WO2013021644A1

WO2013021644A1 - Semiconductor device manufacturing method and film used therein for protecting surface of semiconductor

Info

Publication number: WO2013021644A1
Application number: PCT/JP2012/005058
Authority: WO
Inventors: 英司林下; 尾崎　勝敏; 充酒井; 哲光森本; 小野　博之; 仁志國重
Original assignee: 三井化学株式会社; 三井化学東セロ株式会社; 株式会社ディスコ
Priority date: 2011-08-09
Filing date: 2012-08-09
Publication date: 2013-02-14
Also published as: CN103748664A; TWI544533B; JP5393902B2; TW201316393A; SG189515A1; KR101467718B1; KR20130084695A; CN103748664B; JPWO2013021644A1

Abstract

A film for protecting the surface of a semiconductor wafer is provided that makes it possible to back grind without damaging the semiconductor wafer, even when the semiconductor wafer is hard and brittle. Specifically, the present invention provides a film for protecting the surface of a semiconductor wafer that comprises a substrate layer (A) for which the storage elastic modulus G_A (150) at 150°C is 1 MPa or higher, and a softening layer (B) for which the storage elastic modulus G_B (120-180) at temperatures between 120-180°C is 0.05 MPa or lower and the storage elastic modulus G_B (40) at 40°C is 10 MPa or higher.

Description

Semiconductor device manufacturing method and semiconductor wafer surface protecting film used in the method

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

The semiconductor wafer thinning process in the manufacturing process of the semiconductor device is usually performed by grinding the circuit non-formed surface (back surface) of the semiconductor wafer. Protection of the circuit forming surface of the semiconductor wafer during back grinding is performed by various methods.

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

International Publication No. 2005/090957

However, in the above method, it is necessary to heat and melt the wax resin layer in order to peel the sapphire substrate after back grinding from the wax resin layer. Furthermore, the wax resin remaining on the surface of the sapphire substrate needs to be removed by washing with a solvent, and the process is complicated. Further, since the sapphire substrate after back grinding is very thin and easily warps, there is a problem that it is easily cracked in these steps.

Therefore, the present inventors examined a method of protecting the circuit formation surface of the sapphire substrate with a semiconductor wafer protective film that is relatively easy to peel. A conventional semiconductor wafer protective film has a base material layer and an adhesive layer. And after sticking the adhesion layer of a semiconductor wafer protective film on the circuit formation surface of a semiconductor wafer, a semiconductor wafer is back ground. Thereafter, the semiconductor wafer protective film is peeled off by a tape peeling machine or the like.

However, the conventional method using a semiconductor wafer protective film has a problem that the end of the sapphire substrate is easily damaged during backside grinding. That is, as shown in FIG. 3, in the wax method, since the entire end portion of the sapphire substrate 1 is embedded in the wax resin layer 2, the end portion of the sapphire substrate 1 is easily held stably. On the other hand, as shown in FIG. 4, in the conventional method using the semiconductor wafer protective film, the end portion of the sapphire substrate 1 is not embedded in the semiconductor wafer protective film 4. Is difficult to hold stably. For this reason, it is considered that the end portion of the sapphire substrate 1 is in contact with the grindstone 3 or the like and easily damaged during back surface grinding.

The present invention has been made in view of such circumstances. In particular, the present invention relates to a method of manufacturing a semiconductor device that enables backside grinding without damage even in a hard and brittle semiconductor wafer such as a sapphire substrate, and the manufacturing method. An object of the present invention is to provide a suitable film for protecting the surface of a semiconductor wafer.

The inventors of the present invention have found that damage to the end portion of the semiconductor wafer can be suppressed by holding the vicinity of the end portion of the semiconductor wafer with a raised portion (rim) during back grinding. Further, after extensive studies, the inventors have found a film structure that can form a raised portion (rim) relatively easily by thermocompression bonding and can maintain the shape of the raised portion (rim) well even at the temperature during back grinding. .

That is, the first of the present invention relates to the following semiconductor wafer surface protecting film.
[1] _A base material layer (A) having a storage elastic modulus G _A (150) at 150 ° C. of 1 MPa or more, and a storage elastic modulus G _B (120 to 180) at any temperature of 120 to 180 ° C. And a softening layer (B) having a storage elastic modulus G _B (40) at 40 ° C. of 10 MPa or more.
[2] The film for protecting a semiconductor wafer surface 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 softened layer tensile modulus at 60 ° C. of (B) _E B (60) and the tensile modulus _E B (25) at 25 ° C. _{but, 1> E B (60)} / E B (25)> The film for protecting a semiconductor wafer surface according to [1] or [2], which satisfies a relationship of 0.1.
[4] The adhesive layer (C) further disposed on the side opposite to the base material layer (A) via the softened layer (B), and according to JIS Z0237 of the adhesive layer (C) The film for protecting a semiconductor wafer surface according to any one of [1] to [3], wherein the measured adhesive strength is 0.1 to 10 N / 25 mm.
[5] The semiconductor wafer surface protecting film according to any one of [1] to [4], wherein the base material layer (A) is disposed on the outermost surface.
[6] The adhesive layer (C) according to [4] or [5], wherein the adhesive layer (C) is disposed on the outermost surface opposite to the base material layer (A) through the softening layer (B). Semiconductor wafer surface protection film.
[7] The semiconductor wafer surface according to any one of [1] to [6], wherein the softening layer (B) includes a hydrocarbon olefin homopolymer, a hydrocarbon olefin copolymer, or a mixture thereof. Protective film.
[8] The film for protecting a semiconductor wafer surface according to any one of [1] to [7], wherein the density of the resin constituting the softening layer (B) is 880 to 960 kg / m ³ .
[9] The semiconductor wafer surface protecting film according to any one of [1] to [8], wherein the substrate layer (A) is a polyolefin layer, a polyester layer, or a laminate of a polyolefin layer and a polyester layer.

The second of the present invention relates to the following method for manufacturing a semiconductor device.
[10] A step of placing the semiconductor wafer on the semiconductor wafer surface protection film so that the circuit forming surface of the semiconductor wafer is in contact with the semiconductor wafer surface protection film;
Forming a raised portion of the semiconductor wafer surface protecting film for holding the semiconductor wafer on an outer periphery of the semiconductor wafer;
Grinding the non-circuit-formed surface of the semiconductor wafer held by the raised portions;
Peeling the semiconductor wafer surface protective film from the circuit forming surface of the semiconductor wafer,
The manufacturing method of a semiconductor device whose storage elastic modulus G (100) in 100 degreeC of the said protruding part is 1 Mpa or more.
[11] The semiconductor wafer surface protective film according to any one of [1] to [9], wherein the semiconductor wafer surface protective film comprises:
The method for manufacturing a semiconductor device according to [10], wherein the raised portion is formed by thermocompression bonding the semiconductor wafer surface protecting film and the semiconductor wafer at a temperature of 120 to 180 ° C. and a pressure of 1 to 10 MPa.
[12] The method of manufacturing a semiconductor device according to [11],
Film temperature TM in the step of placing the semiconductor wafer on the semiconductor wafer surface protecting film so that the circuit forming surface of the semiconductor wafer is in contact with the semiconductor wafer surface protecting film, and the semiconductor wafer surface protecting film A method for manufacturing a semiconductor device, wherein the thermocompression bonding temperature TP in the step of forming the raised portion and the softening point temperature TmB of the softening layer (B) satisfy the relationship of the following general formula. [Formula 1] TP ≦ TM [Formula 2] TmB <TP <TmB + 40 ° C.
[13] The semiconductor wafer surface protecting film so that the softened layer (B) of the semiconductor wafer surface protecting film is closer to the circuit forming surface side of the semiconductor wafer than the base material layer (A). The method for manufacturing a semiconductor device according to [11] or [12], which is disposed above.
[14] The method for manufacturing a semiconductor device according to any one of [10] to [13], wherein the semiconductor wafer includes a high-hardness material substrate having a Mohs hardness of 8 or more.

The third aspect of the present invention relates to a semiconductor wafer press apparatus for pressing a mount frame.
[15] The semiconductor wafer, the ring frame A having a frame surrounding the semiconductor wafer, the semiconductor wafer surface protective film according to claim 1 attached over the circuit forming surface of the semiconductor wafer and the frame A, A semiconductor wafer press apparatus that sandwiches and presses a mount frame provided with an upper press plate having a heating mechanism and a lower press plate facing the upper press plate,
The outer diameter DW of the semiconductor wafer and the inner diameter DA _IN of the ring frame A satisfy the relationship of formula (1) DW <DA _IN ,
The lower press plate includes a convex portion on a surface facing the upper press plate,
The semiconductor wafer press apparatus, wherein an outer periphery of a contact surface of the convex portion with the mount frame when pressed is circular.
[16] The semiconductor wafer press apparatus according to [15], wherein the height of the convex portion is 1 to 100 μm.
[17] The semiconductor wafer press according to [15] or [16], wherein the height of the convex portion is in the range of 15 to 100% with respect to the thickness of the softening layer (B) of the semiconductor wafer surface protective film. apparatus.
[18] The semiconductor wafer press apparatus according to any one of [15] to [17], wherein a diameter CD of the convex portion satisfies a relationship of DW <CD <DA _IN .

The fourth aspect of the present invention relates to a semiconductor wafer mount apparatus for manufacturing a mount frame and a method for manufacturing a semiconductor device using the same.
[19] A semiconductor wafer, a ring-shaped auxiliary member B surrounding the semiconductor wafer, a ring frame A surrounding the semiconductor wafer and the ring-shaped auxiliary member B, a circuit forming surface of the semiconductor wafer, and the ring-shaped auxiliary member A semiconductor wafer mounting apparatus for producing a mounting frame including B and a semiconductor wafer surface protective film according to any one of [1] to [9] attached over the ring frame A,
Wherein the outer diameter DW of the semiconductor wafer, and the inner diameter _{DA IN} of the ring frame A, and the ring outer diameter _{DB OUT} of the ring-shaped auxiliary member B, the ring diameter _{DB IN} of the ring-shaped auxiliary member B has the formula (1) The relationship of DW <DB _IN <DB OU _T <DA _IN is satisfied,
A heating unit for heating a surface opposite to a circuit forming surface of the semiconductor wafer;
A pasting roller for rolling over the circuit forming surface of the semiconductor wafer, the ring frame A, and the ring-shaped auxiliary member B to paste the semiconductor wafer surface protective film;
And a tape cutting mechanism for cutting the surface protective film along the outer shape of the ring frame A.
[20] The semiconductor wafer mount device according to [19], wherein both ΔD1 and ΔD2 represented by the following formula are within 1% of DW.
ΔD1 = DB _IN −DW (2)
ΔD2 = DA _IN −DB _OUT (3)

The fifth of the present invention relates to the following method for manufacturing a semiconductor device.
1 ′) a step of preparing a semiconductor wafer, 2 ′) a step of forming a raised portion substantially made of resin on the outer periphery of the semiconductor wafer, and 3 ′) a circuit forming surface of the semiconductor wafer on the semiconductor wafer surface protective film. 4 ') a step of grinding a non-circuit-formed surface of the semiconductor wafer held by the raised portion, and 5') a step of peeling the semiconductor wafer surface protection film. Because
The storage modulus _G B ridges made of resin (40) is not less than 10 MPa, a method of manufacturing a semiconductor device.

The film for protecting the surface of a semiconductor wafer of the present invention can enable backside grinding without damaging even a hard and brittle semiconductor wafer such as a sapphire substrate.

It is a schematic diagram which shows one Embodiment of the semiconductor wafer surface protection film of this invention. It is a schematic diagram which shows another one Embodiment of the semiconductor wafer surface protection film of this invention. It is a figure which shows an example of the process (mounting process) which arrange | positions a semiconductor wafer on the film for semiconductor wafer surface protections. It is a figure which shows the laminated body which has arrange | positioned the semiconductor wafer on the film for semiconductor wafer surface protections. It is a figure which shows an example of the process (press process) which forms the protruding part of the film for semiconductor surface protections on the outer periphery of a semiconductor wafer. It is an enlarged view which shows an example of a protruding part. It is a figure which shows an example of the process of grinding the circuit non-formation surface of a semiconductor wafer. It is a figure which shows an example of the protection method of the semiconductor wafer by the conventional wax construction method. It is a figure which shows an example of the protection method of the semiconductor wafer using the conventional film for semiconductor wafer surface protection. 5A and 5B are diagrams showing another embodiment of the mounting process. It is a figure which shows the state from which the thickness of the film for semiconductor wafer surface protections becomes non-uniform | heterogenous by a press process. FIG. 7A is a diagram showing another embodiment of the pressing step, and FIGS. 7B to 7D are diagrams showing examples of the shape of the convex portion. It is a figure which shows the method of forming the protruding part different from the film for semiconductor surface protections on the outer periphery of a semiconductor wafer.

1. Semiconductor Wafer Surface Protection Film The semiconductor wafer surface protection film of the present invention includes a base material layer (A) and a softening layer (B); if necessary, an adhesive layer (C) (see FIG. 1A) or A light adhesion layer (D) (refer to Drawing 1B) etc. may be further included. The thickness of the film referred to in the present invention is not limited, and may be referred to as a so-called sheet.

About Base Material Layer (A) The base material layer (A) has a function of suppressing the warpage of the semiconductor wafer and maintaining the shape when the semiconductor wafer surface protecting film and the semiconductor wafer are thermocompression bonded. Therefore, the base material layer (A) preferably has a storage elastic modulus of a certain level or higher at the thermocompression bonding temperature (any temperature of about 120 to 180 ° C.). Specifically, the storage elastic modulus G _A (150) at 150 ° C. of the base material layer (A) is preferably 1 MPa or more, and more preferably 2 MPa or more.

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

The resin constituting the base material layer (A) only needs to satisfy the aforementioned storage elastic modulus. As will be described later, when the pressure-sensitive adhesive layer (C) is made of a radiation curable pressure-sensitive adhesive, the resin constituting the base material layer (A) preferably has transparency. Examples of such resins include polyolefins and polyesters. That is, the base material layer (A) can 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 and a polyethylene naphthalate film.

The density of the resin constituting the base material layer (A) is preferably 900 to 1450 kg / m ³ . If the density of the resin constituting the substrate layer (A) is less than 900 kg / m ³ , the shape retention may not be sufficient because the storage elastic modulus is too low.

The thickness of the base material layer (A) is, for example, preferably 5 μm or more, and more preferably 10 μm or more, from the viewpoint of obtaining rigidity sufficient to suppress warpage of the semiconductor wafer. The upper limit of the thickness of the base material layer (A) is set so that the total thickness of the semiconductor wafer surface protective film is not too thick with respect to the ground finish thickness of the semiconductor wafer from the viewpoint of preventing damage to the semiconductor wafer. Good.

Softening layer (B) The softening layer (B) has a function of forming a raised portion (rim) around the semiconductor wafer in order to stably hold the end portion of the semiconductor wafer. As will be described later, the semiconductor wafer surface protective film and the semiconductor wafer may be thermocompression bonded to form a raised portion (rim), so the softening layer (B) is softened at the thermocompression bonding temperature (120 to 180 ° C.). It is necessary to let That is, the softening point temperature TmB of the softening layer (B) is preferably lower than the thermocompression bonding temperature (120 to 180 ° C.). The softening point temperature TmB can be obtained from DSC measurement. Specifically, the melting point (DSC method) of the resin material according to ISO-11357-3 is defined as the softening point temperature.

The storage elastic modulus G _B (120 to 180) of the softened layer (B) at any temperature of 120 to 180 ° C., preferably the storage elastic modulus G _B (150) of the softened layer (B) at 150 ° C. It is preferably no greater than 05 MPa and more preferably no greater than 0.03 MPa.

On the other hand, in order to prevent the raised portion (rim) from being softened during back grinding (wet polishing), it is necessary to prevent the softened layer (B) from being softened at the temperature (around 40 ° C.) during back grinding. Therefore, the storage elastic modulus G _B (40) at 40 ° C. is preferably 10 MPa or more, more preferably 20 MPa or more, and further preferably 30 MPa or more. The upper limit of the storage elastic modulus G _B (40) at 40 ° C. can usually be about 500 MPa or less. In order to set the storage elastic modulus G _B (40) at 40 ° C. of the softened layer (B) to 10 MPa or more, the resin constituting the softened layer (B) may be a resin that is not an elastomer, as will be described later. preferable. 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) at 40 ° C. of the softened layer (B) is 10 MPa or more” means “the tensile elastic modulus E _B (40) of the softened layer (B) at 40 ° C. is 30 MPa or more. Can also be said.

The back surface grinding is usually performed by a wet method, but may be further performed by a dry method if necessary. The temperature of the wafer at the time of dry backside grinding (dry polishing) may be around 100 ° C. because the frictional heat between the grindstone and the semiconductor wafer is large. In Therefore, the raised portions even during the dry polishing (rim) to not soften preferably has a storage modulus _G B at 100 ° C. of softening layer (B) (100) is 1MPa or more, 3 MPa or more More preferably.

Softening layer tensile modulus at 25 ° C. and tensile modulus _E B (60) at 60 ° C. of (B) _E B (25) _{but, 1> E B (60)} / E B (25)> 0.1 Preferably there is. In many cases, the temperature of the semiconductor wafer when the back surface of the semiconductor wafer is ground changes within a range of 25 ° C. to 60 ° C. Therefore, by setting the rate of change of the storage elastic modulus of the softened layer (B) within this temperature range within a certain range, the raised portion made of the softened layer (B) can stably hold the semiconductor wafer. Moreover, it is suppressed that the protruding part which consists of a softening layer (B) deteriorates during the back surface grinding of a semiconductor wafer. Therefore, damage to the semiconductor wafer during back grinding of the semiconductor wafer can be more effectively suppressed.

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

The resin constituting the softened layer (B) is not particularly limited as long as it satisfies the storage elastic modulus, but is preferably not an elastomer. Specifically, a homopolymer or copolymer of a hydrocarbon olefin is preferable, and an ethylene homopolymer, a propylene homopolymer, or a copolymer of ethylene or propylene and another hydrocarbon olefin is more preferable. On the other hand, for example, an ethylene / vinyl acetate copolymer (EVA) is not preferred because it usually has a storage elastic modulus G (40) at 40 ° C. of about 0.01 MPa to 0.1 MPa and less than 10 MPa.

The hydrocarbon 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 α-olefins having 3 to 12 carbon atoms include propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1 -Pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene and the like are included, and propylene, 1-butene and the like are preferable.

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, ABS resin, vinyl chloride resin, methyl methacrylate resin, Nylon, fluororesin, polycarbonate, polyester resin and the like are included, and linear low density polyethylene (LLDPE), low density polyethylene, high density polyethylene, polypropylene and the like are preferable.

The density of the resin constituting the softening layer (B) is preferably 880 to 960 kg / m ³ , more preferably 900 to 960 kg / m ³ , and even more preferably 910 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) is the density of the homopolymer of ethylene or propylene, the type of hydrocarbon olefin other than ethylene or propylene in the copolymer of ethylene or propylene and other hydrocarbon olefins, and the It can be adjusted by the content ratio. For example, in order to increase the storage elastic modulus at 40 ° C. of the softened layer (B), for example, the density of a homopolymer of ethylene or propylene is increased, or the copolymer weight of ethylene or propylene and other hydrocarbon olefins is increased. What is necessary is just to raise the content rate of ethylene or propylene in a coalescence.

The thickness of the softening layer (B) may be such that the rim can be formed by thermocompression bonding with the semiconductor wafer and the unevenness on 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 on the circuit forming surface of the semiconductor wafer, and is preferably 1.1 times or more the maximum value of the step. Specifically, if the step is 50 μm, it is more preferably 55 μm or more, and further preferably 60 μm or more. On the other hand, if the softened layer (B) is too thick, it is difficult to suppress deformation (deflection or bending) of the semiconductor wafer being ground as compared to the case where the softened layer (B) is thin, and it is considered that the softened layer (B) is likely to be damaged. 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 and additives as necessary. Examples of additives include ultraviolet absorbers, antioxidants, heat stabilizers, lubricants, softeners and the like.

About adhesion layer (C) In order to improve the adhesiveness with a semiconductor wafer, it is preferable that the film for semiconductor wafer surface protections of this invention further contains an adhesion layer (C). On the other hand, when the adhesive force of the adhesive layer (C) is too high, adhesive residue is easily left when peeling from the semiconductor wafer. Therefore, the pressure-sensitive adhesive layer (C) only needs to have a minimum pressure-sensitive adhesive force. Specifically, the pressure-sensitive adhesive force measured according to JIS Z0237 is 0.1 to 10 N / 25 mm. preferable.

The storage elastic modulus of the pressure-sensitive adhesive layer (C) may be a level that does not hinder the formation of the raised portion (rim) of the softened layer (B).

The pressure-sensitive adhesive (pressure-sensitive adhesive) constituting the pressure-sensitive adhesive layer (C) can be an acrylic pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, or a rubber-based pressure-sensitive adhesive. Among these, an acrylic pressure-sensitive adhesive having an acrylic polymer as a base polymer is preferable in order to facilitate adjustment of adhesive force.

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

The radiation curable pressure-sensitive adhesive may contain the above-mentioned pressure-sensitive adhesive main component, a compound having a carbon-carbon double bond in the molecule, and a radiation polymerization initiator; or a carbon-carbon double in the molecule. It may contain an adhesive main agent having a polymer having a bond as a base polymer and a radiation polymerization initiator.

Examples of compounds 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 are included. The content of the radiation curable compound can be about 30 parts by weight or less with respect to 100 parts by weight of the pressure-sensitive adhesive.

Examples of radiation polymerization initiators include: acetophenone photopolymerization initiators such as methoxyacetophenone; α-ketol compounds such as 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone; benzyldimethyl ketal A benzoin photopolymerization initiator such as benzoin and benzoin methyl ether; and a benzophenone photopolymerization initiator such as benzophenone and benzoylbenzoic acid.

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

The thickness of the pressure-sensitive adhesive layer (C) is not limited as long as the rim formation by the softened layer (B) is not hindered, for example, about 1 to 20% with respect to the thickness of the softened layer (B). It can be about 20 μm.

About light adhesion layer (D) The film for semiconductor wafer surface protections of this invention has the light adhesion layer (D) for adhere | attaching a base material layer (A) and a softening layer (B) so that peeling is mutually possible. May be. Examples of the material of the light pressure-sensitive adhesive layer (D) include an acrylic pressure-sensitive adhesive.

If the film for protecting a semiconductor wafer surface of the present invention has a light adhesive layer (D), the base material layer (A) and the softened layer (B) can be separated from each other. Therefore, the base material layer (A) can be peeled and removed from the semiconductor wafer surface protective film after the semiconductor wafer surface protective film is attached to the semiconductor wafer. For example, after the step (see FIG. 2C) of forming the raised portion of the semiconductor surface protection film on the outer periphery of the semiconductor wafer, before the step of grinding the circuit non-formation surface of the semiconductor wafer (see FIG. 2E), The base material layer (A) may be peeled off from the semiconductor wafer surface protecting film.

If the non-circuit-formed surface of the semiconductor wafer is ground after the substrate layer (A) is peeled off, more precise grinding can be realized. During grinding of the semiconductor wafer, the semiconductor wafer surface protecting film may be bent or vibrated by the load of the grinding wheel, thereby preventing precise grinding. On the other hand, when the semiconductor wafer is ground after the substrate layer (A) is peeled off and the semiconductor wafer surface protective film is thinned, bending and vibration of the semiconductor wafer surface protective film are suppressed. Therefore, more precise grinding can be realized.

The semiconductor wafer surface protecting film of the present invention may further include other layers as necessary. The other layer may be a release film, for example.

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

FIG. 1A and FIG. 1B are diagrams showing an example of the structure of a semiconductor wafer surface protecting film. As shown in FIG. 1A, the semiconductor wafer surface protecting film 10 includes a base material layer (A) 12, a softening layer (B) 14, and an adhesive layer (C) 16. As shown in FIG. 1B, the semiconductor wafer surface protecting 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. And have. The semiconductor wafer

surface protecting films

10 and 10 ′ are used so that the adhesive layer (C) 16 is in contact with the circuit forming surface of the semiconductor wafer.

The semiconductor wafer surface protecting film of the present invention can be produced by any method. For example, 1) a method of coextruding a base material layer (A) and a softening layer (B) to obtain a film for protecting a semiconductor wafer surface (coextrusion forming method); 2) a film-like base material layer (A) And a film-like softening layer (B) are laminated (laminated) to obtain a semiconductor wafer surface protecting film (laminate method). The semiconductor wafer surface protecting film further including the adhesive layer (C) can be produced by coating and forming an adhesive layer coating solution on the laminated film of the base layer (A) and the softened layer (B).

2. 1. Manufacturing Method of Semiconductor Device An example of a manufacturing method of a semiconductor device using the semiconductor wafer surface protecting film of the present invention is as follows: 1) a step of placing a semiconductor wafer on the semiconductor wafer surface protecting film (mounter step), and 2) A step of forming a raised portion of a semiconductor wafer surface protecting film for holding the semiconductor wafer on the outer periphery of the semiconductor wafer (pressing step); and 3) a step of grinding a non-circuit-formed surface of the semiconductor wafer held by the raised portion; 4) The process of peeling the film for semiconductor wafer surface protections is included. In the present invention, 3) the step of grinding the non-circuit-formed surface of the semiconductor wafer held by the semiconductor wafer surface protection film is a process of thinning the semiconductor wafer to a predetermined thickness without breaking or damaging the semiconductor wafer. Means that. After performing these steps, a step of dicing the semiconductor wafer into chips may be further performed.

Another example of a method for manufacturing a semiconductor device using a semiconductor wafer surface protecting film is as follows: 1 ′) a step of preparing a semiconductor wafer; and 2 ′) a raised portion made substantially of resin on the outer periphery of the semiconductor wafer. A step, 3 ′) a step of disposing a circuit forming surface of the semiconductor wafer on the semiconductor wafer surface protecting film, 4 ′) a step of grinding the non-circuit forming surface of the semiconductor wafer held by the raised portions, and 5 ′. And a step of peeling the semiconductor wafer surface protecting film. Either 2 ′) the step of forming the raised portion or 3 ′) the step of disposing the circuit forming surface of the semiconductor wafer on the semiconductor wafer surface protecting film may be performed first.

In the step 2 ′), the raised portion substantially made of 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 protecting the semiconductor wafer surface. 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 bulging portion substantially made of resin may be 10 MPa or more; and the storage elastic modulus G _B (100) is preferably 1 MPa or more.

Also, the combination of the semiconductor wafer formed through the process 2 'and the raised portion (rim) substantially made of resin disposed on the outer periphery thereof is also referred to as a rim-attached semiconductor wafer. The semiconductor wafer with a rim has only to include a semiconductor wafer and a bulge portion substantially made of a resin; it has a bulge portion substantially made of a semiconductor wafer and a resin, and a semiconductor wafer surface protection film that supports them. You may do it. The semiconductor wafer surface protecting film is affixed to the circuit forming surface of the semiconductor wafer.

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

In the semiconductor wafer with a rim, the distance between the raised portion and the edge of the semiconductor wafer is preferably 0 to 1 mm, more preferably 0 to 500 μm, and the raised portion and the edge of the semiconductor wafer are in contact with each other. Is more preferable. This is because the raised portion holds the semiconductor wafer.

The semiconductor wafer is not particularly limited, and may be a silicon substrate or a sapphire substrate on which a circuit such as a wiring, a capacitor, a diode, or a transistor is formed on the surface. A semiconductor wafer including a high-hardness material substrate having a Mohs hardness of 8 or more is formed by forming a raised portion (rim) on the outer periphery of the semiconductor wafer with the film for protecting the surface of the semiconductor wafer of the present invention and polishing the non-circuit-formed surface of the wafer. Even if it exists, damage to the semiconductor wafer can be suppressed. Further, the semiconductor wafer of the present invention may be one in which a semiconductor layer such as GaN is stacked on a sapphire substrate. When manufacturing a semiconductor device such as an LED element, a sapphire substrate on which a circuit is formed is preferably used. The size of the semiconductor wafer is not particularly limited, and may be 2 inches, 4 inches, 6 inches, 8 inches, or the like. A step of 1 μm to 50 μm is provided on the circuit forming surface of the semiconductor wafer.

The raised portion (rim) of the semiconductor wafer surface protecting film formed around the semiconductor wafer 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 semiconductor wafer surface protecting film may be composed of the semiconductor wafer surface protecting film itself; or may be composed of a material different from the material constituting the semiconductor wafer surface protecting film.

For example, the following method can be used to form the raised portion with a resin material different from the material constituting the semiconductor wafer surface protecting film. In each method, the semiconductor wafer may be a semiconductor wafer mounted on a semiconductor wafer surface protecting film, or may be a semiconductor wafer before being mounted.
Method 1) As shown in FIG. 8A, a method of applying and curing the liquid adhesive 105 around the semiconductor wafer 20 with a coating apparatus such as a dispenser 100. Method 2) As shown in FIG. 8B, the semiconductor wafer 20 is inserted into a resin ring 110 having a through hole having substantially the same diameter as that of the semiconductor wafer 20. Method 3) As shown in FIG. 8C, in the cavity 125 of the mold 120 into which the semiconductor wafer 20 is inserted. , A method of injecting molten resin, cooling and solidifying, and molding the resin around the semiconductor wafer

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

In the method 2), the storage elastic modulus G _B (40) of the resin ring 110 having a through-hole having the same diameter as that of the semiconductor wafer 20 may be 10 MPa or more: the storage elastic modulus G _B (100) Is preferably 1 MPa or more. That is, a material having the same elastic modulus as that of the softened layer (B) in the aforementioned semiconductor wafer surface protecting film is preferable. Examples of the resin constituting the resin ring 110 include polyethylene (high density polyethylene, low density polyethylene, etc.), polypropylene (homopolypropylene, random polypropylene, etc.), polystyrene, nylon, and the like.

In the method 3), the molten resin to be injected into the cavity 125 of the mold 120 may be an epoxy resin or the like, and the storage elastic modulus G _B (40) of the molten resin after cooling and solidification may be 10 MPa or more; The storage elastic modulus G _B (100) is preferably 1 MPa or more. That is, a material having the same elastic modulus as that of the softened layer (B) in the aforementioned semiconductor wafer surface protecting film is preferable.

As described above, the raised portion (rim) formed around the semiconductor wafer can be formed by any method, but the raised portion (rim) can be formed relatively easily and is easy to handle. The semiconductor wafer surface protecting film of the invention is preferably formed by thermocompression bonding.

The storage elastic modulus G (100) at 100 ° C. of the raised portion is preferably 1 MPa or more. As described later, when the bulge is made of a softened layer (B) of the film when the bulge is made using a semiconductor wafer surface protecting film, as described later, in that case, the storage elastic modulus of the bulge is It becomes the same as the storage elastic modulus of the softened layer (B). Further, in the backside grinding process of the semiconductor wafer, which will be described later, the ridge is somewhat flexible so that the grindstone is not easily damaged due to contact with the bulge, and the grindstone can efficiently contact the non-circuit-formed surface of the semiconductor wafer. It is preferably substantially formed of a resin.

An example of a method for manufacturing a semiconductor device using the semiconductor wafer surface protecting film of the present invention will be described with reference to the drawings. FIG. 2A is a diagram showing an example of a process (mounting process) for placing a semiconductor wafer on the semiconductor wafer surface protecting film; FIG. 2B is a diagram showing a laminate in which the semiconductor wafer is placed on the semiconductor wafer surface protecting film. FIG. 2C is a view showing an example of a step (pressing step) of forming a raised portion of the semiconductor surface protecting film on the outer periphery of the semiconductor wafer; FIG. 2D is an enlarged view showing an example of the raised portion; 2E is a diagram illustrating an example of a process of grinding a circuit non-formation surface of a semiconductor wafer.

About a mounting process The example which arrange | positions a semiconductor wafer on the film for semiconductor wafer surface protections is shown by FIG. 2A. First, the semiconductor wafer surface protecting film 10 cut out to a size larger than the semiconductor wafer 20 is prepared. Next, the semiconductor wafer 20 is placed on the semiconductor wafer surface protecting film 10 (step (1)). At this time, the circuit forming surface 20A of the semiconductor wafer 20 is brought into contact with the adhesive layer (C) 16 of the semiconductor wafer surface protecting film 10.

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

Then, the roll 35 is pressed against the semiconductor wafer 20 from one end of the semiconductor wafer surface protecting film 10 to the other end while rotating the roll 35. Thereby, the semiconductor wafer surface protective film 10 is in close contact with the circuit forming surface 20A of the semiconductor wafer 20. While the semiconductor wafer surface protection film 10 is pressed against the semiconductor wafer 20 with the roll 35, the hot plate 40 may remain at room temperature; however, the hot plate 40 is heated to remove the semiconductor wafer surface protection film 10 from the hot plate 40. You may heat until it reaches temperature (TM).

The temperature (TM) of the semiconductor wafer surface protective film 10 in the mounting step is the temperature (TP) of the semiconductor wafer surface protective film 10 in the step (described later) of forming a raised portion of the semiconductor surface protective film on the outer periphery of the semiconductor wafer. It is preferable that the temperature is the same as or higher than that. Although the details of the reason will be described later, wrinkles occur in the semiconductor wafer surface protective film 10 in the step of forming the raised portions, or the semiconductor wafer 20 is removed from the semiconductor wafer surface protective film 10 after the step of forming the raised portions. This is because they may peel off.

After the mounting process, the semiconductor wafer 20 is removed from the hot plate 40 together with the semiconductor wafer surface protection film 10 and the ring frame 30, and the semiconductor wafer is disposed on the semiconductor wafer surface protection film as shown in FIG. 2B. Get things. This laminate is referred to as a “mount frame”.

Next, as shown in FIG. 2C, the semiconductor wafer 20 and the semiconductor wafer surface protecting film 10 are bonded to a pair of hot plates (upper hot plate 22-1 and lower hot plate 22-2) of a hot press machine. Thermocompression bonding (step (2)). Thereby, the semiconductor wafer 20 is pushed into the melted softened layer (B) 14, and the softened layer (B) 14 pushed out thereby forms a raised portion (rim) 24 near the end of the semiconductor wafer 20. The upper heating plate 22-1 is a heating plate disposed on the semiconductor wafer 20 side; the lower heating plate 22-2 is a heating plate disposed on the semiconductor wafer protection film 10 side. The upper heating plate 22-1 and the semiconductor wafer 20 may be in direct contact with each other or via some member (for example, a jig). Similarly, the lower heating plate 22-2 and the semiconductor wafer protective film 10 may be in direct contact with each other or via some member (for example, a jig).

The height of the raised portion (rim) 24 is preferably about 0.2 to 1 times the thickness of the semiconductor wafer 20 to be back-ground, for example. If the height of the raised portion (rim) 24 is too low, the end portion of the semiconductor wafer 20 may not be stably held. Specifically, when the back surface of the semiconductor wafer 20 having a thickness of 1000 μm is processed, the height of the raised portion (rim) 24 is preferably 200 μm or more. Further, FIG. 2B shows a mode in which the corner of the end portion of the semiconductor wafer 20 is not removed, but the end portion of the semiconductor wafer 20 is chamfered (straight) or R-processed (curved) to remove the corner. May be. When the end portion of the semiconductor wafer 20 is chamfered (straight) or R-processed (curved), the height of the raised portion (rim) 24 is the thickness of the end of the semiconductor wafer after chamfering or R-processing. It may be a substantial amount.

The thermocompression bonding temperature (thermocompression bonding temperature TP) and the press pressure may be any conditions that allow the softened layer (B) 14 to melt and form the raised portion (rim) 24. Specifically, the pressing pressure is preferably 1 to 10 MPa, and more preferably 3 to 10 MPa. The pressing time can be, for example, about 1 to 5 minutes. The thermocompression bonding temperature TP is preferably in the range of 120 to 180 ° C, more preferably in the range of 130 to 170 ° C, and further preferably 150 ° C. The thermocompression bonding temperature (TP) is an average temperature of a pair of hot plates (upper hot plate 22-1 and lower hot plate 22-2) of the press.

Furthermore, the thermocompression bonding temperature (TP) is preferably the same as or lower than the temperature (TM) of the semiconductor wafer surface protecting film 10 in the mounting step described above. The semiconductor wafer surface protecting film 10 is about to thermally expand by heating during the pressing process; if the thermocompression bonding temperature (TP) is equal to or lower than the temperature (TM) in the mounting process, the semiconductor wafer surface protecting film is used in the pressing process. The degree of thermal expansion of the film 10 is about the same as or smaller than the degree of thermal expansion of the semiconductor wafer surface protecting film 10 in the mounting step. Since the semiconductor wafer surface protecting film 10 that has been sufficiently thermally expanded in the mounting process is fixed to the semiconductor wafer, the semiconductor wafer surface protecting film 10 is less likely to thermally expand in the pressing process, and wrinkles are less likely to occur. On the other hand, if the thermocompression bonding temperature (TP) and the temperature (TM) are not properly adjusted, wrinkles are likely to occur around the semiconductor wafer 20 of the semiconductor wafer surface protecting film 10.

Furthermore, when the semiconductor wafer surface protecting film 10 is cooled after the pressing step, the semiconductor wafer surface protecting film 10 and the semiconductor wafer 20 may be separated (the semiconductor wafer 20 floats from the film 10). This peeling is also suppressed by setting the thermocompression bonding temperature (TP) to be equal to or lower than the temperature (TM) in the mounting process. Thus, by suppressing wrinkles in the semiconductor surface protective film, the semiconductor wafer can be made more difficult to break in the backside polishing process of the semiconductor wafer.

The thermocompression bonding temperature (TP) is preferably higher than the softening temperature (TmB) of the softening layer (B) of the semiconductor wafer surface protecting film 10. By setting the thermocompression bonding temperature (TP) to be equal to or higher than the softening temperature (TmB), the softened layer (B) is softened and the raised portion (rim) 24 is easily formed. On the other hand, the thermocompression bonding temperature (TP) is preferably lower than “the softening temperature (TmB) + 40 ° C. of the softening layer (B) of the semiconductor wafer surface protecting film 10”. If the thermocompression bonding temperature (TP) is excessively high, the shape of the raised portion (rim) 24 formed by softening the softened layer (B) cannot be maintained and may flow and become a flat shape. Thereby, the height of the raised portion (rim) 24 may be lowered.

As described above, the thermocompression bonding temperature (TP) is an average temperature of a pair of hot plates (upper hot plate 22-1 and lower hot plate 22-2) of the press machine. The temperature (TP1) of the upper heating plate 22-1 and the temperature (TP2) of the lower heating plate 22-2 may be the same temperature, but the temperature (TP1) of the upper heating plate 22-1 is set to the lower heating plate 22-1. It is preferably higher than the temperature (TP2) of -2. As the temperature of the thermocompression bonding (TP) is higher, the raised portion (rim) 24 can be formed more quickly. However, if the temperature (TP2) of the lower heat plate 22-2 is higher, the shape of the raised portion (rim) 24 cannot be maintained. To flow and flatten. On the other hand, since the upper heating plate 22-1 and the semiconductor wafer surface protecting film 10 are not in direct contact (there is a gap between them), the raised portion (at the TP1) of the upper heating plate 22-1 ( The shape of the rim) 24 is difficult to flatten. Therefore, by setting the temperature (TP1) of the upper heating plate 22-1 to be higher than the temperature (TP2) of the lower heating plate 22-2, it is possible to quickly raise the raised portion while maintaining the shape of the raised portion (rim) 24. A (rim) 24 can be formed.

Specifically, the temperature (TP1) of the upper heating plate 22-1 is higher than “the softening temperature (TmB) + 20 ° C. of the softening layer (B) of the semiconductor wafer surface protection film 10”. It is preferably lower than the “softening temperature (TmB) + 40 ° C. of the softening layer (B) of the film 10”. The temperature (TP2) of the lower heating plate 22-2 is higher than “the temperature (TP1) of the upper heating plate 22-1−40 ° C.” and lower than the “temperature (TP1) of the upper heating plate 22-1”. In this case, the thermocompression bonding temperature (TP) is higher than the “temperature of the upper heating plate 22-1 (TP1) −20 ° C.” and lower than the “temperature of the upper heating plate 22-1 (TP1)”. preferable.

As shown in FIG. 2D, the height of the raised portion (rim) 24 is the height from the surface of the semiconductor wafer surface protection film 10 that contacts the circuit forming surface of the semiconductor wafer 20 to the apex of the raised portion (rim) 24. Is defined as h. The height of the raised portion (rim) 24 can be measured by observing the cross-sectional shape of the semiconductor wafer surface protecting film 10 after the semiconductor wafer 20 is peeled off with a microscope.

The raised portion (rim) 24 may not necessarily be in contact with the end portion of the semiconductor wafer 20, but is preferably in contact with the end portion of the semiconductor wafer 20 in order to improve the retention of the semiconductor wafer 20.

Next, as shown in FIG. 2E, the semiconductor wafer surface protecting film 10 is set on the chuck table 26 together with the semiconductor wafer 20. As described above, the semiconductor wafer surface protecting film may have a light adhesive layer (D) between the base material layer (A) and the softened layer (B) (see FIG. 1B). When the light adhesive layer (D) is present, the semiconductor wafer surface protecting film 10 may be set on the chuck table 26 after removing the base material layer (A).

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

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

If necessary, the non-circuit-formed surface (back surface) of the semiconductor wafer is processed between the step (3) of grinding the back surface of the semiconductor wafer and the step (4) of peeling the film for protecting the semiconductor wafer surface from the semiconductor wafer. The process to do may be included. The process of processing the circuit non-formation surface (back surface) of the semiconductor wafer may further perform, for example, a process selected from the group consisting of a metal sputtering process, a plating process, and a heat treatment process. The heat treatment step can be, for example, a step of applying a die bonding tape under heating. Then, the semiconductor wafer is diced. Alternatively, the semiconductor wafer may be diced without peeling off the semiconductor wafer surface protecting film 10.

The semiconductor wafer surface protective film of the present invention can be formed on a semiconductor wafer surface protective film with a raised portion (rim) on the outer periphery of the semiconductor wafer by thermocompression bonding with the semiconductor wafer under predetermined conditions. Further, the raised portion (rim) formed by the semiconductor wafer surface protecting film of the present invention does not melt even at the ultimate temperature (about 40 ° C.) of the semiconductor wafer at the time of back grinding, so that the shape can be maintained satisfactorily. Therefore, at the time of grinding the back surface of the semiconductor wafer, the end portion of the semiconductor wafer can be stably held by the raised portion (rim), and damage to the end portion of the semiconductor wafer due to contact with the grindstone can be suppressed. Therefore, even if the semiconductor wafer is a hard and brittle sapphire substrate, the back surface can be ground without damaging the substrate.

Further, when the semiconductor wafer surface protective film includes an adhesive layer (C) that is cured by radiation, the semiconductor wafer surface protective film can be easily peeled by irradiating the semiconductor wafer surface protective film with radiation. . In this manner, unlike the conventional wax method, it is not necessary to clean the semiconductor wafer to which the wax resin is attached, so that the process can be simplified.

Other Embodiments of Mounting Process As described above, in the mounting process, the semiconductor wafer 20 is arranged inside the ring frame 30 having a frame; one surface of the semiconductor wafer 20 (usually a surface on which a circuit is formed). 20A) and the ring frame 30, the semiconductor wafer surface protecting film 10 is attached (see FIG. 2A). At this time, if the gap between the ring frame 30 and the semiconductor wafer 20 disposed inside the ring frame 30 is large, the semiconductor wafer protection film may loosen between the semiconductor wafer 20 and the ring frame 30. Therefore, it is preferable to arrange the ring-shaped auxiliary member 50 between the ring frame 30 and the semiconductor wafer 20 (see FIGS. 5A and 5B).

The outer diameter DW of the semiconductor wafer 20, the inner diameter DA _IN of the ring frame 30, the ring outer diameter DB _OUT of the ring-shaped auxiliary member 50, and the ring inner diameter DB _IN of the ring-shaped auxiliary member 50 are expressed by the formula (1). The relationship of DW <DB _IN <DB OU _T <DA _IN is satisfied (see FIG. 5A).

Furthermore, it is preferable to make the gap between the semiconductor wafer 20 and the ring-shaped auxiliary member 50 and the gap between the ring-shaped auxiliary member 50 and the ring frame 30 as small as possible. This is for further preventing loosening of the stuck semiconductor wafer protection film 10. That is, the difference ΔD1 between ring diameter _{DB IN} outer diameter DW and the ring-shaped auxiliary member 50 of the semiconductor wafer 20 is preferably within 1% of the outer diameter DW of the semiconductor wafer 20. Similarly, the difference ΔD2 between the ring outer diameter DB _OUT of the ring-shaped auxiliary member 50 and the inner diameter DA _IN of the ring frame 30 is preferably within 1% of the outer diameter DW of the semiconductor wafer 20.
ΔD1 = DB _IN −DW (2)
ΔD2 = DA _IN −DB _OUT (3)

The mounting process can be performed with a semiconductor wafer mounting apparatus. The semiconductor wafer mount apparatus has a heating unit, a tape applying unit, and a tape cutting mechanism.

The heating unit is, for example, a hot plate 40 on which a premount frame is placed. The premount frame means a structure including the semiconductor wafer 20, a ring-shaped auxiliary member 50 surrounding the semiconductor wafer, and a ring frame 30 surrounding the ring-shaped auxiliary member 50 (FIG. 5A). The premount frame is placed on the hot plate 40 such that the surface (circuit non-formed surface) opposite to the circuit forming surface 20 </ b> A of the semiconductor wafer 20 faces the hot plate 40.

While the pre-mount frame semiconductor wafer 20 placed on the hot plate 40 is heated by the hot plate 40, the tape application unit includes the circuit forming surface 20A of the semiconductor wafer 20, the ring-shaped auxiliary member 50, the ring frame 30, and the like. The semiconductor wafer surface protecting film 10 is pasted over. The tape applying unit includes, for example, a roller 35; the roller 35 can roll over the circuit forming surface 20A of the semiconductor wafer 20, the ring-shaped auxiliary member 50, and the ring frame 30.

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

Other Embodiments of Pressing Process As described above, in the pressing process, the mount frame obtained in the mounting process is pressed with a pair of press plates (upper press plate 22-1 and lower press plate 22-2). It is a process (see FIG. 2C). However, as shown in FIG. 6, when the pressure applied by the upper heating plate 22-1 and the lower heating plate 22-2 is released after the pressing process, the outer peripheral portion of the semiconductor wafer surface protection film 10 of the mount frame becomes thinner than the central portion. There was a case. It is inferred that during the pressing process, the outer peripheral portion of the semiconductor wafer surface protective film 10 of the mount frame flows outward while the central portion hardly flows.

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

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

The protrusion height of the protrusion 60 of the lower press plate 22-2 is preferably 1 to 100 μm; more preferably 15 to 100% of the thickness of the softened layer (B) of the semiconductor wafer surface protective film 10 It is preferable to be within the range. The protruding height of the convex portion 60 refers to the maximum height of the convex portion 60.

Diameter CD of the projecting portion 60 of the lower press plate 22-2 is larger than the outer diameter DW of the semiconductor wafer mount frame is 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. Any material suitable for grinding for processing into a convex shape may be used, and for example, ceramics such as alumina and cemented carbide such as tungsten carbide may be used.

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

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

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

The mounting frame is peeled from the upper press plate 22-1 and the lower press plate 22-2, thereby forming a raised portion (rim) on the semiconductor wafer protective film and reducing the thickness of the semiconductor wafer protective film after the pressing step. It can be made uniform.

(Example 1)
Preparation of material As a material of the base material layer (A), homopolypropylene (hPP) (manufactured by Prime Polymer Co., Ltd., density: 910 kg / m ³ ) was prepared. As a material for the softened layer (B), linear low density polyethylene (LLDPE) (manufactured by Prime Polymer Co., Ltd., density 918 kg / m ³ ) was prepared. The following adhesive layer coating solution was prepared as a material for the adhesive layer (C).

Preparation of Coating Solution for Adhesive Layer 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 was added to a benzoyl peroxide polymerization initiator [ Nippon Oil & Fats Co., Ltd., Nyper BMT-K40] Using 0.8 parts by weight (0.32 parts by weight as an initiator), reaction was carried out at 80 ° C. for 10 hours in 65 parts by weight of toluene and 50 parts by weight of ethyl acetate. I let you. After completion of the reaction, the resulting solution was cooled, and further 100 parts by weight of xylene, 10 parts by weight of acrylic acid, and 0.3 parts by weight of tetradecyldimethylbenzylammonium chloride (Nippon Yushi Co., Ltd., cation M2-100). And reacted at 85 ° C. for 50 hours while blowing air. Thereby, the solution (adhesive main ingredient) of the acrylic adhesive polymer was obtained.

Benzyldimethyl ketal [Nippon Ciba Geigy Co., Ltd.] as an intramolecular bond cleavage type photopolymerization initiator was added to the acrylic pressure-sensitive adhesive polymer solution (pressure-sensitive adhesive main component) with respect to 100 parts by weight of the acrylic pressure-sensitive adhesive polymer solid content. , Irgacure 651], a mixture of dipentaerythritol hexaacrylate and dipentaerythritol monohydroxypentaacrylate as a monomer having a polymerizable carbon-carbon double bond in the molecule [manufactured by Toa Gosei Chemical Co., Ltd.] , Aronix M-400] and 0.35 parts by weight of an isocyanate-based cross-linking agent (Mitsui Toatsu Chemical Co., Ltd., Olester P49-75-S) as a thermal cross-linking agent ( 1 part by weight as a thermal crosslinking agent) was added to obtain a UV adhesive. It was 3N / 25mm when the adhesive force of the obtained UV adhesive was measured based on JISZ0237.

1) Measurement of storage elastic modulus Homopolypropylene (hPP) (manufactured by Prime Polymer Co., Ltd., density: 910 kg / m ³ ) to be the base material layer (A) was extruded to prepare a sample film having a thickness of 500 μm. Similarly, a linear low density polyethylene (LLDPE) (Prime Polymer Co., Ltd., density 918 kg / m ³ ) to be the softened layer (B) was extruded to prepare a sample film having a thickness of 500 μm. The above-mentioned UV pressure-sensitive adhesive serving as the pressure-sensitive adhesive layer (C) was applied on a glass substrate and dried, and then peeled 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 set in a dynamic viscoelasticity measuring apparatus (manufactured by TA Instruments Inc .: ARES), and using a parallel plate type attachment having a diameter of 8 mm, the heating rate was increased from 30 ° C. to 3 ° C./min. The storage elastic modulus when the temperature was raised to 200 ° C. was measured. The measurement frequency was 1 Hz. After the measurement, for the sample films of the base material layer (A) and the softened layer (B), the obtained storage elastic modulus at 40 ° C., 100 ° C., and 150 ° C. from the storage elastic modulus-temperature curve of 10 to 200 ° C. Each value was read. 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 to 200 ° C.

Production of Film for Surface Protection of Semiconductor Wafer Homopolypropylene (hPP) (Prime Polymer Co., Density: 910 kg / m ³ ) to be used as a base material layer (A) and linear low density polyethylene (B) to be used as a softening layer (B) LLDPE) (manufactured by Prime Polymer, density 918 kg / m ³ ) was coextruded to obtain a two-layer coextruded film. On the softened layer (B) of the obtained coextruded film, the aforementioned UV adhesive was applied and then dried to form an adhesive layer (C) to obtain a semiconductor wafer surface protecting film. The thickness of the base material layer (A) / softening layer (B) / adhesive layer (C) of the semiconductor wafer surface protecting film was 60 μm / 70 μm / 5 μm, and the total thickness was 135 μm.

2) Evaluation of formability of raised portion (rim) The obtained semiconductor wafer surface protecting film was cut into a size larger than that of the sapphire wafer. Subsequently, a sapphire wafer having a thickness of 650 μm and a size of 4 inches was placed on the semiconductor wafer surface protecting film. At this time, the circuit forming surface of the sapphire wafer was in contact with the adhesive layer (C) of the semiconductor wafer surface protecting film. These were set in a hot press machine and thermocompression bonded at 140 ° C. and a pressure of 10 MPa for 2 minutes.

Next, after irradiating the semiconductor wafer surface protective film with ultraviolet rays of about 1000 mJ, the semiconductor wafer surface protective film was peeled off from the semiconductor wafer, and the cross-sectional shape of the obtained semiconductor wafer surface protective film was observed with a microscope. The height of two raised portions (rims) in the cross section of the semiconductor wafer surface protecting film was measured, and the average value thereof was determined. The height of the raised portion (rim) was measured by measuring the height of the apex of the raised portion (rim) with respect to the surface of the semiconductor wafer surface protecting film that was in contact with the circuit forming surface of the semiconductor wafer. Evaluation of the formability of the raised portion (rim) was performed based on the following criteria.
○: The height of the raised portion (rim) is 200 μm or more. ×: The height of the raised portion (rim) is less than 200 μm.

3) Evaluation of back surface grindability In the same manner as described above, the obtained semiconductor wafer surface protecting film was cut into a size larger than that of the sapphire wafer. Subsequently, a sapphire wafer having a thickness of 650 μm and a size of 4 inches was placed on the semiconductor wafer surface protecting film. These were set in a hot press machine and thermocompression bonded at 140 ° C. and a pressure of 10 MPa for 2 minutes.

90 μm backside grindability A semiconductor wafer surface protection film, to which a sapphire wafer is thermocompression bonded, is set on the chuck table of Disco DGP8761, and the circuit non-formation surface (backside) of the sapphire wafer is wetted until the wafer thickness reaches 90 μm. Grinded. The wafer temperature during grinding was about 40 ° C. And back surface grindability was evaluated based on the following criteria.
○: Backside grinding is possible until the wafer thickness reaches 90 μm ×: Substrate breaks before the wafer thickness reaches 90 μm (backside grinding is impossible)

70 μm Backside Grindability A sapphire wafer that had been back-ground until the wafer thickness reached 90 μm was wet-ground until the wafer thickness reached 70 μm. And back surface grindability was evaluated based on the following criteria.
○: Backside grinding is possible until the wafer thickness reaches 70 μm ×: Substrate breaks before the wafer thickness reaches 70 μm (backside grinding is impossible)

4) Evaluation of the shape of the raised part after DP (dry polishing) The sample after completion of the wet back grinding in 3) was further subjected to dry grinding (dry polishing) for 5 minutes. The temperature of the wafer during dry polishing was about 100 ° C. Then, after irradiating the semiconductor wafer surface protecting film with ultraviolet rays of about 1000 mJ, the sapphire wafer was peeled off from the semiconductor wafer surface protecting film. The cross-sectional shape of the obtained semiconductor wafer surface protecting film was observed with a microscope, and the height of the raised portion (rim) was measured. DP heat resistance was evaluated based on the following criteria.
○: The height of the raised portion (rim) is about the thickness after grinding of the wafer (the rim remains without melting)
X: The height of the raised portion (rim) is lower than the grinding thickness of the wafer (the rim has melted and disappeared)

5) Surface smoothness of the base material layer (A) after grinding The surface smoothness of the base material layer (A) after DP (dry polishing) in the above 4) is measured using a stylus type surface shape measuring instrument (Veeco Dektac 3). It was evaluated by. The evaluation of the surface smoothness was performed based on the following criteria.
○: Ra of unevenness on the surface of the base material layer (A) due to transfer of the surface shape of the chuck table is less than 1 μm ×: Ra of the unevenness of the surface of the base material layer (A) due to transfer of the surface shape of the chuck table is 1 μm or more Is

(Example 2)
A film for protecting a semiconductor wafer surface was prepared in the same manner as in Example 1 except that the thicknesses of the base layer (A) and the softened layer (B) were changed to 30 μm, and the same evaluation was performed.

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

(Example 4)
The material of the softening layer (B) is changed to linear low density polyethylene (LLDPE) (Prime Polymer, density 938 kg / m ³ ), and the thickness of the base layer (A) and the softening layer (B) is changed. A semiconductor wafer surface protective film was prepared and evaluated in the same manner as in Example 1 except that the thickness was changed to 30 μm.

(Example 5)
The material of the softening layer (B) was changed to random polypropylene (rPP) (manufactured by Prime Polymer Co., Ltd., density: 910 kg / m ³ ), and the thickness of the base layer (A) and the softening layer (B) was changed to 30 μm. A semiconductor wafer surface protective film was produced in the same manner as in Example 1 except that the above evaluation was performed.

(Comparative Example 1)
The material of the base material layer (A) is random polypropylene (rPP) (manufactured by Prime Polymer, density: 910 kg / m ³ ), and the material of the softening layer (B) is an ethylene-α-olefin copolymer (Tafmer (Mitsui Chemicals). A semiconductor wafer surface protective film was prepared in the same manner as in Example 1 except that the density was changed to 893 kg / m ³ ) and the same evaluation was performed.

(Comparative Example 2)
The material of the base layer (A) is linear low density polyethylene (LLDPE) (Prime Polymer, density 918 kg / m ³ ), and the material of the softening layer (B) is an ethylene-α-olefin copolymer (Tuffmer). A semiconductor wafer surface protective film was prepared in the same manner as in Example 1 except that the density was changed to (Mitsui Chemicals Co., Ltd.) and density: 893 kg / m ³ ), and the same evaluation was performed.

(Comparative Example 3)
The material of the base layer (A) is linear low density polyethylene (LLDPE) (Prime Polymer, density 918 kg / m ³ ), and the material of the softening layer (B) is an ethylene-α-olefin copolymer (Tuffmer). A film for protecting a semiconductor wafer surface was prepared in the same manner as in Example 1 except that the density was changed to (Mitsui Chemicals Co., Ltd.) and density: 861 kg / m ³ ), and the same evaluation was performed.

(Comparative Example 4)
The material of the softening layer (B) is made of an ethylene-α-olefin copolymer (Tuffmer (manufactured by Mitsui Chemicals), density: 861 kg / m ³ ), and the thickness of the base material layer (A) and the softening layer (B). A semiconductor wafer surface protective film was prepared and evaluated in the same manner as in Example 1 except that the thickness was changed to 30 μm.

Tables 1 to 3 show 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 semiconductor wafer surface protective film.

Table 1 and as shown in Table 2, the semiconductor wafer surface protection films of Examples 1 to 5 the storage modulus G _{B (40)} is not less than 10MPa at 40 ° C. softening layer (B), heat press Thus, it can be seen that the raised portion (rim) can be satisfactorily formed and the wafer is not damaged even during back grinding. This is presumably because the raised portion (rim) does not melt even during back grinding, and the end portion of the wafer can be held stably.

On the other hand, the semiconductor wafer surface protective films of Comparative Examples 3 and 4 in which the storage elastic modulus G _B (40) at 40 ° C. of the softened layer (B) is less than 10 MPa can form a raised portion (rim) by hot pressing. However, it can be seen that the wafer is damaged during back grinding. This is thought to be because the raised portion (rim) is softened even during backside grinding, and the end portion of the wafer cannot be stably held.

Among Examples 1 to 5, in Example 3, the wafer was cracked during 70 μm grinding, whereas in Example 2, the wafer was not cracked even during 70 μm grinding. This is because the softening layer (B) in the film for protecting a semiconductor wafer surface of Example 2 has a higher storage elastic modulus G _B (40) at 40 ° C. than that for the film for protecting a semiconductor wafer surface of Example 3. it is conceivable that. In Example 1, the wafer was cracked during the 70 μm grinding because the semiconductor wafer surface protective film was too thick with respect to the finished thickness of the wafer, and the deformation (deflection, bending) of the semiconductor wafer could not be suppressed. it is conceivable that.

Further, in the semiconductor wafer surface protective films of Examples 1 and 2, the ridges (rims) are not softened even at a high temperature near 100 ° C. during dry polishing (DP), and the end portions of the sapphire wafer can be stably held. I understand.

Further, it can be seen that in Comparative Examples 1 to 3, the surface smoothness of the base material layer (A) after grinding is low. This is because the base layer (A) of the semiconductor wafer surface protecting film of Comparative Examples 1 to 3 has a storage elastic modulus G _A (150) at 150 ° C. of less than 1 MPa, and the surface shape of the chuck table during back grinding. This is probably due to the fact that was transferred. Thus, when the surface shape of the chuck table is transferred to the surface of the base material layer (A) during back surface grinding, when fixing the semiconductor wafer surface protection film on another chuck table in the subsequent dicing step, Air leaks easily occur between the chuck table and the base layer (A) of the semiconductor wafer surface protecting film. When such an air leak occurs, the semiconductor wafer surface protecting film is not fixed on the chuck table, which is not preferable.

(Example 6)
A film similar to the film used in Example 2 was attached to a sapphire wafer (mounting process) and thermocompression bonded (pressing process) to form a raised portion (rim).

Specifically, the semiconductor wafer surface protective film was cut into a size larger than that of the sapphire wafer. A sapphire wafer having a thickness of 650 μm and a size of 4 inches was prepared. As shown to FIG. 2A, it has arrange | positioned on the film for semiconductor wafer surface protections. The hot plate temperature was heated to 140 ° C., and the film for protecting the semiconductor wafer surface was pressed onto the sapphire wafer with a roller to obtain a laminate of the sapphire wafer and the film for protecting the semiconductor wafer surface. The roller pressure was 0.5 MPa, and the roller speed was 10 mm / second.

Next, as shown in FIG. 2C, it was obtained with an upper hot plate (a hot plate placed on the semiconductor wafer surface protecting film) and a lower hot plate (a hot plate placed on the sapphire wafer side) as shown in FIG. The laminate was sandwiched and pressed at 10 MPa for 180 seconds. At this time, the temperature of the upper heating plate was 140 ° C., the temperature of the lower heating plate was 120 ° C., that is, the average temperature TP of both was 130 ° C.

Next, after irradiating the semiconductor wafer surface protecting film with ultraviolet rays of about 1000 mJ, the semiconductor wafer surface protecting film was peeled off from the sapphire wafer, and the cross-sectional shape of the obtained semiconductor wafer surface protecting film was observed with a microscope. The height of two raised portions (rims) in the cross section of the semiconductor wafer surface protecting film was measured, and the average value thereof was determined.

1. Presence / absence of radial tension After the pressing step, a 150 g weight was placed on the center of the sapphire wafer with the semiconductor wafer surface protecting film attached to the ring frame, and the amount of film sinking was measured. The thing which sank 2 mm or more was evaluated as x as what does not have tension | tensile_strength.

2. Wrinkle After the pressing step, a film in which 10 or more radial wrinkles were generated on the semiconductor wafer surface protecting film around the sapphire wafer was visually rated as x.

3. Peeling after 48 hours After the pressing step, the semiconductor wafer surface protective film was stuck on the sapphire wafer and left at room temperature for 48 hours. After that, a film in which peeling of 1 mm or more was observed between the wafer surface protective film and the sapphire wafer edge was rated as x.

(Example 7)
A film similar to the film used in Example 2 was attached to a sapphire wafer (mounting process) and thermocompression bonded (pressing process) to form a raised portion (rim). Specifically, the semiconductor wafer surface protective film was cut into a size larger than that of the sapphire wafer. A sapphire wafer having a thickness of 650 μm and a size of 4 inches was prepared. As shown to FIG. 2A, it has arrange | positioned on the film for semiconductor wafer surface protections. The hot plate temperature was heated to 100 ° C., and the film for protecting the semiconductor wafer surface was pressed onto the sapphire wafer with a roller to obtain a laminate of the sapphire wafer and the film for protecting the semiconductor wafer surface. The roller pressure was 0.5 MPa, and the roller speed was 10 mm / second.

Next, as shown in FIG. 2C, it was obtained with an upper hot plate (a hot plate placed on the semiconductor wafer surface protecting film) and a lower hot plate (a hot plate placed on the sapphire wafer side) as shown in FIG. The laminate was sandwiched and pressure-bonded at 10 MPa for 180 seconds. At this time, the temperature of the upper heating plate was 140 ° C., the temperature of the lower heating plate was 120 ° C., that is, the average temperature TP of both was 130 ° C.

In the same manner as in Example 6, the height of the raised portion (rim) was determined, and “existence of radial tension”, “existence of wrinkles”, “existence of floating (peeling) after 48 hours” was evaluated.

(Example 8)
A film similar to the film used in Example 2 was attached to a sapphire wafer (mounting process) and thermocompression bonded (pressing process) to form a raised portion (rim). Specifically, the semiconductor wafer surface protective film was cut into a size larger than that of the sapphire wafer. A sapphire wafer having a thickness of 650 μm and a size of 4 inches was prepared. As shown to FIG. 2A, it has arrange | positioned on the film for semiconductor wafer surface protections. The hot plate temperature was set to 25 ° C., and the semiconductor wafer surface protective film was pressed onto the sapphire wafer with a roller to obtain a laminate of the sapphire wafer and the semiconductor wafer surface protective film. The roller pressure was 0.5 MPa, and the roller speed was 10 mm / second.

(Reference Example 5)
A film similar to the film used in Example 2 was attached to a sapphire wafer (mounting process) and thermocompression bonded (pressing process) to form a raised portion (rim). Specifically, the semiconductor wafer surface protective film was cut into a size larger than that of the sapphire wafer. A sapphire wafer having a thickness of 650 μm and a size of 4 inches was prepared. As shown to FIG. 2A, it has arrange | positioned on the film for semiconductor wafer surface protections. The hot plate temperature was set to 100 ° C., and the semiconductor wafer surface protective film was pressed onto the sapphire wafer with a roller to obtain a laminate of the sapphire wafer and the semiconductor wafer surface protective film. The roller pressure was 0.5 MPa, and the roller speed was 10 mm / second.

Next, as shown in FIG. 2C, it was obtained with an upper hot plate (a hot plate placed on the semiconductor wafer surface protecting film) and a lower hot plate (a hot plate placed on the sapphire wafer side) as shown in FIG. The laminate was sandwiched and pressed at 10 MPa for 180 seconds. At this time, the temperature of the upper heating plate was 110 ° C., the temperature of the lower heating plate was 90 ° C., that is, the average temperature TP of both was 100 ° C.

In the same manner as in Example 6, the height of the raised portion (rim) was determined, and “existence of radial tension”, “existence of wrinkles”, “existence of float (peeling) after 48 hours” were evaluated.

In Example 6, the temperature TM in the mounting process is higher than the temperature TP in the pressing process; and the temperature TP is 14 ° C. higher than the softening point temperature (TmB) of the softening layer (B). Therefore, a rim having a sufficient height was formed, and there was no generation of wrinkles and no peeling between the sapphire substrate and the protective film.

In Example 7, the temperature TM in the mounting process is 30 ° C. lower than the temperature TP in the pressing process. Therefore, although a rim having a sufficient height could be formed, generation of wrinkles was confirmed. Furthermore, in Example 8, the temperature TM in the mounting process is 105 ° C. lower than the temperature TP in the pressing process. Therefore, although a rim having a sufficient height could be formed, a rim having a sufficient height could be formed, but generation of wrinkles was confirmed, and peeling between the sapphire substrate and the protective film was also confirmed.

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

Example 9
A film similar to the film used in Example 2 was attached to a sapphire wafer (mounting process) and thermocompression bonded (pressing process) to form a raised portion (rim). Specifically, the semiconductor wafer surface protective film was cut into a size larger than that of the sapphire wafer. A sapphire wafer having a thickness of 650 μm and a size of 4 inches was prepared. As shown to FIG. 2A, it has arrange | positioned on the film for semiconductor wafer surface protections. The hot plate temperature was heated to 140 ° C., and the film for protecting the semiconductor wafer surface was pressed onto the sapphire wafer with a roller to obtain a laminate of the sapphire wafer and the film for protecting the semiconductor wafer surface. The roller pressure was 0.5 MPa, and the roller speed was 10 mm / second.

Next, as shown in FIG. 2C, it was obtained with an upper hot plate (a hot plate placed on the semiconductor wafer surface protecting film) and a lower hot plate (a hot plate placed on the sapphire wafer side) as shown in FIG. The laminate was sandwiched and pressed at 10 MPa for 180 seconds. At this time, the temperature of the upper heating plate was 140 ° C., the temperature of the lower heating plate was 100 ° C., that is, the average temperature of both was 120 ° C.

Next, as in Example 6, the height of the raised portion (rim) was determined.

(Example 10)
A film similar to the film used in Example 2 was attached to a sapphire wafer (mounting process) and thermocompression bonded (pressing process) to form a raised portion (rim). Specifically, the semiconductor wafer surface protective film was cut into a size larger than that of the sapphire wafer. A sapphire wafer having a thickness of 650 μm and a size of 4 inches was prepared. As shown to FIG. 2A, it has arrange | positioned on the film for semiconductor wafer surface protections. The hot plate temperature was heated to 140 ° C., and the film for protecting the semiconductor wafer surface was pressed onto the sapphire wafer with a roller to obtain a laminate of the sapphire wafer and the film for protecting the semiconductor wafer surface. The roller pressure was 0.5 MPa, and the roller speed was 10 mm / second.

Next, as shown in FIG. 2C, it was obtained with an upper hot plate (a hot plate placed on the semiconductor wafer surface protecting film) and a lower hot plate (a hot plate placed on the sapphire wafer side) as shown in FIG. The laminate was sandwiched and pressed at 10 MPa for 180 seconds. At this time, the temperature of the upper heating plate was 140 ° C., the temperature of the lower heating plate was 140 ° C., that is, the average of both was 140 ° C.

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

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

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

(Examples 11 to 14)
A film similar to the film used in Example 2 was attached to a sapphire wafer (mounting process) and thermocompression bonded (pressing process) to form a raised portion (rim). Specifically, the semiconductor wafer surface protective film was cut into a size larger than that of the sapphire wafer. A sapphire wafer having a thickness of 650 μm and a size of 4 inches was prepared. As shown to FIG. 2A, it has arrange | positioned on the film for semiconductor wafer surface protections. The hot plate temperature was heated to 140 ° C., and the film for protecting the semiconductor wafer surface was pressed onto the sapphire wafer with a roller to obtain a laminate of the sapphire wafer and the film for protecting the semiconductor wafer surface. The roller pressure was 0.5 MPa, and the roller speed was 10 mm / second.

Next, as shown in FIG. 7A, an upper heat plate (a heat plate disposed on the semiconductor wafer surface protecting film) of the heat press machine and a lower heat plate having a conical convex portion as shown in FIG. 7B ( The obtained laminate was sandwiched with a hot plate disposed on the sapphire wafer side and pressed at 10 MPa for 180 seconds. At this time, the temperature of the upper heating plate was 140 ° C., and the temperature of the lower heating plate was 120 ° C. In Example 11, the height of the convex portion is 0 μm (no convex portion), in Example 12, the height of the convex portion is 5 μm, in Example 13, the height of the convex portion is 15 μm, and in Example 14, the convex portion is The height was set to 25 μm. About each, the thickness dispersion | variation (difference of the maximum thickness and the minimum thickness) of the film for semiconductor wafer surface protections after a press process was measured, and the height of the protruding part (rim | limb) was calculated | required similarly to Example 6. FIG.

As shown in Table 6, it can be seen that by providing a convex portion on the lower heating plate, variation in the thickness of the semiconductor wafer surface protecting film after the pressing step can be suppressed, and a raised portion (rim) can also be formed.

DESCRIPTION OF SYMBOLS 1 Sapphire substrate 2 Wax resin layer 3 Grinding stone 4 Conventional semiconductor wafer protective film 10 Film for semiconductor wafer surface protection 12 Base material layer (A)
14 Softening layer (B)
16 Adhesive layer (C)
18 Light adhesion layer (D)
20 Semiconductor wafer 20A Semiconductor wafer circuit formation surface 20B Semiconductor wafer circuit non-formation surface (back surface)
22-1 Upper heat plate 22-2 Lower heat plate 24 Raised part (rim)
26 Chuck table 28 Grinding wheel

Claims

A base material layer (A) having a storage elastic modulus G A (150) at 150 ° C. of 1 MPa or more;
Softening layer (B) having a storage elastic modulus G B (120 to 180) at a temperature of 120 to 180 ° C. of 0.05 MPa or less and a storage elastic modulus G B (40) at 40 ° C. of 10 MPa or more. And a film for protecting a surface of a semiconductor wafer.
The softened layer is storage modulus at 100 ° C. of (B) G B (100) , it is 1MPa or more, the semiconductor wafer surface protection film according to claim 1.
The softened layer and tensile modulus Tensile at a 25 ° C. modulus E B (60) at 60 ° C. of (B) E B (25) but, 1> E B (60) / E B (25)> 0.1 The film for protecting a semiconductor wafer surface according to claim 1, satisfying the relationship:
An adhesive layer (C) disposed on the opposite side of the base material layer (A) via the softening layer (B);
The film for protecting a semiconductor wafer surface according to claim 1, wherein the adhesive strength of the adhesive layer (C) measured in accordance with JIS Z0237 is 0.1 to 10 N / 25 mm.
The film for protecting a semiconductor wafer surface according to claim 1, wherein the base material layer (A) is disposed on the outermost surface.
The film for protecting a semiconductor wafer surface according to claim 4, wherein the adhesive layer (C) is disposed on the outermost surface opposite to the base material layer (A) through the softening layer (B).
2. The semiconductor wafer surface protecting film according to claim 1, wherein the softening layer (B) contains a homopolymer of hydrocarbon olefin, a copolymer of hydrocarbon olefin, or a mixture thereof.
The semiconductor wafer surface protecting film according to claim 1, wherein the density of the resin constituting the softened layer (B) is 880 to 960 kg / m 3 .
The semiconductor wafer surface protecting film according to claim 1, wherein the base material layer (A) is a polyolefin layer, a polyester layer, or a laminate of a polyolefin layer and a polyester layer.
Placing the semiconductor wafer on the semiconductor wafer surface protecting film such that the circuit forming surface of the semiconductor wafer is in contact with the semiconductor wafer surface protecting film;
Forming a raised portion of the semiconductor wafer surface protecting film for holding the semiconductor wafer on an outer periphery of the semiconductor wafer;
Grinding the non-circuit-formed surface of the semiconductor wafer held by the raised portions;
Peeling the semiconductor wafer surface protective film from the circuit forming surface of the semiconductor wafer,
The manufacturing method of a semiconductor device whose storage elastic modulus G (100) in 100 degreeC of the said protruding part is 1 Mpa or more.
The film for protecting a semiconductor wafer surface is the film for protecting a semiconductor wafer surface according to claim 1,
11. The method of manufacturing a semiconductor device according to claim 10, wherein the raised portion is formed by thermocompression bonding the semiconductor wafer surface protecting film and the semiconductor wafer at a temperature of 120 to 180 ° C. and a pressure of 1 to 10 MPa.
A method for manufacturing a semiconductor device according to claim 11, comprising:
Film temperature TM in the step of placing the semiconductor wafer on the semiconductor wafer surface protecting film so that the circuit forming surface of the semiconductor wafer is in contact with the semiconductor wafer surface protecting film, and the semiconductor wafer surface protecting film A method for manufacturing a semiconductor device, wherein the thermocompression bonding temperature TP in the step of forming the raised portion and the softening point temperature TmB of the softening layer (B) satisfy the relationship of the following general formula.
[Formula 1] TP ≦ TM
[Formula 2] TmB <TP <TmB + 40 ° C.
The semiconductor wafer is arranged on the semiconductor wafer surface protection film so that the softening layer (B) of the semiconductor wafer surface protection film is closer to the circuit forming surface side of the semiconductor wafer than the base material layer (A). A method for manufacturing a semiconductor device according to claim 11.
11. The method of manufacturing a semiconductor device according to claim 10, wherein the semiconductor wafer includes a high-hardness material substrate having a Mohs hardness of 8 or more.
A semiconductor wafer, a ring frame A having a frame surrounding the semiconductor wafer, and a semiconductor wafer surface protection film according to claim 1 attached over a circuit forming surface of the semiconductor wafer and the frame A. A semiconductor wafer press device for sandwiching and pressing a mount frame between an upper press plate provided with a heating mechanism and a lower press plate facing the upper press plate,
The outer diameter DW of the semiconductor wafer and the inner diameter DA IN of the ring frame A satisfy the relationship of formula (1) DW <DA IN ,
The lower press plate includes a convex portion on a surface facing the upper press plate,
The semiconductor wafer press apparatus, wherein an outer periphery of a contact surface of the convex portion with the mount frame when pressed is circular.
The semiconductor wafer press apparatus according to claim 15, wherein the height of the convex portion is 1 to 100 μm.
The semiconductor wafer press apparatus according to claim 15, wherein the height of the convex portion is in the range of 15 to 100% with respect to the thickness of the softened layer (B) of the semiconductor wafer surface protective film.
The semiconductor wafer press apparatus according to claim 15, wherein a diameter CD of the convex portion satisfies a relationship of DW <CD <DA IN .
A semiconductor wafer; a ring-shaped auxiliary member B surrounding the semiconductor wafer; a ring frame A surrounding the semiconductor wafer and the ring-shaped auxiliary member B; a circuit forming surface of the semiconductor wafer; the ring-shaped auxiliary member B; A semiconductor wafer mounting apparatus for producing a mounting frame including the semiconductor wafer surface protective film according to claim 1 attached over the ring frame A,
Wherein the outer diameter DW of the semiconductor wafer, and the inner diameter DA IN of the ring frame A, and the ring outer diameter DB OUT of the ring-shaped auxiliary member B, the ring diameter DB IN of the ring-shaped auxiliary member B has the formula (1) The relationship of DW <DB IN <DB OU T <DA IN is satisfied,
A heating unit for heating a surface opposite to a circuit forming surface of the semiconductor wafer;
A pasting roller for rolling over the circuit forming surface of the semiconductor wafer, the ring frame A, and the ring-shaped auxiliary member B to paste the semiconductor wafer surface protective film;
And a tape cutting mechanism for cutting the surface protective film along the outer shape of the ring frame A.
20. The semiconductor wafer mount device according to claim 19, wherein both ΔD1 and ΔD2 represented by the following formulas are within 1% of DW.
ΔD1 = DB IN −DW (2)
ΔD2 = DA IN −DB OUT (3)