JP2011129606A - Method of processing semiconductor wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of processing a semiconductor wafer, capable of reducing chip warpage when dividing the semiconductor wafer in an expansion process and reducing chip recognition defects owing to the chip warpage in a pickup process. <P>SOLUTION: The method of processing the semiconductor wafer includes a step of sticking a surface protection tape to the pattern surface of the semiconductor wafer whose backside is stuck to a tape for wafer processing and which has the origins of dicing or cutting formed by a chip unit. Preferably, the method may have the expansion step of expanding the tape for wafer working by elevating an upthrust member from the lower surface of the tape for wafer processing, and also dividing the semiconductor wafer into semiconductor chips. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for processing a semiconductor wafer used in a manufacturing process of a semiconductor device having an expanding process.

  In the manufacturing process of a semiconductor device by a new technology developed in recent years, after attaching a stretchable wafer processing tape to a semiconductor wafer, a step of dicing the semiconductor wafer in units of chips, a step of expanding the wafer processing tape, Further, a step of picking up the diced chip and a die bonding step are performed.

As a wafer processing tape used in the manufacturing process of the semiconductor device, a wafer processing tape in which an adhesive layer is provided on a base film, or a structure in which an adhesive layer is further laminated on the adhesive layer. A general semiconductor wafer dicing process, expanding process, and pick-up process that have been proposed and already put into practical use will be described with reference to FIG. As shown in FIG. 6A, first, a semiconductor wafer 91 and a wafer processing tape 90 in which a base film 93a, an adhesive layer 93b formed thereon, and an adhesive layer 94 are laminated in this order. The ring frame 92 is bonded together. Here, the ring frame 92 is bonded to the pressure-sensitive adhesive layer 93 b, and the semiconductor wafer 91 is bonded to the adhesive layer 94.

  Next, as shown in FIG. 6B, the wafer processing tape 90 is sucked and supported by the suction stage 96 from the base film 93a side. Then, the semiconductor wafer 91 and the adhesive layer 94 are diced into units of semiconductor chips 97 by the dicing blade 95 and separated into individual pieces.

  Thereafter, as shown in FIG. 6C, an expanding process is performed in which the wafer processing tape 90 holding the diced semiconductor chip 97 and the adhesive layer 94 is stretched in the radial direction and the circumferential direction of the ring frame 92. Specifically, with respect to the wafer processing tape 90 in a state where the plurality of diced semiconductor chips 97 and the adhesive layer 94 are held, a hollow cylindrical push-up member 98 is provided from the lower surface side of the wafer processing tape 90. Then, the wafer processing tape 90 is stretched in the radial direction and the circumferential direction of the ring frame 92. By the expanding step, it is possible to widen the distance between the chips and improve the chip recognizability by a CCD camera or the like, and to prevent re-adhesion of the chips caused by contact between adjacent chips during pickup.

  After performing the expanding process, a pick-up process for picking up the semiconductor chip 97 and the adhesive layer 94 is performed while the wafer processing tape 90 is expanded.

  As a method for dividing a semiconductor wafer, there has been proposed a method for dividing a wafer in a non-contact manner using a laser processing apparatus.

  For example, Patent Document 1 discloses that a semiconductor substrate is irradiated with a laser beam focused on the inside of a semiconductor substrate on which a sheet wafer processing tape with a die bond resin layer (adhesive layer) interposed is attached. A step of forming a modified region by multiphoton absorption inside, forming a portion to be divided at the modified region, and a step of dividing the semiconductor substrate and the die bond resin layer along the portion to be divided by expanding the sheet A method for dividing a semiconductor substrate comprising:

  In the method for dividing a semiconductor substrate disclosed in Patent Document 1, a semiconductor wafer and a die bond resin layer (adhesive layer) can be divided in a non-contact manner by laser light irradiation and wafer processing tape expansion, so a dicing blade is used. The semiconductor wafer can be divided without causing chipping as in the case.

JP 2003-338467 A

  As described above, the expanding process is performed in order to widen the distance between semiconductor chips separated by a dicing blade (hereinafter referred to as “chips”), or the semiconductor wafer and the adhesive layer irradiated with laser light in units of chips. Implemented to break up. However, in the wafer processing tape expand as described with reference to FIG. 6, the chip that has been singulated is warped due to the stress on the pattern surface caused by the deposited oxide film, etc. There is a problem that chip recognition failure by a camera or the like occurs, and chip breakage occurs due to contact between adjacent chips when picking up a chip.

  Therefore, the present invention has been made to solve the above-described problems, and in the expanding process, it is possible to prevent warping of chips separated by dividing the semiconductor wafer, and to improve the chip quality. An object of the present invention is to provide a semiconductor wafer processing method capable of obtaining sufficient chip recognizability for pick-up.

The present invention
(1) A wafer processing tape is bonded to the back surface of a semiconductor wafer, and a starting point for half-cutting or cutting is formed for each chip on the pattern surface of the semiconductor wafer on which a starting point for dicing or cutting is formed for each chip. A step of pasting the surface protection tape, and by raising the push-up member from the lower surface of the wafer processing tape, the wafer processing tape is stretched and the semiconductor wafer is divided into semiconductor chips, and at the same time, the surface protection An expanding step of dividing the tape, and a method for processing a semiconductor wafer, comprising:
(2) A step of bonding a surface protective tape to a pattern surface of a semiconductor wafer in which a wafer processing tape is bonded to the back surface of the semiconductor wafer, and a starting point of dicing or cutting is formed on a chip basis, and the wafer A semiconductor wafer comprising: an expanding step for extending the wafer processing tape and the surface protection tape by raising a push-up member from a lower surface of the processing tape, and dividing the semiconductor wafer into semiconductor chips. Processing method,
(3) A step of bonding a surface protection tape to the pattern surface of the semiconductor wafer, a step of grinding the back surface of the semiconductor wafer, and affixing the back surface of the ground semiconductor wafer and the ring frame to the tape for wafer processing. A step of dicing the semiconductor wafer in units of chips without peeling off the surface protective tape, and raising a push-up member from the lower surface of the wafer processing tape without peeling off the surface protective tape. An expanding step of stretching the wafer processing tape and dividing the semiconductor wafer into semiconductor chips, and a method for processing a semiconductor wafer,
(4) The wafer processing tape has a base film, a pressure-sensitive adhesive layer, and an adhesive layer, and is adhered to the lower surface of the ring frame by the pressure-sensitive adhesive layer. The method for processing a semiconductor wafer according to any one of (1) to (3), wherein the semiconductor wafer is bonded to a layer,
(5) The surface protection tape is formed by laminating a base film and a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is composed of a single layer or multiple layers, and at least one of the pressure-sensitive adhesive layers is a radiation curable type. The method for processing a semiconductor wafer according to any one of (1) to (4),
(6) A step of bonding a wafer processing tape bonded to the lower surface of the ring frame to a pattern surface of a semiconductor wafer, a step of forming a starting point of dicing or cutting on the semiconductor wafer in units of chips, and the wafer A semiconductor wafer processing method comprising: an expanding step of extending the wafer processing tape by extending a push-up member from a lower surface of the processing tape and dividing the semiconductor wafer into semiconductor chips,
Is to provide.

  According to the present invention, it is possible to provide a semiconductor wafer processing method capable of reducing chip warpage when a semiconductor wafer is divided in an expanding process and reducing chip recognition failure due to chip warpage in a pickup process.

(A)-(c) The schematic sectional drawing explaining the processing method of the semiconductor wafer which concerns on 1st Embodiment. The perspective view of the semiconductor wafer fixed to the ring frame. (A)-(b) The schematic sectional drawing explaining another example of the processing method of the semiconductor wafer which concerns on 1st Embodiment. (A)-(e) The schematic sectional drawing explaining the processing method of the semiconductor wafer which concerns on 2nd Embodiment. (A)-(b) The schematic sectional drawing explaining the processing method of the semiconductor wafer which concerns on 3rd Embodiment. (A)-(c) The schematic sectional drawing explaining the dicing process of a semiconductor wafer, an expanding process, and a pick-up process.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In the following description and drawings, components having substantially the same functional configuration will be denoted by the same reference numerals, and redundant description will be omitted.

(First embodiment)
First, a first embodiment of a semiconductor wafer processing method according to the present invention will be described with reference to FIGS.
FIG. 1 is a schematic cross-sectional view showing a method for processing a semiconductor wafer according to the first embodiment, FIG. 2 is a perspective view of the semiconductor wafer 1 fixed to a ring frame 13, and FIG. 3 shows the first embodiment. It is a figure which shows another example of the processing method of the semiconductor wafer which concerns.

  A semiconductor wafer 1 according to the present invention is a silicon wafer or the like having a pattern surface 3 on which a circuit or the like is formed on one side, and a back grinding process and a dicing process have already been completed. Layering is performed, and a part serving as a starting point of cutting or cutting is formed for each chip.

  The adhesive layer 9 of the wafer processing tape 11 is bonded to the back surface of the pattern surface 3 of the semiconductor wafer 1, and the adhesive layer 7 of the wafer processing tape 11 is bonded to the lower surface of the ring frame 13. ing. The ring frame 13 is an annular flat plate and is made of metal or resin, particularly stainless steel.

  The wafer processing tape 11 is formed by laminating an adhesive layer 7 and an adhesive layer 9 in this order on a base film 5.

(Base film)
The material constituting the base film 5 can be used without particular limitation as long as it is a conventionally known material. However, as will be described later, in the present embodiment, as the pressure-sensitive adhesive layer 7, energy curable is used. Since a radiation curable material is used among these materials, a material having radiation transparency is used. In addition, it is preferable to use an ultraviolet ray as the radiation, and it is preferable to use an ultraviolet curable material as the pressure-sensitive adhesive layer 7 as the base film 5 has ultraviolet transparency.

  For example, as the material, polyethylene, polypropylene, ethylene-propylene copolymer, polybutene-1, poly-4-methylpentene-1, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic Α-olefin homopolymer or copolymer such as acid methyl copolymer, ethylene-acrylic acid copolymer, ionomer or a mixture thereof, polyurethane, styrene-ethylene-butene or pentene copolymer, polyamide-polyol Listed are thermoplastic elastomers such as copolymers, and mixtures thereof. Moreover, the base film 5 may be a mixture of two or more materials selected from these groups, or may be a single layer or a multilayer. The thickness of the base film 5 is not particularly limited and may be appropriately set, but is preferably 50 to 200 μm.

(Adhesive layer)
The pressure-sensitive adhesive layer 7 can be produced by applying a pressure-sensitive adhesive on the base film 5. The pressure-sensitive adhesive layer 7 is not particularly limited. For example, in the case of the wafer processing tape 11 shown in FIG. Furthermore, since it peels between the adhesive layer 7 and the adhesive layer 9, what is necessary is just to have the ease of peeling from the adhesive layer 9. In order to improve the pickup property, the pressure-sensitive adhesive layer 7 is preferably a radiation curable material, and is preferably a material that can be easily peeled off from the adhesive layer 9 after the radiation curing.

  On the other hand, in the case of a wafer processing tape that does not have the adhesive layer 9, when expanding, the retainability to the extent that a diced and separated semiconductor chip does not peel off, Any material having ease of peeling may be used. In order to improve the pick-up property, the pressure-sensitive adhesive layer 7 is preferably a radiation curable material, and is preferably a material that can be easily separated from the semiconductor chip after the radiation curing.

  The pressure-sensitive adhesive layer 7 can also function as the adhesive layer 9 for bonding and fixing a diced semiconductor chip. That is, after the dicing and singulated semiconductor chip and the pressure-sensitive adhesive layer 7 are picked up integrally, the pressure-sensitive adhesive layer 7 is heated to function as an adhesive that fixes the semiconductor chip in a predetermined position. it can.

  For example, the main component is an acrylic copolymer having at least a radiation-curable carbon-carbon double bond-containing group, a hydroxyl group and a carboxyl group-containing group, and the gel fraction is 60% or more. It is preferable that Furthermore, at least one selected from a compound (A) having a radiation curable carbon-carbon double bond having an iodine value of 0.5 to 20 in the molecule, a polyisocyanate, a melamine / formaldehyde resin, and an epoxy resin. It is preferable to contain a polymer obtained by addition reaction of the compound (B).

  The compound (A) that is one of the main components of the pressure-sensitive adhesive layer 7 will be described. A preferable introduction amount of the radiation curable carbon-carbon double bond of the compound (A) is 0.5 to 20, more preferably 0.8 to 10 in terms of iodine value. If the iodine value is 0.5 or more, an effect of reducing the adhesive strength after irradiation can be obtained. If the iodine value is 20 or less, the fluidity of the adhesive after irradiation is sufficient and after stretching. Therefore, the problem that the image recognition of each element becomes difficult at the time of pick-up can be suppressed. Furthermore, the compound (A) itself is stable and easy to manufacture.

  The compound (A) preferably has a glass transition point (hereinafter referred to as Tg) of −70 ° C. to 0 ° C., more preferably −66 ° C. to −28 ° C. If Tg is −70 ° C. or higher, the heat resistance against heat associated with radiation irradiation is sufficient, and if it is 0 ° C. or lower, the effect of preventing scattering of elements after dicing in a semiconductor wafer having a rough surface state is sufficiently obtained.

  The compound (A) may be produced by any method, and has, for example, a radiation curable carbon-carbon double bond such as an acrylic copolymer or a methacrylic copolymer, and a functional group. A compound obtained by reacting a compound having the functional group ((1)) with a compound having a functional group capable of reacting with the functional group ((2)) is used.

  Among these, the compound ((1)) having the radiation curable carbon-carbon double bond and the functional group is a single compound having a radiation curable carbon-carbon double bond such as an acrylic acid alkyl ester or a methacrylic acid alkyl ester. It can be obtained by copolymerizing a monomer ((1) -1) and a monomer ((1) -2) having a functional group. About the amount of adhesive double bonds, the amount of carbon-carbon double bonds contained in about 10 g of the heat-dried adhesive can be quantitatively measured by a weight increase method by bromine addition reaction in a dark place in vacuum.

  As a monomer ((1) -1), C6-C12 hexyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, decyl acrylate, or a single quantity of 5 or less carbon atoms The pentyl acrylate, n-butyl acrylate, isobutyl acrylate, ethyl acrylate, methyl acrylate, or methacrylates similar to these can be listed.

  As the monomer ((1) -1) is used, the glass transition point becomes lower as the monomer having a larger carbon number is used, so that the desired Tg can be produced. In addition to Tg, it is also possible to blend a low molecular compound having a carbon-carbon double bond such as vinyl acetate, styrene, acrylonitrile for the purpose of improving compatibility and various performances of the monomer ((1) -1). It is possible within the range of 5% by mass or less of the total mass.

  Examples of the functional group of the monomer ((1) -2) include a carboxyl group, a hydroxyl group, an amino group, a cyclic acid anhydride group, an epoxy group, and an isocyanate group. The monomer ((1)- Specific examples of 2) include acrylic acid, methacrylic acid, cinnamic acid, itaconic acid, fumaric acid, phthalic acid, 2-hydroxyalkyl acrylates, 2-hydroxyalkyl methacrylates, glycol monoacrylates, glycol monomethacrylates. N-methylolacrylamide, N-methylolmethacrylamide, allyl alcohol, N-alkylaminoethyl acrylates, N-alkylaminoethyl methacrylates, acrylamides, methacrylamides, maleic anhydride, itaconic anhydride, fumaric anhydride, Phthalic anhydride, glycidyl acrylic And glycidyl methacrylate, allyl glycidyl ether, and those obtained by urethanizing a part of the isocyanate group of a polyisocyanate compound with a monomer having a hydroxyl group or a carboxyl group and a radiation curable carbon-carbon double bond. it can.

  In the compound (2), as the functional group used, when the functional group of the compound (1), that is, the monomer ((1) -2) is a carboxyl group or a cyclic acid anhydride group, a hydroxyl group, Examples include an epoxy group and an isocyanate group. In the case of a hydroxyl group, examples include a cyclic acid anhydride group and an isocyanate group. In the case of an amino group, examples include an epoxy group and an isocyanate group. In the case of an epoxy group, a carboxyl group, a cyclic acid anhydride group, an amino group and the like can be mentioned. Specific examples include those listed in the specific examples of the monomer ((1) -2) Can be listed.

  By leaving an unreacted functional group in the reaction between the compound (1) and the compound (2), it is possible to produce those specified in the present invention with respect to characteristics such as acid value or hydroxyl value.

  In the synthesis of the above compound (A), as the organic solvent when the reaction is carried out by solution polymerization, ketone, ester, alcohol, and aromatic solvents can be used, among which toluene, ethyl acetate , Isopropyl alcohol, benzene methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, etc., are generally good solvents for acrylic polymers, preferably having a boiling point of 60 to 120 ° C., and α, α′-azobisisobutyl as a polymerization initiator A radical generator such as an azobis type such as nitrile or an organic peroxide type such as benzoyl peroxide is usually used. At this time, a catalyst and a polymerization inhibitor can be used together as necessary, and the compound (A) having a desired molecular weight can be obtained by adjusting the polymerization temperature and the polymerization time. In terms of adjusting the molecular weight, it is preferable to use a mercaptan or carbon tetrachloride solvent. This reaction is not limited to solution polymerization, and other methods such as bulk polymerization and suspension polymerization may be used.

  Although the compound (A) can be obtained as described above, the weight average molecular weight of the compound (A) is preferably about 300,000 to 1,000,000. If it is less than 300,000, the cohesive force due to radiation irradiation becomes small, and when the semiconductor wafer is diced, chip displacement tends to occur, and image recognition may be difficult. In order to prevent this chip displacement as much as possible, the weight average molecular weight is preferably 400,000 or more. Moreover, when a weight average molecular weight exceeds 1 million, there exists a possibility of gelatinizing at the time of a synthesis | combination and a coating. In addition, the weight average molecular weight in this invention is a weight average molecular weight of polystyrene conversion.

  In addition, it is preferable that the compound (A) has a hydroxyl group having a hydroxyl value of 5 to 100 because the risk of pick-up mistakes can be further reduced by reducing the adhesive strength after radiation irradiation. Moreover, it is preferable that a compound (A) has a carboxyl group used as acid value 0.5-30.

  Here, if the hydroxyl value of the compound (A) is too low, the effect of reducing the adhesive strength after irradiation is not sufficient, and if it is too high, the fluidity of the adhesive after irradiation tends to be impaired. If the acid value is too low, the effect of improving the tape restoring property is not sufficient, and if it is too high, the fluidity of the pressure-sensitive adhesive tends to be impaired.

  Next, the compound (B) which is another main component of the pressure-sensitive adhesive layer 7 will be described. The compound (B) is a compound selected from polyisocyanates, melamine / formaldehyde resins, and epoxy resins, and can be used alone or in combination of two or more. This compound (B) acts as a cross-linking agent, and the cohesive force of the pressure-sensitive adhesive mainly composed of the compounds (A) and (B) is reduced by the cross-linking structure formed as a result of reaction with the compound (A) or the base film 5. It can be improved after applying the agent.

  The polyisocyanates are not particularly limited, and examples thereof include 4,4′-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, 4,4′-diphenyl ether diisocyanate, 4,4 ′-[2,2-bis (4 -Phenoxyphenyl) propane] aromatic isocyanate such as diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethyl-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate Lysine diisocyanate, lysine triisocyanate and the like. Specifically, Coronate L (made by Nippon Polyurethane Co., Ltd., trade name) or the like can be used.

  Specific examples of the melamine / formaldehyde resin include Nicalac MX-45 (trade name, manufactured by Sanwa Chemical Co., Ltd.), Melan (trade name, manufactured by Hitachi Chemical Co., Ltd.), and the like. Furthermore, as an epoxy resin, TETRAD-X (Mitsubishi Chemical Corporation make, brand name) etc. can be used.

  The addition amount of (B) needs to be selected so as to be a ratio of 0.1 to 10 parts by mass, preferably 0.4 to 3 parts by mass with respect to 100 parts by mass of the compound (A). By selecting within this range, it is possible to obtain an appropriate cohesive force, and the crosslinking reaction does not proceed abruptly, so that workability such as blending and application of the adhesive is improved.

  The pressure-sensitive adhesive layer 7 preferably contains a photopolymerization initiator (C). There is no restriction | limiting in particular in the photoinitiator (C) contained in the adhesive layer 7, A conventionally well-known thing can be used. For example, benzophenones such as benzophenone, 4,4′-dimethylaminobenzophenone, 4,4′-diethylaminobenzophenone and 4,4′-dichlorobenzophenone, acetophenones such as acetophenone and diethoxyacetophenone, 2-ethylanthraquinone, t- Examples include anthraquinones such as butylanthraquinone, 2-chlorothioxanthone, benzoin ethyl ether, benzoin isopropyl ether, benzyl, 2,4,5-triallylimidazole dimer (rophine dimer), and acridine compounds. These can be used alone or in combination of two or more. As addition amount of (C), it is preferable to set it as 0.1-10 mass parts with respect to 100 mass parts of compounds (A), and it is more preferable to set it as 0.5-5 mass parts.

  Furthermore, a tackifier, a tackifier, a surfactant, or other modifiers can be blended with the radiation curable pressure-sensitive adhesive as necessary. Moreover, you may add an inorganic compound filler suitably. The thickness of the pressure-sensitive adhesive layer 7 is preferably at least 5 μm, more preferably 10 μm or more. The pressure-sensitive adhesive layer 7 may have a configuration in which a plurality of layers are laminated.

(Adhesive layer)
When the chip is picked up after the semiconductor wafer is bonded and divided, the adhesive layer 9 is peeled off from the adhesive layer 7 and attached to the chip when the chip is picked up. It functions as a bonding film for fixing to a lead frame.

  Although it does not specifically limit as the adhesive bond layer 9, The film adhesive generally used as an adhesive film can be used conveniently, a polyimide adhesive, an acrylic adhesive, An epoxy resin / phenolic resin / acrylic resin / inorganic filler blend adhesive is preferred. The thickness may be appropriately set, but is preferably about 5 to 100 μm.

  The wafer processing tape 11 can be formed by laminating an adhesive film as the adhesive layer 9 that has been cut into a circular shape in advance on the pressure-sensitive adhesive layer 7 at room temperature or by heating and applying pressure.

  Further, the wafer processing tape 11 includes a form cut for each semiconductor wafer and a form obtained by winding a plurality of long films formed in a roll shape.

(Surface protection tape)
The surface protection tape 19 includes a base film 15 and a pressure-sensitive adhesive layer 17, and the base film 15 can use the same material as that used for the base film 5. The same material as that used for the pressure-sensitive adhesive layer 7 can be used. The pressure-sensitive adhesive layer is composed of a single layer or multiple layers, and at least one layer is a radiation curable type.

(Explanation of wafer processing method)
Next, the semiconductor wafer processing method according to the first embodiment will be described with reference to FIGS.
First, the back surface of the semiconductor wafer 1 subjected to back grinding is bonded to the adhesive layer 9 of the wafer processing tape 11. The wafer processing tape 11 is previously attached to the lower surface of the ring frame 13, and the semiconductor wafer 1 is fixed to the ring frame 13. A perspective view of the semiconductor wafer 1 fixed to the ring frame 13 is shown in FIG.
Subsequently, a semiconductor wafer 1 shown in FIG. 1A is obtained in which a portion serving as a starting point for cutting into the wafer is formed by full-cut dicing, wafer dicing by laser grooving, or stealth dicing.

  Subsequently, as shown in FIG. 1B, a surface protection tape 19 is bonded to the pattern surface 3 of the semiconductor wafer 1. Here, the surface protection tape is not limited to a state in which the surface protection tape is pasted up to a state of covering the portion of the ring frame 13 as shown in FIG. 1B, but only the wafer 1 or the wafer 1 and the adhesive layer 9, It may be in a state of being bonded to a portion on the wafer processing tape 11.

  Prior to the step of dicing the semiconductor wafer 1, the surface protective tape 19 may be bonded. If a stealth dicing method or the like is used, the laser beam passes through the surface protective tape 19, and the portion that becomes the starting point of cutting can be formed only on the wafer 1 without cutting the surface protective tape 19.

  Thereafter, as shown in FIG. 1C, an expanding process is performed in which the hollow cylindrical push-up member 21 rises from the lower surface of the wafer processing tape 11 and stretches the wafer processing tape 11 in the circumferential direction of the ring frame 13. In the expanding step, the surface protective tape 19 is previously formed with a portion serving as a starting point of cutting by half dicing or the like for each chip. Such a surface protection tape 19 is bonded to the semiconductor wafer 1, and together with the cutting start point of the surface protection tape 19, a portion serving as a cutting start point is formed on the semiconductor wafer 1 on a chip basis. The surface protection tape 19 is divided together with the semiconductor chip 23 by being stretched.

  The expanding step can widen the distance between the chips to improve the chip recognition by a CCD camera or the like, and can prevent re-adhesion of the chips caused by contact between adjacent chips during pickup.

  After performing the expanding process, the pick-up process for picking up the semiconductor chip 23 and the adhesive layer 9 is performed while the wafer processing tape 11 is expanded.

  Further, as shown in FIGS. 3A and 3B, in another example of the first embodiment, the surface protection tape 19 has high stretchability, and the semiconductor chip 23 is divided in the expanding process. However, the surface protection tape 19 is not divided but only stretched. Thereafter, UV irradiation can be performed from the surface protective tape side, and the film can be peeled off with a transfer tape or the like.

  According to the first embodiment, since the pattern surface of the semiconductor wafer that is likely to be warped is protected by the surface protection tape, the warpage of the pattern surface can be prevented even in the expanding process.

(Second Embodiment)
Next, a second embodiment will be described. In the following embodiment, the same number is attached | subjected to the element which fulfill | performs the same aspect as 1st Embodiment, and the overlapping description is avoided.
FIG. 4 is a diagram illustrating a semiconductor wafer processing method according to the second embodiment.

  The second embodiment is characterized in that the surface protection tape used in the back surface grinding process is not peeled off after the back surface grinding process, but is stuck to the expanding process and used as a tape for warping prevention.

  The pressure-sensitive adhesive 17 of the surface protective tape 19 preferably has a property of being cured by ultraviolet rays. Thereby, the adhesive force of a surface protection tape falls by irradiating an ultraviolet-ray, and peeling from the chip | tip after an expanded parting becomes easy.

  As shown in FIG. 4A, a surface protection tape 19 is attached to the pattern surface 3 of the semiconductor wafer 1. Then, as shown in FIG.4 (b), the back surface of the semiconductor wafer 1 is ground with the grinding wheel 25, and a back surface grinding process is performed.

  As shown in FIG. 4C, the semiconductor wafer 1 is thinned by the back grinding process. For example, the original semiconductor wafer 1 having a thickness of 750 μm is thinned to 200 μm or less.

Thereafter, as shown in FIG. 4D, the back surface of the semiconductor wafer 1 is attached to the wafer processing tape 11, and the semiconductor wafer 1 is fixed to the ring frame 13.

  Thereafter, as shown in FIG. 4E, a dicing process is performed to cut the surface protective tape 19, the semiconductor wafer 1, and the adhesive 9 into individual semiconductor chips. Alternatively, in the case of stealth dicing, a part to be a starting point for cutting is formed for each semiconductor chip, and a protective tape 19 in which a part to be a starting point for cutting is formed in advance by half dicing for each chip is bonded.

  After that, as in the first embodiment, the expanding member 21 is used to perform an expanding process, and the semiconductor chip 23 is divided.

  According to the second embodiment, since the pattern surface that is likely to be warped is bonded to the surface protection tape 19, the pattern surface is not warped even in the expanding step.

  In addition, according to the second embodiment, after the back grinding process is completed, the expanding process can be performed without peeling off the surface protective tape, so that the semiconductor wafer is prevented from being damaged when the surface protective tape is peeled off. Can do.

(Third embodiment)
Next, a third embodiment will be described.
FIG. 5 is a diagram illustrating a semiconductor wafer processing method according to the third embodiment.

  In the third embodiment, as shown in FIG. 5A, the semiconductor wafer 1 is fixed to the ring frame 13 by being bonded to the wafer processing tape 11 with the pattern surface 3 facing downward. Thereafter, the semiconductor wafer 1 is diced, and the semiconductor wafer 1 and the adhesive layer 9 are cut into chips to obtain the semiconductor wafer 1 shown in FIG.

  Subsequently, as shown in FIG. 5B, the expanding step is performed in the same manner as in the first embodiment.

  According to the third embodiment, since the pattern surface that is likely to be warped is bonded to the wafer processing tape 11, the warping of the pattern surface is prevented even in the expanding process without using a surface protection tape. can do.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea disclosed in the present application, and these naturally belong to the technical scope of the present invention. Understood.

1 ... Semiconductor wafer 3 ... Pattern surface 5 ... Base film 7 ... Adhesive layer 9 ... Adhesive layer 11 ... Wafer processing tape 13 ... Ring ring 15 ... ... Base film 17 ......... Adhesive layer 19 ......... Surface protection tape 21 ......... Push-up member 23 ......... Semiconductor chip 25 ......... Grinding wheel

Claims (6)

Wafer processing tape is bonded to the backside of the semiconductor wafer,
On the pattern surface of the semiconductor wafer where the starting point of dicing or cutting is formed on a chip basis,
A step of bonding a surface protection tape on which a starting point of half-cut or cutting is formed on a chip basis,
Expanding the wafer processing tape by extending the push-up member from the lower surface of the wafer processing tape, expanding the wafer processing tape, dividing the semiconductor wafer into semiconductor chips, and simultaneously dividing the surface protection tape;
A method for processing a semiconductor wafer, comprising: Wafer processing tape is bonded to the back surface of the semiconductor wafer, and a step of bonding a surface protection tape to the pattern surface of the semiconductor wafer in which the starting point of dicing or cutting is formed in units of chips;
Expanding the wafer processing tape and the surface protection tape by raising the push-up member from the lower surface of the wafer processing tape, and an expanding step of dividing the semiconductor wafer into semiconductor chips;
A method for processing a semiconductor wafer, comprising: Bonding the surface protective tape to the pattern surface of the semiconductor wafer;
Grinding the back surface of the semiconductor wafer;
Adhering the ground surface of the semiconductor wafer and the ring frame to the wafer processing tape;
Dicing the semiconductor wafer into chips without peeling off the surface protection tape;
Expanding the wafer processing tape by extending the push-up member from the lower surface of the wafer processing tape without peeling off the surface protection tape, and dividing the semiconductor wafer into semiconductor chips; and
A method for processing a semiconductor wafer, comprising: The wafer processing tape has a base film, an adhesive layer and an adhesive layer, and is attached to the lower surface of the ring frame by the adhesive layer,
The method for processing a semiconductor wafer according to claim 1, wherein a back surface of the semiconductor wafer is bonded to the adhesive layer. The surface protection tape is formed by laminating a base film and an adhesive layer,
The pressure-sensitive adhesive layer consists of a single layer or multiple layers,
The semiconductor wafer processing method according to any one of claims 1 to 4, wherein at least one of the pressure-sensitive adhesive layers is a radiation curable type. Bonding the wafer processing tape bonded to the lower surface of the ring frame to the pattern surface of the semiconductor wafer;
Forming a starting point of dicing or cutting in the semiconductor wafer on a chip basis;
Expanding the wafer processing tape by raising the push-up member from the lower surface of the wafer processing tape, and expanding the semiconductor wafer into semiconductor chips,
A method for processing a semiconductor wafer, comprising:

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