TW201316393A - Method for producing semiconductor device and film for protecting surface of semiconductor wafer, semiconductor wafer press apparatus and semiconductor wafer mount apparatus used in the method - Google Patents

Abstract

A film for protecting a surface of a semiconductor wafer is provided to prevent breakage even when back-grinding a hard and brittle semiconductor wafer. Specifically, a film for protecting a surface of a semiconductor wafer is provided, including a substrate layer (A) in which the storage elastic modulus GA (150) at 150 DEG C is 1 MPa or more, and a softening layer (B) in which the storage elastic modulus GB at 120 DEG C to 180 DEG C is 0.05 MPa or less, and the storage elastic modulus GB at 40 DEG C is 10 MPa or more.

Description

Method for manufacturing semiconductor device and film for semiconductor wafer surface protection using the same

The present invention relates to a method of manufacturing a semiconductor device and a film for surface protection of a semiconductor wafer which can be used in the method.

The thinning process of the semiconductor wafer in the manufacturing process of the semiconductor device is usually performed by polishing the non-formed surface (back surface) of the semiconductor wafer. The protection of the circuit formation surface of the semiconductor wafer during back grinding can be performed by various methods.

For example, the protection of the circuit formation surface of the semiconductor wafer including the sapphire substrate can be performed by the following methods (for example, Patent Document 1 and Non-Patent Document 1). That is, a ceramic plate having a wax resin layer on its surface is prepared. Next, the wax resin layer is heated and melted, and the circuit formation surface of the sapphire substrate is embedded in the molten wax resin layer. Next, the wax resin layer is cooled and solidified. Thereby, the entire circuit formation surface of the sapphire substrate is protected by the wax resin layer. The wax resin usually contains a rosin-based wax (including a wax such as rosin, montan wax, and phenol resin, and has a melting point of about 50 ° C).

[Previous Technical Literature] [Patent Literature]

Patent Document 1: International Publication No. 2005/099057

[Non-patent literature]

Non-Patent Document 1: 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, in order to peel the sapphire substrate after the back surface polishing from the wax resin layer, it is necessary to heat and melt the wax resin layer. Further, it is necessary to remove the wax resin remaining on the surface of the sapphire substrate by solvent cleaning, which is cumbersome. Further, since the sapphire substrate after the back grinding is extremely thin and warpage is likely to occur, there is a problem that it is easily broken in these steps.

Therefore, the inventors of the present invention have studied a method of protecting a circuit forming surface of a sapphire substrate by peeling off a relatively easy semiconductor wafer protective film. The prior semiconductor wafer protective film has a substrate layer and an adhesive layer. Then, after attaching the adhesive layer of the semiconductor wafer protective film to the circuit formation surface of the semiconductor wafer, the back surface of the semiconductor wafer is polished. Then, the semiconductor wafer protective film is peeled off by a tape peeling machine or the like.

However, in the method of using the conventional semiconductor wafer protective film, there is a problem that the end portion of the sapphire substrate is easily broken during back grinding. That is, as shown in FIG. 3, all the end portions of the sapphire substrate 1 are embedded in the wax resin layer 2 by the waxing method, so that the end portion of the sapphire substrate 1 can be easily held stably. On the other hand, as shown in FIG. 4, in the method of using the conventional semiconductor wafer protective film, the end portion of the sapphire substrate 1 is not embedded in the inside of the semiconductor wafer protective film 4, so that it is difficult to stably maintain the sapphire substrate 1. Ends. Therefore, it is considered that the end portion of the sapphire substrate 1 at the time of back grinding is in contact with the grindstone 3 or the like and is easily broken.

The present invention has been made in view of the above circumstances, and aims to provide a special It is a method of manufacturing a semiconductor device which is back-polished without damage in a hard and brittle semiconductor wafer such as a sapphire substrate, or a film for semiconductor wafer surface protection suitable for the above-described manufacturing method.

The inventors of the present invention have found that it is possible to suppress breakage of the end portion of the semiconductor wafer by holding the vicinity of the end portion of the semiconductor wafer by the ridge portion (rim) during back surface polishing. As a result of intensive studies, it has been found that the formation of a film having a shape in which the ridge portion (edge) can be favorably maintained even at the temperature at the time of back surface polishing can be formed by thermocompression bonding. .

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

[1] A film for surface protection of a semiconductor wafer, comprising: a substrate layer (A) having a storage elastic modulus G _A (150) at 150 ° C of 1 MPa or more; and a softening layer (B) at 120 The storage elastic modulus G _B (120 to 180) at any temperature of °C to 180 °C is 0.05 MPa or less, and the storage elastic modulus G _B (40) at 40 ° C is 10 MPa or more.

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

[3] The film for semiconductor wafer surface protection according to [1] or [2] wherein the softening layer (B) has a tensile elastic modulus E _B (60) at 60 ° C and an elongation at 25 ° C. The elastic modulus E _B (25) satisfies the relationship of 1>E _B (60)/E _B (25)>0.1.

[4] The semiconductor wafer surface protection according to any one of [1] to [3] The film further includes an adhesive layer (C) disposed on the opposite side of the base material layer (A) via the softened layer (B), and an adhesive layer measured according to JIS Z0237 of the adhesive layer (C) The force is 0.1 N/25 mm~10 N/25 mm.

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

[6] The film for semiconductor wafer surface protection according to [4], wherein the adhesive layer (C) is disposed on the opposite side of the base material layer (A) via the softened layer (B). The most surface.

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

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

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

A second invention of the present invention relates to a method of manufacturing a semiconductor device described below.

[10] A method of manufacturing a semiconductor device, comprising: a step of disposing a semiconductor wafer on a surface of a semiconductor wafer surface protection film in such a manner that a circuit formation surface of the semiconductor wafer is in contact with a semiconductor wafer surface protection film; a step of forming a raised portion of the semiconductor wafer surface protective film of the semiconductor wafer on an outer circumference of the semiconductor wafer; and a step of polishing a circuit non-formed surface of the semiconductor wafer held by the raised portion; The step of peeling off the semiconductor wafer surface protective film from the circuit formation surface of the semiconductor wafer; the storage elastic modulus G (100) of the raised portion at 100 ° C is 1 MPa or more.

The semiconductor wafer surface protection film according to any one of [1] to [9], wherein the semiconductor wafer surface protection film according to any one of [1] to [9], The semiconductor wafer surface protective film and the semiconductor wafer are thermocompression-bonded at a temperature of 120 ° C to 180 ° C and a pressure of 1 MPa to 10 MPa to form the raised portion.

[12] A method of manufacturing a semiconductor device according to the above [11], wherein the semiconductor wafer surface protection film is formed on the semiconductor wafer surface protection film and the semiconductor wafer The temperature TM of the film in the step of arranging the semiconductor wafer, the thermocompression bonding temperature TP in the step of forming the ridge portion of the semiconductor wafer surface protective film, and the softening layer (B) The softening point temperature TmB satisfies the relationship of the following formula: [Formula 1] TP≦TM, [Formula 2] TmB<TP<TmB+40°C.

[13] The method of manufacturing a semiconductor device according to [11] or [12] wherein the softening layer (B) of the film for semiconductor wafer surface protection is a substrate The layer (A) is formed on the circuit formation surface side of the semiconductor wafer, and the semiconductor wafer is placed on the semiconductor wafer surface protection film.

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

A third invention of the present invention is a semiconductor wafer pressing apparatus relating to a press mounting frame.

[15] A semiconductor wafer pressing apparatus, which is formed by sandwiching a mounting frame with an upper pressing plate having a heating mechanism and a lower pressing plate opposite to the upper pressing plate, the mounting frame including a semiconductor wafer and having the semiconductor surrounding a ring frame A of a frame of the wafer, a semiconductor wafer surface protective film according to claim 1 attached to the circuit forming surface of the semiconductor wafer and the frame A; and the semiconductor wafer is external to the semiconductor wafer The diameter DW and the inner diameter DA _{IN of} the ring frame A satisfy the relationship of the formula (1) DW < DA _IN ; the lower pressing plate has a convex portion on a surface opposite to the upper pressing plate; and the convex portion at the time of pressing The outer circumference of the contact surface of the above mounting frame is circular.

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

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

[18] The semiconductor wafer pressing 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 invention of the present invention relates to a semiconductor wafer mounting apparatus for manufacturing a mounting frame, and a method of manufacturing a semiconductor device using the same.

[19] A semiconductor wafer mounting apparatus for fabricating a mounting frame, the mounting frame including a semiconductor wafer, an annular auxiliary member B surrounding the semiconductor wafer, and a surrounding of the semiconductor wafer and the annular auxiliary member B The ring-shaped frame A, the semiconductor wafer surface protective film according to any one of [1] to [9], which is attached to the circuit-forming surface of the semiconductor wafer, and the ring-shaped auxiliary member B and the ring frame A. And an outer diameter DW of the semiconductor wafer, an inner diameter DA _{IN of} the ring frame A, an outer diameter DB _OUT of the annular auxiliary member B, and an inner diameter DB _{IN of} the annular auxiliary member B, satisfying expression (1) a relationship of DW < DB _IN < DB _OUT < DA _IN ; the semiconductor wafer mounting apparatus includes: a heating unit that heats an opposite surface of a circuit formation surface of the semiconductor wafer, and a circuit formation over the semiconductor wafer a surface, the ring frame A, and the annular auxiliary member B are rotated to attach the attachment roller of the semiconductor wafer surface protective film, and the tape cutting of the surface protection film along the outer shape of the ring frame A mechanism

[20] The semiconductor wafer mounting device according to [19], wherein any one of ΔD1 and ΔD2 represented by the following formula is within 1% of DW: ΔD1 = DB _{IN -} DW... 2)

ΔD2=DA _IN -DB _OUT ... (3).

A fifth invention of the present invention relates to a method of manufacturing a semiconductor device described below.

A method of manufacturing a semiconductor device, comprising: 1') a step of preparing a semiconductor wafer; 2') forming a ridge portion substantially containing a resin on an outer circumference of the semiconductor wafer; 3') protecting the surface of the semiconductor wafer a step of arranging a circuit forming surface of the semiconductor wafer on the film; 4') a step of polishing a circuit non-formed surface of the semiconductor wafer held by the bump; and 5') a step of peeling off the film for semiconductor wafer surface protection And the storage elastic modulus G _B (40) of the embossed portion including the resin is 10 MPa or more.

The film for semiconductor wafer surface protection of the present invention can be back-polished without damage even for a hard and brittle semiconductor wafer such as a sapphire substrate.

1. Film for semiconductor wafer surface protection

The film for semiconductor wafer surface protection of the present invention includes a base material layer (A) and a softening layer (B); and may further include an adhesive layer (C) (refer to FIG. 1A) or a light adhesive layer (D) as needed (refer to the drawing) 1B) and so on. The thickness of the film described in the present invention is not limited and may be referred to as a so-called sheet.

About the substrate layer (A)

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

The storage elastic modulus of the substrate layer (A) can be measured by the following method. That is, a sample film having a thickness of 500 μm including the resin constituting the base material layer (A) was prepared. Next, the sample film was placed in a dynamic viscoelasticity measuring apparatus (manufactured by TA Instruments: ARES), and a parallel plate type attachment device having a diameter of 8 mm was used, and the temperature was raised from 30 ° C to 200 at a temperature rising rate of 3 ° C /min. At °C, the storage elastic modulus was measured. The measurement frequency can be set to 1 Hz. After the end of the measurement, the value of the storage elastic modulus G (Pa) at 150 ° C was read from the obtained storage elastic modulus-temperature curve of 30 ° C to 200 ° C.

The resin constituting the base material layer (A) may satisfy the above-described storage elastic modulus. In addition, when the adhesive layer (C) contains a radiation curable adhesive as described later, it is preferred that the resin constituting the base material layer (A) has transparency. Examples of such resins include polyolefins or polyesters and the like. That is, the base material 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 the polyolefin film include a polypropylene film. Examples of the polyester film include a polyethylene terephthalate film, a polyethylene naphthalate film, and the like.

The density of the resin constituting the substrate layer (A) is preferably from 900 kg/m ³ to 1450 kg/m ³ . When the density of the resin constituting the base material layer (A) is less than 900 kg/m ³ , the storage elastic modulus is too low, and thus the shape retainability may be insufficient.

The thickness of the base material layer (A) is preferably 5 μm or more, and more preferably 10 μm or more from the viewpoint of obtaining rigidity to suppress warpage of the semiconductor wafer. The upper limit of the thickness of the base material layer (A) is such that the total thickness of the semiconductor wafer surface protective film is not excessively thick with respect to the thickness of the polishing finish of the semiconductor wafer from the viewpoint of preventing breakage of the semiconductor wafer. Just fine.

About the softening layer (B)

The softened layer (B) has a function of forming a ridge (edge) around the semiconductor wafer in order to stably hold the end of the semiconductor wafer. As described later, since the semiconductor wafer surface protective film and the semiconductor wafer are thermally pressure-bonded to form a ridge (edge), it is necessary to form the softened layer at a thermocompression bonding temperature (120 ° C to 180 ° C). )soften. That is, the softening point temperature TmB of the softened layer (B) is preferably lower than the hot pressing temperature (120 ° C to 180 ° C). The softening point temperature TmB can be determined by a differential scanning calorimeter (DSC) measurement. Specifically, the melting point (DSC method) of the resin material according to ISO-11357-3 is set as the softening point temperature.

The storage elastic modulus G _B (150-180) of the softened layer (B) at any temperature from 120 ° C to 180 ° C, preferably the storage elastic modulus G _B (150) of the softened layer (B) at 150 ° C, Preferably, it is 0.05 MPa or less, more preferably 0.03 MPa or less.

On the other hand, in order to prevent the ridges (edges) from softening during back grinding (wet polishing), it is necessary to make the softened layer (B) not soften at the temperature (near 40 ° C) at the time of 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 particularly preferably 30 MPa or more. The upper limit of the storage elastic modulus G _B (40) at 40 ° C can be usually set to about 500 MPa or less. In order to make the softening layer (B) have a storage elastic modulus G _B (40) of 40 MPa or more at 40 ° C, it is preferred that the resin constituting the softened layer (B) be a resin which is not an elastomer as will be described later. As will be 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) of the softened layer (B) at 40 ° C is 10 MPa or more", which may also be called "the tensile elastic modulus E of the softened layer (B) at 40 ° C" _B (40) is 30 MPa or more."

The back grinding is usually carried out by a wet method, and can be further carried out by dryness as needed. The wafer temperature at the time of dry back grinding (dry polishing) is about 100 ° C because the friction heat between the grindstone and the semiconductor wafer is large. Therefore, in order to prevent softening of the ridge portion (edge) during dry polishing, it is preferred 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.

Softened layer (B) at 60 deg.] C a tensile modulus of elasticity E _B (60) at 25 deg.] C and a tensile modulus of elasticity E _B (25), preferably _{1> E B (60) /} E B (25 )>0.1. The temperature of the semiconductor wafer when the semiconductor wafer is back-polished is often changed within a range of 25 ° C to 60 ° C. Therefore, by changing the rate of change in the storage elastic modulus of the softened layer (B) in the temperature range within a fixed range, the ridge portion including the softened layer (B) can stably hold the semiconductor wafer. In addition, it is possible to suppress deterioration of the ridge portion including the soft layer (B) during back surface polishing of the semiconductor wafer. Therefore, damage of the semiconductor wafer in the back surface polishing of the semiconductor wafer can be more effectively suppressed.

The measurement of the tensile elastic modulus E of the softened layer (B) can be carried out as follows. i) A film having a thickness of 100 μm was cut, and a short strip of a sample having a width (TD direction) of 10 mm and a length (MD direction) of 100 mm was prepared. Ii) Next, according to JIS K7161, the tensile elastic modulus of the sample piece was measured by a tensile tester under the conditions of a distance between the chucks of 50 mm and a tensile speed of 300 mm/min. The measurement of the tensile elastic modulus was carried out under the conditions of a temperature of 23 ° C and a relative humidity of 55%. The tensile elastic modulus E is mostly 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, and is preferably a non-elastomer. Specifically, a homopolymer or copolymer of a hydrocarbon olefin is preferred, and a copolymer of ethylene homopolymer, propylene homopolymer, or ethylene or propylene other than a hydrocarbon olefin is more preferred. On the other hand, for example, the ethylene-vinyl acetate copolymer (EVA) usually has a storage elastic modulus G (40) of 40 ° C of about 0.01 MPa to 0.1 MPa, and is less than 10 MPa, which is not preferable.

The hydrocarbon or olefin other than ethylene or propylene in the copolymer of ethylene or propylene and other hydrocarbon olefins is preferably an α-olefin having 3 to 12 carbon atoms. Examples of the α-olefin having 3 to 12 carbon atoms include: propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene And 3-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, etc., preferably propylene, 1-butene or the like.

Preferred specific examples of the resin constituting the softening layer (B) include linear low density polyethylene (LLDPE), low density polyethylene, high density polyethylene, polypropylene, polystyrene, acrylonitrile-butadiene- Styrene copolymer (Acrylonitrile Butadiene Styrene, ABS) resin, vinyl chloride resin, methyl methacrylate resin, nylon, fluororesin, polycarbonate, polyester resin, etc., preferably linear low density polyethylene (LLDPE), low density Polyethylene, high density polyethylene, polypropylene, etc.

The density of the resin constituting the softened layer (B) is preferably 880 kg/m ³ to 960 kg/m ³ , more preferably 900 kg/m ³ to 960 kg/m ³ , and particularly preferably 910 kg/m ³ to 950. Kg/m ³ . If the density of the resin constituting the softened layer (B) is less than 880 kg/m ³ , it may be softened at 40 ° C. 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 elastic modulus of the softened layer (B) can be determined according to the density of the homopolymer of ethylene or propylene, the type of the hydrocarbon olefin other than ethylene or propylene in the copolymer of ethylene or propylene and the hydrocarbon olefin other than the propylene, and the content ratio thereof. Adjustment. For example, in order to increase the storage elastic modulus of the softened layer (B) at 40 ° C, for example, it is necessary to increase the density of the homopolymer of ethylene or propylene or to increase the content of ethylene or propylene in the copolymer of ethylene or propylene and other hydrocarbon olefins. The ratio can be.

The thickness of the softened layer (B) may be such that an edge can be formed by thermocompression bonding with a semiconductor wafer, and the unevenness of the surface of the semiconductor wafer can be embedded. Therefore, the thickness of the softened layer (B) is preferably larger than the maximum value of the step of 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 μm, the thickness of the softened layer (B) is more preferably 55 μm or more, and particularly preferably 60 μm or more. On the other hand, it is considered that if the softened layer (B) is too thick, it is difficult to suppress the grinding during the polishing. The semiconductor wafer is deformed (bent or flexed) and is therefore easily broken. Therefore, the thickness of the softened layer (B) is preferably 100 μm or less, and more preferably 70 μm or less.

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

About Adhesive Layer (C)

The film for semiconductor wafer surface protection of the present invention preferably further includes an adhesive layer (C) in order to improve adhesion to the semiconductor wafer. On the other hand, if the adhesive force of the adhesive layer (C) is too high, the adhesive is liable to be lost when peeling off from the semiconductor wafer. Therefore, the adhesive layer (C) is only required to have a minimum adhesive force. Specifically, the adhesive force measured in accordance with JIS Z0237 is preferably 0.1 N/25 mm to 10 N/25 mm.

The storage elastic modulus of the adhesive layer (C) may be such a degree as not to hinder the formation of the ridges (edges) of the softened layer (B).

The adhesive (adhesive agent) constituting the adhesive layer (C) may be an acrylic adhesive, an anthrone adhesive, or a rubber adhesive. Among them, an acrylic adhesive having an acrylic polymer as a base polymer is preferred in terms of easy adjustment of adhesion and the like.

The adhesive constituting the adhesive layer (C) may be a radiation hardening type adhesive. The reason is that the adhesive layer containing the radiation-curable adhesive is hardened by irradiation of radiation, and thus can be easily peeled off from the wafer. The radiation may be ultraviolet rays, electron beams, infrared rays or the like.

The radiation hardening adhesive may include: the above adhesive main agent, intramolecular A compound having a carbon-carbon double bond and a radiation polymerization initiator; and may further comprise: a binder which has 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 adhesive.

Examples of the radiation polymerization initiator include: an acetophenone-based photopolymerization initiator such as methoxyacetophenone; 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)one; An α-keto alcohol compound; a ketal compound such as benzoin dimethyl ketal; a benzoin photopolymerization initiator such as benzoin or benzoin methyl ether; a benzophenone such as benzophenone or benzoyl benzoic acid; A photopolymerization initiator.

The radiation hardening type adhesive may further contain a crosslinking agent as needed. Examples of the crosslinking agent include isocyanate crosslinking agents such as diphenylmethane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, and polyisocyanate.

The thickness of the adhesive layer (C) may be such that it does not inhibit the formation of the edge of the softened layer (B). For example, the thickness of the softened layer (B) may be set to about 1% to 20%, and specifically may be 1 μm. ~20 μm or so.

About light adhesive layer (D)

The film for semiconductor wafer surface protection of the present invention may have a lightly-adhesive layer (D) for allowing the base material layer (A) and the softening layer (B) to be peeled off from each other. Examples of the material of the light adhesive layer (D) include an acrylic adhesive and the like.

When the film for semiconductor wafer surface protection of the present invention has the light adhesive layer (D), the base material layer (A) and the softened layer (B) can be peeled off from each other. Therefore, after the semiconductor wafer surface protective film is attached to the semiconductor wafer, the base material 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 film for semiconductor surface protection on the outer periphery of the semiconductor wafer (see FIG. 2C), and before the step of polishing the surface of the semiconductor wafer (see FIG. 2E), the substrate may be used. The material layer (A) is peeled off from the film for surface protection of the semiconductor wafer.

When the base material layer (A) is peeled off and the circuit non-formed surface of the semiconductor wafer is polished, more precise polishing can be achieved. In the polishing of a semiconductor wafer, the film for semiconductor wafer surface protection is bent or vibrated by the load of the grindstone, thereby impeding fine polishing. On the other hand, when the base material layer (A) is peeled off and the semiconductor wafer surface protective film is thinned, and the semiconductor wafer is polished, bending or vibration of the semiconductor wafer surface protective film is suppressed. therefore. More precise grinding is possible.

The film for semiconductor wafer surface protection of the present invention may further contain other layers as needed. The other layer may be, for example, a release film or the like.

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

1A and 1B show the constitution of a film for protecting a surface of a semiconductor wafer. A picture of an example. As shown in FIG. 1A, a film 10 for semiconductor wafer surface protection includes a substrate layer (A) 12, a softened layer (B) 14, and an adhesive layer (C) 16. As shown in FIG. 1B, the semiconductor wafer surface protection film 10' includes a base material layer (A) 12, a light adhesive layer (D) 18, a softening layer (B) 14, and an adhesive layer (C) 16. The semiconductor wafer surface protection films 10 and 10' are used in such a manner that the adhesive layer (C) 16 is in surface contact with the circuit formation surface of the semiconductor wafer.

The film for semiconductor wafer surface protection of the present invention can be produced by any method. For example, there are: 1) a method of co-extruding a base material layer (A) and a softening layer (B) to obtain a film for surface protection of a semiconductor wafer (co-extrusion formation method); 2) a film-form substrate layer (A) A method (lamination method) in which a film for film surface protection of a semiconductor wafer is laminated (laminated) with a film-like softened layer (B). The film for semiconductor wafer surface protection further including the adhesive layer (C) can be produced by applying a coating liquid for forming an adhesive layer on a laminated film of the base material layer (A) and the softening layer (B).

2. Method of manufacturing a semiconductor device

An example of a method of manufacturing a semiconductor device using the semiconductor wafer surface protective film of the present invention includes: 1) a step of disposing a semiconductor wafer on a film for protecting a semiconductor wafer surface (mounting step); and 2) a semiconductor wafer a step of forming a raised portion of the semiconductor wafer surface protective film for holding the semiconductor wafer on the outer periphery (pressing step); 3) a step of polishing the non-formed surface of the semiconductor wafer held by the raised portion; and 4) The step of peeling off the film for semiconductor wafer surface protection. 3) in the present invention, a circuit non-forming surface of a semiconductor wafer held by a film for semiconductor wafer surface protection The step of polishing means that the semiconductor wafer is not broken or thinned to a specific thickness without damage. After these steps are performed, the step of cutting the semiconductor wafer and wafer formation can be further performed.

Other examples of the method of manufacturing a semiconductor device using a film for semiconductor wafer surface protection include: 1') a step of preparing a semiconductor wafer; 2') a step of forming a ridge portion substantially containing a resin on the outer periphery of the semiconductor wafer; ') a step of arranging a circuit formation surface of the semiconductor wafer on the semiconductor wafer surface protection film; 4') a step of polishing the circuit non-formation surface of the semiconductor wafer held by the ridge portion; 5') a semiconductor The step of peeling off the film for wafer surface protection. 2') The step of forming the ridge portion and the step of 3') arranging the circuit formation surface of the semiconductor wafer on the semiconductor wafer surface protection film may be performed first.

In the step 2'), the ridge portion substantially including the resin formed on the outer periphery of the semiconductor wafer may be made of a resin material different from the material constituting the film for semiconductor wafer surface protection. In this case, the semiconductor wafer surface protective film is not limited to the above-described 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 ridge portion substantially including the resin may be 10 MPa or more, and the storage elastic modulus G _B (100) is preferably 1 MPa or more.

Further, the combination of the semiconductor wafer formed by the 2') step and the ridge portion (edge) substantially including the resin disposed on the outer periphery thereof is referred to as a semiconductor wafer with an edge. The edge-attached semiconductor wafer may include a semiconductor wafer and a ridge substantially containing a resin; and may include a semiconductor wafer and a ridge substantially containing a resin, and a semiconductor supporting the member Film for wafer surface protection. The film for semiconductor wafer surface protection is attached to the circuit formation surface of the semiconductor wafer.

In addition, the step of 6') arranging the ring frame (refer to symbol 30 in FIG. 2B) so as to surround the semiconductor wafer may be included. The step of arranging the ring frame may be performed after the step of preparing the semiconductor wafer 1') and before the step of polishing 4'). Further, it is only necessary to have a ridge portion in the gap between the ring frame (see reference numeral 30 in FIG. 2B) and the semiconductor wafer.

In the semiconductor wafer with the edge, the distance between the ridge and the edge of the semiconductor wafer is preferably 0 mm to 1 mm, more preferably 0 μm to 500 μm, and particularly preferably the ridge is in contact with the edge of the semiconductor wafer. The reason is that the ridges hold the semiconductor wafer.

The semiconductor wafer is not particularly limited, and may be a tantalum 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. The semiconductor wafer surface protection film or the like according to the present invention forms a raised portion (edge) on the outer periphery of the semiconductor wafer and polishes the circuit non-formed surface of the wafer, thereby providing a high hardness including a Mohs hardness of 8 or more. The semiconductor wafer of the material substrate can also suppress breakage of the semiconductor wafer. Further, the semiconductor wafer of the present invention may be a semiconductor wafer in which a semiconductor layer such as GaN is laminated on a sapphire substrate. When manufacturing a semiconductor device such as a light emitting diode (LED) device, it is preferable to use a sapphire substrate on which a circuit is formed. 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 μm to 50 μm can be set on the circuit formation surface of the semiconductor wafer.

Semiconductor wafer surface protection formed around a semiconductor wafer The raised portion (edge) of the film is a portion formed on the outer periphery of the semiconductor wafer and holding the end portion of the semiconductor wafer. The raised portion of the film for semiconductor wafer surface protection may be composed of a film for protecting the surface of the semiconductor wafer, or may be made of a material different from the material constituting the film for protecting the surface of the semiconductor wafer.

In order to form the ridge portion by a resin material different from the material constituting the film for semiconductor wafer surface protection, for example, the following method is available. In each method, the semiconductor wafer may be a semiconductor wafer mounted on a film for semiconductor wafer surface protection, or may be a semiconductor wafer before mounting.

Method 1) As shown in FIG. 8A, a method of applying a liquid adhesive 105 by a coating device such as a dispenser 100 and hardening it around a semiconductor wafer 20

Method 2) As shown in FIG. 8B, a method of inserting a semiconductor wafer 20 into a resin ring 110 having through holes having substantially the same diameter as that of the semiconductor wafer 20

Method 3) As shown in FIG. 8C, a method of injecting molten resin into a cavity 125 of a mold 120 in which a semiconductor wafer 20 is inserted, and 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 at the time of coating (before hardening) is only about 1 Pa‧s to 500 Pa‧s; the cured product of the adhesive 105 is The storage elastic modulus G _B (40) may be 10 MPa or more, and 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 the softened layer (B) in the film for semiconductor wafer surface protection. Examples of the liquid adhesive 105 include an epoxy resin, an acrylic resin, a urethane resin, a phenol resin, and the like.

In the method 2), the storage elastic modulus G _B (40) of the resin ring 110 having the through hole having the same diameter as the diameter of the semiconductor wafer 20 may be 10 MPa or more; and 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 the softened layer (B) in the film for semiconductor wafer surface protection. Examples of the resin constituting the resin ring 110 include polyethylene (high density polyethylene, low density polyethylene, etc.), polypropylene (homopolypropylene, atactic polypropylene, etc.), polystyrene, nylon, and the like.

In the method 3), the molten resin 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; Further, 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 the softened layer (B) in the film for semiconductor wafer surface protection.

Thus, the ridges (edges) formed around the semiconductor wafer can be performed by any method, but the ridges (edges) can be formed relatively easily, and in terms of ease of handling, it is preferable to The film for semiconductor wafer surface protection of the present invention is formed by thermocompression bonding.

The storage elastic modulus G (100) of the ridge at 100 ° C is preferably 1 MPa or more. As described later, when the ridge portion is formed using the film for semiconductor wafer surface protection, the embossed portion is composed of the softened layer (B) of the film. Therefore, in this case, the storage elastic modulus of the ridge portion and the softened layer ( B) has the same storage elastic modulus. In addition, the back side of the semiconductor wafer described later In the grinding step, the grinding stone is difficult to be broken in contact with the ridge portion, and the grinding stone can effectively contact the circuit non-formed surface of the semiconductor wafer. Preferably, the ridge portion (edge) is substantially a resin having a certain degree of flexibility. form.

An example of a method of 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 step (mounting step) of arranging a semiconductor wafer on a film for protecting a semiconductor wafer surface, and FIG. 2B is a view showing a laminate in which a semiconductor wafer is placed on a film for protecting a semiconductor wafer surface. 2C is a view showing an example of a step (pressing step) of forming a raised portion of a film for protecting a semiconductor surface on the outer periphery of a semiconductor wafer; FIG. 2D is an enlarged view showing an example of a raised portion; and FIG. 2E is a view showing a semiconductor; A diagram showing an example of a step in which the circuit of the wafer is not surface-polished.

About the installation steps

FIG. 2A shows an example in which a semiconductor wafer is placed on a film for protecting a semiconductor wafer surface. First, the semiconductor wafer surface protection film 10 larger than the size of the semiconductor wafer 20 is prepared. Next, 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 adhesion layer (C) 16 of the semiconductor wafer surface protection film 10.

Specifically, the semiconductor wafer 20 and the ring frame 30 surrounding the semiconductor wafer 20 are placed on the heater board 40. Next, 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 is brought into contact with the adhesion layer (C) 16 of the semiconductor wafer surface protection film 10.

Then, one end portion of the semiconductor wafer surface protection film 10 is pressed against the semiconductor wafer 20 from the other end portion while rotating the roller 35. Thereby, the circuit formation surface 20A of the semiconductor wafer 20 is in close contact with the semiconductor wafer surface protection film 10. The semiconductor wafer surface protection film 10 is pressed between the semiconductor wafers 20 by the roller 35, and the heating plate 40 can be kept at a normal temperature; or the heating plate 40 can be heated to heat the semiconductor wafer surface protection film 10 to Arrival temperature (TM).

The temperature (TM) of the semiconductor wafer surface protection film 10 in the mounting step is preferably a semiconductor wafer surface protection in a step (described later) of forming a bump portion of the semiconductor surface protection film on the outer periphery of the semiconductor wafer. The temperature (TP) of the film 10 is the same temperature or higher than the temperature thereof. The reason for the reason is explained below because there is a case where wrinkles are formed on the semiconductor wafer surface protecting film 10 in the step of forming the ridge portion; or after the step of forming the ridge portion, the semiconductor wafer 20 The film 10 for semiconductor wafer surface protection is peeled off.

After the mounting step, the semiconductor wafer 20 is taken out from the heating plate 40 together with the semiconductor wafer surface protective film 10 and the ring frame 30, and a semiconductor crystal is disposed on the semiconductor wafer surface protective film as shown in FIG. 2B. Round laminate. This laminate is referred to as a "mounting frame."

About the pressing step

Next, as shown in FIG. 2C, the semiconductor wafer 20 and the semiconductor wafer surface protective film 10 are thermocompression-bonded by a pair of hot plates (the upper hot plate 22-1 and the lower hot plate 22-2) of the hot press. (Steps of (2)). Thereby, the semiconductor wafer 20 is pressed into the molten softened layer (B) 14, whereby the softened layer is extruded. (B) 14 forms a ridge (edge) 24 near the end of the semiconductor wafer 20. The upper hot plate 22-1 is a hot plate disposed on the side of the semiconductor wafer 20, and the lower hot plate 22-2 is a hot plate disposed on the side of the semiconductor wafer protective film 10. The upper hot plate 22-1 may be in direct contact with the semiconductor wafer 20, or may be separated by several members (for example, a jig or the like). Similarly, the lower hot plate 22-2 may be in direct contact with the semiconductor wafer protective film 10, or may be separated by several members (for example, a jig or the like).

The height of the raised portion (edge) 24 is preferably, for example, about 0.2 to 1 times the thickness of the semiconductor wafer 20 to be back-polished. If the height of the ridges (edges) 24 is too low, the ends of the semiconductor wafer 20 cannot be stably held. Specifically, when the semiconductor wafer 20 having a thickness of 1000 μm is subjected to back surface processing, the height of the ridge portion (edge) 24 is preferably 200 μm or more. 2B shows a form in which the corners of the end portions of the semiconductor wafer 20 are not removed. However, the ends of the semiconductor wafer 20 may be chamfered (straight line) or R-processed (curved) to remove the corners. When chamfering (straight line) or R processing (curve) is performed on the end portion of the semiconductor wafer 20, the height of the ridge portion (edge) 24 may be the thickness of the end portion of the semiconductor wafer after chamfering or R processing. quite.

The thermocompression bonding temperature (thermocompression bonding temperature TP) or the pressing pressure may be a condition in which the softening layer (B) 14 is melted to form the ridge portion (edge) 24. Specifically, the pressing pressure is preferably from 1 MPa to 10 MPa, more preferably from 3 MPa to 10 MPa. The pressing time can be, for example, about 1 minute to 5 minutes. The thermocompression bonding temperature TP is preferably in the range of 120 ° C to 180 ° C, more preferably in the range of 130 ° C to 170 ° C, and particularly preferably 150 ° C. The thermocompression bonding temperature (TP) refers to the average temperature of a pair of hot plates (upper hot plate 22-1 and lower hot plate 22-2) of the press.

Further, the thermocompression bonding temperature (TP) is preferably the same temperature as or lower than the temperature (TM) of the semiconductor wafer surface protective film 10 in the mounting step. The semiconductor wafer surface protection film 10 will thermally expand by heating in the pressing step; if the thermocompression bonding temperature (TP) is below the temperature (TM) in the mounting step, the semiconductor wafer surface protection in the pressing step is used. The degree of thermal expansion of the film 10 is equal to or less than the degree of thermal expansion of the semiconductor wafer surface protective film 10 in the mounting step. Since the semiconductor wafer surface protective film 10 which is sufficiently thermally expanded in the mounting step is fixed to the semiconductor wafer, the semiconductor wafer surface protecting film 10 is hard to thermally expand in the pressing step, and wrinkles are less likely to occur. On the other hand, if the thermocompression bonding temperature (TP) and the temperature (TM) are improperly adjusted, the semiconductor wafer surface protection film 10 is likely to wrinkle around the semiconductor wafer 20.

Further, when the semiconductor wafer surface protective film 10 is cooled after the pressing step, the semiconductor wafer surface protecting film 10 and the semiconductor wafer 20 may be peeled off (the semiconductor wafer 20 floats from the film 10). This peeling can also be suppressed by setting the thermocompression bonding temperature (TP) to be lower than the temperature (TM) of the mounting step. Thus, by suppressing wrinkles in the semiconductor surface protective film, it is more difficult to break the semiconductor wafer in the back grinding step of the semiconductor wafer.

Further, the thermocompression bonding temperature (TP) is preferably higher than the softening temperature (TmB) of the softening layer (B) of the semiconductor wafer surface protective film 10. The softened layer (B) is softened by setting the thermocompression bonding temperature (TP) to a softening temperature (TmB) or more, and the ridge portion (edge) 24 is easily formed. On the other hand, it is preferable that the thermocompression bonding temperature (TP) is lower than the film for semiconductor wafer surface protection. The softening temperature (TmB) of the softened layer (B) of 10 + 40 ° C". When the thermocompression bonding temperature (TP) is too high, the shape of the ridge portion (edge) 24 formed by softening the softened layer (B) cannot be maintained, and the flow becomes a flat shape. Thereby, the height of the ridge (edge) 24 becomes low.

Further, as described above, the thermocompression bonding temperature (TP) means the average temperature of a pair of hot plates (the upper hot plate 22-1 and the lower hot plate 22-2) of the press. The temperature of the upper hot plate 22-1 (TP1) and the temperature of the lower hot plate 22-2 (TP2) may be the same temperature, preferably the temperature of the upper hot plate 22-1 (TP1) is higher than that of the lower hot plate 22 -2 temperature (TP2). The higher the temperature of the thermocompression bonding temperature (TP), the more rapidly the ridge (edge) 24 is formed, but if the temperature (TP2) of the lower hot plate 22-2 is high, the ridge (edge) 24 cannot be maintained. The shape is flowing and flattened. On the other hand, since the upper hot plate 22-1 is not in direct contact with the semiconductor wafer surface protection film 10 (there is a gap therebetween), it is difficult to make the ridge portion by the temperature (TP1) of the upper hot plate 22-1. The shape of (edge) 24 is flattened. Therefore, by making the temperature (TP1) of the upper hot plate 22-1 higher than the temperature (TP2) of the lower hot plate 22-2, the shape of the ridge (edge) 24 can be maintained, and the ridges (edges) can be quickly formed. )twenty four.

Specifically, it is preferable that the temperature (TP1) of the upper hot plate 22-1 is higher than the "softening temperature (TmB) + 20 ° C of the softened layer (B) of the semiconductor wafer surface protective film 10", and is lower than " The softening temperature (TmB) + 40 ° C" of the softened layer (B) of the film 10 for semiconductor wafer surface protection. Further, it is preferable that the temperature (TP2) of the lower hot plate 22-2 is higher than "the temperature of the upper hot plate 22-1 (TP1) - 40 ° C" and lower than the temperature of the upper hot plate 22-1 (TP1). "." Thus, it is preferable that the thermocompression bonding temperature (TP) is higher than "the temperature of the upper hot plate 22-1 (TP1) - 20 ° C", It is lower than the "temperature (TP1) of the upper hot plate 22-1".

The height of the ridge portion (edge) 24 is defined as the height h of the surface of the semiconductor wafer surface protection film 10 from the surface where the circuit formation surface of the semiconductor wafer 20 contacts to the apex of the ridge portion (edge) 24, as shown in FIG. 2D. The height of the raised portion (edge) 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 by a microscope.

The raised portion (edge) 24 does not have to be in contact with the end portion of the semiconductor wafer 20, but in order to improve the retention of the semiconductor wafer 20, it is preferable to be in contact with the end portion of the semiconductor wafer 20.

Next, as shown in FIG. 2E, the semiconductor wafer surface protective film 10 is placed on the absorbing table 26 together with the semiconductor wafer 20. As described above, the film for semiconductor wafer surface protection may have a light adhesion layer (D) between the base material layer (A) and the softening layer (B) (see FIG. 1B). When the light-adhesive layer (D) is provided, the semiconductor wafer surface protective film 10 can be placed on the absorbing table 26 by removing the base material layer (A).

Next, the circuit non-forming surface (back surface) 20B of the semiconductor wafer is polished by the grindstone 28 until the wafer reaches a certain thickness or less (step (3)). The thickness of the semiconductor wafer after the back surface polishing can be, for example, 300 μm or less, or preferably 100 μm or less. The grinding process is a mechanical grinding process by grinding stones. The polishing method is not particularly limited, and may be a known polishing method such as a straight-through type or a feed-through type. The grinding process can be performed not only by wet grinding (wet polishing) but also by dry grinding (dry polishing).

Next, the film for semiconductor wafer surface protection 10 is peeled off at normal temperature (step of (4)). The peeling of the film 10 for semiconductor wafer surface protection can be performed, for example, by A known tape peeling machine is used. In addition, when the semiconductor wafer surface protection film 10 includes the radiation-curable pressure-sensitive adhesive layer (C), the semiconductor wafer surface protection film 10 is irradiated with radiation to cure the adhesive layer (C), and the semiconductor wafer surface protection film is used. 10 is peeled off from the semiconductor wafer 20.

Between the step (3) of performing back surface polishing of the semiconductor wafer and the step (4) of peeling off the film for protecting the surface of the semiconductor wafer from the semiconductor wafer, the non-formed surface of the semiconductor wafer may be included as needed ( Back) The step of processing. The step of processing the non-formed surface (back surface) of the semiconductor wafer may be further performed, for example, by a step selected from the group consisting of a metal sputtering step, a plating treatment step, and a heat treatment step. The heat treatment step may be, for example, a step of attaching the adhesive layer under heating, or the like. Next, the semiconductor wafer is diced. Alternatively, the semiconductor wafer may be diced without peeling off the semiconductor wafer surface protective film 10.

The film for semiconductor wafer surface protection of the present invention can form a ridge (edge) of a film for semiconductor wafer surface protection on the outer periphery of a semiconductor wafer by thermocompression bonding with a semiconductor wafer under specific conditions. In addition, the ridges (edges) formed by the film for semiconductor wafer surface protection of the present invention are not melted at the temperature (about 40 ° C) of the semiconductor wafer during back surface polishing, so that the shape can be favorably maintained. Therefore, when the back surface of the semiconductor wafer is polished, the end portion of the semiconductor wafer can be stably maintained by the ridge portion (edge), and the damage of the end portion of the semiconductor wafer due to the contact with the grindstone can be suppressed. . Therefore, even if the semiconductor wafer is a hard and brittle sapphire substrate, the back surface polishing can be performed without damaging the substrate.

Moreover, the film for protecting the surface of the semiconductor wafer is contained by radiation In the case of the cured adhesive layer (C), the semiconductor wafer surface protective film can be easily peeled off by irradiating the semiconductor wafer surface protective film with radiation. Thus, as in the previous waxing method, it is not necessary to clean the semiconductor wafer to which the wax resin is attached, so the steps can be simplified.

Other embodiments regarding the installation steps

As described above, the semiconductor wafer 20 is disposed inside the framed ring frame 30 in the mounting step; the semiconductor is attached to one surface of the semiconductor wafer 20 (usually the surface 20A on which the circuit is formed), and the ring frame 30, and the semiconductor is attached The wafer surface protection film 10 (see FIG. 2A). At this time, when the gap between the ring frame 30 and the semiconductor wafer 20 disposed inside the ring frame 30 is large, the film for semiconductor wafer protection is slack between the semiconductor wafer 20 and the ring frame 30. Therefore, it is preferable to arrange the annular 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 outer diameter DB _OUT of the annular auxiliary member 50, and the inner diameter DB _{IN of the} annular auxiliary member 50 satisfy the formula (1) DW< The relationship of DB _IN <DB _OUT <DA _IN (refer to FIG. 5A).

Further, it is preferable to reduce the gap between the semiconductor wafer 20 and the annular auxiliary member 50 and the gap between the annular auxiliary member 50 and the ring frame 30 as much as possible. The reason is to further prevent the slack of the attached semiconductor wafer protective film 10. That is, the difference ΔD1 between the outer diameter DW of the semiconductor wafer 20 and the inner diameter DB _IN of the annular auxiliary member 50 is preferably within 1% of the outer diameter DW of the semiconductor wafer 20. Similarly, the difference ΔD2 between the outer diameter DB _{OUT of the} annular auxiliary member 50 and the inner diameter DA _IN of the ring frame 30 is preferably within 1% of the outer diameter DW of the semiconductor wafer 20.

△D1=DB _IN -DW.........(2)

△D2=DA _IN -DB _OUT .........(3)

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

The heating unit is, for example, a heating plate 40 on which a pre-mounting frame is placed. The pre-mounting frame refers to a structure including a semiconductor wafer 20, an annular auxiliary member 50 surrounding the semiconductor wafer, and a ring frame 30 surrounding the annular auxiliary member 50 (FIG. 5A). The pre-mounting frame is placed on the opposite side of the circuit forming surface 20A of the semiconductor wafer 20 (circuit non-forming surface) so as to be opposed to the heating plate 40.

The semiconductor wafer 20 of the pre-mounted frame placed on the heating plate 40 is heated by the heating plate 40, and the tape attaching unit extends over the circuit forming surface 20A of the semiconductor wafer 20, the annular auxiliary member 50, and the ring. The film 10 for semiconductor wafer surface protection is attached to the frame 30. The tape attaching unit includes, for example, a roller 35; the roller 35 is rotatable throughout the circuit forming surface 20A of the semiconductor wafer 20, the annular auxiliary member 50, and the ring frame 30.

The tape cutting mechanism cuts the semiconductor wafer protective film 10 according to the outer diameter of the ring frame before or after attaching the semiconductor wafer protective film 10 to the pre-mounting frame. The tape cutting mechanism may be a cutter or the like (not shown). The semiconductor wafer 20, the annular auxiliary member 50, and the ring frame are thus obtained. 30. A mounting frame of the semiconductor wafer protective film 10.

Other embodiments regarding the pressing step

As described above, the pressing step is a step of pressing the mounting frame obtained in the mounting step by a pair of press plates (the upper press plate 22-1 and the lower press plate 22-2) (refer to Fig. 2C). However, as shown in FIG. 6, if the pressure of the upper hot plate 22-1 and the lower hot plate 22-2 is released after the pressing step, the outer peripheral portion of the semiconductor wafer surface protective film 10 of the mounting frame is thinner than the central portion. . It is presumed that in the pressing step, the outer peripheral portion of the semiconductor wafer surface protection film 10 of the mounting frame flows outward, and the central portion is less likely to flow.

Therefore, it is preferable that the lower pressing plate 22-2 has the convex portion 60 on the surface opposite to the upper pressing plate 22-1 among the pair of pressing plates. The convex portion 60 provided on the lower press plate 22-2 intrudes into the semiconductor wafer protective film 10 during pressing (Fig. 7A). Therefore, the thickness of the semiconductor wafer surface protective film 10 of the mounting frame after the pressing step can be made uniform, and the ridges (edges) 24 can also be formed.

The outer circumference (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 preferably circular. Thus, the protrusion 60 can be a cone (Fig. 7B) or can be a dome (Fig. 7C).

The protruding height of the convex portion 60 of the lower pressing plate 22-2 is preferably from 1 μm to 100 μm, more preferably from 15% to 100% of the thickness of the softening layer (B) of the film 10 for semiconductor wafer surface protection. Inside. The protruding 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 pressing plate 22-2 is larger than the outer diameter DW of the semiconductor wafer of the mounting frame, and smaller than the inner diameter DA _{IN of the} ring frame. That is, the relationship of DW<CD<DA _IN is satisfied.

The material of the convex portion 60 is not particularly limited. The polishing may be carried out in a convex shape, and may be, for example, a ceramic such as alumina or a superhard alloy such as tungsten carbide.

The pressing step can be performed using a semiconductor wafer pressing apparatus. The semiconductor wafer pressing apparatus includes an upper pressing plate 22-1 having a heating mechanism, and a lower pressing plate 22-2 having a convex portion 60 on a surface opposite to the upper pressing plate 22-1. In the pressing step, first, the mounting frame obtained in the mounting step is disposed between the upper pressing plate 22-1 and the lower pressing plate 22-2. At this time, the semiconductor wafer 20 of the mounting frame is opposed to the upper pressing plate 22-1, and the semiconductor wafer surface protecting film 10 of the mounting frame is disposed to face the lower pressing plate 22-2.

As shown in FIG. 7A, the mounted mounting frame includes a semiconductor wafer 20, a ring frame 30, and a structure of the semiconductor wafer surface protecting film 10 (see FIG. 2B).

After the mounting frame is placed, the mounting frame is heated by the heating mechanism of the upper pressing plate 22-1. Next, the mounting frame sandwiched by the upper pressing plate 22-1 and the lower pressing plate 22-2 is pressed by the upper pressing plate 22-1 and the lower pressing plate 22-2.

By peeling the mounting frame from the upper pressing plate 22-1 and the lower pressing plate 22-2, a ridge portion (edge) can be formed on the semiconductor wafer protective film, and the thickness of the semiconductor wafer protective film after the pressing step can be made. Achieve uniformity.

Instance (Example 1) Material preparation

A homopolypropylene (hPP) (manufactured by Prime Polymer Co., Ltd., density: 910 kg/m ³ ) was prepared as a material of the substrate layer (A). A linear low-density polyethylene (LLDPE) (manufactured by Prime Polymer Co., Ltd., density: 918 kg/m ³ ) was prepared as a material of the softening layer (B). The following coating liquid for an adhesive layer was prepared as a material of the adhesive layer (C).

Preparation of coating liquid for adhesive layer

Using a monomer mixture of 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, and using benzoyl peroxide polymerization 0.8 parts by weight of the initiator (manufactured by Nippon Oil & Fats Co., Ltd., Nyper BMT-K40) (0.32 part by weight as a starter) was reacted at 80 ° C for 10 hours in 65 parts by weight of toluene and 50 parts by weight of ethyl acetate. After completion of the reaction, the obtained solution was cooled, and then 100 parts by weight of xylene, 10 parts by weight of acrylic acid, and tetradecyldimethylbenzylammonium chloride [manufactured by Nippon Oil & Fats Co., Ltd., CATION M2-100] 0.3 weight were added. The mixture was reacted at 85 ° C for 50 hours while blowing air. Thereby, a solution (adhesive main component) of the acrylic adhesive polymer was obtained.

In the solution (adhesive main component) of the obtained acrylic pressure-sensitive adhesive polymer, benzophenone II as an intramolecular bond cleavage type photopolymerization initiator is added to 100 parts by weight of the solid component of the acrylic pressure-sensitive adhesive polymer. Methyl ketal [Japan Ciba-Geigy Co., Irgacure-651] 2 parts by weight, dipentaerythritol hexaacrylate as a monomer having a polymerizable carbon-carbon double bond in the molecule, and dipentaerythritol monohydroxypentaacrylate 0.3 parts by weight of a mixture [manufactured by East Asian Synthetic Chemical Industry Co., Ltd., ARONIX M-400], followed by addition of an isocyanate crosslinking agent as a thermal crosslinking agent [Mitsubishi Toyo Chemical Co., Ltd., Olester P49-75-S] 1.35 parts by weight (1 weight as a thermal crosslinking agent) Quantitative), and obtain ultraviolet (UV) adhesive. The adhesion of the obtained UV adhesive was measured in accordance with JIS Z0237, and it was 3 N/25 mm.

1) Determination of storage elastic modulus

A homopolypropylene (hPP) (manufactured by Prime Polymer Co., Ltd., density: 910 kg/m ³ ) which is a base material layer (A) was extrusion-molded to prepare 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 ) which is a softened layer (B) was extrusion-molded to prepare a sample film having a thickness of 500 μm. The UV adhesive which is the adhesive layer (C) was applied onto a glass substrate and dried, and then peeled off to prepare a sample film having a thickness of 300 μm.

The storage elastic modulus of these sample films was measured by the following method. That is, the sample film was placed in a dynamic viscoelasticity measuring apparatus (manufactured by TA Instruments: ARES), and a parallel plate type attachment device having a diameter of 8 mm was used to measure the temperature rise from 30 ° C to 200 ° C at a temperature increase rate of 3 ° C /min. Store the elastic modulus. The measurement frequency is set to 1 Hz. After the measurement, the sample film of the base material layer (A) and the softened layer (B) was read at 40 ° C, 100 ° C, and 150 ° C according to the obtained storage elastic modulus-temperature curve of 10 ° C to 200 ° C, respectively. The value of the stored elastic modulus. For the sample film of the adhesive layer (C), the value of the storage elastic modulus at 25 ° C was read from the obtained storage elastic modulus-temperature curve of 10 ° C to 200 ° C.

Fabrication of semiconductor wafer surface protection film

A homopolypropylene (hPP) (manufactured by Prime Polymer Co., Ltd., density: 910 kg/m ³ ) to be a base layer (A), and a linear low-density polyethylene (LLDPE) to be a softened layer (B) (Prime) Copolymerized at a density of 918 kg/m ³ manufactured by Polymer, and a 2-layer co-extruded film was obtained. The UV adhesive is applied onto the softened layer (B) of the obtained coextruded film, and then dried to form an adhesive layer (C) to obtain a film for semiconductor wafer surface protection. The thickness of the base material layer (A)/softening layer (B)/adhesive layer (C) of the film for semiconductor wafer surface protection is 60 μm/70 μm/5 μm, and the total thickness is 135 μm.

2) Evaluation of the formation of the ridge (edge)

The obtained film for semiconductor wafer surface protection is cut to a size larger than that of the sapphire wafer. Next, a sapphire wafer having a thickness of 650 μm and a size of 4 inches was placed on the film for semiconductor wafer surface protection. At this time, the circuit formation surface of the sapphire wafer is brought into contact with the adhesion layer (C) of the film for semiconductor wafer surface protection. These layers were placed in a hot press and thermocompression bonded at 140 ° C, 10 MPa for 2 minutes.

Then, the semiconductor wafer surface protective film is irradiated with ultraviolet rays for about 1000 mJ, and the semiconductor wafer surface protective film is peeled off from the semiconductor wafer, and the cross-sectional shape of the obtained semiconductor wafer surface protective film is observed by a microscope. The height of the ridges (edges) at two locations in the cross section of the film for semiconductor wafer surface protection was measured, and the average value of these heights was obtained. The height of the ridge (edge) is a height at which the apex of the ridge (edge) is measured with respect to the surface of the semiconductor wafer surface protective film that is in contact with the circuit forming surface of the semiconductor wafer. The evaluation of the formability of the ridges (edges) was performed based on the following criteria.

○: The height of the ridge (edge) is 200 μm or more

×: The height of the ridge (edge) is less than 200 μm

3) Evaluation of back grinding property

In the same manner as described above, the obtained film for semiconductor wafer surface protection was cut out to a size larger than that of the sapphire wafer. Next, a sapphire wafer having a thickness of 650 μm and a size of 4 inches was placed on the film for semiconductor wafer surface protection. These layers were placed in a hot press and thermocompression bonded at 140 ° C, 10 MPa for 2 minutes.

90 μm back grinding

The semiconductor wafer surface protective film for thermocompression bonding of the sapphire wafer was placed on the sorption table of the Disco DGP8761 by wet-grinding the non-formed surface (back surface) of the sapphire wafer until the wafer thickness was 90 μm. The temperature of the wafer during polishing was about 40 °C. Further, the back surface polishing property was evaluated based on the following criteria.

○: Back grinding can be performed until the thickness of the wafer is 90 μm

×: The substrate is broken before the thickness of the wafer is 90 μm (cannot be back-grinded)

70 μm back grinding

The sapphire wafer is back-polished to a thickness of 90 μm, and further wet-polished until the wafer thickness is 70 μm. Further, the back grinding property was evaluated based on the following criteria.

○: Back grinding can be performed until the thickness of the wafer is 70 μm

×: The substrate is broken before the thickness of the wafer is 70 μm (cannot be back-grinded)

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

The sample after completion of the wet back grinding of the above 3) was further subjected to a dry process (dry polishing) for 5 minutes. The temperature of the wafer during dry polishing is about 100 °C. Next, after the semiconductor wafer surface protective film is irradiated with ultraviolet rays for about 1000 mJ, the sapphire wafer is peeled off from the semiconductor wafer surface protective film. The cross-sectional shape of the obtained film for semiconductor wafer surface protection was observed by a microscope, and the height of the ridge (edge) was measured. The evaluation of DP heat resistance was carried out based on the following criteria.

○: The height of the ridge (edge) is the thickness of the wafer after polishing (the edge is not melted and remains)

×: The height of the ridge (edge) is lower than the polishing thickness of the wafer (the edge melts and disappears)

5) Surface smoothness of the substrate layer (A) after grinding

The surface smoothness of the base material layer (A) after the DP (dry polishing) of the above 4) was evaluated by a stylus type surface shape measuring machine (Veeco Dektac 3). The evaluation of the surface smoothness was performed based on the following criteria.

○: Ra of the unevenness of the surface of the base layer (A) due to the transfer of the surface shape of the absorbing table is less than 1 μm

×: Ra of the unevenness on the surface of the base layer (A) is 1 μm or more due to the transfer of the surface shape of the absorbing table

(Example 2)

A semiconductor wafer surface protective film was produced in the same manner as in Example 1 except that the thickness of the base layer (A) and the softened layer (B) was changed to 30 μm, and the same evaluation was performed.

(Example 3)

A semiconductor wafer was produced in the same manner as in Example 1 except that the material of the softening layer (B) was changed to an ethylene-α-olefin copolymer (TAFMER (manufactured by Mitsui Chemicals, Inc.), density: 893 kg/m ³ ). The film for surface protection was evaluated in the same manner.

(Example 4)

The material of the softened layer (B) was changed to a 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 the softened layer (B) were respectively A semiconductor wafer surface protective film was produced in the same manner as in Example 1 except that the film was changed to 30 μm, and the same evaluation was performed.

(Example 5)

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

(Comparative Example 1)

The material of the base material layer (A) was changed to a random polypropylene (rPP) (manufactured by Prime Polymer Co., Ltd., density: 910 kg/m ³ ), and the material of the softened layer (B) was changed to ethylene-α-olefin copolymerization. A semiconductor wafer surface protective film was produced in the same manner as in Example 1 except that the material (TAFMER (manufactured by Mitsui Chemicals, Inc.), density: 893 kg/m ³ ) was used, and the same evaluation was performed.

(Comparative Example 2)

The material of the base material layer (A) was changed to a linear low-density polyethylene (LLDPE) (manufactured by Prime Polymer Co., Ltd., density: 918 kg/m ³ ), and the material of the softened layer (B) was changed to ethylene-α- A semiconductor wafer surface protective film was produced in the same manner as in Example 1 except that the olefin copolymer (TAFMER (manufactured by Mitsui Chemicals, Inc.), density: 893 kg/m ³ ) was used, and the same evaluation was performed.

(Comparative Example 3)

The material of the base material layer (A) was changed to a linear low-density polyethylene (LLDPE) (manufactured by Prime Polymer Co., Ltd., density: 918 kg/m ³ ), and the material of the softened layer (B) was changed to ethylene-α- A semiconductor wafer surface protective film was produced in the same manner as in Example 1 except that the olefin copolymer (TAFMER (manufactured by Mitsui Chemicals, Inc.), density: 861 kg/m ³ ) was used, and the same evaluation was performed.

(Comparative Example 4)

The material of the softening layer (B) was changed to an ethylene-α-olefin copolymer (TAFMER (manufactured by Mitsui Chemicals, Inc.), density: 861 kg/m ³ ), and the substrate layer (A) and the softened layer (B) were A film for semiconductor wafer surface protection was produced in the same manner as in Example 1 except that the thickness was changed to 30 μm, and the same evaluation was performed.

The storage elastic modulus of the sample films of Examples 1 to 5 and Comparative Examples 1 to 4 and the evaluation results of the film for semiconductor wafer surface protection are shown in Tables 1 to 3.

As shown in Tables 1 and 2, the film of the semiconductor wafer surface protection of Examples 1 to 5 in which the softening layer (B) has a storage elastic modulus G _B (40) at 40 ° C of 10 MPa or more is obtained by heat. The embossing (edge) is well formed by pressing, and the wafer is not damaged at the time of back grinding. The reason for this is considered to be that the ridge portion (edge) is not melted during back grinding, and the end portion of the wafer can be stably held.

On the other hand, it is understood that the film for semiconductor wafer surface protection of Comparative Example 3 and Comparative Example 4 in which the softening layer (B) has a storage elastic modulus G _B (40) of 40 ° C or less is 10 MPa, although it can be formed by hot pressing. The ridge (edge), but the wafer is broken during back grinding. The reason for this is that the ridge portion (edge) is also softened during back grinding, and the end portion of the wafer cannot be stably held.

In Examples 1 to 5, the wafer was broken at 70 μm in Example 3, whereas in Example 2, the wafer was not broken even at 70 μm. The reason for this is that the softening layer (B) of the film for semiconductor wafer surface protection of Example 2 has a storage elastic modulus G _B (40) at 40 ° C higher than that of the semiconductor wafer surface protective film of Example 3. In addition, the reason why the wafer was broken at the time of polishing at 70 μm in Example 1 was that the film for semiconductor wafer surface protection was too thick with respect to the final processed thickness of the wafer, and the deformation of the semiconductor wafer (bending, flexing) could not be suppressed. ).

Further, it can be seen that the film for semiconductor wafer surface protection of Examples 1 and 2 does not soften the ridge portion (edge) at a high temperature of approximately 100 ° C at the time of dry polishing (DP), and can stably maintain the sapphire wafer. Ends.

Further, in Comparative Examples 1 to 3, the surface smoothness of the base material layer (A) after polishing was low. The reason why the base material layer (A) of the semiconductor wafer surface protective film of Comparative Example 1 to Comparative Example 3 has a storage elastic modulus G _A (150) at 150 ° C of less than 1 MPa, and is transferred at the time of back grinding. The surface shape of the platform. As described above, when the surface shape of the absorbing table is transferred to the surface of the base material layer (A) during the back surface polishing, when the semiconductor wafer surface protective film is fixed to the other absorbing table in the subsequent dicing step, Air leakage is likely to occur between the sorption table and the base material layer (A) of the semiconductor wafer surface protection film. If such a leak occurs, the film for semiconductor wafer surface protection cannot be fixed on the absorbing table, which is not preferable.

(Example 6)

The same film as that used in Example 2 was attached to a sapphire wafer (mounting step), and thermocompression bonding (pressing step) was performed to form a ridge (edge).

Specifically, the film for semiconductor wafer surface protection is cut to a size larger than that of the sapphire wafer. In addition, a sapphire wafer having a thickness of 650 μm and a size of 4 inches was prepared. As shown in FIG. 2A, it is disposed on a film for semiconductor wafer surface protection. The temperature of the hot plate was heated to 140 ° C, and the semiconductor wafer surface protective film was pressure-bonded to the sapphire wafer by a roll to obtain a laminate of the sapphire wafer and the semiconductor wafer surface protective film. The roll pressure was set to 0.5 MPa and the roll speed was set to 10 mm/sec.

Next, as shown in FIG. 2C, the upper hot plate (the hot plate disposed on the semiconductor wafer surface protective film) and the lower hot plate (the hot plate disposed on the sapphire wafer side) of the hot press are sandwiched. The laminate was crimped at 180 seconds and 10 MPa. At this time, the temperature of the upper hot plate was set to 140 ° C, and the temperature of the lower hot plate was set to 120 ° C, that is, the average temperature TP of both was set to 130 ° C.

Then, the semiconductor wafer surface protective film was irradiated with ultraviolet rays for about 1000 mJ, and the semiconductor wafer surface protective film was peeled off from the sapphire wafer, and the cross-sectional shape of the obtained semiconductor wafer surface protective film was observed by a microscope. Measuring the height of two parts in the cross section of the film for semiconductor wafer surface protection The height of the starting part (edge) is obtained by averaging these heights.

1. The presence or absence of tension in the radial direction

After the pressing step, a film of the semiconductor wafer surface protection was attached to the ring frame, and a 150 g weight was placed on the center of the sapphire wafer to measure the amount of film sinking. The case where the sinking was 2 mm or more was regarded as the case of no tension and was evaluated as ×.

2. Wrinkles

After the pressing step, 10 or more radial wrinkles were formed on the semiconductor wafer surface protective film around the sapphire wafer by visual observation.

3. Stripping after 48 hours

After the pressing step, the semiconductor wafer surface protective film was attached to the sapphire wafer at room temperature for 48 hours. Then, the case where the wafer surface protective film and the sapphire wafer end portion were peeled off by 1 mm or more was evaluated as ×.

(Example 7)

The same film as that used in Example 2 was attached to a sapphire wafer (mounting step), and thermocompression bonding (pressing step) was performed to form a ridge (edge). Specifically, the film for semiconductor wafer surface protection is cut to a size larger than that of the sapphire wafer. In addition, a sapphire wafer having a thickness of 650 μm and a size of 4 inches was prepared. As shown in FIG. 2A, it is disposed on a film for semiconductor wafer surface protection. The temperature of the hot plate was heated to 100 ° C, and the film for semiconductor wafer surface protection was pressure-bonded to the sapphire wafer by a roll to obtain a laminate of the sapphire wafer and the film for semiconductor wafer surface protection. The roller pressure is set to 0.5 MPa, The roller speed was set to 10 mm/sec.

Next, as shown in FIG. 2C, the upper hot plate (the hot plate disposed on the semiconductor wafer surface protective film) and the lower hot plate (the hot plate disposed on the sapphire wafer side) of the hot press are sandwiched. The laminate was crimped at 180 seconds and 10 MPa. At this time, the temperature of the upper hot plate was set to 140 ° C, and the temperature of the lower hot plate was set to 120 ° C, that is, the average temperature TP of both was set to 130 ° C.

In the same manner as in Example 6, the height of the raised portion (edge) was determined, and "the presence or absence of the tension in the radial direction", "the presence or absence of the wrinkle", and the presence or absence of the swelling (peeling after 48 hours) were evaluated.

(Example 8)

The same film as that used in Example 2 was attached to a sapphire wafer (mounting step), and thermocompression bonding (pressing step) was performed to form a ridge (edge). Specifically, the film for semiconductor wafer surface protection is cut to a size larger than that of the sapphire wafer. In addition, a sapphire wafer having a thickness of 650 μm and a size of 4 inches was prepared. As shown in FIG. 2A, it is disposed on a film for semiconductor wafer surface protection. The temperature of the hot plate was set to 25 ° C, and the film for semiconductor wafer surface protection was pressure-bonded to the sapphire wafer by a roll to obtain a laminate of the sapphire wafer and the film for semiconductor wafer surface protection. The roll pressure was set to 0.5 MPa and the roll speed was set to 10 mm/sec.

Next, as shown in FIG. 2C, the upper hot plate (the hot plate disposed on the semiconductor wafer surface protective film) and the lower hot plate (the hot plate disposed on the sapphire wafer side) of the hot press are sandwiched. The laminate was crimped at 180 seconds and 10 MPa. At this time, the temperature of the upper hot plate was set to 140 ° C, and the temperature of the lower hot plate was set to 120 ° C, that is, the average temperature TP of both was set to 130 ° C.

In the same manner as in Example 6, the height of the raised portion (edge) was determined, and "the presence or absence of the tension in the radial direction", "the presence or absence of the wrinkle", and the presence or absence of the floating (peeling after 48 hours) were evaluated.

(Reference example 5)

The same film as that used in Example 2 was attached to a sapphire wafer (mounting step), and thermocompression bonding (pressing step) was performed to form a ridge (edge). Specifically, the film for semiconductor wafer surface protection is cut to a size larger than that of the sapphire wafer. In addition, a sapphire wafer having a thickness of 650 μm and a size of 4 inches was prepared. As shown in FIG. 2A, it is disposed on a film for semiconductor wafer surface protection. The temperature of the hot plate was set to 100 ° C, and the semiconductor wafer surface protective film was pressure-bonded to the sapphire wafer by a roll to obtain a laminate of the sapphire wafer and the semiconductor wafer surface protective film. The roll pressure was set to 0.5 MPa and the roll speed was set to 10 mm/sec.

Next, as shown in FIG. 2C, the upper hot plate (the hot plate disposed on the semiconductor wafer surface protective film) and the lower hot plate (the hot plate disposed on the sapphire wafer side) of the hot press are sandwiched. The laminate was crimped at 180 seconds and 10 MPa. At this time, the temperature of the upper hot plate was set to 110 ° C, and the temperature of the lower hot plate was set to 90 ° C, that is, the average temperature TP of both was set to 100 ° C.

In the same manner as in Example 6, the height of the raised portion (edge) was determined, and "the presence or absence of the tension in the radial direction", "the presence or absence of the wrinkle", and the presence or absence of the floating (peeling after 48 hours) were evaluated.

In Example 6, the temperature TM in the mounting step was higher than the temperature TP in the pressing step; and the temperature TP was 14 ° C higher than the softening point temperature (TmB) of the softening layer (B). Therefore, an edge having a sufficient height is formed without wrinkles, And the sapphire substrate and the protective film are not peeled off.

In Example 7, the temperature TM in the mounting step was 30 ° C lower than the temperature TP in the pressing step. Therefore, although an edge having a sufficient height can be formed, it is confirmed that wrinkles are generated. Also in Example 8, the temperature TM in the mounting step was 105 ° C lower than the temperature TP in the pressing step. Therefore, although an edge having a sufficient height can be formed, although an edge having a sufficient height can be formed, it was confirmed that wrinkles were generated, and it was confirmed that the sapphire substrate and the protective film were peeled off.

In Reference Example 5, the temperature TP in the pressing step was lower than the softening point temperature (TmB) of the softening layer (B). Therefore, a sufficient edge cannot be formed.

(Example 9)

The same film as that used in Example 2 was attached to a sapphire wafer (mounting step), and thermocompression bonding (pressing step) was performed to form a ridge (edge). Specifically, the film for semiconductor wafer surface protection is cut to a size larger than that of the sapphire wafer. In addition, a sapphire wafer having a thickness of 650 μm and a size of 4 inches was prepared. As shown in FIG. 2A, it is disposed on a film for semiconductor wafer surface protection. The temperature of the hot plate was heated to 140 ° C, and the semiconductor wafer surface protective film was pressure-bonded to the sapphire wafer by a roll to obtain a laminate of the sapphire wafer and the semiconductor wafer surface protective film. The roll pressure was set to 0.5 MPa and the roll speed was set to 10 mm/sec.

Next, as shown in FIG. 2C, the upper hot plate (the hot plate disposed on the semiconductor wafer surface protective film) and the lower hot plate (the hot plate disposed on the sapphire wafer side) of the hot press are sandwiched. The laminate was crimped at 180 seconds and 10 MPa. At this time, the temperature of the upper hot plate was set to 140 ° C, and the temperature of the lower hot plate was set to 100 ° C, that is, the average temperature of both was 120 ° C.

Next, in the same manner as in Example 6, the height of the ridge portion (edge) was obtained.

(Example 10)

The same film as that used in Example 2 was attached to a sapphire wafer (mounting step), and thermocompression bonding (pressing step) was performed to form a ridge (edge). Specifically, the film for semiconductor wafer surface protection is cut to a size larger than that of the sapphire wafer. In addition, a sapphire wafer having a thickness of 650 μm and a size of 4 inches was prepared. As shown in FIG. 2A, it is disposed on a film for semiconductor wafer surface protection. The temperature of the hot plate was heated to 140 ° C, and the semiconductor wafer surface protective film was pressure-bonded to the sapphire wafer by a roll to obtain a laminate of the sapphire wafer and the semiconductor wafer surface protective film. The roll pressure was set to 0.5 MPa and the roll speed was set to 10 mm/sec.

Next, as shown in FIG. 2C, the upper hot plate (the hot plate disposed on the semiconductor wafer surface protective film) and the lower hot plate (the hot plate disposed on the sapphire wafer side) of the hot press are sandwiched. The laminate was crimped at 180 seconds and 10 MPa. At this time, the temperature of the upper hot plate was set to 140 ° C, and the temperature of the lower hot plate was set to 140 ° C, that is, the average temperature of both was 140 ° C.

Next, in the same manner as in Example 6, the height of the ridge portion (edge) was obtained.

In Example 9, the temperature TM in the mounting step was higher than the temperature TP in the pressing step; and the temperature TP was 4 ° C higher than the softening point temperature (TmB) of the softening layer (B). Moreover, the upper hot plate temperature TP1 in the pressing step is higher than the lower hot plate temperature TP2. Therefore, an edge having a sufficient height is formed.

On the other hand, in Example 10, the temperature TM in the mounting step is the same as the temperature TP in the pressing step; moreover, the upper heat in the pressing step The plate temperature TP1 and the lower hot plate temperature TP2 are the same temperature. Therefore, the edge is slightly flattened, and the height of the edge is lowered as compared with Example 7.

(Example 11 to Example 14)

The same film as that used in Example 2 was attached to a sapphire wafer (mounting step), and thermocompression bonding (pressing step) was performed to form a ridge (edge). Specifically, the film for semiconductor wafer surface protection is cut to a size larger than that of the sapphire wafer. In addition, a sapphire wafer having a thickness of 650 μm and a size of 4 inches was prepared. As shown in FIG. 2A, it is disposed on a film for semiconductor wafer surface protection. The temperature of the hot plate was heated to 140 ° C, and the semiconductor wafer surface protective film was pressure-bonded to the sapphire wafer by a roll to obtain a laminate of the sapphire wafer and the semiconductor wafer surface protective film. The roll pressure was set to 0.5 MPa and the roll speed was set to 10 mm/sec.

Next, as shown in FIG. 7A, the upper hot plate (the hot plate disposed on the semiconductor wafer surface protective film) of the hot press machine and the lower hot plate having the conical convex portion as shown in FIG. 7B (configuration) On the sapphire wafer side hot plate), the obtained laminate was sandwiched and crimped at 180 seconds and 10 MPa. At this time, the temperature of the upper hot plate was set to 140 ° C, and the temperature of the lower hot plate was set to 120 ° C. In Example 11, the height of the convex portion was set to 0 μm (no convex portion), in Example 12, the height of the convex portion was set to 5 μm, and in Example 13, the height of the convex portion was set to 15 μm, in Example 14. , set the height of the convex part to 25 μm. The thickness unevenness (the difference between the maximum thickness and the minimum thickness) of the semiconductor wafer surface protective film after the pressing step was measured, and the height of the ridge portion (edge) was determined in the same manner as in Example 6.

As shown in Table 6, it is understood that by providing the convex portion on the lower heat plate, thickness unevenness of the semiconductor wafer surface protective film after the pressing step can be suppressed, and a ridge portion (edge) can be formed.

[Industrial availability]

The film for semiconductor wafer surface protection of the present invention can be back-polished without damage even for a hard and brittle semiconductor wafer such as a sapphire substrate.

1‧‧‧Sapphire substrate

2‧‧‧ wax resin layer

3‧‧‧磨石

4‧‧‧Previous semiconductor wafer protective film

10', 10‧‧‧Semiconductor wafer surface protection film

12‧‧‧Substrate layer (A)

14‧‧‧Softening layer (B)

16‧‧‧Adhesive layer (C)

18‧‧‧Light adhesive layer (D)

20‧‧‧Semiconductor wafer

20A‧‧‧Circuit forming surface of semiconductor wafer

20B‧‧‧Semiconductor wafer circuit non-formed surface (back)

22-1‧‧‧Upper hot plate

22-2‧‧‧Next hot plate

24‧‧‧Uplift (edge)

26‧‧‧ suction table

28‧‧‧磨石

30‧‧‧ ring frame

35‧‧‧roll

40‧‧‧heating plate

50‧‧‧Ring auxiliary components

60‧‧‧ convex

100‧‧‧Distributor

105‧‧‧Binder

110‧‧‧Resin ring

120‧‧‧Mold

125‧‧‧ cavity

H‧‧‧height

DW‧‧‧ outer diameter of semiconductor wafer 20

DB _IN ‧‧‧ring diameter of the annular auxiliary member 50

Outer diameter of the DB _OUT ‧‧‧ annular auxiliary member 50

DA _IN ‧‧‧ inner diameter of ring frame 30

Fig. 1A is a schematic view showing an embodiment of a semiconductor wafer surface protective film of the present invention.

Fig. 1B is a schematic view showing another embodiment of the semiconductor wafer surface protective film of the present invention.

2A is a view showing an example of a step (mounting step) of arranging a semiconductor wafer on a film for protecting a semiconductor wafer surface.

2B is a view showing a laminate in which a semiconductor wafer is placed on a film for protecting a semiconductor wafer surface.

2C is a view showing an example of a step (pressing step) of forming a raised portion of the film for semiconductor surface protection on the outer circumference of the semiconductor wafer.

2D is an enlarged view showing an example of a raised portion.

2E is a view showing an example of a procedure of polishing a circuit non-formation surface of a semiconductor wafer.

3 is a view showing an example of a method of protecting a semiconductor wafer by the prior waxing method.

4 is a view showing an example of a method of protecting a semiconductor wafer using a conventional semiconductor wafer surface protection film.

5A and 5B are views showing another embodiment of the mounting step.

FIG. 6 is a view showing a state in which the thickness of the film for semiconductor wafer surface protection is made uneven by the pressing step.

Fig. 7A is a view showing another embodiment of a pressing step, and Figs. 7B to 7C are views showing an example of a shape of a convex portion.

8A, 8B, and 8C are views showing a method of forming a ridge portion different from the film for semiconductor surface protection on the outer circumference of the semiconductor wafer.

10‧‧‧Semiconductor wafer surface protection film

12‧‧‧Substrate layer (A)

14‧‧‧Softening layer (B)

16‧‧‧Adhesive layer (C)

Claims (20)

A film for protecting a surface of a semiconductor wafer, comprising: a substrate layer (A) having a storage elastic modulus G _A (150) at 150 ° C of 1 MPa or more; and a softening layer (B) at 120 ° C to 180 ° C The storage elastic modulus G _B (120-180) at a temperature is 0.05 MPa or less, and the storage elastic modulus G _B (40) at 40 ° C is 10 MPa or more. The film for semiconductor wafer surface protection according to claim 1, wherein the softening layer (B) has a storage elastic modulus G _B (100) at 100 ° C of 1 MPa or more. The film for semiconductor wafer surface protection according to claim 1, wherein the softening layer (B) has a tensile elastic modulus E _B (60) at 60 ° C and a tensile elastic modulus at 25 ° C. The number E _B (25) satisfies the relationship of 1>E _B (60)/E _B (25)>0.1. The film for semiconductor wafer surface protection according to claim 1, further comprising an adhesive layer (C) disposed on the opposite side of the base material layer (A) via the softened layer (B) The adhesive force of the above adhesive layer (C) measured according to JIS Z0237 is 0.1 N/25 mm to 10 N/25 mm. The film for semiconductor wafer surface protection according to claim 1, wherein the base material layer (A) is disposed on the outermost surface. The film for semiconductor wafer surface protection according to claim 4, wherein the adhesive layer (C) is disposed on the outermost surface opposite to the base material layer (A) via the softened layer (B). . The film for semiconductor wafer surface protection according to claim 1, wherein the softening layer (B) comprises a homopolymer of a hydrocarbon olefin, a copolymer of a hydrocarbon olefin, or a mixture thereof. The film for semiconductor wafer surface protection according to claim 1, wherein the resin constituting the softened layer (B) has a density of 880 kg/m ³ to 960 kg/m ³ . The film for semiconductor wafer surface protection according to claim 1, wherein the substrate layer (A) is a polyolefin layer, a polyester layer, or a laminate of a polyolefin layer and a polyester layer. A method of manufacturing a semiconductor device, comprising: a step of disposing a semiconductor wafer on a surface of a semiconductor wafer surface protection film in such a manner that a circuit formation surface of the semiconductor wafer is in contact with the semiconductor wafer surface protection film; a step of forming a raised portion of the semiconductor wafer surface protective film for holding the semiconductor wafer on the outer periphery of the wafer; and a step of polishing a circuit non-formed surface of the semiconductor wafer held by the raised portion; The step of peeling off the semiconductor wafer surface protective film on the circuit forming surface of the wafer; the storage elastic modulus G (100) of the raised portion at 100 ° C is 1 MPa or more. The method for producing a semiconductor device according to claim 10, wherein the film for protecting a surface of the semiconductor wafer is the film for surface protection of a semiconductor wafer according to the first aspect of the invention, and The semiconductor wafer surface protective film and the semiconductor wafer are thermocompression-bonded at a temperature of 120 ° C to 180 ° C and a pressure of 1 MPa to 10 MPa to form the raised portion. A method of manufacturing a semiconductor device according to claim 11, wherein the semiconductor wafer surface protection film has a circuit formation surface of the semiconductor wafer and the semiconductor wafer The temperature TM of the film in the step of arranging the semiconductor wafer, the thermocompression bonding temperature TP in the step of forming the ridge portion of the semiconductor wafer surface protective film, and the softening layer (B) The softening point temperature TmB satisfies the relationship of the following formula: [Formula 1] TP≦TM [Formula 2] TmB<TP<TmB+40°C. The method of manufacturing a semiconductor device according to claim 11, wherein the softened layer (B) of the semiconductor wafer surface protective film is a circuit forming surface of the semiconductor wafer with respect to the base material layer (A) In a side view, the semiconductor wafer is placed on the semiconductor wafer surface protective film. The method of manufacturing a semiconductor device according to claim 10, wherein the semiconductor wafer comprises a high hardness material substrate having a Mohs hardness of 8 or more. A semiconductor wafer pressing device is formed by pressing an upper pressing plate having a heating mechanism and a lower pressing plate opposite to the upper pressing plate, wherein the mounting frame comprises a semiconductor wafer and has a semiconductor wafer surrounding the semiconductor wafer. a ring frame A of the frame, a semiconductor wafer surface protection film according to claim 1 attached to the circuit forming surface of the semiconductor wafer and the frame A; and an outer diameter DW of the semiconductor wafer The inner diameter DA _{IN of} the ring frame A satisfies the relationship of the formula (1) DW < DA _IN ; the lower pressing plate has a convex portion on a surface opposite to the upper pressing plate; the convex portion and the above-mentioned mounting frame at the time of pressing The outer circumference of the contact surface is circular. The semiconductor wafer pressing apparatus according to claim 15, wherein the height of the convex portion is 1 μm to 100 μm. The semiconductor wafer pressing apparatus according to claim 15, wherein the 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. The semiconductor wafer pressing apparatus according to claim 15, wherein the diameter CD of the convex portion satisfies the relationship of DW < CD < DA _IN . A semiconductor wafer mounting device for fabricating a mounting frame including a semiconductor wafer, an annular auxiliary member B surrounding the semiconductor wafer, and a ring frame A surrounding the semiconductor wafer and the annular auxiliary member B a semiconductor wafer surface protection film according to claim 1, wherein the semiconductor wafer surface protection film is attached to the circuit forming surface of the semiconductor wafer, the annular auxiliary member B, and the ring frame A; and the semiconductor wafer is external to the semiconductor wafer The diameter DW, the inner diameter DA _{IN of} the ring frame A, the outer diameter DB _OUT of the annular auxiliary member B, and the inner diameter DB _{IN of} the annular auxiliary member B satisfy the formula (1) DW < DB _IN < a relationship of DB _OUT <DA _IN ; the semiconductor wafer mounting apparatus includes: a heating unit that heats an opposite surface of the circuit formation surface of the semiconductor wafer; a circuit formation surface that extends over the semiconductor wafer; the ring frame A; The ring-shaped auxiliary member B is rotated to attach the semiconductor wafer surface protective film, and the tape cutting mechanism for cutting the surface protective film along the outer shape of the ring frame A The semiconductor wafer mounting device according to claim 19, wherein any one of ΔD1 and ΔD2 represented by the following formula is within 1% of DW: ΔD1=DB _IN -DW......... 2) △ D2 = DA _{IN -} DB _OUT ... (3).