1] TP? TM

[Equation 2] TmB <TP <TmB + 40 ° C

(13) The semiconductor wafer is placed on the semiconductor wafer surface protection film so that the softened layer (B) of the semiconductor wafer surface protection film is closer to the circuit formation surface side of the semiconductor wafer than the base layer (A) Or the method of manufacturing a semiconductor device according to [12].

[14] The method for manufacturing a semiconductor device according to any one of [10] to [13], wherein the semiconductor wafer includes a high hardness material substrate having a Moh hardness of 8 or more.

A third aspect of the present invention relates to a semiconductor wafer press apparatus for pressing a mount frame.

[15] A semiconductor device comprising: a semiconductor wafer; a ring frame A having a frame surrounding the semiconductor wafer; and a mount frame having a semiconductor wafer surface protection film according to claim 1 attached to the circuit formation surface of the semiconductor wafer and the frame A Is press-fitted with an upper press plate having a heating mechanism and a lower press plate facing the upper press plate,

The outer diameter DW of the semiconductor wafer and the inner diameter DA _IN of the ring frame A satisfy the relation of the expression (1) DW < DA _IN ,

Wherein the lower press plate has a convex portion on a surface facing the upper press plate,

Wherein an outer periphery of a contact surface of the convex portion with the mount frame is circular when pressed.

[16] The semiconductor wafer press apparatus according to [15], wherein the convex portion has a height of 1 to 100 μm.

[17] The semiconductor wafer pressing apparatus according to [15] or [16], wherein the height of the convex portion is within a range of 15 to 100% with respect to a thickness of the softened layer (B) of the semiconductor wafer surface protective film.

[18] The semiconductor wafer press apparatus according to any one of [15] to [17], wherein the diameter CD of the convex portion satisfies the relationship of DW <CD <DA < _IN .

A fourth aspect of the present invention relates to a semiconductor wafer mounting apparatus for manufacturing a mount frame and a method of manufacturing a semiconductor device using the semiconductor wafer mounting apparatus.

A ring-shaped auxiliary member B surrounding the semiconductor wafer; a ring frame A surrounding the semiconductor wafer and the ring-shaped auxiliary member B; and a circuit-forming surface of the semiconductor wafer and the ring-shaped auxiliary member B A semiconductor wafer mounting apparatus for manufacturing a mount frame including the semiconductor wafer surface protective film according to any one of [1] to [9], which is attached over the ring frame A,

The outer diameter DW of the semiconductor wafer, the inner diameter DA _IN of the ring frame A, the ring outer diameter DB _OUT of the ring-shaped auxiliary member B, and the ring inner diameter DB _IN of the ring-shaped auxiliary member B satisfy the formula (1) DW &Lt; DB _IN < DB _OUT < DA _IN ,

A heating unit for heating a surface opposite to the circuit forming surface of the semiconductor wafer;

An attachment roller for rolling over the circuit formation surface of the semiconductor wafer, the ring frame A, and the ring-shaped auxiliary member B to attach the semiconductor wafer surface protective film,

And a tape cutting mechanism for cutting the surface protection film along the outer shape of the ring frame A.

[20] The semiconductor wafer mounting apparatus according to [19], wherein both of ΔD1 and ΔD2 expressed by the following formula are within 1% of DW.

DELTA D1 = DB _IN- DW (2)

DELTA D2 = DA _IN -DB _OUT (3)

A fifth aspect of the present invention relates to the following method of manufacturing a semiconductor device.

1 ') preparing a semiconductor wafer, 2') forming a protruding portion substantially made of resin on the outer periphery of the semiconductor wafer, 3 ') arranging the circuit formation surface of the semiconductor wafer on the semiconductor wafer surface protective film A step of grinding a circuit non-formation surface of the semiconductor wafer held by the 4 'ridge portion; and 5') a step of peeling the semiconductor wafer surface protection film,

Wherein the storage elastic modulus G _B (40) of the ridge portion made of the resin is 10 MPa or more.

The semiconductor wafer surface protective film of the present invention can enable backgrinding without damaging even a hard and brittle semiconductor wafer such as a sapphire substrate.

1A is a schematic view showing one embodiment of a semiconductor wafer surface protective film of the present invention.
1B is a schematic view showing another embodiment of the semiconductor wafer surface protective film of the present invention.
2A is a diagram showing an example of a process (mounting process) for disposing a semiconductor wafer on a semiconductor wafer surface protective film.
2B is a view showing a laminate in which a semiconductor wafer is disposed on a semiconductor wafer surface protective film.
2C is a view showing an example of a step (press step) of forming a ridge portion of a semiconductor surface protection film on the periphery of a semiconductor wafer.
2D is an enlarged view showing an example of a raised portion.
FIG. 2E is a view showing an example of a step of grinding a circuit-unformed surface of a semiconductor wafer. FIG.
3 is a view showing an example of a method of protecting a semiconductor wafer by a conventional wax method.
4 is a view showing an example of a method of protecting a semiconductor wafer using a conventional semiconductor wafer surface protective film.
5A and 5B of FIG. 5 are views showing another embodiment of the mounting process.
6 is a diagram showing a state in which the thickness of the semiconductor wafer surface protective film is uneven by a pressing process.
7A is a view showing another embodiment of the pressing process, and Figs. 7B to 7C are views showing examples of the shape of the convex portion.
8 is a view showing a method of forming a protruding portion separate from the semiconductor surface protective film on the outer periphery of the semiconductor wafer.

1. Semiconductor wafer surface protection film

The semiconductor wafer surface protective film of the present invention comprises a base layer (A) and a softening layer (B); The pressure-sensitive adhesive layer (C) (see FIG. 1A) and lightly adhesive layer D (see FIG. 1B) may be further included as necessary. The thickness of the film in the present invention is not limited and may be referred to as a so-called sheet.

For the base layer (A)

The base layer (A) has a function of suppressing the warpage of the semiconductor wafer and keeping the shape when the semiconductor wafer is thermally bonded to the semiconductor wafer surface protective film. Therefore, it is preferable that the substrate layer (A) has a storage elastic modulus at a certain temperature or more at a thermocompression bonding temperature (any one of 120 to 180 DEG C). Specifically, the storage elastic modulus G _A (150) of the base layer (A) at 150 캜 is preferably 1 MPa or more, more preferably 2 MPa or more.

The storage elastic modulus of the base layer (A) can be measured by the following method. That is, a sample film having a thickness of 500 mu m made of the resin constituting the base layer (A) is prepared. Subsequently, the sample film was set on a dynamic viscoelasticity measuring device (TA Instruments: ARES) manufactured by TA Instruments Co., Ltd., and a parallel plate type attachment having a diameter of 8 mm was used. And the storage elastic modulus is measured. The measurement frequency can be set to 1 Hz. After completion of the measurement, the value of the storage elastic modulus G (Pa) at 150 캜 is read from the obtained storage modulus-temperature curve at 30 to 200 캜.

The resin constituting the base layer (A) may be any resin that satisfies the above-mentioned storage elastic modulus. Further, as described later, when the pressure-sensitive adhesive layer (C) is made of a radiation-curing pressure-sensitive adhesive, the resin constituting the base layer (A) preferably has transparency. Examples of such resins include polyolefins, polyesters, and the like. That is, the base layer (A) may be a polyolefin film, a polyester film, a laminated film of a polyolefin layer and a polyester layer, or the like. Examples of polyolefin films include polypropylene films. Examples of the polyester film include a polyethylene terephthalate film, a polyethylene naphthalate film and the like.

The density of the resin constituting the base layer (A) is preferably 900 to 1,450 kg / m ³ . When the density of the resin constituting the base layer (A) is less than 900 kg / m ³ , the storage elastic modulus is excessively low, so that the shape retainability may not be sufficient.

The thickness of the base layer (A) is preferably 5 mu m or more, more preferably 10 mu m or more, from the viewpoint of obtaining a rigidity enough to suppress the warpage of the semiconductor wafer. The upper limit of the thickness of the base layer (A) may be such that the total thickness of the semiconductor wafer surface protective film is not excessively thick with respect to the finished thickness of the semiconductor wafer, from the viewpoint of preventing breakage of the semiconductor wafer.

For the softened layer (B)

The softened layer B has a function of forming a ridge around the semiconductor wafer in order to stably maintain the end of the semiconductor wafer. It is necessary to soften the softened layer (B) at a thermal compression bonding temperature (120 to 180 DEG C) because there is a case where the semiconductor wafer surface protective film and the semiconductor wafer are thermocompression bonded to form a ridge portion have. That is, the softening point temperature TmB of the softened layer B is preferably lower than the thermal compression bonding temperature (120 to 180 ° C). The softening point temperature TmB can be obtained from the DSC measurement. Specifically, the melting point (DSC method) of the resin material according to ISO-11357-3 is the softening point temperature.

The storage modulus of the soft layer (B) of which in a temperature of 120~180 ℃ G _B (120~180), preferably a storage elastic modulus G _B (150) of the softening layer (B) in 150 ℃ is 0.05MPa Or less, more preferably 0.03 MPa or less.

On the other hand, in order to prevent softening of the ridges at the time of back grinding (wet polishing), it is necessary not to soften the softened layer B at the temperature (around 40 deg. C) during back grinding. Therefore, the storage elastic modulus G _B (40) at 40 ° C is preferably 10 MPa or more, more preferably 20 MPa or more, and still more preferably 30 MPa or more. The upper limit of the storage elastic modulus G _B (40) at 40 ° C can be usually about 500 MPa or less. It is preferable that the resin constituting the softened layer B be a resin other than an elastomer as described later in order to make the softening layer B have a storage elastic modulus G _B (40) at 40 캜 of 10 MPa or more. As described later, the storage elastic modulus G is about 1/3 of the tensile elastic modulus E. For example, "the storage elastic modulus G _B (40) at 40 ° C of the softening layer B is at least 10 MPa" means that the softening layer B has a tensile elastic modulus E _B (40) at 40 ° C of 30 MPa or more I can say "I do."

The back side grinding is usually performed by a wet method, but it may be performed by dry method as necessary. The temperature of the wafer at the time of dry grinding (dry polishing) may be about 100 캜 because of the large frictional heat between the grinding wheel and the semiconductor wafer. Therefore, it is preferable that the softening layer B has a storage elastic modulus G _B (100) at 100 ° C of 1 MPa or more, more preferably 3 MPa or more, so that the ridge portion is not softened even during dry polishing.

It is preferable that the softening layer B has a tensile elastic modulus E _B (60) at 60 ° C and a tensile modulus E _B (25) at 25 ° C of 1> E _B (60) / E _B (25)> 0.1. The temperature of the semiconductor wafer at the time of back-grinding the semiconductor wafer is often changed within the range of 25 占 폚 to 60 占 폚. Therefore, by making the rate of change of the storage elastic modulus of the softened layer B within this temperature range within a certain range, the protruded portion of the softened layer B can stably maintain the semiconductor wafer. Further, the protrusions made of the softened layer (B) are prevented from deteriorating during back grinding of the semiconductor wafer. Therefore, breakage of the semiconductor wafer during back grinding of the semiconductor wafer can be more effectively suppressed.

The measurement of the tensile modulus of elasticity E of the softened layer (B) can be carried out as follows. (i) A film having a thickness of 100 mu m is cut to prepare a sample piece having a width of 10 mm in the TD direction and a length of 100 mm in the MD direction. ii) Next, according to JIS K7161, the tensile modulus of the sample piece is measured by a tensile tester under the conditions of a distance between chucks of 50 mm and a tensile speed of 300 mm / min. The tensile modulus of elasticity is measured at a temperature of 23 DEG C and a relative humidity of 55%. The tensile elastic modulus E is often about three times the storage elastic modulus G.

The resin constituting the softened layer (B) is not particularly limited as long as it satisfies the above storage elastic modulus, but is preferably not an elastomer. Specifically, homopolymers or copolymers of hydrocarbon olefins are preferable, and ethylene homopolymers, propylene homopolymers, or copolymers of ethylene or propylene and other hydrocarbon olefins are more preferable. On the other hand, for example, the ethylene-vinyl acetate copolymer (EVA) is not preferable because the storage elastic modulus G (40) at 40 캜 is usually about 0.01 MPa to 0.1 MPa and less than 10 MPa.

In the copolymer of ethylene or propylene and the other hydrocarbon olefin, the hydrocarbon olefin other than ethylene or propylene is preferably an? -Olefin having 3 to 12 carbon atoms. Examples of? -Olefins having 3 to 12 carbon atoms include propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, Pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene and the like, and preferably propylene and 1-butene.

Specific examples of the resin constituting the softened layer B include linear low density polyethylene (LLDPE), low density polyethylene, high density polyethylene, polypropylene, polystyrene, ABS resin, vinyl chloride resin, methyl methacrylate resin, nylon, fluorine (LLDPE), low density polyethylene, high density polyethylene, polypropylene, and the like. The term &quot; low-density polyethylene &quot;

The density of the resin constituting the soft layer (B) is more preferably a preferably, 910~950kg / m ³ more preferably it is preferred, and 900~960kg / m ³ of 880~960kg / m ^3. When the density of the resin constituting the softened layer (B) is less than 880 kg / m ³ , softening may occur at 40 캜. On the other hand, if the density of the resin exceeds 960 kg / m ³ , it may be difficult to soften at the thermocompression bonding temperature.

The storage modulus of the softened layer (B) is adjusted by the density of the homopolymer of ethylene or propylene, the type and content of hydrocarbon olefins other than ethylene or propylene in the copolymer of ethylene or propylene and other hydrocarbon olefin . For example, in order to increase the storage elastic modulus of the softened layer (B) at 40 占 폚, it is preferable to increase the density of the homopolymer of ethylene or propylene or increase the content of ethylene or propylene in the copolymer of ethylene or propylene and other hydrocarbon olefin You can increase the ratio.

The thickness of the softened layer (B) is not limited so long as it can form the rim by thermocompression bonding with the semiconductor wafer and can embed irregularities on the surface of the semiconductor wafer. Therefore, the thickness of the softened layer B is preferably larger than the maximum value of the step on the circuit formation surface of the semiconductor wafer, and is preferably 1.1 times or more of the maximum value of the step. Specifically, when the step is 50 탆, it is more preferably 55 탆 or more, and more preferably 60 탆 or more. On the other hand, if the softened layer (B) is too thick, it is difficult to suppress the deformation (warpage) of the semiconductor wafer during grinding as compared with the case where the softened layer (B) is thin. Therefore, the thickness of the softened layer B is preferably 100 탆 or less, and more preferably 70 탆 or less.

The softening layer (B) may further contain other resins or additives as required. Examples of the additives include ultraviolet absorbers, antioxidants, heat stabilizers, lubricants, softeners and the like.

With respect to the adhesive layer (C)

It is preferable that the semiconductor wafer surface protective film of the present invention further includes an adhesive layer (C) in order to improve the adhesion with the semiconductor wafer. On the other hand, if the adhesive force of the adhesive layer (C) is too high, the adhesive tends to remain when peeling off from the semiconductor wafer. Therefore, the adhesive layer (C) may have a minimum adhesive force, and specifically, it is preferable that the adhesive force measured in accordance with JIS Z0237 is 0.1 to 10 N / 25 mm.

The storage modulus of the pressure-sensitive adhesive layer (C) may be set so as not to hinder the formation of ridges (rim) of the softened layer (B).

The pressure sensitive adhesive (pressure sensitive adhesive) constituting the pressure sensitive adhesive layer (C) may be an acrylic pressure sensitive adhesive, a silicone pressure sensitive adhesive, a rubber pressure sensitive adhesive or the like. Above all, an acrylic pressure-sensitive adhesive having an acryl-based polymer as a base polymer is preferred for easy adjustment of adhesion.

The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (C) may be a radiation-curable pressure-sensitive adhesive. This is because the adhesive layer composed of the radiation-curable pressure-sensitive adhesive can be easily peeled off from the wafer because it is cured by irradiation of radiation. The radiation may be ultraviolet, electron beam, infrared or the like.

The radiation-curable pressure-sensitive adhesive may include the above-mentioned pressure sensitive adhesive, a compound having a carbon-carbon double bond in the molecule, and a radiation polymerization initiator; An adhesive base containing a polymer having a carbon-carbon double bond in the molecule as a base polymer, and a radiation polymerization initiator.

Examples of the compound having a carbon-carbon double bond in the molecule include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tetraethylene Glycol di (meth) acrylate and the like. The content of the radiation-curable compound may be about 30 parts by weight or less based on 100 parts by weight of the pressure-sensitive adhesive.

Examples of the radiation polymerization initiator include an acetophenone-based photopolymerization initiator such as methoxyacetophenone; Alpha -ketol compounds such as 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone; Ketal compounds such as benzyl dimethyl ketal; Benzoin-based photopolymerization initiators such as benzoin and benzoin methyl ether; Benzophenone-based photopolymerization initiators such as benzophenone, benzoylbenzoic acid and the like.

The radiation-curing pressure-sensitive adhesive may further contain a crosslinking agent, if necessary. Examples of the crosslinking agent include isocyanate crosslinking agents such as diphenylmethane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, and polyisocyanate.

The thickness of the pressure-sensitive adhesive layer (C) is not particularly limited as long as the rim formation by the softened layer (B) is not impeded. For example, the thickness of the softened layer (B) is about 1 to 20% can do.

Sensitive adhesive layer (D)

The semiconductor wafer surface protective film of the present invention may have a light-hardening adhesive layer (D) for releasably adhering the base layer (A) and the softening layer (B) to each other. Examples of the material of the light and adhesive layer (D) include an acrylic pressure-sensitive adhesive and the like.

When the semiconductor wafer surface protective film of the present invention has the light-hardening layer (D), the base layer (A) and the softening layer (B) can be peeled from each other. Therefore, after the semiconductor wafer surface protective film is attached to the semiconductor wafer, the base layer (A) can be peeled off from the semiconductor wafer surface protective film. For example, after the step of forming the ridge portion of the semiconductor surface protection film on the outer periphery of the semiconductor wafer (see FIG. 2C) and before the step of grinding the circuit non-formation surface of the semiconductor wafer (see FIG. 2E) It may be peeled off from the wafer surface protective film.

More precise grinding can be realized by grinding the circuit non-formation surface of the semiconductor wafer after peeling off the base layer (A). During the grinding of the semiconductor wafer, the semiconductor wafer surface protective film may be bent or vibrated by the load of the grinding stone, which may hinder precise grinding. On the other hand, when the semiconductor wafer is polished after the base film (A) is peeled to make the semiconductor wafer surface protective film thin, warpage and vibration of the semiconductor wafer surface protective film are suppressed. Therefore, more accurate grinding can be realized.

The semiconductor wafer surface protective film of the present invention may further include another layer as necessary. The other layer may be, for example, a release film or the like.

As described above, the semiconductor wafer surface protective film includes the base layer (A) and the softening layer (B). The base layer (A) is preferably disposed on the outermost surface of the semiconductor wafer surface protective film. When the semiconductor wafer surface protective film further includes the adhesive layer (C), it is preferable that the adhesive layer (C) is disposed on the outermost surface opposite to the base layer (A). The softened layer B may be a single layer or a plurality of layers.

1A and 1B are views showing an example of a configuration of a semiconductor wafer surface protective film. 1A, the semiconductor wafer surface protective film 10 has a base layer (A) 12, a softened layer (B) 14, and an adhesive layer (C) 16. 1B, a semiconductor wafer surface protective film 10 'is formed by laminating a base layer (A) 12, a light-hardening adhesive layer (D) 18, a softening layer (B) 14, Layer (C) (16). The semiconductor wafer surface protective films 10 and 10 'are used such that the adhesive layer (C) 16 is in contact with the circuit formation surface of the semiconductor wafer.

The semiconductor wafer surface protective film of the present invention can be produced by any method. For example, 1) a method of co-extruding the base layer (A) and the softened layer (B) to obtain a semiconductor wafer surface protective film (coextrusion formation method); 2) a method (lamination method) of obtaining a film for protecting the surface of a semiconductor wafer by laminating (laminating) the base layer (A) on the film and the softened layer (B) on the film. The semiconductor wafer surface protective film further comprising the adhesive layer (C) can be produced by applying a coating liquid for an adhesive layer onto the laminated film of the base layer (A) and the softened layer (B).

2. Manufacturing Method of Semiconductor Device

An example of a method for manufacturing a semiconductor device using the semiconductor wafer surface protective film of the present invention includes the steps of: 1) a step of placing a semiconductor wafer on a surface of a semiconductor wafer surface protective film (a mounter process); 2) (Press process) of forming a ridge portion of the semiconductor wafer surface protective film for holding the semiconductor wafer surface protecting film, (3) grinding the circuit non-formation surface of the semiconductor wafer held by the ridge portion, and (4) . 3) In the present invention, the step of grinding the circuit non-formation surface of the semiconductor wafer held by the semiconductor wafer surface protective film means that the semiconductor wafer is thinned to a predetermined thickness without breaking or breaking the semiconductor wafer . A step of dicing the semiconductor wafer into chips after performing these steps may be further performed.

Another example of a method of manufacturing a semiconductor device using a semiconductor wafer surface protective film includes the steps of: 1 ') preparing a semiconductor wafer; 2') forming a ridge portion substantially made of resin on the periphery of the semiconductor wafer; ) Placing a circuit formation surface of a semiconductor wafer on a semiconductor wafer surface protective film, 4 ') grinding a circuit non-formation surface of the semiconductor wafer held by the ridge portion, and 5' . 2 ') protrusions on the surface of the semiconductor wafer, and the step of arranging the circuit formation surface of the semiconductor wafer on the 3') semiconductor wafer surface protective film may be performed first.

2 '), the protruding portion formed substantially on the outer periphery of the semiconductor wafer may be made of a resin material different from the material constituting the semiconductor wafer surface protective film. In this case, the semiconductor wafer surface protective film is not limited to the above-mentioned semiconductor wafer surface protective film of the present invention, and may be a commonly used semiconductor wafer surface protective film. The storage elastic modulus G _B (40) of the raised portion substantially made of resin should be 10 MPa or more; The storage elastic modulus G _B (100) is preferably 1 MPa or more.

The combination of the semiconductor wafer formed through the 2 &apos; process and the ridge portion made of substantially resin disposed on the outer periphery thereof is also referred to as a semiconductor wafer with a rim. The rim-attached semiconductor wafer may include a semiconductor wafer and a ridge portion substantially made of resin; The semiconductor wafer may have a raised portion made of a semiconductor wafer and a substantially resin, and a semiconductor wafer surface protective film for supporting the raised portion. The semiconductor wafer surface protective film is attached to the circuit formation surface of the semiconductor wafer.

Also, it may include a step of disposing a ring frame (refer to reference numeral 30 in Fig. 2B) so as to surround the semiconductor wafer. The step of disposing the ring frame may be before the step of preparing the 1 ') semiconductor wafer and the step of 4') of grinding. Further, a protruding portion may be provided in the gap between the ring frame (see reference numeral 30 in Fig. 2B) and the semiconductor wafer.

In the case of the rimmed semiconductor wafer, the distance between the ridge portion and the edge of the semiconductor wafer is preferably 0 to 1 mm, more preferably 0 to 500 m, and more preferably the ridge portion and the edge of the semiconductor wafer are in contact with each other. So that the protrusions can hold the semiconductor wafer.

The semiconductor wafer is not particularly limited and may be a silicon substrate or a sapphire substrate on which a circuit such as a wiring, a capacitor, a diode, or a transistor is formed on the surface. Even a semiconductor wafer including a hardness material substrate having a hardness of Moh's hardness of 8 or more can be obtained by forming a rim on the outer periphery of the semiconductor wafer with the semiconductor wafer surface protective film or the like of the present invention to polish the circuit non- Breakage of the semiconductor wafer can be suppressed. Further, the semiconductor wafer of the present invention may be obtained by laminating a semiconductor layer such as GaN on a sapphire substrate. In the case of manufacturing a semiconductor device such as an LED element, a sapphire substrate on which a circuit is formed is preferably used. The size of the semiconductor wafer is not particularly limited and may be 2 inches, 4 inches, 6 inches, 8 inches, and the like. A step of 1 占 퐉 to 50 占 퐉 is provided on the circuit formation surface of the semiconductor wafer.

The ridge portion of the semiconductor wafer surface protective film formed around the semiconductor wafer is a portion formed on the outer periphery of the semiconductor wafer and also holding the end portion of the semiconductor wafer. The ridge portion of the semiconductor wafer surface protective film may be composed of the semiconductor wafer surface protective film itself; And may be made of a material different from the material constituting the semiconductor wafer surface protective film.

For example, the following methods can be used to constitute the ridge portion by the resin material different from the material constituting the semiconductor wafer surface protective film. In each method, the semiconductor wafer may be a semiconductor wafer mounted on a semiconductor wafer surface protective film, or may be a semiconductor wafer before being mounted.

Method 1) As shown in Fig. 8A, a method of applying a liquid adhesive 105 to the periphery of a semiconductor wafer 20 with a coating device such as a dispenser 100 and curing

Method 2) As shown in Fig. 8B, a method of inserting the semiconductor wafer 20 into the resin ring 110 having a through-hole having a diameter substantially equal to the diameter of the semiconductor wafer 20

Method 3) As shown in Fig. 8C, a method of injecting a molten resin into a cavity 125 of a mold 120 into which a semiconductor wafer 20 is inserted, cooling and solidifying the resin to form a resin around the semiconductor wafer

In the method 1), the viscosity of the liquid adhesive 105 applied by the dispenser 100 (before curing) may be about 1 to 500 Pa · s; The storage elastic modulus G _B (40) of the cured product of the adhesive 105 may be 10 MPa or more; The storage elastic modulus G _B (100) is preferably 1 MPa or more. That is, the cured product of the adhesive 105 preferably has the same elastic modulus as that of the softened layer (B) in the above-described semiconductor wafer surface protective film. Examples of the liquid adhesive 105 include an epoxy resin, an acrylic resin, a urethane resin, a phenol resin, and the like.

The storage elastic modulus G _B (40) of the resin ring 110 having the through-holes of the same diameter as the diameter of the semiconductor wafer 20 may be 10 MPa or more in the method 2); The storage elastic modulus G _B (100) is preferably 1 MPa or more. That is, it is preferable to have the same elastic modulus as that of the softened layer (B) in the above-mentioned semiconductor wafer surface protective film. Examples of the resin constituting the resin ring 110 include polyethylene (high density polyethylene, low density polyethylene and the like), polypropylene (homopolypropylene, random polypropylene and the like), polystyrene, nylon and the like.

The molten resin to be injected into the cavity 125 of the mold 120 may be an epoxy resin or the like and the storage elastic modulus G _B (40) of the molten resin after cooling and solidification may be 10 MPa or more; The storage elastic modulus G _B (100) is preferably 1 MPa or more. That is, it is preferable to have the same elastic modulus as that of the softened layer (B) in the above-mentioned semiconductor wafer surface protective film.

As described above, the ridge portion formed around the semiconductor wafer can be formed by any method, but since the ridge can be relatively easily formed and easily handled, It is preferable to form the surface protection film by thermocompression bonding.

The storage elastic modulus G (100) of the raised portion at 100 캜 is preferably 1 MPa or more. As described later, when the protruding portion is formed using the semiconductor wafer surface protective film, the protruding portion is composed of the softened layer (B) of the film; In this case, the storage elastic modulus of the raised portion becomes equal to the storage elastic modulus of the softened layer (B). Further, in the back-grinding process of a semiconductor wafer to be described later, the ridge is made of a flexible resin so that the ridge is not likely to be damaged by contact with the ridge portion and can be efficiently brought into contact with the circuit- And it is preferably formed substantially.

An example of a method for manufacturing a semiconductor device using the semiconductor wafer surface protective film of the present invention will be described with reference to the drawings. 2A is a view showing an example of a process (mounting process) for disposing a semiconductor wafer on a semiconductor wafer surface protective film; FIG. 2B is a view showing a laminate in which a semiconductor wafer is disposed on a semiconductor wafer surface protective film; FIG. 2C is a view showing an example of a step (press step) of forming a ridge portion of a semiconductor surface protection film on the periphery of a semiconductor wafer; FIG. 2D is an enlarged view showing an example of a ridge portion; FIG. FIG. 2E is a view showing an example of a step of grinding a circuit-unformed surface of a semiconductor wafer. FIG.

Mounting process

An example of disposing a semiconductor wafer on a semiconductor wafer surface protective film is shown in Fig. First, a semiconductor wafer surface protective film 10 cut out to a size larger than that of the semiconductor wafer 20 is prepared. Then, the semiconductor wafer 20 is placed on the semiconductor wafer surface protection film 10 (step (1)). At this time, the circuit formation surface 20A of the semiconductor wafer 20 is brought into contact with the adhesive layer (C) 16 of the semiconductor wafer surface protection film 10.

More specifically, the semiconductor wafer 20 and the ring frame 30 surrounding the semiconductor wafer 20 are placed on the hot plate 40. Further, the semiconductor wafer surface protection film 10 is placed on the semiconductor wafer 20 and the ring frame 30. At this time, the circuit formation surface 20A of the semiconductor wafer 20 and the adhesive layer (C) 16 of the semiconductor wafer surface protection film 10 are brought into contact with each other.

Then, the roll 35 is rotated while pushing the semiconductor wafer 20 from one end to the other end of the semiconductor wafer surface protection film 10. Thereby, the semiconductor wafer surface protection film 10 adheres closely to the circuit formation surface 20A of the semiconductor wafer 20. While pushing the semiconductor wafer surface protective film 10 onto the semiconductor wafer 20 with the roll 35, the hot plate 40 may remain at normal temperature; The hot plate 40 may be heated and the semiconductor wafer surface protective film 10 may be heated until the temperature becomes TM.

The temperature TM of the semiconductor wafer surface protective film 10 in the mounting process is a temperature of the semiconductor wafer surface protective film 10 in the process of forming the ridge portion of the semiconductor surface protective film on the periphery of the semiconductor wafer (TP), or higher than that. The reason for this will be described later. However, when the semiconductor wafer 20 is peeled off from the semiconductor wafer surface protection film 10 after wrinkles are generated in the semiconductor wafer surface protection film 10 in the step of forming the protrusions or after the step of forming the protrusions, Or may be peeled off.

After the mounting process, the semiconductor wafer 20 is detached from the hot plate 40 together with the semiconductor wafer surface protection film 10 and the ring frame 30 to form a semiconductor wafer surface protection film as shown in FIG. Thereby obtaining a laminate in which the wafers are arranged. This laminate is referred to as &quot; mount frame &quot;.

About the press process

Next, as shown in Fig. 2C, the semiconductor wafer 20 and the semiconductor wafer surface protective film 10 are fixed to a pair of heat plates (the upper heat plate 22-1 and the lower heat plate 22-2) of a hot press machine (Step (2)). Thereby, the semiconductor wafer 20 is pushed into the molten softened layer (B) 14, and the softened layer (B) 14 pushed out by this pushes the semiconductor wafer 20 in the vicinity of the end of the semiconductor wafer 20, (Rim) 24 is formed. The upper heat plate 22-1 is a heat plate disposed on the semiconductor wafer 20 side; The lower heating plate 22-2 is a heating plate disposed on the semiconductor wafer protective film 10 side. The upper heat plate 22-1 and the semiconductor wafer 20 may be in direct contact with each other or may be interposed between any member (for example, a jig). Similarly, the lower heating plate 22-2 and the semiconductor wafer protective film 10 may be in direct contact with each other or may be interposed between any member (for example, a jig).

The height of the ridge 24 is preferably 0.2 to 1 times the thickness of the semiconductor wafer 20 to be ground-back. If the height of the ridge 24 is excessively low, the end portion of the semiconductor wafer 20 may not be stably held. Specifically, when backing the semiconductor wafer 20 having a thickness of 1000 占 퐉, the height of the ridge 24 is preferably 200 占 퐉 or more. 2B shows an example in which the angle of the end of the semiconductor wafer 20 is not removed but chamfering (straight line) or R machining (curve) is applied to the end of the semiconductor wafer 20, . When the edge of the semiconductor wafer 20 is subjected to chamfering (straight line) or R machining (curve), the height of the ridge 24 is set to a value corresponding to the thickness of the end portion of the semiconductor wafer after chamfering or R machining .

The thermocompression bonding temperature (the thermocompression bonding temperature TP) and the press pressure are only required to be such that the softened layer (B) 14 can be melted to form the raised rim 24. Specifically, the press pressure is preferably 1 to 10 MPa, and more preferably 3 to 10 MPa. The press time can be, for example, about 1 to 5 minutes. The thermocompression bonding temperature TP is preferably in the range of 120 to 180 캜, more preferably in the range of 130 to 170 캜, and further preferably 150 캜. The thermocompression bonding temperature TP is an average temperature of a pair of hot plates (upper heat plate 22-1 and lower heat plate 22-2) of the press machine.

The thermocompression bonding temperature TP is preferably equal to or lower than the temperature TM of the semiconductor wafer surface protective film 10 in the mounting process described above. The semiconductor wafer surface protective film 10 tries to thermally expand by heating during the press process; The degree of thermal expansion of the semiconductor wafer surface protective film 10 in the pressing step is lower than the thermal expansion degree of the semiconductor wafer surface protective film 10 in the mounting step when the thermocompression bonding temperature TP is lower than the temperature TM in the mounting step Or smaller than that of the first embodiment. Since the semiconductor wafer surface protective film 10 sufficiently thermally expanded in the mounting process is fixed to the semiconductor wafer, the semiconductor wafer surface protective film 10 is hardly thermally expanded in the pressing step, and wrinkles are less likely to be generated. On the other hand, if the thermocompression bonding temperature TP and the temperature TM are not appropriately adjusted, wrinkles tend to occur around the semiconductor wafer 20 of the semiconductor wafer surface protection film 10.

When the semiconductor wafer surface protective film 10 is cooled after the pressing step, the case where the semiconductor wafer surface protective film 10 and the semiconductor wafer 20 are peeled off (the semiconductor wafer 20 is peeled from the film 10) there was. This exfoliation is also suppressed by making the thermocompression bonding temperature TP lower than the temperature TM in the mounting process. By suppressing the wrinkles on the semiconductor surface protective film as described above, it is possible to make the semiconductor wafer more difficult to break in the back side polishing process of the semiconductor wafer.

The thermocompression bonding temperature TP is preferably higher than the softening temperature TmB of the softened layer B of the semiconductor wafer surface protective film 10. By making the thermocompression bonding temperature TP equal to or higher than the softening temperature TmB, the softened layer B is softened and the raised rim 24 is easily formed. On the other hand, the thermocompression bonding temperature TP is preferably lower than the softening temperature TmB of the softened layer B of the semiconductor wafer surface protective film 10 + 40 占 폚. If the thermocompression bonding temperature TP is excessively high, the shape of the ridge 24 formed by softening the softened layer B may not be maintained and may flow into a flat shape. Thereby, the height of the ridge 24 may be lowered.

As described above, the thermocompression bonding temperature TP is an average temperature of a pair of hot plates (upper heat plate 22-1 and lower heat plate 22-2) of the press machine. The temperature TP1 of the upper heat plate 22-1 and the temperature TP2 of the lower heat plate 22-2 may be the same temperature but the temperature TP1 of the upper heat plate 22-1 may be the same as the temperature TP2 of the lower heat plate 22 -2), which is higher than the temperature (TP2). The ridge 24 can be rapidly formed as the temperature of the thermocompression bonding temperature TP is higher. However, if the temperature TP2 of the lower heat plate 22-2 is high, the shape of the ridge 24 Flows without being retained and is flattened. On the other hand, since the upper heat plate 22-1 and the semiconductor wafer surface protective film 10 are not in direct contact with each other (there is a gap therebetween), the temperature TP1 of the upper heat plate 22-1, ) 24 is not easily flattened. Therefore, by making the temperature TP1 of the upper heat plate 22-1 higher than the temperature TP2 of the lower heat plate 22-2, the temperature of the ridge 24 can be rapidly increased while maintaining the shape of the ridge 24, ) 24 can be formed.

Specifically, the temperature TP1 of the upper heating plate 22-1 is higher than the softening temperature (TmB) + 20 占 폚 of the softened layer (B) of the semiconductor wafer surface protective film 10, Is preferably lower than the softening temperature (TmB) + 40 占 폚 of the softened layer (B) of the film (10). The temperature TP2 of the lower heat plate 22-2 is higher than the temperature TP1 of the upper heat plate 22-1 -40 ° C and lower than the temperature TP1 of the upper heat plate 22-1 Low. In this case, it is preferable that the thermocompression bonding temperature TP is higher than the temperature (TP1) -20 占 폚 of the upper heat plate 22-1 and lower than the temperature TP1 of the upper heat plate 22-1.

The height of the ridge 24 is set such that the height of the ridge 24 of the semiconductor wafer surface protection film 10 from the surface on which the circuit forming surface of the semiconductor wafer 20 is in contact, Is defined as the height h to the vertex. The height of the ridge 24 can be measured by observing the cross-sectional shape of the semiconductor wafer surface protective film 10 after the semiconductor wafer 20 is peeled off with a microscope.

The ridge 24 does not necessarily contact the end of the semiconductor wafer 20 but is preferably in contact with the end of the semiconductor wafer 20 in order to improve the retention of the semiconductor wafer 20.

Next, as shown in FIG. 2E, the semiconductor wafer surface protection film 10 is set on the chuck table 26 together with the semiconductor wafer 20. As described above, the semiconductor wafer surface protective film may have a light-hardening layer (D) between the base layer (A) and the softening layer (B) (see FIG. If the light-hardening adhesive layer (D) is present, the semiconductor wafer surface protective film (10) may be set on the chuck table (26) after the base layer (A) is removed.

Then, the non-circuit forming surface (back surface) 20B of the semiconductor wafer is ground with the grinding wheel 28 until the thickness of the wafer becomes a certain value or less (step (3)). The thickness of the semiconductor wafer after the back side grinding can be, for example, 300 mu m or less, preferably 100 mu m or less. The grinding process is mechanical grinding by a grinding wheel. The grinding method is not particularly limited and may be a known grinding method such as a through-feed type or an in-feed type. The grinding process may be performed not only by wet grinding (wet polishing) but also by dry grinding (dry polishing).

Next, the semiconductor wafer surface protective film 10 is peeled off at room temperature (step (4)). The semiconductor wafer surface protective film 10 can be peeled off, for example, by a known tape peeling machine. When the semiconductor wafer surface protective film 10 includes a radiation curable adhesive layer C, the adhesive layer C is cured by irradiating the semiconductor wafer surface protective film 10 with radiation, The film 10 is peeled from the semiconductor wafer 20.

A step of machining the circuit non-formation surface (back surface) of the semiconductor wafer as needed between the step (3) of back grinding the semiconductor wafer and the step (4) of peeling the semiconductor wafer surface protective film from the semiconductor wafer May be included. The step of processing the circuit non-formation surface (back surface) of the semiconductor wafer may further include a step selected from the group consisting of a metal sputtering process, a plating process process, and a heat treatment process. The heat treatment step may be, for example, a step of adhering the die bonding tape under heating. Then, the semiconductor wafer is diced. Alternatively, the semiconductor wafer may be diced without peeling off the semiconductor wafer surface protective film 10.

The semiconductor wafer surface protective film of the present invention can form a ridge of a semiconductor wafer surface protective film on the outer periphery of a semiconductor wafer by thermocompression bonding under a predetermined condition with the semiconductor wafer. Further, since the raised rim formed by the semiconductor wafer surface protective film of the present invention is not melted even at the reaching temperature (about 40 캜) of the semiconductor wafer during the back grinding, the shape can be well maintained. Therefore, at the time of grinding the back surface of the semiconductor wafer, the end portion of the semiconductor wafer can be stably maintained by the ridge portion, and breakage of the end portion of the semiconductor wafer due to contact with the grinding wheel can be suppressed. Therefore, even if the semiconductor wafer is a hard and brittle sapphire substrate, the back surface can be ground without damaging the substrate.

Further, when the semiconductor wafer surface protective film includes the adhesive layer (C) that is cured by radiation, the semiconductor wafer surface protective film can be easily peeled off by irradiating the semiconductor wafer surface protective film with radiation. As described above, since the semiconductor wafer with the wax resin is not required to be cleaned like the conventional wax method, the process can be simplified.

For another embodiment of the mounting process

As described above, in the mounting process, the semiconductor wafer 20 is disposed inside the ring frame 30 having the frame; The semiconductor wafer surface protection film 10 is attached over one side (usually the surface 20A on which the circuit is formed) of the semiconductor wafer 20 and the ring frame 30 (see FIG. At this time, if the gap between the ring frame 30 and the semiconductor wafer 20 disposed inside the ring frame 30 is large, the semiconductor wafer protective film is loosened between the semiconductor wafer 20 and the ring frame 30 There is a case. Therefore, it is preferable to arrange the ring-shaped auxiliary member 50 between the ring frame 30 and the semiconductor wafer 20 (see FIGS. 5A and 5B).

The outer diameter DW of the semiconductor wafer 20, the inner diameter DA _IN of the ring frame 30, the ring outer diameter DB _OUT of the ring-shaped auxiliary member 50, and the ring inner diameter DB _IN of the ring- The relationship DW <DB _IN <DBOUT <DA _IN is satisfied (see FIG. 5A).

It is also preferable that the clearance between the semiconductor wafer 20 and the ring-shaped auxiliary member 50 be as small as possible between the ring-shaped auxiliary member 50 and the ring frame 30. This is to further prevent loosening of the attached semiconductor wafer protection film 10. That is, the outer diameter of the DW ringsang ring difference ΔD1 in the diameter DB _IN of the auxiliary member 50 of the semiconductor wafer 20, preferably in less than 1% of the outer diameter DW of the semiconductor wafer 20. It is preferable that the difference DELTA D2 between the ring outer diameter DB _OUT of the ring-shaped auxiliary member 50 and the inner diameter DA _IN of the ring frame 30 is within 1% of the outer diameter DW of the semiconductor wafer 20.

DELTA D1 = DB _IN- DW (2)

DELTA D2 = DA _IN -DB _OUT (3)

The mounting process can be performed by a semiconductor wafer mounting apparatus. The semiconductor wafer mounting apparatus has a heating unit, a tape attaching unit, and a tape cutting mechanism.

The heating unit is, for example, a hot plate 40 on which a pre-mount frame is placed. The free mount frame means a structure including a semiconductor wafer 20, a ring-shaped auxiliary member 50 surrounding the semiconductor wafer, and a ring frame 30 surrounding the ring-shaped auxiliary member 50 (Fig. 5A) . The free mount frame is mounted on the hot plate 40 such that the surface opposite to the circuit forming surface 20A of the semiconductor wafer 20 (circuit non-forming surface) faces the hot plate 40.

The tape attaching unit is mounted on the circuit forming surface 20A of the semiconductor wafer 20 and the ring-shaped auxiliary member (not shown) while heating the semiconductor wafer 20 of the free mount frame placed on the hot plate 40 with the hot plate 40 50 and the ring frame 30, the semiconductor wafer surface protective film 10 is attached. The tape attaching unit includes, for example, a roller 35; The roller 35 can roll over the circuit forming surface 20A of the semiconductor wafer 20, the ring-shaped auxiliary member 50, and the ring frame 30. [

The tape cutting mechanism cuts the semiconductor wafer protective film 10 in accordance with the outer diameter of the ring frame before or after attaching the semiconductor wafer protective film 10 to the free mount frame. The tape cutting mechanism may be a cutter or the like (not shown). Thus, a mount frame including the semiconductor wafer 20, the ring-shaped auxiliary member 50, the ring frame 30, and the semiconductor wafer protective film 10 is obtained.

For another embodiment of the pressing process

As described above, the pressing step is a step of pressing the mount frame obtained in the mounting step with a pair of press plates (upper press plate 22-1 and lower press plate 22-2) (see Fig. 2C) ). 6, when the pressures of the upper and lower heating plates 22-1 and 22-2 are released after the pressing process, the outer peripheral portion of the semiconductor wafer surface protective film 10 of the mount frame is pressed against the center portion There is a case where the thickness becomes smaller. It is presumed that during the pressing process, the outer peripheral portion of the semiconductor wafer surface protective film 10 of the mount frame flows outward, while the central portion is difficult to flow.

Therefore, of the pair of press plates, the lower press plate 22-2 preferably has the convex portion 60 on the surface facing the upper press plate 22-1. The convex portion 60 provided on the lower press plate 22-2 enters the semiconductor wafer protective film 10 during the press (Fig. 7A). Therefore, the thickness of the semiconductor wafer surface protective film 10 of the mount frame after the pressing process can be made uniform, and the raised rim 24 can be formed.

It is preferable that the outer periphery (peripheral edge) of the contact surface of the convex portion 60 of the lower press plate 22-2 with the semiconductor wafer protective film is circular. Therefore, the convex portion 60 may be a cone (Fig. 7B) or a dome (Fig. 7C).

 The projecting height of the convex portion 60 of the lower press plate 22-2 is preferably 1 to 100 mu m; More preferably, it is preferably within a range of 15 to 100% of the thickness of the softened layer (B) of the semiconductor wafer surface protection film (10). The projection height of the convex portion 60 refers to the maximum height of the convex portion 60. [

The diameter CD of the convex portion 60 of the lower press plate 22-2 is larger than the outer diameter DW of the semiconductor wafer of the mount frame and smaller than the inner diameter DA _IN of the ring frame. That is, the relationship DW <CD <DA _IN is satisfied.

The material of the convex portion 60 is not particularly limited. For example, ceramics such as alumina, cemented carbide such as tungsten carbide, or the like.

The press process can be performed using a semiconductor wafer press apparatus. The semiconductor wafer press apparatus has an upper press plate 22-1 having a heating mechanism and a lower press plate 22-2 having a convex portion 60 on the surface facing the upper press plate 22-1 . In the press process, first, the mount frame obtained in the mounting process is disposed between the upper press plate 22-1 and the lower press plate 22-2. At this time, the semiconductor wafer 20 of the mount frame faces the upper press plate 22-1, and the semiconductor wafer surface protective film 10 of the mount frame faces the lower press plate 22-2.

The mount frame to be disposed includes a semiconductor wafer 20, a ring frame 30 and a structure (see FIG. 2B) of the semiconductor wafer surface protective film 10 as shown in FIG. 7A.

After the mount frame is disposed, the mount frame is heated by the heating mechanism of the upper press plate 22-1. Further, the mount frame sandwiched between the upper press plate 22-1 and the lower press plate 22-2 is pressed by the upper press plate 22-1 and the lower press plate 22-2.

 The mount frame is peeled off from the upper press plate 22-1 and the lower press plate 22-2 so that the thickness of the semiconductor wafer protective film after the pressing step is uniformed while the rim is formed on the semiconductor wafer protective film can do.

Example

(Example 1)

Preparation of materials

Homopolypropylene (hPP) (manufactured by Prime Polymer Co., Ltd., density: 910 kg / m ³ ) was prepared as the material of the base layer (A). As the material of the softened layer (B), linear low density polyethylene (LLDPE) (manufactured by Prime Polymer, density 918 kg / m ³ ) was prepared. As a material for the adhesive layer (C), the following coating liquid for a pressure-sensitive adhesive layer was prepared.

Preparation of coating liquid for adhesive layer

30 parts by weight of ethyl acrylate, 40 parts by weight of 2-ethylhexyl acrylate, 10 parts by weight of methyl acrylate and 20 parts by weight of glycidyl methacrylate were mixed with a benzoyl peroxide type polymerization initiator (NOF CORPORATION 0.8 parts by weight of NIPER BMT-K40 (0.32 parts by weight as an initiator) were reacted at 65 ° C in toluene and 50 parts by weight of ethyl acetate at 80 ° C for 10 hours. After completion of the reaction, the resulting solution was cooled, and further, 100 parts by weight of xylene, 10 parts by weight of acrylic acid, and 10 parts by weight of tetradecyldimethylbenzylammonium chloride (CATION M2-100, manufactured by Nippon Oil & , And the mixture was reacted at 85 캜 for 50 hours while blowing air. As a result, a solution of the acrylic pressure-sensitive adhesive polymer (pressure-sensitive adhesive subject) was obtained.

To 100 parts by weight of the acrylic pressure-sensitive adhesive polymer solid solution, a solution of benzyl dimethyl ketal (Nihon Ciba- cigarette Co., Ltd.) as an intramolecular bond cleavage type photopolymerization initiator was added to the solution of the acrylic pressure- Geigy K., K.) and IRGACURE-651] as a monomer having a polymerizable carbon-carbon double bond in the molecule, 2 parts by weight of dipentaerythritol hexaacrylate and dipentaerythritol monohydrate Except that 0.3 part by weight of a mixture of a polyoxyethylene (meth) acrylate and a hydroxypentaacrylate (ARONIX M-400, manufactured by TOAGOSEI CO., LTD.) Was further added, 1.35 parts by weight (1 part by weight as a heat crosslinking agent) of a crosslinking agent (OLESTER P49-75-S, manufactured by Mitsui Chemicals Inc.) was added to obtain a UV pressure-sensitive adhesive. The adhesion of the obtained UV-sensitive adhesive was measured in accordance with JIS Z0237, and found to be 3 N / 25 mm.

1) Measurement of storage modulus

Homopolypropylene (hPP) (manufactured by Prime Polymer Co., Ltd., density: 910 kg / m ³ ) serving as the base layer (A) was extrusion-molded to produce a sample film having a thickness of 500 μm. Similarly, a linear low-density polyethylene (LLDPE) (manufactured by Prime Polymer Co., Ltd., density 918 kg / m ³ ) serving as the softened layer B was extrusion-molded to produce a sample film having a thickness of 500 μm. The above-mentioned UV adhesive to be the adhesive layer (C) was coated on a glass substrate, dried, and peeled to produce a sample film having a thickness of 300 mu m.

The storage elastic modulus of these sample films was measured by the following method. That is, when the sample film was set on a dynamic viscoelasticity measuring device (ARES manufactured by TA Instruments Co., Ltd.) and heated to 30 ° C from a parallel plate type attachment of 8 mm in diameter to a temperature of 200 ° C at a heating rate of 3 ° C / Was measured. The measurement frequency was set to 1 Hz. After the completion of the measurement, the values of the storage elastic modulus at 40 DEG C, 100 DEG C and 150 DEG C were measured from the storage elastic modulus-temperature curve at 10 to 200 DEG C obtained for the base film (A) and the softened layer (B) Respectively. With respect to the sample film of the adhesive layer (C), the value of the storage elastic modulus at 25 캜 was read from the obtained storage elastic modulus-temperature curve at 10 to 200 캜.

Fabrication of semiconductor wafer surface protection film

Homopolypropylene (hPP) which the base material layer (A) (Prime Polymer Co., Ltd., density: 910kg / m ³⁾ and a linear low-density polyethylene (LLDPE) (Prime Polymer Co., Ltd. which is softened layer (B), a density 918kg / m ³ ) were co-extruded to obtain a two-layer co-extruded film. On the softened layer (B) of the obtained coextruded film, the above-mentioned UV adhesive was applied and then dried to form an adhesive layer (C), and a semiconductor wafer surface protective film was obtained. The thickness of the base layer (A) / softened layer (B) / adhesive layer (C) of the semiconductor wafer surface protective film was 60 占 퐉 / 70 占 퐉 / 5 占 퐉 and the total thickness was 135 占 퐉.

2) Evaluation of formability of ridge

The resulting semiconductor wafer surface protective film was cut to a size larger than that of the sapphire wafer. Then, a sapphire wafer having a thickness of 650 탆 and a size of 4 inches was placed on the semiconductor wafer surface protective film. At this time, the circuit formation surface of the sapphire wafer was brought into contact with the adhesive layer (C) of the semiconductor wafer surface protection film. These were set on a hot press machine and thermocompression-bonded at 140 DEG C and 10 MPa for 2 minutes.

Next, the semiconductor wafer surface protective film was irradiated with about 1000 mJ of ultraviolet rays, and then the semiconductor wafer surface protective film was peeled from the semiconductor wafer, and the sectional shape of the obtained semiconductor wafer surface protective film was observed with a microscope. The heights of the two raised rims on the cross section of the semiconductor wafer surface protective film were measured and their average values were obtained. The height of the ridge was measured as the height of the apex of the ridge relative to the surface of the semiconductor wafer surface protective film that was in contact with the circuit formation surface of the semiconductor wafer. Evaluation of formability of ridges (rims) was made based on the following criteria.

?: The height of the ridge (rim) was 200 占 퐉 or more

X: height of ridge (base) is less than 200 占 퐉

3) Evaluation of backgrinding property

Similarly to the above, the obtained semiconductor wafer surface protective film was cut to a size larger than that of the sapphire wafer. Then, a sapphire wafer having a thickness of 650 탆 and a size of 4 inches was placed on the semiconductor wafer surface protective film. These were set on a hot press machine and thermocompression-bonded at 140 DEG C and 10 MPa for 2 minutes.

When it is 90 탆,

The semiconductor wafer surface protective film on which the sapphire wafer was thermocompression was set on the chuck table of Disco DGP8761 and the circuit non-formation surface (back surface) of the sapphire wafer was wet-ground until the wafer thickness became 90 탆. The temperature of the wafer at the time of grinding was about 40 캜. Then, the back-side grindability was evaluated based on the following criteria.

○: Backgrinding is possible until the thickness of the wafer becomes 90 μm

X: The substrate was broken before the thickness of the wafer became 90 탆 (back grinding impossible)

When the thickness is 70 탆,

The back-side sapphire wafer was further wet-polished until the wafer thickness became 70 mu m until the thickness of the wafer became 90 mu m. Then, the back-side grindability was evaluated based on the following criteria.

○: Backgrinding is possible until the thickness of the wafer becomes 70 μm

X: The substrate was broken before the thickness of the wafer became 70 탆 (back grinding impossible)

4) Evaluation of shape of ridge after DP (dry polishing)

The sample after the back grinding in the wet type of 3) was subjected to grinding (dry polishing) by dry for another 5 minutes. The temperature of the wafer at dry polishing was about 100 캜. After irradiating ultraviolet rays of about 1000 mJ onto the semiconductor wafer surface protective film, the sapphire wafer was peeled from the semiconductor wafer surface protective film. The sectional shape of the obtained semiconductor wafer surface protective film was observed with a microscope to measure the height of the raised rim. The evaluation of DP heat resistance was carried out based on the following criteria.

A: The height of the ridge was about the thickness of the wafer after grinding (the rim remained unmelted)

X: The height of the ridge is lower than the grinding thickness of the wafer (the rim melts and disappears)

5) Surface smoothness of base layer (A) after grinding

The surface smoothness of the base layer (A) after the DP (dry polishing) of the above 4) was evaluated by a contact type surface shape measuring instrument (Veeco Company Dektac3). Evaluation of surface smoothness was carried out based on the following criteria.

?: Ra of concave and convex on the surface of the substrate layer (A) due to transfer of the surface shape of the chuck table is less than 1 占 퐉

X: Roughness of irregularities on the surface of the base layer (A) due to transfer of the surface shape of the chuck table is 1 占 퐉 or more

(Example 2)

A semiconductor wafer surface protective film was produced in the same manner as in Example 1 except that the thicknesses of the base layer (A) and softened layer (B) were changed to 30 mu m, respectively, and the same evaluation was made.

(Example 3)

Except that the material of the softened layer (B) was changed to an ethylene -? - olefin copolymer (TAFMER (manufactured by Mitsui Chemicals), density: 893 kg / m ³ ) A film was prepared and evaluated in the same manner.

(Example 4)

The material of the softened layer B was changed to linear low density polyethylene (LLDPE) (manufactured by Prime Polymer Co., Ltd., density 938 kg / m ³ ), and the thicknesses of the base layer A and softened layer B were changed to 30 μm , A semiconductor wafer surface protective film was produced in the same manner as in Example 1 and evaluated in the same manner.

(Example 5)

The material of the softened layer B was changed to random polypropylene (rPP) (manufactured by Prime Polymer Co., density: 910 kg / m ³ ), and the thicknesses of the base layer A and the softened layer B were changed to 30 μm , A semiconductor wafer surface protective film was produced in the same manner as in Example 1 and evaluated in the same manner.

(Comparative Example 1)

The material of the base layer (A) was mixed with random polypropylene (rPP) (Prime Polymer Co., density: 910 kg / m ³ ), the material of the softened layer (B) was mixed with ethylene -? - olefin copolymer ) And a density of 893 kg / m ³ , respectively, in the same manner as in Example 1, and evaluated in the same manner.

(Comparative Example 2)

The material of the base layer (A) was changed to linear low density polyethylene (LLDPE) (Prime Polymer Co., density 918 kg / m ³ ) and the material of the softened layer (B) was changed to ethylene- ) And a density of 893 kg / m ³ , respectively, in the same manner as in Example 1, and evaluated in the same manner.

(Comparative Example 3)

The material of the base layer (A) was changed to linear low density polyethylene (LLDPE) (Prime Polymer Co., density 918 kg / m ³ ) and the material of the softened layer (B) was changed to ethylene- ) And a density of 861 kg / m ³ , respectively, in the same manner as in Example 1, and evaluated in the same manner.

(Comparative Example 4)

Softening layer (B) an ethylene-olefin -α- the material of the copolymer (Tarp Murray (Mitsui Chemicals Co., Ltd.), density: 861kg / m ³⁾ to, 30㎛ the thickness of the substrate layer (A) and the soft layer (B), respectively , A semiconductor wafer surface protective film was produced in the same manner as in Example 1 and evaluated in the same manner.

Tables 1 to 3 show the storage elastic moduli of the sample films of Examples 1 to 5 and Comparative Examples 1 to 4 and the evaluation results of the semiconductor wafer surface protective film.

As shown in Tables 1 and 2, the semiconductor wafer surface protective films of Examples 1 to 5, in which the softening layer (B) had a storage elastic modulus G _B (40) of 10 MPa or more at 40 캜, It can be seen that the wafer is not damaged even when the back side grinding is performed. This is considered to be because the ridge portion is not melted when the back side grinding is performed, and the end portion of the wafer can be stably maintained.

On the other hand, in the semiconductor wafer surface protective films of Comparative Examples 3 and 4 in which the softening layer B had a storage elastic modulus G _B (40) at 40 캜 of less than 10 MPa, the raised rim could be formed by hot pressing, It can be seen that the wafer is broken at the time of back side grinding. This is considered to be because the raised rim is softened even when the back side grinding is performed, and the end portion of the wafer can not be stably maintained.

In Examples 1 to 5, in Example 3, the wafer broke at the time of 70 μm grinding, whereas in Example 2, the wafer was not broken at 70 μm. This is presumably because the storage elastic modulus G _B (40) of the softened layer (B) at 40 ° C in the semiconductor wafer surface protective film of Example 2 is higher than that of the semiconductor wafer surface protective film of Example 3. The reason why the wafer breaks at the time of 70 占 퐉 grinding in the first embodiment is that the semiconductor wafer surface protective film is excessively thick relative to the finish thickness of the wafer and the deformation (warpage and warpage) of the semiconductor wafer can not be suppressed do.

In addition, in the semiconductor wafer surface protective films of Examples 1 and 2, it is possible to stably maintain the end portions of the sapphire wafers without softening the ridges even at a high temperature of about 100 DEG C during dry polishing (DP) Able to know.

In Comparative Examples 1 to 3, the surface smoothness of the base layer (A) after grinding was found to be low. This is because the base layer (A) of the semiconductor wafer surface protective film of Comparative Examples 1 to 3 had a storage elastic modulus G _A (150) at 150 ° C of less than 1 MPa and the surface shape of the chuck table was transferred during back side grinding . As described above, when the surface shape of the chuck table is transferred to the surface of the base layer (A) during back grinding, when the semiconductor wafer surface protective film is fixed on a separate chuck table in the subsequent dicing step, Air leakage tends to occur between the base layer (A) of the wafer surface protective film. If such an air leakage occurs, the semiconductor wafer surface protective film can not be fixed on the chuck table, which is undesirable.

(Example 6)

A film like the film used in Example 2 was attached to a sapphire wafer (mounting step), and a ridge was formed by thermocompression (pressing step).

More specifically, the semiconductor wafer surface protective film was cut to a size larger than that of the sapphire wafer. Further, a sapphire wafer having a thickness of 650 탆 and a size of 4 inches was prepared. As shown in FIG. 2A, the film was placed on a film for protecting a surface of a semiconductor wafer. The hot plate temperature was heated to 140 占 폚, and the semiconductor wafer surface protective film was pressed on the sapphire wafer with a roller to obtain a laminate of a sapphire wafer and a semiconductor wafer surface protective film. The roller pressure was 0.5 MPa and the roller speed was 10 mm / sec.

Next, as shown in Fig. 2C, the obtained laminate was sandwiched between an upper heating plate (a heating plate arranged on the semiconductor wafer surface protective film) and a lower heating plate (a heating plate arranged on the sapphire wafer side) of the hot press machine, 10 MPa. At this time, the temperature of the upper heating plate was set to 140 캜, and the temperature of the lower heating plate was set to 120 캜, that is, the average temperature TP of both was set to 130 캜.

Subsequently, after the semiconductor wafer surface protective film was irradiated with ultraviolet light of about 1000 mJ, the semiconductor wafer surface protective film was peeled off from the sapphire wafer, and the sectional shape of the obtained semiconductor wafer surface protective film was observed with a microscope. The heights of the two raised rims on the cross section of the semiconductor wafer surface protective film were measured and their average values were obtained.

1. Presence or absence of radial tension

After the pressing step, a weight of 150 g was placed in the center of the sapphire wafer with the semiconductor wafer surface protective film attached to the ring frame, and the penetration amount (sinking degree) of the film was measured. It was evaluated as &quot; x &quot;

2. Wrinkles

After the pressing step, the sample was observed with a naked eye and the surface of the semiconductor wafer surface protective film around the sapphire wafer was observed to have 10 or more radial wrinkles.

3. Peeling after 48 hours

After the pressing step, the sapphire wafer was allowed to stand at room temperature for 48 hours while the semiconductor wafer surface protective film was attached. Thereafter, peeling of at least 1 mm was observed on the wafer surface protective film and the sapphire wafer edge, and the result was rated as x.

(Example 7)

A film like the film used in Example 2 was attached to a sapphire wafer (mounting step), and a ridge was formed by thermocompression (pressing step). More specifically, the semiconductor wafer surface protective film was cut to a size larger than that of the sapphire wafer. Further, a sapphire wafer having a thickness of 650 탆 and a size of 4 inches was prepared. As shown in FIG. 2A, the film was placed on a film for protecting a surface of a semiconductor wafer. The temperature of the hot plate was heated to 100 占 폚, and a film for protecting a semiconductor wafer surface was adhered to a sapphire wafer with a roller to obtain a laminate of a sapphire wafer and a semiconductor wafer surface protective film. The roller pressure was 0.5 MPa and the roller speed was 10 mm / sec.

Next, as shown in Fig. 2C, the obtained laminate was sandwiched between an upper heating plate (a heating plate arranged on the semiconductor wafer surface protective film) and a lower heating plate (a heating plate arranged on the sapphire wafer side) of the hot press machine, 10 MPa. At this time, the temperature of the upper heating plate was set to 140 캜, and the temperature of the lower heating plate was set to 120 캜, that is, the average temperature TP of both was set to 130 캜.

The presence or absence of tension in the radial direction, the presence or absence of wrinkles, and the presence or absence of lifting (peeling) after 48 hours were evaluated by measuring the height of the ridge portion as in Example 6.

(Example 8)

A film like the film used in Example 2 was attached to a sapphire wafer (mounting step), and a ridge was formed by thermocompression (pressing step). More specifically, the semiconductor wafer surface protective film was cut to a size larger than that of the sapphire wafer. Further, a sapphire wafer having a thickness of 650 탆 and a size of 4 inches was prepared. As shown in FIG. 2A, the film was placed on a film for protecting a surface of a semiconductor wafer. The temperature of the hot plate was set to 25 占 폚, and a film for protecting a semiconductor wafer surface was adhered to the sapphire wafer with a roller to obtain a laminate of a sapphire wafer and a semiconductor wafer surface protective film. The roller pressure was 0.5 MPa and the roller speed was 10 mm / sec.

Next, as shown in Fig. 2C, the obtained laminate was sandwiched between an upper heating plate (a heating plate arranged on the semiconductor wafer surface protective film) and a lower heating plate (a heating plate arranged on the sapphire wafer side) of the hot press machine, 10 MPa. At this time, the temperature of the upper heating plate was set to 140 캜, and the temperature of the lower heating plate was set to 120 캜, that is, the average temperature TP of both was set to 130 캜.

The presence or absence of tension in the radial direction, the presence or absence of wrinkles, and the presence or absence of lifting (peeling) after 48 hours were evaluated by measuring the height of the ridge portion as in Example 6.

(Reference Example 5)

A film like the film used in Example 2 was attached to a sapphire wafer (mounting step), and a ridge was formed by thermocompression (pressing step). More specifically, the semiconductor wafer surface protective film was cut to a size larger than that of the sapphire wafer. Further, a sapphire wafer having a thickness of 650 탆 and a size of 4 inches was prepared. As shown in FIG. 2A, the film was placed on a film for protecting a surface of a semiconductor wafer. The temperature of the hot plate was set to 100 占 폚, and a film for protecting a semiconductor wafer surface was adhered to the sapphire wafer with a roller to obtain a laminate of a sapphire wafer and a semiconductor wafer surface protective film. The roller pressure was 0.5 MPa and the roller speed was 10 mm / sec.

Next, as shown in Fig. 2C, the obtained laminate was sandwiched between an upper heating plate (a heating plate arranged on the semiconductor wafer surface protective film) and a lower heating plate (a heating plate arranged on the sapphire wafer side) of the hot press machine, 10 MPa. At this time, the temperature of the upper heating plate was set at 110 占 폚, and the temperature of the lower heating plate was set at 90 占 폚, that is, the average temperature TP was set at 100 占 폚.

The presence or absence of tension in the radial direction, the presence or absence of wrinkles, and the presence or absence of lifting (peeling) after 48 hours were evaluated by measuring the height of the ridge portion as in Example 6.

In Example 6, the temperature TM in the mounting process is higher than the temperature TP in the pressing process; And the temperature TP is 14 占 폚 higher than the softening point temperature (TmB) of the softened layer (B). As a result, a rim having a sufficient height was formed, no wrinkles were formed, and no separation of the sapphire substrate and the protective film occurred.

In the seventh embodiment, the temperature TM in the mounting process is 30 deg. C lower than the temperature TP in the pressing process. Therefore, although a rim having a sufficient height can be formed, the occurrence of wrinkles was confirmed. Furthermore, in Example 8, the temperature TM in the mounting process is 105 deg. C lower than the temperature TP in the pressing process. Therefore, although a rim having a sufficient height could be formed, the occurrence of wrinkles was confirmed, and the peeling of the sapphire substrate and the protective film was also confirmed.

In Reference Example 5, the temperature TP in the pressing step is lower than the softening point temperature (TmB) of the softened layer (B). Therefore, sufficient rim could not be formed.

(Example 9)

A film like the film used in Example 2 was attached to a sapphire wafer (mounting step), and a ridge was formed by thermocompression (pressing step). More specifically, the semiconductor wafer surface protective film was cut to a size larger than that of the sapphire wafer. Further, a sapphire wafer having a thickness of 650 탆 and a size of 4 inches was prepared. As shown in FIG. 2A, the film was placed on a film for protecting a surface of a semiconductor wafer. The hot plate temperature was heated to 140 占 폚, and the semiconductor wafer surface protective film was pressed on the sapphire wafer with a roller to obtain a laminate of a sapphire wafer and a semiconductor wafer surface protective film. The roller pressure was 0.5 MPa and the roller speed was 10 mm / sec.

Next, as shown in Fig. 2C, the laminate obtained by the upper heat plate (heat plate arranged on the semiconductor wafer surface protective film) of the hot press machine and the lower heat plate (heat plate arranged on the sapphire wafer side) were sandwiched, . At this time, the temperature of the upper heating plate was set at 140 캜, and the temperature of the lower heating plate was set at 100 캜, that is, the average temperature of both was set at 120 캜.

Then, as in Example 6, the height of the raised rim was determined.

(Example 10)

A film like the film used in Example 2 was attached to a sapphire wafer (mounting step), and a ridge was formed by thermocompression (pressing step). More specifically, the semiconductor wafer surface protective film was cut to a size larger than that of the sapphire wafer. Further, a sapphire wafer having a thickness of 650 탆 and a size of 4 inches was prepared. As shown in FIG. 2A, the film was placed on a film for protecting a surface of a semiconductor wafer. The hot plate temperature was heated to 140 占 폚, and the semiconductor wafer surface protective film was pressed on the sapphire wafer with a roller to obtain a laminate of a sapphire wafer and a semiconductor wafer surface protective film. The roller pressure was 0.5 MPa and the roller speed was 10 mm / sec.

Next, as shown in Fig. 2C, the obtained laminate was sandwiched between an upper heating plate (a heating plate arranged on the semiconductor wafer surface protective film) and a lower heating plate (a heating plate arranged on the sapphire wafer side) of the hot press machine, 10 MPa. At this time, the temperature of the upper heat plate was set at 140 캜, and the temperature of the lower heat plate was set at 140 캜, that is, the average of both was set at 140 캜.

Then, as in Example 6, the height of the raised rim was determined.

In Example 9, the temperature TM in the mounting process is higher than the temperature TP in the pressing process; And the temperature TP is 4 占 폚 higher than the softening point temperature (TmB) of the softened layer (B). Also, the upper heating plate temperature TP1 in the pressing process is higher than the lower heating plate temperature TP2. Therefore, a rim having a sufficient height was formed.

On the other hand, in Example 10, the temperature TM in the mounting process is the same as the temperature TP in the pressing process; Also, the upper heating plate temperature TP1 in the pressing process is the same as the lower heating plate temperature TP2. Therefore, the rim was somewhat flattened, and the height of the rim was lowered as compared with Example 7.

(Examples 11 to 14)

A film like the film used in Example 2 was attached to a sapphire wafer (mounting step), and a ridge was formed by thermocompression (pressing step). More specifically, the semiconductor wafer surface protective film was cut to a size larger than that of the sapphire wafer. Further, a sapphire wafer having a thickness of 650 탆 and a size of 4 inches was prepared. As shown in FIG. 2A, the film was placed on a film for protecting a surface of a semiconductor wafer. The hot plate temperature was heated to 140 占 폚, and the semiconductor wafer surface protective film was pressed on the sapphire wafer with a roller to obtain a laminate of a sapphire wafer and a semiconductor wafer surface protective film. The roller pressure was 0.5 MPa and the roller speed was 10 mm / sec.

Next, as shown in Fig. 7A, the upper heating plate (a heating plate arranged on the semiconductor wafer surface protective film) of the hot press machine and the lower heating plate having the convex portions as shown in Fig. 7B ), And the resultant laminate was sandwiched and pressed at 10 MPa for 180 seconds. At this time, the temperature of the upper heat plate was set at 140 占 폚, and the temperature of the lower heat plate was set at 120 占 폚. In Example 11, the height of the convex portion was 0 占 퐉 (no convex portion), the height of the convex portion in Example 12 was 5 占 퐉, the height of the convex portion in Example 13 was 15 占 퐉, And a height of 25 mu m. (The difference between the maximum thickness and the minimum thickness) of the semiconductor wafer surface protective film after the pressing process was measured, and the height of the raised rim was obtained as in Example 6. [

As shown in Table 6, it can be seen that, by providing the convex portion on the lower heat plate, the thickness variation of the semiconductor wafer surface protective film after the pressing process can be suppressed and the ridge can be formed.

The semiconductor wafer surface protective film of the present invention can enable backgrinding without damaging even a hard and brittle semiconductor wafer such as a sapphire substrate.

1: sapphire substrate
2: Wax resin layer
3: Grinding stone
4: Conventional semiconductor wafer protective film
10: Semiconductor wafer surface protective film
12: Base layer (A)
14: Softened layer (B)
16: Adhesive layer (C)
18: Lightly adhesive layer (D)
20: Semiconductor wafer
20A: Circuit forming surface of a semiconductor wafer
20B: Circuit non-formation surface (back surface) of the semiconductor wafer
22-1: upper plate
22-2: Lower heat plate
24: ridge (rim)
26: Chuck table
28: Grinding wheel

Claims (20)

_A base layer (A) having a storage elastic modulus G _A (150) at 150 DEG C of 1 MPa or more,
( _B ) having a storage elastic modulus G _B (120 to 180) of 0.05 MPa or less at any one of 120 to 180 캜 and a storage modulus G _B (40) at 40 캜 of 10 MPa or more, Semiconductor wafer surface protection film. The method according to claim 1,
Wherein the softening layer (B) has a storage elastic modulus G _B (100) at 100 캜 of 1 MPa or more. The method according to claim 1,
The relationship between the tensile modulus E _B (60) at 60 ° C and the tensile modulus E _B (25) at 25 ° C of the softened layer _B satisfies 1> E _B (60) / E _B (25)> 0.1 A semiconductor wafer surface protective film. The method according to claim 1,
And an adhesive layer (C) disposed on the side opposite to the substrate layer (A) through the softened layer (B)
Wherein the adhesive force of the adhesive layer (C) measured according to JIS Z0237 is 0.1 to 10 N / 25 mm. The method according to claim 1,
Wherein the base layer (A) is disposed on the outermost surface. 5. The method of claim 4,
Wherein the adhesive layer (C) is disposed on the outermost surface opposite to the base layer (A) through the softened layer (B). The method according to claim 1,
Wherein the softening layer (B) comprises a homopolymer of hydrocarbon olefin, a copolymer of hydrocarbon olefin, or a mixture thereof. The method according to claim 1,
And the resin constituting the softened layer (B) has a density of 880 to 960 kg / m ³ . The method according to claim 1,
Wherein the base layer (A) is a polyolefin layer, a polyester layer, or a laminate of a polyolefin layer and a polyester layer. delete A process for manufacturing a semiconductor wafer, comprising the steps of: arranging a semiconductor wafer on the semiconductor wafer surface protection film according to claim 1 so that the circuit formation surface of the semiconductor wafer is in contact with the semiconductor wafer surface protection film;
The semiconductor wafer surface protective film and the semiconductor wafer are thermocompression bonded at a temperature of 120 to 180 DEG C under a pressure of 1 to 10 MPa to form a protruding portion of the semiconductor wafer surface protective film for holding the semiconductor wafer ;
A step of grinding a circuit non-formation surface of the semiconductor wafer held by the raised portion,
And peeling the semiconductor wafer surface protection film from the circuit formation surface of the semiconductor wafer,
Wherein the storage elastic modulus G (100) of the ridge portion at 100 占 폚 is 1 MPa or more. 12. The method of claim 11,
The temperature TM of the film in the step of disposing the semiconductor wafer on the semiconductor wafer surface protective film so that the circuit forming surface of the semiconductor wafer is in contact with the semiconductor wafer surface protective film and the temperature rise TM of the semiconductor wafer surface protective film And the softening point temperature TmB of the softening layer (B) satisfies the following formula: < EMI ID = 1.0 &gt;
[Formula 1] TP? TM
[Equation 2] TmB <TP <TmB + 40 ° C 12. The method of claim 11,
Wherein the semiconductor wafer is placed on the semiconductor wafer surface protection film so that the softened layer (B) of the semiconductor wafer surface protection film is closer to the circuit formation surface side of the semiconductor wafer than the base layer (A). 12. The method of claim 11,
Wherein the semiconductor wafer comprises a high hardness material substrate having a Mohs hardness of 8 or more. A mount frame comprising a semiconductor wafer, a ring frame A having a frame surrounding the semiconductor wafer, a circuit forming surface of the semiconductor wafer, and a semiconductor wafer surface protective film according to claim 1 attached over the frame A, 1. A semiconductor wafer press apparatus which presses an upper press plate having a heating mechanism and a lower press plate facing the upper press plate,
The outer diameter DW of the semiconductor wafer and the inner diameter DA _IN of the ring frame A satisfy the relationship of DW < DA _IN (1)
Wherein the lower press plate has a convex portion on a surface facing the upper press plate,
Wherein an outer periphery of a contact surface of the convex portion with the mount frame is circular when pressed. 16. The method of claim 15,
And the convex portion has a height of 1 to 100 mu m. 16. The method of claim 15,
Wherein a height of the convex portion is in a range of 15 to 100% with respect to a thickness of the softened layer (B) of the semiconductor wafer surface protective film. 16. The method of claim 15,
And the diameter CD of the convex portion satisfies the relationship of DW < CD < DA _IN . A ring-shaped auxiliary member B surrounding the semiconductor wafer, a ring frame A surrounding the semiconductor wafer and the ring-shaped auxiliary member B, a ring-shaped auxiliary member B surrounding the ring-shaped auxiliary member B, A semiconductor wafer mounting apparatus for manufacturing a mount frame including the semiconductor wafer surface protective film according to claim 1,
The outer diameter DW of the semiconductor wafer, the inner diameter DA _IN of the ring frame A, the ring outer diameter DB _OUT of the ring-shaped auxiliary member B, and the ring inner diameter DB _IN of the ring-shaped auxiliary member B satisfy the formula (1) DW &Lt; DB _IN < DB _OUT < DA _IN ,
A heating unit for heating a surface opposite to the circuit forming surface of the semiconductor wafer;
An attaching roller that rolls over the circuit forming surface of the semiconductor wafer, the ring frame A, and the ring-shaped auxiliary member B to attach the semiconductor wafer surface protective film,
And a tape cutting mechanism for cutting the surface protection film along the outer shape of the ring frame A. 20. The method of claim 19,
Wherein both of? D1 and? D2 represented by the following formula are within 1% of the DW.
DELTA D1 = DB _IN- DW (2)
DELTA D2 = DA _IN -DB _OUT (3)

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