KR20090117612A - Method and apparatus for manufacturing wafer, and curable resin composition - Google Patents

Abstract

PURPOSE: A method and a device for manufacturing a wafer, and a curable resin composition are provided to remove bending and waviness of a wafer surface in a slice process. CONSTITUTION: A thin wafer obtained by slicing an ingot is prepared(S110). A curable resin composition is painted on a first surface with the thickness of 10 to 200 um. A curable resin composition layer is planarized by pressurizing a second surface of the wafer coated with the curable resin composition(S130). After releasing the pressurization, the curable resin composition layer is cured on a wafer surface by irradiating the active energy to the curable resin composition layer(S140). The second surface of the wafer fixed in the curable resin composition layer(S150). A first surface is ground based on the second surface of the planarized wafer by a first grinding process(S170).

Description

Wafer manufacturing method and manufacturing apparatus, and curable resin composition {METHOD AND APPARATUS FOR MANUFACTURING WAFER, AND CURABLE RESIN COMPOSITION}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a wafer for use in a semiconductor device, and more particularly, to means for removing warpage and waviness of a wafer generated when a single crystal ingot represented by silicon is sliced.

Conventional wafer fabrication is produced, for example, by the process shown in FIG. First, in step S10, for example, after performing the outer circumferential grinding of the single crystal ingot manufactured by the single crystal pulling method, for example, orientation flat processing or notch processing for positioning in the crystal direction is performed, and the single crystal is performed by the inner edge saw or the wire saw. The ingot is sliced (step S10: slice process). Subsequently, after grinding (beveling) the outer periphery of the sliced wafer by the grinding grindstone (step S20: chamfering step) in step S20, a uniform thickness is obtained by a lapping step or a double head grinding step in step S30. .

Thereafter, in step S40, the grinding surface is ground (grinding) the surface of the wafer one by one or both sides simultaneously to remove the warping caused by the slice, thereby flattening both sides of the wafer. At this time, when both surfaces of the wafer are ground by a grinder, a processed deterioration layer is generated on the wafer surface. Thus, in step S50, the processed deteriorated layer is removed by etching with acid or alkali or by polishing such as CMP (Chemical Mechanical Polishing).

Conventionally, the wafer represented by silicon was manufactured in this way, but since the number of processes from a single crystal ingot to manufacturing a wafer is large, the wafer manufacturing process was simplified.

Therefore, it was considered to omit the lapping step or the double head grinding step. However, there was a problem that warpage and curvature of the wafer surface generated at the time of slicing the single crystal ingot cannot be removed only by the normal grinding step.

Patent Literature 1 or Patent Literature 2 discloses a method for removing such bending. In these methods, wax, resin, etc. are first coated on either side of the sliced wafer, and this is hardened. At the time of hardening, a flat plate is pressed against the surface of a wax or resin, and the surface of hardened resin becomes a uniform flat surface (reference surface). Subsequently, after curing the wax or the resin, the cured surface is placed downward, the reference surface is brought into contact with the surface of the chuck table, and the wafer is held on the chuck table. In addition, the upper surface of the wafer held on the chuck table is ground by grinding grindstone. Thereby, a uniform flat surface can be formed by removing the curvature on the surface and grinding the required amount. Thereafter, the flat surface formed on the upper surface of the wafer is turned downward to hold the wafer on the chuck table. Then, after removing the cured wax or resin before grinding, bending and grinding of the other surface of the wafer can be finished to a predetermined thickness while making the surface flat.

However, in the above method, since the thickness of the wax or the resin coated on the surface of the wafer is not specified, the following problems may occur depending on this thickness. For example, if the thickness of the resin or the like coated on the wafer is too thin, the curvature cannot be sufficiently absorbed by the resin or the like, and the curvature is transferred to the processed surface of the wafer during grinding, and as a result, the curvature cannot be removed. On the other hand, if the thickness of the resin or the like coated on the wafer is too thick, the wafer is thrown out of the grinding grindstone by the elastic action of the resin, so that even if the surface curvature can be removed, the wafer cannot be ground to a uniform thickness. .

In order to solve such a problem, Patent Document 3 and Patent Document 4 use a curable material in the form of a paste as a surface fixation means for providing a reference plane on the wafer surface, and the curable material absorbs warpage and bending of the wafer. Technology is proposed.

In patent document 3, only the use of an adhesive material as a means for fixing a wafer is disclosed as a structure for absorbing bending and curvature. In addition, Patent Document 4 discloses a technique in which bending can be absorbed by coating a curable material to a specific thickness.

However, it is difficult to simultaneously remove both curvature and curvature of the wafer surface, and in the case of using a curable resin composition, since coating and curing are usually performed on a substrate and then hardening occurs, the shrinkage occurs due to the shrinkage. Warping occurs. For this reason, the development of the material which can remove the curvature and curvature of the wafer at the time of grinding processing, and can suppress that the warpage of the wafer at the time of hardening of a curable resin composition arises is desired.

[Patent Document 1] Japanese Unexamined Patent Application Publication No. 11-111653

[Patent Document 2] Japanese Patent Application Laid-Open No. 2000-5982

[Patent Document 3] Japanese Unexamined Patent Application Publication No. 8-66850

[Patent Document 4] Japanese Unexamined Patent Publication No. 2006-269761

This invention is made | formed in view of the said problem, The objective is that a curvature does not generate | occur | produce in a wafer at the time of hardening of the curable resin composition coated on the wafer surface, and in the grinding process of a wafer surface, the curvature and curvature of a wafer surface are carried out. The present invention provides a novel and improved method for producing a wafer and a manufacturing apparatus capable of grinding the wafer to a required thickness, and a curable resin composition used in the above production method.

MEANS TO SOLVE THE PROBLEM This invention devised in order to solve the said subject is a manufacturing method of the wafer which consists of the following structures. In other words,

(A) a preliminary step of preparing a thin wafer obtained by slicing from an ingot,

(B) Curable resin composition layer forming process which coats curable resin composition which has the characteristics of following (b1) and (b2) to the film | membrane of 10 micrometers-200 micrometers on the 1st surface of the said wafer,

(b1) curing shrinkage is 7% or less

(b2) The value at 25 degrees C of the storage elastic modulus (E ') of a hardened | cured material is 1.0 * 10 < ⁶ > Pa ~ 3.0 * 10 <^9> Pa

(C) the planarization process of planarizing the curable resin composition layer apply | coated to the 1st surface by pressing the 2nd surface of the wafer which coated the said curable resin composition with a pressurizing means,

(D) after releasing the pressurization by the pressurizing means, irradiating an active energy ray to the curable resin composition layer coated on the wafer, and curing the curable resin composition layer immobilized on the wafer surface;

(E) a first grinding step of smoothly grinding the second surface of the wafer fixed in the curable resin composition layer;

(F) It is a manufacturing method of the wafer including the 2nd grinding process which grinds a 1st surface with respect to the 2nd surface of the wafer planarized by the said 1st grinding process as a reference surface.

Moreover, this invention relates also to the wafer manufacturing apparatus used for the said wafer manufacturing method. That is, the wafer has a stage having a substantially horizontal holding surface for holding the first surface of the wafer coated with the curable resin composition to expose the second surface, and the wafer disposed opposite to the stage and held on the stage. Pressing means for pressurizing from the surface side to the stage direction, active energy ray irradiation means for irradiating an active energy ray to the curable resin composition applied to the wafer, and the second of the wafer fixed in the curable resin composition layer. At least a first grinding means for grinding the surface flat and at least a second grinding means for grinding the first surface with reference to the second surface of the wafer flattened by the first grinding means as a reference surface. It is a wafer manufacturing apparatus characterized by the above-mentioned.

In the manufacturing method of such a wafer, specific curable resin composition is coated on the 1st surface of the wafer obtained by slicing from an ingot, and a curable resin composition layer is formed. This coating method can be carried out by coating the curable resin composition on a light-transmitting member such as a PET film in advance, and placing the wafer on the curable resin composition layer, but it is not particularly limited as long as it does not interfere with the function of the present invention. It doesn't work. Subsequently, in order to make the surface on the side where the curable resin composition layer is formed as a reference plane, the wafer is uniformly pressed by pressing means such as a flat plate-like member and processed into a flat surface such that the surface where the curable resin composition layer is present is the bottom surface. do. Then, active energy rays, such as an ultraviolet-ray, an electron beam, and a gamma ray, are irradiated to curable resin composition layer, and this is hardened | cured. Moreover, at this time, after pressurizing means is separated from a wafer, an active energy ray is irradiated to harden the said curable resin composition layer. This is because internal stress does not remain in the curable resin composition layer. Then, the wafer is placed so that the flat surface is in contact with a member such as a chuck table constituting the wafer holding means, and the second surface of the wafer on the other side of the flat surface is ground. Here, curable resin composition has the characteristic that the value in 25 degreeC of storage elastic modulus (E ') is 1.0 * 10 < ⁶ > Pa ~ 3.0 * 10 <^9> Pa, and also makes the thickness into 10 micrometers-200 micrometers, Curvature and curvature of a wafer can fully be absorbed by curable resin composition layer, and curvature and curvature are not transferred to the process surface of a wafer in a grinding process. In addition, the wafer surface can be ground to a uniform thickness by appropriate elastic action of the curable resin composition layer. In addition, since the curable resin composition layer has a characteristic that the curing shrinkage ratio is 7% or less, the phenomenon in which the wafer follows the shrinkage of the curable resin composition at the time of curing of the curable resin composition and a new warp occurs in the wafer is also improved. can do.

In this way, the 2nd surface of a wafer is processed into the uniform flat surface by which the bending and curvature were removed by the grinding process, without performing a lapping process or a double head grinding process. Thereafter, the first surface of the wafer is processed, where the curable resin composition layer coated on the first surface may be removed before the first surface is ground. As a removal method, since the curable composition layer of this invention can be peeled easily by immersing in 60 degreeC-90 degreeC hot water, it is preferable to peel off and remove by hot water immersion, However, in this invention, it is limited to this. Instead, for example, a method of peeling and removing by organic solvent immersion, steam steam, or the like may be adopted. Moreover, when the curable resin composition layer is formed on a film, the said curable resin composition layer can be easily peeled off by peeling a film. Thereafter, the wafer is placed on a fixing member such as a chuck table and the first surface is ground so that the second surface, which is flatly processed, comes into contact. At this time, since the second surface in contact with the fixing member is a flat surface, it is possible to process the flat surface with uniform thickness without bending or bending the first surface.

In addition, instead of grinding the first surface after removing the curable resin composition layer in advance as described above, the curable resin composition layer is attached on the first surface of the wafer without removing the curable resin composition layer, and then You may grind the 1st surface of a wafer with this curable resin composition layer at a process. Thus, by one cutting process, the curable resin composition can be removed, the wafer can be bent and the bend can be removed, and the wafer can be processed into a flat surface having a uniform thickness.

In the present invention, the curable resin composition may be coated with a light-transmissive flexible thin film in advance, and the wafer may be placed on the curable resin composition of the film after the treatment as a curable resin composition layer forming step. By forming the curable resin composition layer on the film, it is possible to easily peel off from the wafer when removing the curable resin composition layer after processing the first surface of the wafer, so that the peeling process can be simplified and at the time of peeling Too much stress on the wafer can reduce the risk of damaging the wafer. As a material of a film, since it is excellent in flexibility and the followability of the curable resin composition layer is excellent in PET and a polyolefin, it is especially suitable, but it is not limited to this.

Moreover, this invention relates also to the curable resin composition used for the said manufacturing method of the said wafer. That is, it is a curable resin composition characterized by having the characteristic of following (b1) and (b2).

(b1) curing shrinkage is 7% or less

(b2) The value at 25 degrees C of the storage elastic modulus (E ') of a hardened | cured material is 1.0 * 10 < ⁶ > Pa ~ 3.0 * 10 <^9> Pa

As described above, according to the present invention, in the grinding step, warping and bending of the wafer surface generated at the time of slicing can be removed, and the wafer is ground to the required thickness without causing any new warping on the wafer surface. The wafer manufacturing method and manufacturing apparatus which can be used, and curable resin composition used for the said manufacturing method can be provided.

EMBODIMENT OF THE INVENTION Preferred embodiment of this invention is described in detail, referring an accompanying drawing below. In addition, in this specification and drawing, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol about the component which has substantially the same functional structure.

First, the manufacturing method of the wafer of this invention is demonstrated based on drawing. 1 is a flowchart illustrating a method of manufacturing a wafer according to an exemplary embodiment of the invention. It is a schematic diagram for demonstrating the process (A)-(F) in the manufacturing method of a wafer.

This invention removes the curvature of the wafer and the curvature of the surface which were not removable in the conventional grinding process in the manufacturing method of a wafer in a grinding process.

In the step (A) in the wafer manufacturing method of the present invention, as shown in Fig. 1, first, a single crystal ingot is sliced to obtain a sliced wafer (step S110: slicing step). In step S110, for example, after performing the outer circumferential grinding of the single crystal ingot manufactured by the single crystal pulling method, for example, orientation flat processing or notching processing for positioning in the crystal direction is performed. Then, for example, a single crystal ingot is sliced by a wire saw to obtain a wafer.

Subsequently, in step (B), the curable resin composition is coated on the first surface of the sliced wafer to form a curable resin composition layer (step S120: curable resin composition layer forming step). As shown in FIG. 2 (a), the sliced wafer 10 has warpage and curvature that occurred when the single crystal ingot was sliced. When these curved and curved surfaces are placed on a fixing member 12 such as a chuck table, and the processed surface on the other side is ground, the curved surface is transferred to the processed surface. For this reason, it is necessary to form a flat reference surface, and a curable resin composition is coated on the 1st surface 10a of the wafer 10, and a flat surface is formed.

The method of coating the curable resin composition on the first surface 10a of the wafer 10 in step S120 is not particularly limited, and for example, filming, spin coating, screen printing, roll coater, die coater, or the like of the curable resin composition It can carry out by methods, such as a curtain coater. In FIG. 2B, the curable resin composition is coated on the light-transmissive flexible thin film 11 to a predetermined film thickness in advance to form a curable resin composition layer, and the wafer 10 is formed on the curable resin composition layer 20. The state which forms the curable resin composition layer 20 on the 1st surface 10a of the wafer 10 is shown by putting up.

Moreover, the film thickness of the curable resin composition layer 20 to coat is 10 micrometers-200 micrometers, Preferably you may be 20 micrometers-100 micrometers. By forming the curable resin composition layer 20 of the film thickness of this range, the curvature and curvature which exist in a wafer surface can fully be absorbed. If the film thickness is smaller than 10 mu m, the curable resin composition layer 20 cannot sufficiently absorb the impact during grinding of the wafer 10, resulting in curvature and curvature remaining. At the time of grinding, it is thrown off from the grinding grindstone, and as a result, bending and curvature remain. Moreover, when larger than 200 micrometers, when peeling and removing curable resin composition layer 20 by hot water immersion, moisture cannot penetrate enough to an adhesive interface, and it becomes difficult to peel cleanly without a residue.

Here, as curable resin composition to coat, (b1) hardening shrinkage rate is 7% or less, (b2) The value in 25 degreeC of the storage elastic modulus of a hardened | cured material is 1.0 * 10 < ⁶ > Pa ~ 3.0 * 10 <^9> Pa, More preferably, it is 5.0 It is curable resin composition which has a characteristic of * 10 < ⁶ > Pa ~ 1.5 * 10 <^9> Pa. When the cure shrinkage rate exceeds 7%, when the curable resin composition is cured, the wafer 10 follows the curable resin composition and warpage occurs in the wafer 10. If the value at 25 ° C of the storage modulus of the cured product exceeds 3.0 x 10 ⁹ GPa, the warpage and curvature of the wafer 10 cannot be absorbed. If the value is smaller than 1.0 x 10 ⁶ GPa, the wafer 10 at the time of grinding processing ) Is bounced off the grinding grindstone, and the warp and the bend are transferred to the processing surface, and the warp and the bend remain on the wafer surface, respectively.

Although it does not have a restriction | limiting in the kind as long as it is curable resin composition which has the characteristics as mentioned above, In this invention, (A) polyester di (meth) acrylate, polyurethane di (meth) acrylate, epoxy di (meth) acrylate And a (meth) acrylic compound having at least two (meth) acryl groups at both ends of the molecular chain, (b) a hydrophilic (meth) acryl compound having at least two (meth) acryl groups in the molecule, and (c) a photopolymerization initiator. It is preferable that it is curable resin composition. In addition, (meth) acryl is a generic term of acryl and methacryl as common.

Here, each component of (a), (b), and (c) is demonstrated. As (a) component used preferably in this invention, it selects from the polyester (meth) acrylate which has a (meth) acryl group in the both terminal of a molecular chain at least, a polyurethane (meth) acrylate, and an epoxy (meth) acrylate. It will not specifically limit, if it is at least 1 sort (s). Polyester (meth) acrylate is a compound which has the main chain structure of the polyester obtained by making a polyol and polybasic acid react, and has at least 2 acryl groups in the both ends of a molecular chain. Polyurethane (meth) acrylate is a compound which has a main chain skeleton of the polyurethane obtained by making a polyol and polyisocyanate react, and has an acryl group in the both terminal of a molecular chain at least. Epoxy (meth) acrylate is (meth) acrylic acid in an epoxy resin having at least two glycidyl groups in a molecule, such as bisphenol A or bisphenol F type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, and the like. It is a (meth) acryl compound which has the (meth) acryl group synthesize | combined by making it react and (meth) acrylation a glycidyl group in the both terminal of a molecular chain. In this invention, it is especially preferable that the number average molecular weights of (A) component are 600-1800 so that the cure shrinkage rate of curable resin composition may be 7% or less.

It will not specifically limit, if it is a hydrophilic (meth) acryl compound which has two (meth) acryl groups in a molecule at least as (b) component used preferably in this invention. The hydrophilic term herein refers to a structure having a high polarity atom or atomic group in a molecule and exhibiting a constant solubility in water or hot water. For example, a polyalkylene glycol structure such as polyethylene glycol or polypropylene glycol, an amide structure, a sulfonic acid The bifunctional (meth) acryl compound which has a structure, an alcohol structure, and the structure which has other polar functional group in a molecule | numerator, etc. are mentioned, Especially, the (meth) acryl compound [polyethylene glycoldi (meth) which has a polyethyleneglycol structure is mentioned. Acrylate] is preferred. Further, where the structure is to say a polyethylene _{glycol, - (CH 2 CH 2 O} ) - indicates that the structure has a repeating unit of two or more.

In order to make the value in 25 degreeC of the storage elastic modulus of the hardened | cured material of curable resin composition in this invention become 1.0 * 10 < ⁶ > Pa ~ 3.0 * 10 <^9> Pa, the number average molecular weight of polyethyleneglycol di (meth) acrylate is 1000 or less It is preferable to use the thing. In addition, when the curable resin composition layer 20 is formed on a PET film, by using polyethyleneglycol di (meth) acrylate as the (b) component, the curable resin composition layer 20 of the curable resin composition layer 20 No residue is left and peeling can be easily performed.

As (a) component, although the polymerization initiator compatible for (meth) acrylic-type resin can be used, it is preferable to use a photoinitiator in this invention in order to provide photocurability to curable resin composition. As an example of a photoinitiator, benzophenone, acetophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, tetramethyl thiuram sulfide, thioxane trichloro thioxanthone, benzyl dimethyl ketal, methyl benzoyl phospho Mate etc. are mentioned, but it is not limited to these. As a commercial item, DAROCURE 1173 (2-hydroxy-2-methyl-1-phenylpropan-1-one), IRGACURE 2959 (1- [4- (2-hydroxyethoxy) -phenyl] 2-hydroxy- 2-methyl-1-propan-1-one), IRGACURE 184 (1-hydroxycyclohexylphenyl ketone), IRGACURE 651 (2,2-dimethoxy-1,2-diphenylethan-1-one), IRGACURE 369 (2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1), IRGACURE 379 (2-dimethylamino-2- (4-methyl-benzyl) -1- (4 -Morpholin-4-yl-phenyl) -butan-1-one), IRGACURE 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, the said Chiba Specialty company make), etc. are mentioned. Among them, IRGACURE 184 is particularly preferred in the present invention from the viewpoint of curability, storage properties and peelability.

Curable resin composition of the said structure WHEREIN: In order that the value of hardening shrinkage rate of a hardened | cured body may be 7% or less, and the value in 25 degreeC of the storage elastic modulus (E ') of hardened | cured material is 1.0 * 10 < ⁶ > Pa ~ 3.0 * 10 <^9> Pa The active energy ray irradiation condition of is preferably 30 kJ / m 2, but the present invention is not limited thereto.

Moreover, from the viewpoint of workability at the time of coating, it is preferable that the viscosity at the time of uncuring is 1000 mPa * s-50000 mPa * s, Preferably it is 3000 mPa * s-10000 mPa * s, More preferably, Is preferably in the range of 4500 mPa · s to 6500 mPa · s. When the uncured viscosity of the curable resin composition is less than 1000 mPa · s, since the shape retention is too small, a coating film having a constant thickness cannot be formed, and formation on a film also becomes difficult. If the viscosity at the time of uncuring becomes larger than 50000 mPa * s, since fluidity | liquidity is too low, the coating process itself will become difficult.

Curable resin compositions used in the present invention include transparent fillers such as pigments, colorants such as dyes, reactive diluents such as low molecular weight monomers, fumed silica, glass microspheres, etc., in a range that does not impair the properties of the present invention. Inorganic fillers such as small amounts of calcium carbonate, magnesium carbonate, calcium sulfate, calcium silicate, barium sulfate, barium titanate, amorphous silica, clay, clay, diatomaceous earth, graphite, talc, carbon, silica sand, bengal, alumina, aluminum hydroxide, flame retardants, You may mix | blend suitably additives, such as a plasticizer, antioxidant, an antifoamer, a coupling agent, a leveling agent, and a rheology control agent. By addition of these, curable resin composition of more preferable physical property can be obtained.

By using curable resin composition of the said structure for this invention, the curvature of the wafer 10 which is a to-be-adhered member can be absorbed at the time of a grinding process, and the hardened | cured material of curable resin composition is easily carried out from the wafer 10 by hot water immersion. It can peel off.

The curable resin composition used by this invention also has the purpose of preventing the influence of the heat | fever to a wafer at the time of hardening, and is a photosensitive resin composition hardened | cured by irradiating active energy rays, such as an ultraviolet-ray, an electron beam, and a gamma ray. In addition, hardening of curable resin composition is performed by irradiating an active energy ray, after pressing the pressurizing means 13 from the wafer 10. This is because internal stress does not remain in the curable resin composition layer 20. If the internal stress remains in the curable resin composition layer 20, when the curable resin composition layer is removed from the wafer 10 after the grinding process, the wafer 10 is released from the internal stress and bent and bent again. This tends to occur.

Subsequently, the surface of the curable resin composition layer 20 coated on the first surface 10a of the wafer 10 is processed to be flat (step S130: planarization step). As a method of processing, for example, as shown in Fig. 2C, before curing the curable resin composition, by pressing means 13, such as a flat plate-like member, for example, a ceramic plate having a high flatness, is curable. The resin composition layer 20 is pressurized evenly. At this time, the surface which coated the curable resin composition is arrange | positioned on the stage 12 which has a flat and horizontal holding surface. Then, when pressurizing means 13 is spaced and coated on the surface which coated the curable resin composition, for example, the translucent film 11, an active energy ray is irradiated from the surface with the translucent film 11, and curable resin The composition layer 20 is cured (step S140: curable resin composition layer fixing step). By this process, the surface of the curable resin composition layer 20 on the opposite side to the wafer 10 is a cured body formed of a uniform flat surface. Since the cure shrinkage rate of the cured product of the curable resin composition is 7% or less, the new curvature due to the wafer 10 following the shrinkage of the curable resin composition does not occur by curing at this time, and a flat surface is formed. As shown in d), the flat surface of curable resin composition can be made into the reference surface at the time of processing the 2nd surface 10b of the wafer 10. FIG.

Thereafter, the second surface 10b of the wafer 10 is ground (step S150: first grinding step). In this step, the wafer 10 is placed so that the flat surface of the curable resin composition as the reference surface is brought into contact with the flat fixing member 12 such as the chuck table of the grinding apparatus, and is firmly held on the chuck table by vacuum suction or the like. . Thereafter, the driving force of the motor is transmitted through the spindle or the like to rotate the chuck table at a predetermined speed in the horizontal direction. Then, the driving force of the motor is transmitted from the upper side of the chuck table through the spindle and the diamond wheel to lower the grinding wheel while rotating at high speed. And the grinding grindstone is pressed to the 2nd surface 10b of the wafer 10, and it grinds until the wafer 10 becomes predetermined thickness. Thereby, the curvature of the 2nd surface 10b can be removed and the wafer 10 can be ground by the required thickness. In this way, the processing surface 10b is formed in the uniform flat surface by which the bending was removed as shown to (e) of FIG.

At this time, since the wafer 10 is fixed on the flat fixing member 12 by vacuum adsorption or the like of the vacuum adsorption apparatus, the relative position of the wafer 10 does not change even if a large stress acts on the wafer 10. Moreover, the curable resin composition layer 20 hardened | cured to the specific thickness is formed firmly in the wafer 10, and the hardened | cured material of curable resin composition has the value of E 'at 25 degreeC from 1.0x10 <^6> Pa ~ Since it has the characteristic of 3.0x10 <^9> Pa, since the curable resin composition layer 20 absorbs this stress even if a large stress acts on the wafer 10, elastic deformation does not generate | occur | produce in the wafer 10, Therefore, it is possible to eliminate the bend. Moreover, the curvature of the wafer 10 by hardening of curable resin composition can also be remarkably reduced by the characteristic that the cure shrinkage rate of the hardened | cured material of curable resin composition is 7% or less.

In the next step, the wafer 10 in which the curable resin composition layer 20 is integrated is inverted (FIG. 1 (f)). At this time, the curable resin composition layer 20 coated on the wafer 10 may be removed ( Step S160: curable resin composition layer removing process). In step S160, the curable resin composition layer 20 coated on the first surface 10a is removed before the first surface 10a is processed, but without removing the curable resin composition layer 20 in this step, You may grind and remove the curable resin composition layer 20 simultaneously with grinding a wafer in a 2nd grinding process. It does not specifically limit as a method of removing the curable resin composition layer 20, For example, the method of melt | dissolving and removing the curable resin composition layer 20 with a solvent, the curable resin composition layer 20 is deformed by radiation, such as light, The method of peeling and removing, the method of apply | coating a force in the direction which the coated curable resin composition layer 20 peels easily, and peeling and removing the curable resin composition layer 20 or immersed in hot water of 60 degreeC-90 degreeC, and it is curable The method of peeling removal etc. can be employ | adopted by swelling the resin composition layer 20. When the curable resin composition layer 20 is formed on the light transmissive film 11, it can be easily peeled off with the light transmissive film 11. In addition, although the curable resin composition layer 20 may remain in the 1st surface 10a of the wafer 10, the residue is also removed in the next 2nd grinding process.

In addition, after inverting the wafer by the above steps, the first surface 10a is ground (step S170: second grinding step). As shown in Fig. 2G, in step S170, the wafer 10 is fixed so that the second surface 10b processed in step S140 abuts on a flat fixing member 12 such as a chuck table. Put on (12). Then, the grinding grindstone is pressed against the first surface 10a of the wafer 10, and the first surface 10a is ground to remove the bending of the first surface 10a, thereby making the wafer 10 the required thickness. Grinding is possible. In this way, the bend of the first surface 10a and the second surface 10b, as shown in Fig. 2H, is removed, and a wafer ground to a predetermined thickness is formed.

Here, after removing the curable resin composition layer 20 in step S160, the first surface 10a was ground in step S170, but step S160 may be omitted. In this case, after grinding the 2nd surface 10b by step S150, the wafer 10 is mounted so that the ground 2nd surface 10b may contact the fixing member 12. As shown in FIG. Then, the grinding grindstone is pressed to the curable resin composition layer 20, and the curable resin composition is ground and removed. When grinding progresses, the grinding grindstone reaches the 1st surface 10a, and further grinds the wafer 10, removes the curvature of the 1st surface 10a, and cuts the wafer 10 to predetermined thickness. . In this way, by one pass grinding, the curable resin composition can be removed and the first surface 10a can be ground, and the curvature of the first surface 10a and the second surface 10b is removed, and predetermined To form a wafer ground to a thickness of.

After that, the wafer is preferably removed by etching with acid or alkali or by polishing such as CMP (Chemical Mechanical Polishing) (step S180).

In the above, the manufacturing method of the wafer which concerns on this embodiment was demonstrated. This invention is characterized by specifying the hardened | cured material characteristic of the curable resin composition coated by step S120 as follows. (b1) The cure shrinkage rate of the cured product is 7% or less, and the value at 25 ° C. of the storage elastic modulus (E ′) of the cured product is 1.0 × 10 ⁶ Pa to 3.0 × 10 ⁹ Pa. Moreover, as curable resin composition which has such a characteristic, it is chosen from (A) polyester di (meth) acrylate, polyurethane di (meth) acrylate, and epoxy di (meth) acrylate, and it is at least at both terminal of a molecular chain. The thing comprised by the (meth) acryl compound which has a (meth) acryl group, (b) a hydrophilic (meth) acryl compound which has two (meth) acryl groups in at least a molecule | numerator, and a (c) photoinitiator can be used especially preferably.

This invention also includes the manufacturing apparatus of the wafer which can implement the said process. For example, the apparatus of the structure shown in FIG. 3, ie, the resin coating means which can convey and coat the strip | belt-shaped film 100 which can carry a wafer, and the curable resin composition on the surface of the film 100 ( 101), a unit (not shown) for supplying and placing the wafer 110 on the film 100 coated with the curable resin composition, and the wafer 110 placed on the film 100 on the stage 120. Pressurizing means 121 for pressurizing and planarizing, curing means 130 for curing the curable resin composition on the surface of the wafer 110 by irradiating an active energy ray to the wafer 110, and curing the curable resin composition. Thereafter, the cutting means 140 which cuts together with the film 100 so as to surround the wafer 110 and the unplanarized surface of the wafer 110 which was cut together with the film 100, although not all illustrated, are ground. First grinding means for Although the wafer 110, which has been ground on one side, is inverted from the front to back, the device is constituted by second grinding means for grinding the other surface that is not planarized, but the present invention is not limited thereto. .

When the said manufacturing apparatus is explained in full detail, the film 100 formed in roll shape is sent out from the motor of one end, and wound up by the motor of the other end.

In the resin application means 101, after apply | coating the said liquid curable resin composition on the film 100 with a slit coater etc., the wafer 110 is supplied from a wafer supply means (not shown) on the applied curable resin composition. Then, the wafer 110 and the film 100 are sandwiched between the rollers and then transferred to the pressing means 121.

The hardening means 130 is arrange | positioned inside the stage 120 of the pressurizing means 121, and irradiates the UV lamp 131 from the film side, and hardens curable resin composition. Moreover, the blocking means 132 which opens and closes is arrange | positioned on the upper part of the UV lamp 131, and when this blocking means 132 is closed, all the light emitted from the UV lamp 131 is interrupted | blocked. In addition, a filter 133 for blocking light other than ultraviolet light is disposed above the blocking means 132. In addition, since the temperature inside the stage 120 rises due to the irradiation of the UV lamp 131 and the stage 120 may thermally expand, the exhaust means 135 discharges the internal atmosphere to the outside. have.

The cutting means 140 is provided with a ring-shaped cutting edge larger than the diameter of the wafer 110 and cut out together with the film 100 to surround the wafer 110 on the stage.

Subsequently, the wafer 110 advances in the direction of the arrow and is accommodated in a cassette or the like. Then, only the film 150 cut around the wafer is wound up.

Thereafter, the wafer 110 is conveyed to the grinding apparatus and the surface is ground flat.

Moreover, although this invention also contains curable resin composition used for the manufacturing method of the wafer demonstrated above, curable resin composition of this invention satisfy | fills (b1) and (b2) mentioned above.

<Example>

Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, the manufacturing method of the wafer of this invention is not limited to these examples.

The following apparatus and conditions were applied and the wafer which concerns on this invention was manufactured.

Substrate wafer: Silicon as a φ 200 mm slice wafer (wire top finish).

Curing shrinkage rate: Curing shrinkage rate was calculated by curing the curable resin composition under irradiation conditions of cumulative light amount 30 kJ / m 2 x 2 times using the volume shrinkage rate specified in JIS-K-6901 and measuring the volume change before and after curing. .

Storage modulus: The curable resin composition was cured under viscous spectrometer (DMS, manufactured by SAI Eye Nanotechnology Co., Ltd.) under irradiation conditions of 30 kJ / m 2 x accumulated light quantity, and the storage modulus of the cured product was measured.

Film formability evaluation: When the curable resin composition is coated with a slit coater on a PET film having a thickness of 75 µm with a predetermined thickness, it is possible to form a film integrated with the curable resin composition layer. Evaluated. The passability of the curable resin composition layer having a constant film thickness was passed, and the failure to form the curable resin composition layer having a constant film thickness was rejected due to excessive fluidity or a problem in workability. It was. In addition, in Example 6, curable resin composition was directly coated on the wafer, without using a film.

-Warpage evaluation: WARP and a best fit were measured by the optical interference type flatness measuring device (made by ADE company). (Circle) and the thing which became 10 micrometers or less (circle) and the thing larger than 10 micrometers which made curvature became about 8 micrometers or less were made into x.

Bending evaluation: Visually evaluated the remaining property of a bending by performing a magic mirror observation with YIS-3000 by Yamashita Denso. As shown in Fig. 4, the curve completely disappeared,?, The curve almost disappeared as shown in Fig. 5, ○, and the residual of the curve was shown as shown in Fig. 6 ×.

Film peeling: When peeling the curable resin composition layer formed on the film, it was represented by (circle) as pass that the curable resin composition layer was able to peel cleanly without a residue, and the residue which remained was represented by x as rejection.

Curable resin composition used by the Example and the comparative example is as follows.

Curable resin composition A: 60 weight part of polyurethane diacrylates (Mn 1600), 40 weight part of polyethyleneglycol diacrylates (Mn 550), 5 weight part of cleavage type radical polymerization initiators (IRGACURE 184), viscosity It consists of 3 weight part of modifiers (dry silica powder).

Curable resin composition B: It consists of 50 weight part of polyurethane diacrylates (Mn 1600), 50 weight part of polyethyleneglycol diacrylates (Mn550), and 5 weight part of cleavage type radical polymerization initiators.

Curable resin composition C: It consists of 65 weight part of epoxy diacrylates (Mn 1500), 35 weight part of polyethyleneglycol diacrylates (Mn 1150), 5 weight part of cleavage type radical polymerization initiators, and 3 weight part of viscosity modifiers.

Curable resin composition D: It consists of 60 weight part of polyester diacrylates (Mn1200), 40 weight part of polyethyleneglycol diacrylates (Mn550), and 5 weight part of cleavage type radical polymerization initiators.

Curable resin composition E: It consists of 30 weight part of polyurethane diacrylates (Mn 1600), 20 weight part of polyethyleneglycol diacrylates (Mn 550), 50 weight part of acrylic monomers, and 5 weight part of cleavage type radical polymerization initiators.

Curable resin composition F: 65 weight part of polyurethane diacrylates (Mn 1600), 35 weight part of 2-hydroxy-3- (acryloyloxy) propyl methacrylate, 5 weight part of cleavage type radical polymerization initiators, a viscosity The adjuster consists of 5 parts by weight.

Curable resin composition G: It consists of 50 weight part of polyurethane diacrylates (Mn2000), 50 weight part of polyethyleneglycol diacrylates (Mn550), 5 weight part of cleavage type radical polymerization initiators, and 4 weight part of viscosity modifiers.

Curable resin composition H: 50 weight part of polyester monoacrylates (Mn 950), 50 weight part of polyethyleneglycol diacrylates (Mn 800), 20 weight part of alicyclic monoacryl monomers, 5 weight part of cleavage type radical polymerization initiators, It consists of 11 weight part of viscosity modifiers.

Curable resin composition I: It consists of 50 weight part of epoxy diacrylates (Mn 1500), 50 weight part of polyethyleneglycol monoacrylates (Mn360), 5 weight part of cleavage type radical polymerization initiators, and 7 weight part of viscosity modifiers.

Curable resin composition J: It consists of 65 weight part of epoxy diacrylates (Mn 1500), 35 weight part of hydroxyalkyl monoacryl monomers, 5 weight part of cleavage type radical polymerization initiators, and 7 weight part of viscosity modifiers.

Curable resin composition K: It consists of 100 weight part of polyethyleneglycol diacrylates (Mn800), 5 weight part of cleavage type radical polymerization initiators, and 10 weight part of viscosity modifiers.

In Comparative Example 1, the wafer surface was ground without using the curable resin composition, but as a result of the flatness measurement, large warpage remained, and as shown in the magic mirror observation photograph of FIG. 7, curvature remained on the surface. On the other hand, in the wafer manufactured using curable resin composition contained in the structure of this invention, the curvature and the surface curvature were all lost.

Moreover, even when curable resin composition is used, in curable resin composition which does not satisfy said (b1) and (b2) according to this invention, it turns out that the curvature of a wafer and curvature of a surface remain | survive. That is, it can be seen that the cured shrinkage is greater than 7%, the storage modulus is greater than 3.0 x 10 ⁹ GPa, and less than 1.0 x 10 ⁶ GPa, the curvature or bending remains on the wafer surface. Even curing shrinkage percentage is less than 7%, the storage elastic modulus is 1.0 × 10 ⁶ ㎩~3.0 × not in the range of 10 ⁹ ㎩ warp, bending, and both remaining, opposed to storage modulus is 3.0 × 10 ⁹ ㎩ below even the curing shrinkage ratio of 7% In larger cases, the curvature disappeared but the curvature remained. This is considered to be bent by following the wafer due to the curing shrinkage of the curable resin composition. Moreover, even if both the cure shrinkage rate and the storage elastic modulus were in the prescribed range, when the film thickness was larger than 200 micrometers, it was confirmed that curvature and curvature cannot be removed.

According to the present invention, since the wafer can be processed with high accuracy and smoothness in grinding the wafer, a high quality wafer can be provided.

1 is a flowchart showing a method of manufacturing a wafer of the present invention.

It is a schematic diagram for demonstrating the coating process of this invention and the surface processing process of curable resin composition layer.

It is a schematic diagram of an example of the wafer manufacturing apparatus of this invention.

4 is a photograph of a magic mirror observation of the wafer where the bending is completely lost.

5 is a photograph of a magic mirror observation of the wafer with almost no bends.

6 is a magic mirror observation photograph of a wafer in which residual curvature is observed.

7 is a magic mirror observation photograph of a wafer manufactured without using the curable resin composition.

8 is a flowchart showing a conventional method for manufacturing a wafer.

<Description of the symbols for the main parts of the drawings>

10: wafer 10a: first surface of the wafer

10b: second surface 11 of wafer: translucent film

12: flat fixing member 13: flat plate pressing member

20: curable resin composition layer

Claims (6)

A wafer manufacturing method comprising the following steps (A) to (F). (A) Pre-process of preparing thin wafer obtained by slice from ingot (B) Curable resin composition layer forming process which coats curable resin composition which has the characteristics of following (b1) and (b2) with the film thickness of 10 micrometers-200 micrometers on the 1st surface of the said wafer. (b1) curing shrinkage is 7% or less (b2) The value at 25 degrees C of the storage elastic modulus (E ') of a hardened | cured material is 1.0 * 10 < ⁶ > Pa ~ 3.0 * 10 <^9> Pa (C) Flattening process which planarizes the curable resin composition layer apply | coated to the 1st surface by pressing the 2nd surface of the wafer which coated the said curable resin composition with a pressurizing means. (D) After releasing the pressurization by the pressurizing means, the curable resin composition layer immobilization step of irradiating an active energy ray to the curable resin composition layer coated on the wafer and curing it on the wafer surface. (E) First grinding step of smoothly grinding the second surface of the wafer fixed in the curable resin composition layer (F) A second grinding step of grinding the first surface by using the second surface of the wafer flattened by the first grinding step as a reference surface. The curable resin composition according to claim 1, wherein the curable resin composition in the step (B) is selected from (a) polyester di (meth) acrylate, polyurethane di (meth) acrylate, epoxydi (meth) acrylate, It is a curable resin composition which consists of a (meth) acryl compound which has a (meth) acryl group in the both ends of a molecular chain, a (b) hydrophilic (meth) acryl compound which has two (meth) acryl groups in a molecule | numerator, and (c) photoinitiator. The manufacturing method of the wafer made into. The curable resin composition layer forming process in the said (B) process is a process of putting the said wafer on the curable resin composition previously coated on the film which has translucency, The said (B) process characterized by the above-mentioned. Wafer manufacturing method. The wafer manufacturing method of Claim 1 or 2 whose viscosity at the time of uncuring of curable resin composition in the said (B) process is 1000 mPa * s-50000 mPa * s. A wafer manufacturing apparatus used in the method for manufacturing a wafer according to claim 1 or 2, comprising: a stage having a horizontal holding surface for holding the first surface to expose the second surface of the wafer coated with the curable resin composition. And pressurizing means for pressing the wafer, which is disposed opposite to the stage and held on the stage, from the second surface side to the stage direction, and active energy for irradiating an active energy ray to the curable resin composition applied to the wafer. A reference plane based on a line irradiation means, first grinding means for smoothly grinding the second surface of the wafer fixed in the curable resin composition layer, and the second surface of the wafer flattened by the first grinding means The wafer manufacturing apparatus characterized by including the 2nd grinding means which grinds the said 1st surface. Curable resin composition used for the manufacturing method of the wafer of Claim 1 or 2 which has the characteristics of following (b1) and (b2), Curable resin composition characterized by the above-mentioned. (b1) curing shrinkage is 7% or less (b2) The value at 25 ° C of the storage modulus (E ') of the cured product was 1.0 × 10 ⁶ Pa to 3.0 × 10 ⁹ Pa

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