Semiconductor device, protective layer-forming composition, semiconductor device manufacturing method, and authenticity determination method

Abstract

The semiconductor device includes a semiconductor substrate, a protective layer for protecting the semiconductor substrate, and an anti-counterfeit layer provided on the protective layer. The anti-counterfeit layer includes a pattern-forming material for forming a pattern for determining the authenticity of the semiconductor device. The protective layer includes spherical fillers.

Description

[Technical Field]

[0001] The present invention relates to a semiconductor device, a composition for forming a protective layer, a method for manufacturing a semiconductor device, and a method for determining authenticity. [Background technology]

[0002] In the field of semiconductor devices, the distribution of counterfeit products has become a problem. Therefore, there is a demand for technology that can determine the authenticity of semiconductor devices. To determine authenticity, it is conceivable to attach a unique pattern to the semiconductor device in advance.

[0003] In relation to the above, Patent Document 1 (JP 2007-242973 A) describes a semiconductor device having a structure in which a semiconductor circuit is sealed with sealing resin, the semiconductor device having a semiconductor circuit and sealing resin with a mottled pattern on at least the surface that differs for each individual device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-242973 Summary of the Invention

[0005] A semiconductor device is usually provided with a protective layer (e.g., an encapsulant layer, a protective film on the back surface of a semiconductor chip, etc.) as its outermost layer. An authenticity determination pattern is usually formed on the outermost protective layer. When determining authenticity, an image of the authenticity determination pattern of the genuine product is captured in advance, and the image data is saved. When determining authenticity, an image of the authenticity determination pattern of the product to be determined is captured in the same way. Then, the authenticity determination pattern of the product to be determined is compared with that of the genuine product, and authenticity is determined.

[0006] However, the lighting conditions may be different when capturing an image of a genuine product and when capturing an image of a product to be judged. The different lighting conditions may result in different images being obtained. As a result, it may not be possible to accurately judge the authenticity of a product.

[0007] Therefore, an object of the present invention is to provide a technology that can accurately determine authenticity even if the environment at the time of image capture is different.

[0008] The present inventors have found that the shape of the filler contained in the protective layer affects the image obtained when the authenticity determination pattern is imaged, and have discovered that if the filler is spherical, the same image is likely to be obtained regardless of the imaging environment, leading to the present invention.

[0009] That is, in one aspect, the present invention relates to a semiconductor device. The semiconductor device includes a semiconductor substrate, a protective layer for protecting the semiconductor substrate, and an anti-counterfeit layer provided on the protective layer. The anti-counterfeit layer includes a pattern-forming material that forms a pattern for determining the authenticity of the semiconductor device. The protective layer includes spherical fillers.

[0010] In another aspect, the present invention relates to a composition for forming a protective layer, which is used to form a protective layer in the semiconductor device described above.

[0011] In another aspect, the present invention relates to a method for manufacturing a semiconductor device. This manufacturing method includes the steps of forming a protective layer having spherical fillers on a semiconductor substrate, and forming an anti-counterfeit layer on the protective layer, the anti-counterfeit layer containing a pattern-forming material that forms an authenticity determination pattern. The step of forming the protective layer includes the steps of supplying a protective layer-forming composition on the semiconductor substrate and curing the supplied protective layer-forming composition. The step of forming the anti-counterfeit layer includes the steps of supplying a anti-counterfeit layer-forming composition and curing the supplied anti-counterfeit layer-forming composition. The step of curing the anti-counterfeit layer-forming composition is performed before the step of curing the protective layer-forming composition, simultaneously with the step of curing the protective layer-forming composition, or after the step of curing the protective layer-forming composition.

[0012] In another aspect, the present invention relates to a method for determining the authenticity of a semiconductor device, the method comprising: a step of providing an authentic product of the above-mentioned semiconductor device; a genuine product data generating step of imaging an anti-counterfeit layer of the authentic product and generating genuine product data indicating an authenticity determination pattern of the authentic product; a determination target data generating step of imaging an anti-counterfeit layer of a product to be determined and generating determination target data indicating the authenticity determination pattern of the product to be determined; and a determination step of comparing the genuine product data with the determination target data to determine whether the product to be determined is authentic.

[0013] According to the present invention, a technique is provided that can accurately determine authenticity even if the environment at the time of image capture is different. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a semiconductor device according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view schematically showing a semiconductor device according to a reference example. [Figure 3] FIG. 3 is a schematic diagram showing an example of an image of the anti-counterfeit layer of the semiconductor device according to the reference example. [Figure 4] FIG. 4 is a schematic diagram showing an example of an image of the anti-counterfeit layer of the semiconductor device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] (1) Semiconductor device 1 is a cross-sectional view schematically showing a semiconductor device 1 according to this embodiment. The semiconductor device 1 has a semiconductor substrate 2, a protective layer 3, and an anti-counterfeit layer 4.

[0017] The semiconductor substrate 2 is a substrate on which an integrated circuit 7 is formed. For example, the semiconductor substrate 2 is a semiconductor chip or a semiconductor wafer. For example, the semiconductor substrate 2 is made of silicon.

[0018] The protective layer 3 is provided to protect the semiconductor substrate 2. In the example shown in Fig. 1, the protective layer 3 is provided on the back surface (the surface opposite to the surface on which the integrated circuits 7 are formed) of the semiconductor substrate 2. In other words, the protective layer 3 is a back surface protective film for the semiconductor substrate 2.

[0019] The protective layer 3 contains a filler 6 in order to adjust the physical properties of the protective layer 3. For example, by using the filler 6, the physical properties of the protective layer 3 can be made closer to the physical properties of the semiconductor substrate 2.

[0020] In this embodiment, the protective layer 3 contains spherical fillers as the fillers 6 .

[0021] The anti-counterfeit layer 4 is provided on the protective layer 3. The anti-counterfeit layer 4 is a layer used to determine the authenticity of the semiconductor device 1. The anti-counterfeit layer 4 contains a pattern-forming material 5. A pattern for determining the authenticity of the semiconductor device 1 (hereinafter, sometimes simply referred to as an authenticity pattern) is formed on the anti-counterfeit layer 4 by the pattern-forming material 5. The authenticity pattern is a pattern unique to the semiconductor device 1. The authenticity pattern is preferably a pattern that cannot be recognized by the naked eye but can be recognized using an optical microscope.

[0022] Preferably, the pattern-forming material 5 is particulate and randomly dispersed. Preferably, the pattern-forming material 5 is formed of particles that are observed as bright spots when the anti-counterfeit layer 4 is observed using an optical microscope. The pattern formed by the bright spots is used as the pattern for determining authenticity. Note that the bright spots are not necessarily limited to those that can be visually observed using an optical microscope. For example, the bright spots may be points that emit scattered light in the near-infrared range but do not substantially emit scattered light in the visible range. In such cases, the bright spots may be recognized not visually but by an infrared sensor.

[0023] The above is a schematic configuration of the semiconductor device 1 according to this embodiment.

[0024] In this embodiment, the anti-counterfeit layer 4 of an authentic product is imaged in advance by the imaging device 8, and authentic product data is generated. The authentic product data is data that indicates the pattern for determining the authenticity of the authentic product. When determining authenticity, the anti-counterfeit layer of the product to be determined is observed. Then, the pattern for determining authenticity of the product to be determined is compared with the authentic product data, and it is determined whether the product to be determined is authentic or not.

[0025] According to this embodiment, the filler 6 contained in the protective layer 3 is a spherical filler, so that the authenticity can be determined with high accuracy. This point will be described below with reference to a reference example.

[0026] FIG. 2 is a schematic cross-sectional view showing a semiconductor device 1 according to a reference example. In this reference example, the filler 6 contained in the protective layer 3 is amorphous. FIG. 3 is a schematic diagram showing an example of an image obtained by observing the anti-counterfeit layer 4 of the semiconductor device 1 according to the reference example with an optical microscope. FIG. 3(a) shows an image obtained when observed with omnidirectional illumination, and FIG. 3(b) shows image data obtained with lateral illumination in one direction. That is, the illumination environments during observation are different between FIG. 3(a) and FIG. 3(b). As shown in FIG. 3, in the reference example, differences in the illumination environments result in differences in the authentication pattern formed by the pattern-forming material 5. Specifically, differences occur in the number and color of the bright points formed by the pattern-forming material 5. When the filler contained in the protective layer 3 is amorphous, illumination light incident on the protective layer 3 through the anti-counterfeit layer 4 is reflected according to the angle of the filler surface. Therefore, if the incident direction of the illumination light changes, the intensity and color of the reflected light also change. As a result, differences occur in the observed authenticity pattern, which may make it impossible to accurately determine authenticity.

[0027] Meanwhile, FIG. 4 is a schematic diagram showing an example of an image obtained when observing the anti-counterfeit layer 4 of the semiconductor device 1 according to this embodiment with an optical microscope. FIG. 4(a) shows an image obtained with omnidirectional illumination, and FIG. 4(b) shows an image obtained with unidirectional radiometric illumination. As shown in FIG. 4, in this embodiment, there is no difference in the authenticity determination pattern even if the illumination environment is different. In this embodiment, because the filler contained in the protective layer 3 is spherical, the intensity and direction of the reflected light from the filler are less likely to depend on the incident direction of the illumination light. In other words, even if the illumination environment is different, it is easy to obtain the same authenticity determination pattern as shown in FIG. 4. Therefore, it is possible to perform authenticity determination with high accuracy.

[0028] The above is an outline of the semiconductor device 1 according to this embodiment. Next, the details of this embodiment will be described.

[0029] (2) Protective layer As described above, the protective layer 3 is a layer for protecting the semiconductor substrate 2. In the example shown in FIG. 1, the protective layer 3 is a back surface protective film for the semiconductor substrate 2. More preferably, the protective layer 3 is a back surface protective film provided on the back surface of a semiconductor chip that is mounted face-down. However, the protective layer 3 does not necessarily have to be a back surface protective film. The protective layer 3 is a layer that protects the semiconductor substrate 2 and may be a layer that can serve as a base for the anti-counterfeit layer 4. For example, the protective layer 3 may be an encapsulant layer that encapsulates the semiconductor substrate 2. In other words, it may be a layer formed of a so-called encapsulating resin.

[0030] The protective layer 3 is formed from a protective layer-forming composition. The protective layer-forming composition is preferably a curable composition. For example, the protective layer 3 is formed by supplying the protective layer-forming composition onto the semiconductor substrate 2 and curing the supplied protective layer-forming composition. The protective layer-forming composition may be a thermosetting composition or an energy ray-curable composition. Alternatively, it may be a composition that has both thermosetting and energy ray-curing properties.

[0031] When the protective layer 3 is a back surface protective film, the protective layer-forming composition is preferably provided in the form of a film. For example, a film in which the protective layer-forming composition is supported on a support film is prepared as the protective layer-forming film. Then, the protective layer-forming composition is laminated onto the semiconductor substrate 2 using the protective layer-forming film. Thereafter, the protective layer-forming composition is cured on the semiconductor substrate 2 to form the protective layer 3.

[0032] On the other hand, when the protective layer 3 is an encapsulant layer, the protective layer 3 can also be formed by molding the protective layer-forming composition on the semiconductor substrate 2 using a mold.

[0033] However, in a preferred embodiment, the protective layer 3 is a back surface protective film formed using a protective layer-forming film. When the protective layer 3 is an encapsulant layer and a mold is used for molding it, a release agent is usually used. Therefore, components of the release agent may be transferred to the surface of the protective layer 3. The transferred components of the release agent may reduce the adhesion of the anti-counterfeit layer 4. In contrast, when a back surface protective film is formed using a protective layer-forming film, the release film used as a support film for the protective layer-forming film is relatively resistant to the transfer of the release agent. Therefore, from the viewpoint of adhesion, it is preferable to use a back surface protective film formed using a protective layer-forming film as the protective layer 3. In other words, it is preferable to use the back surface protective film formed in this manner as the base layer for the anti-counterfeit layer 4.

[0034] Furthermore, the surface of the back surface protective film formed by transfer from the protective layer-forming film is more likely to be smooth than the surface of the sealing material layer obtained using a mold. A smooth surface of the underlying protective layer 3 makes it easier to obtain good contrast when imaging the anti-counterfeit layer 4. As a result, the authenticity pattern is more likely to be accurately recognized. From this perspective, it is preferable to use the back surface protective film formed using the protective layer-forming film as the underlying layer for the anti-counterfeit layer 4 (i.e., as the protective layer 3).

[0035] When the protective layer 3 is a back surface protective film, the thickness of the protective layer 3 is, for example, 1 to 100 μm, and preferably 5 to 50 μm.

[0036] As described above, the protective layer 3 is formed from a protective layer-forming composition. As described above, the protective layer-forming composition may be provided in the form of a film, but may also be provided, for example, in the form of a liquid containing a solvent, or in the form of a solventless liquid curable composition fluidized by blending a low-molecular-weight polymerizable monomer. Below, the composition of the protective layer-forming composition will be described in more detail, and the substances contained in the protective layer 3 will be described in more detail.

[0037] (spherical filler) First, the spherical filler will be described. The protective layer-forming composition contains the spherical filler described above. The shape of the filler in the protective layer-forming composition or the protective layer can be confirmed, for example, by dissolving components other than the filler (such as resin) contained in the protective layer-forming composition or the protective layer, extracting only the filler, and observing the extracted filler under a microscope or the like. Alternatively, the protective layer-forming composition or the protective layer may be fired to remove components other than the filler that function as a binder, thereby extracting only the filler.

[0038] The content of the spherical filler in the composition for forming a protective layer (i.e., the content of the spherical filler in the protective layer) is preferably 30 to 70% by mass relative to the total mass of the composition for forming a protective layer (calculated as active ingredients excluding the solvent). If the content of the spherical filler is 30% by mass or more, the physical properties of the protective layer can be made sufficiently close to those of the semiconductor substrate. If the content is 70% by mass or less, the toughness of the protective layer can be increased, making it easier to obtain a better image when imaging the anti-counterfeit layer. More preferably, the content of the spherical filler is 35 to 65% by mass relative to the total mass of the protective layer.

[0039] The protective layer-forming composition may contain fillers other than spherical fillers as long as they do not affect the identification of the authenticity pattern. However, preferably, 80% by mass or more of the total fillers are spherical fillers. More preferably, 90% by mass or more of the total fillers are spherical fillers, and even more preferably, 95% by mass or more of the total fillers are spherical fillers. Most preferably, substantially all of the fillers are spherical fillers.

[0040] The spherical filler may be either an oblate spheroid or a perfect sphere, and preferably is a perfect sphere.

[0041] The material of the spherical filler is not particularly limited. The spherical filler may be an inorganic filler or an organic filler. Preferably, it is an inorganic filler. Examples of inorganic fillers include at least one selected from the group consisting of silica, alumina, aluminum compounds such as aluminum nitride, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, and boron nitride. From the viewpoint of easily obtaining a spherical filler, the spherical filler is preferably at least one selected from silica, an aluminum compound, and boron nitride. From the viewpoint of obtaining a filler that is close to a perfect sphere, it is more preferably at least one selected from silica and an aluminum compound, and even more preferably silica.

[0042] The size of the spherical filler is not particularly limited. The average particle size of the spherical filler is, for example, 0.05 to 5 μm, preferably 0.1 to 1.0 μm, and more preferably 0.1 to 0.5 μm. The average particle size here refers to the median diameter D50 in the particle size distribution measured using a laser diffraction particle size distribution analyzer.

[0043] (Thermosetting protective layer-forming composition) When the composition for forming a protective layer is a thermosetting composition, it contains, for example, a polymer component (A), a thermosetting component (B), a curing accelerator (C), a silane coupling agent (D), and a colorant (E).

[0044] (A) Polymer component Examples of the polymer component (A) include acrylic resins (e.g., resins obtained by addition polymerization of monomers containing at least an acrylic acid ester monomer), polyesters, urethane resins (e.g., resins having a urethane bond), acrylic urethane resins, silicone resins (e.g., resins having a siloxane bond), rubber resins (e.g., resins having a rubber structure), and phenoxy resins, with acrylic resins being preferred.

[0045] The content of the polymer component (A) is, for example, 5 to 50 mass %, preferably 10 to 40 mass %, and more preferably 15 to 35 mass %, based on the total mass of the composition for forming a protective layer excluding the solvent.

[0046] (B) Thermosetting component Examples of the thermosetting component (B) include epoxy-based thermosetting resins, thermosetting polyurethanes, unsaturated polyesters, and silicone rubbers, etc. Epoxy-based thermosetting resins are preferred.

[0047] The epoxy thermosetting resin may be, for example, one made of an epoxy resin (B1) and a thermosetting agent (B2).

[0048] Examples of the epoxy resin (B1) include bifunctional or higher functional epoxy compounds such as polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenated products, orthocresol novolac epoxy resins, dicyclopentadiene epoxy resins, biphenyl epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, and phenylene skeleton epoxy resins. Among these, it is preferable to use bisphenol A epoxy resins.

[0049] The thermosetting agent (B2) is a substance that functions as a curing agent for epoxy resins. Examples of thermosetting agents include compounds having at least two functional groups per molecule that can react with epoxy groups. Examples of such functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxy groups, and groups resulting from anhydride conversion of acid groups. Preferably, the thermosetting agent includes an amino-based curing agent having an amino group. Examples of amino-based curing agents include dicyandiamide.

[0050] The content of the thermosetting component (B) (e.g., the content of the epoxy resin (B1) and the thermosetting agent (B2)) is, for example, 5 to 30 mass %, preferably 15 to 20 mass %, based on the total mass of the composition for forming a protective layer excluding the solvent.

[0051] (C) Curing accelerator Examples of the curing accelerator (C) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles (imidazoles in which at least one hydrogen atom is substituted with a group other than a hydrogen atom) such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; organic phosphines (phosphines in which at least one hydrogen atom is substituted with an organic group) such as tributylphosphine, diphenylphosphine, and triphenylphosphine; and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate. Preferably, the curing accelerator (C) includes 2-phenyl-4,5-dihydroxymethylimidazole.

[0052] The content of the curing accelerator (C) is, for example, 0.1 to 1% by mass based on the total mass of the composition for forming a protective layer excluding the solvent.

[0053] (D) Silane coupling agent Examples of the silane coupling agent (D) include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-amino Examples of suitable silane coupling agents include 3-(ethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazole silane. Preferably, the silane coupling agent (D) includes 3-glycidoxypropyltrimethoxysilane.

[0054] The content of the silane coupling agent (D) is, for example, 0.1 to 1 mass % based on the total mass of the composition for forming a protective layer excluding the solvent.

[0055] (E) Colorant As the colorant (E), inorganic pigments, organic pigments, organic dyes, etc. can be used. Among these, inorganic pigments are preferred because they are less prone to fading. Examples of inorganic pigments include carbon black, cobalt-based pigments, iron-based pigments, chromium-based pigments, titanium-based pigments, vanadium-based pigments, zirconium-based pigments, molybdenum-based pigments, ruthenium-based pigments, platinum-based pigments, ITO (indium tin oxide)-based pigments, and ATO (antimony tin oxide)-based pigments. Preferably, the colorant (E) contains carbon black.

[0056] The content of the colorant (E) is, for example, 0.1 to 10% by mass, and preferably 0.5 to 5% by mass, based on the total mass of the composition for forming a protective layer excluding the solvent.

[0057] (Energy ray-curable protective layer-forming composition) As described above, the protective layer-forming composition may be an energy-curable composition. In this case, the composition for forming the protective layer is not particularly limited. For example, an energy-ray-curable protective layer-forming composition can be obtained by including an energy-ray-curable compound and a photopolymerization initiator, which will be described later for the "anti-counterfeiting layer."

[0058] (3) Anti-counterfeiting layer Next, a description will be given of the anti-counterfeit layer 4. As described above, the anti-counterfeit layer 4 contains a pattern forming material. An authenticity determining pattern is formed in the anti-counterfeit layer 4 by the pattern forming material.

[0059] The thickness of the anti-counterfeit layer 4 is, for example, 0.1 to 20 μm, preferably 0.2 to 10 μm, and more preferably 0.5 to 5 μm.

[0060] The anti-counterfeit layer 4 is formed from a composition for an anti-counterfeit layer. The composition for an anti-counterfeit layer may be provided in the form of a film, or, for example, in a liquid form containing a solvent, or in the form of a solventless liquid curable composition obtained by blending and fluidizing a low-molecular-weight polymerizable monomer. The composition for an anti-counterfeit layer is preferably a resin composition. In other words, the anti-counterfeit layer 4 is a cured product of the resin composition. The anti-counterfeit layer 4 can be formed by supplying a curable composition for an anti-counterfeit layer onto the protective layer 3 and curing it.

[0061] The composition of the anti-counterfeit layer composition will be explained below, and the structure of the anti-counterfeit layer will be explained.

[0062] (Pattern-forming materials) The composition for the anti-counterfeit layer contains the above-mentioned pattern-forming material. As mentioned above, the pattern-forming material is preferably particulate. Specifically, it is preferably a particulate material that generates bright spots when observed using an optical microscope. If such particulate pattern-forming material is randomly dispersed, the bright spots derived from each particle can be used as an authenticity determination pattern. Since it is only necessary to randomly disperse each particle, an authenticity determination pattern can be easily formed.

[0063] Preferably, the pattern forming material contains a plurality of particles that emit different colors. This configuration allows for the formation of more complex patterns. The more complex the patterns formed, the greater the amount of information available for authenticity determination, making it possible to perform authenticity determination with greater accuracy.

[0064] Preferably, the pattern forming material contains a plurality of particles having different shapes, which allows for the formation of more complex patterns.

[0065] Specific examples of pattern-forming materials include pearl pigments and effect pigments. Examples of pearl pigments include pigments in which a substrate, such as a mica frame, is coated with a metal oxide (such as titanium oxide or iron oxide). Examples of effect pigments include pigments in which a substrate, such as synthetic alumina flakes, synthetic silica flakes, borosilicate glass flakes, titanium oxide coatings, and synthetic mica flakes, is coated with a metal oxide (such as titanium oxide or iron oxide). Alternatively, a common silica filler can be used as the pattern-forming material.

[0066] The average particle size of the pattern forming material is, for example, 0.05 to 5.0 μm, and preferably 0.1 to 1.0 μm. The average particle size here refers to the median diameter D50 in the particle size distribution measured using a laser diffraction particle size distribution analyzer.

[0067] The content of the pattern forming substance is, for example, 0.01 to 5 mass %, and preferably 0.05 to 1 mass %, based on the total mass of the composition for the anti-counterfeit layer excluding the solvent.

[0068] (Other components in the anti-counterfeit layer) As described above, the composition for the anti-counterfeit layer is preferably a curable resin composition. The composition for the anti-counterfeit layer may be a thermosetting composition or an energy ray curable composition. Alternatively, the composition may be a composition having both thermosetting and energy ray curing properties. Note that if the curing type of the composition for the anti-counterfeit layer is the same as that of the composition for forming the protective layer, the composition for forming the protective layer and the composition for forming the anti-counterfeit layer can be cured together.

[0069] In the case of an energy ray-curable composition, the composition for the anti-counterfeit layer contains an energy ray-curable compound (for example, a monomer or an oligomer) and a photopolymerization initiator.

[0070] Examples of the energy ray-curable compound include polyvalent (meth)acrylate monomers such as trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol (meth)acrylate, and oligomers such as urethane (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, and epoxy (meth)acrylate. Preferably, polyester (meth)acrylate is used.

[0071] As the energy ray-curable compound, a polymer having a photopolymerizable functional group such as a (meth)acryloyl group or a vinyl group in a side chain may be used. For example, an acrylic polymer can be used as such a polymer, and a method is known in which an acrylic polymer having a reactive functional group such as a hydroxyl group in a side chain is reacted with a compound having a photopolymerizable functional group and capable of reacting with the reactive functional group, such as methacryloyloxyisocyanate, to add the photopolymerizable functional group to the side chain.

[0072] When these energy ray-curable compounds are used, the photopolymerization initiator is preferably a photoradical polymerization initiator.

[0073] The content of the energy ray-curable compound is, for example, 70 to 99 mass %, and preferably 80 to 95 mass %, based on the total mass of the composition for the anti-counterfeit layer excluding the solvent.

[0074] The photopolymerization initiator is not particularly limited, and the content of the photopolymerization initiator is, for example, 0.5 to 15% by mass, and preferably 1 to 10% by mass, based on the total mass of the composition for the anti-counterfeit layer excluding the solvent.

[0075] The composition for the anti-counterfeit layer may also contain a silane coupling agent. When the spherical filler contained in the protective layer is an inorganic filler, the inclusion of a silane coupling agent in the anti-counterfeit layer can improve adhesion between the anti-counterfeit layer and the protective layer, thereby preventing peeling or falling off of the anti-counterfeit layer. The amount of the silane coupling agent is, for example, 0.5 to 15 mass %, preferably 1 to 10 mass %, based on the total mass of the composition for the anti-counterfeit layer excluding the solvent.

[0076] As described above, the composition for the anti-counterfeit layer may be a thermosetting composition. The thermosetting composition for the anti-counterfeit layer can be realized, for example, by a composition containing the polymer component (A) and the thermosetting component (B) described in the "composition for forming the protective layer" section.

[0077] (4) Manufacturing method Next, an example of a method for manufacturing the semiconductor device 1 will be described.

[0078] First, a semiconductor substrate 2 is prepared, and a protective layer 3 is formed on the semiconductor substrate 2. Specifically, a composition for forming a protective layer is supplied onto the semiconductor substrate 2. The composition for forming a protective layer is then cured. This forms the protective layer 3. Subsequently, a composition for forming an anti-counterfeit layer is supplied onto the protective layer 3. The supplied composition for forming an anti-counterfeit layer is then cured. This forms the anti-counterfeit layer 4. This results in a semiconductor device 1.

[0079] As described above, the curing of the protective layer-forming composition and the anti-counterfeit layer composition may be performed simultaneously. That is, the protective layer-forming composition is supplied onto the semiconductor substrate 2. Next, before the curing of the protective layer-forming composition, the anti-counterfeit layer composition is supplied onto the protective layer-forming composition. The protective layer-forming composition and the anti-counterfeit layer composition are then cured simultaneously. For example, if the protective layer-forming composition and the anti-counterfeit layer composition are both heat-curable, they can be cured simultaneously by heating. Alternatively, if the protective layer-forming composition and the anti-counterfeit layer composition are both energy-ray-curable, they can be cured simultaneously by irradiating them with energy rays. This shortens the manufacturing process. Furthermore, the anti-counterfeit layer composition may be cured before the anti-counterfeit layer composition. However, in this case, if the protective layer-forming composition and the anti-counterfeit layer composition are the same curing type, it is highly likely that the protective layer-forming composition will be at least partially cured simultaneously when the anti-counterfeit layer composition is cured.

[0080] The semiconductor device 1 may be fabricated by a so-called wafer-level packaging process or a panel-level packaging process. Examples of wafer-level packaging processes include wafer-level chip-size packaging (WLCSP) and fan-out wafer-level packaging. Examples of panel-level packaging processes include fan-out panel-level packaging. In these packaging processes, a protective layer 3 is formed collectively on multiple semiconductor devices 1 (typically multiple semiconductor chips). The multiple semiconductor devices 1 are then singulated. Here, the anti-counterfeit layer 4 can be formed collectively after the formation of the protective layer 3 and before singulation. This is efficient because the anti-counterfeit layer 4 can be formed on multiple semiconductor devices 1 at once.

[0081] In a preferred example, the semiconductor substrate 2 is a face-down type semiconductor chip. During manufacturing, the protective layer 3 is formed as a back surface protective film on the back surface of a wafer for the face-down type semiconductor chip.

[0082] (5) Authenticity determination method Next, an example of a method for determining the authenticity of a semiconductor device will be described. First, a genuine semiconductor device is prepared. Then, the anti-counterfeit layer of the genuine product is imaged using an imaging device equipped with an optical microscope, and genuine product data indicating a pattern for determining the authenticity of the genuine product is generated. The genuine product data may be the image data of the anti-counterfeit layer itself, or may be data obtained by extracting a required portion of information through image analysis using a computer or the like. The genuine product data is stored in advance on a server or the like.

[0083] When authenticating a product, the anti-counterfeiting layer of the product is observed under an optical microscope. The authenticity pattern of the product is then compared with the authentic product data to determine whether the product is authentic. The comparison process may be performed by visually inspecting the image data, or by comparing data extracted by image analysis using a computer or the like with the data extracted from the authentic product.

[0084] The lighting environment when observing the genuine product and the product to be judged is not particularly limited. For example, it may be lateral lighting, direct lighting, or a combination of both. Other lighting may also be used. According to this embodiment, as described above, it is easy to obtain the same data even if the lighting environment is different. Therefore, even if the lighting environment when observing the genuine product and the lighting environment when the data to be judged are different, it is possible to accurately judge authenticity.

[0085] Note that the imaging of the genuine product may be performed after the manufacture of the genuine product, or may be performed during the manufacture of the genuine product. That is, the genuine semiconductor device may be a semi-finished product. For example, if there is no change in the appearance of the anti-counterfeit layer before and after hardening, the anti-counterfeit layer before hardening may be imaged and genuine product data may be generated.

[0086] The size of the area used to verify the authentic product and the product to be verified is not particularly limited. For example, verification can be performed using an area in the anti-counterfeit layer with one side measuring 10 to 1000 μm.

[0087] The magnification of the optical microscope used to capture an image of the authentic product and observe the product to be judged is not particularly limited. For example, an optical microscope with a magnification of 300 to 3000 times can be used. [Example]

[0088] Next, in order to explain the present invention in more detail, examples carried out by the present inventors will be described, but the present invention should not be construed as being limited to the following examples.

[0089] Example 1 <Production of protective layer forming film> (Preparation of protective layer-forming composition) The following raw materials were mixed with methyl ethyl ketone solvent and stirred for 60 minutes at 23° C. to prepare a composition for forming a protective layer having an active ingredient (components other than the solvent) content of 52% by mass. In the following description, the amount of each component indicates the amount of the active ingredient.

[0090] (1) Acrylic polymer (20 parts by mass): an acrylic polymer (weight average molecular weight: 600,000) obtained by copolymerizing 15 parts by mass of n-butyl acrylate, 10 parts by mass of methyl methacrylate, 60 parts by mass of methyl acrylate, and 15 parts by mass of 2-hydroxyethyl acrylate. (2) Bisphenol A liquid epoxy resin (15 parts by mass): Nippon Shokubai Co., Ltd. "BPA328" (3) Bisphenol A type epoxy resin (1.8 parts by mass): "jER1055" manufactured by Mitsubishi Chemical Corporation (4) Dicyandiamide (0.45 parts by mass): heat-activated latent epoxy resin curing agent, ADEKA Corporation "ADEKA Hardener EH-3636AS" (5) 2-phenyl-4,5-dihydroxymethylimidazole (0.45 parts by mass): "Curezol 2PHZ" manufactured by Shikoku Chemicals Corporation (6) Spherical silica filler (60 parts by mass): Admatechs Co., Ltd. "SC105G-MMQ: spherical silica" (average particle size 0.3 μm) (7) Silane coupling agent: 3-glycidoxypropyltrimethoxysilane (3-glycidyloxypropyltrimethoxysilane) (0.4 parts by mass), "KBM403" manufactured by Shin-Etsu Chemical Co., Ltd. (8) Colorant: Carbon black (1.9 parts by mass), Mitsubishi Chemical Corporation "MA600B" (average particle size 28 nm)

[0091] (Formation of protective layer forming film) A release film having a release-treated surface was prepared. Then, the protective layer-forming composition prepared above was coated onto the release-treated surface using a knife coater. After coating, the composition was dried at 110°C for 2 minutes. The thickness of the protective layer-forming composition after drying was 25 μm. Furthermore, the release-treated surface of another release film was attached to the protective layer-forming composition, thereby preparing a protective layer-forming film sandwiched between two release films.

[0092] (Manufacturing silicon chips with backside protection film) A 6-inch silicon wafer (thickness: 100 μm) having a #2000 polished surface was prepared as a semiconductor substrate. One release film was then peeled off from the protective layer-forming film, and the exposed protective layer-forming composition was attached facing the silicon wafer. The other release film remaining on the protective layer-forming film was peeled off and removed. The silicon wafer was then heat-treated at 130°C for 2 hours to harden the protective layer-forming composition and form a protective layer (rear surface protective film) on the silicon wafer.

[0093] (Preparation of Composition for Anti-Counterfeit Layer) On the other hand, a composition for an anti-counterfeit layer was prepared by mixing 91 parts by mass of polyester acrylate (Arkema CN2270NS), 0.1 parts by mass of silica filler (Admatechs SC2050MA, average particle size 0.5 μm), 4.6 parts by mass of a photoinitiator (IGM Resins Omirad 127D), and 4.6 parts by mass of a silane coupling agent (Shin-Etsu Chemical KBM-1083).

[0094] The prepared composition for the anti-counterfeit layer was applied to a thickness of 5 μm on the back surface protective film using a Baker Applicator YBA model manufactured by YOSHIMITSU SEIKI Co., Ltd. The composition was then cured by UV irradiation under the following conditions to obtain a 5 μm thick anti-counterfeit layer. Equipment: UV irradiation machine (GS Yuasa Corporation, CSN2-40) Conditions: N2 purge, UV irradiance 360 mJ / cm 2 , irradiation speed 7m / min, oxygen concentration 0.3% or less

[0095] The above procedure was used to obtain the silicon wafer according to Example 1. This was attached to an adhesive sheet for semiconductor processing, Adwill D-485H manufactured by Lintec Corporation, and cut into individual pieces of 10 mm x 10 mm squares using a dicer (DFD6362 manufactured by Disco Corporation), to obtain semiconductor chips with an anti-counterfeiting layer that imitated semiconductor devices.

[0096] (Comparative Example 1) A 50% by mass methyl ethyl ketone solution having the following composition was used as the composition for forming a protective layer. Other points were the same as in Example 1, and a silicon wafer according to Comparative Example 1 was obtained. In the following composition, the content is the amount of the active ingredient.

[0097] (1) Binder resin (17 parts by mass): an acrylic polymer (weight average molecular weight: 800,000) containing 55% by mass of butyl acrylate, 10% by mass of methyl acrylate, 15% by mass of 2-hydroxyethyl acrylate, and 20% by mass of glycidyl methacrylate as monomers. (2) Thermosetting resin (17 parts by mass): a mixed epoxy resin of 60% by mass of liquid bisphenol A type epoxy resin, 10% by mass of solid bisphenol A type epoxy resin, and 30% by mass of dicyclopentadiene type epoxy resin (3) Heat curing agent (0.3 parts by mass): dicyanamide, manufactured by ADEKA Corporation "ADEKA Hardener 3636AS" (4) Curing accelerator (0.3 parts by mass): 2-phenyl-4,5-di(hydroxymethyl)imidazole, "Curesol 2PHZ" manufactured by Shikoku Chemicals Corporation (5) Colorant (2 parts by mass): carbon black, Mitsubishi Chemical Corporation "#MA650" ( average particle size 28nm) (6) Silane coupling agent (0.4 parts by mass): γ-glycidoxypropyltrimethoxysilane, “KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd. (7) Irregular silica filler (63 parts by mass): Irregular silica filler obtained by physically crushing “SV-10” manufactured by Tatsumori Co., Ltd.

[0098] (evaluation) For Example 1 and Comparative Example 1, the semiconductor chips with the anti-counterfeit layer were photographed at 1000x magnification using a digital microscope (Keyence Digital Microscope VHX-7000). Photographs were taken while changing the lighting environment, and the resulting image data was observed to see if there were any changes in the position and color of the bright spots of the pattern-forming material (silica filler). Specifically, it was observed whether there were any changes in the image data when photographs were taken with omnidirectional lighting from the side (total illumination) and when photographs were taken with only one-way lighting.

[0099] As a result, no change in the number or color of bright spots was observed in Example 1. On the other hand, the number and color of bright spots changed in Comparative Example 1. From this, it was found that the same image data was obtained in Example 1 regardless of the lighting environment, whereas the image data in Comparative Example 1 changed depending on the lighting environment. In other words, it can be seen that the pattern of bright spots changed depending on the lighting environment in Comparative Example 1, which used an amorphous filler, whereas the same pattern was obtained in Example 1, which used a spherical filler, regardless of the lighting environment.

[0100] (Addendum) A typical configuration of this embodiment will be summarized below as an appendix.

[0101] (Appendix 1) A semiconductor device comprising: a semiconductor substrate; a protective layer that protects the semiconductor substrate; and an anti-counterfeit layer provided on the protective layer, wherein the anti-counterfeit layer contains a pattern-forming substance that forms an authenticity determination pattern, and the protective layer contains spherical fillers. (Appendix 2) 2. The semiconductor device according to claim 1, wherein the protective layer is an encapsulant layer that encapsulates the semiconductor substrate or a back surface protective film that protects the back surface of the semiconductor substrate. (Appendix 3) 3. The semiconductor device according to claim 1, wherein the pattern formation material is in particulate form. (Appendix 4) 4. The semiconductor device of claim 3, wherein the pattern forming material includes a plurality of particles that emit different colors. (Appendix 5) 5. The semiconductor device of claim 3, wherein the pattern forming material includes a plurality of particles having different shapes. (Appendix 6) A composition for forming a protective layer, used to form the protective layer in the semiconductor device according to any one of Appendices 1 to 5. (Appendix 7) 7. The composition for forming a protective layer according to claim 6, which is in the form of a film. (Appendix 8) 8. The composition for forming a protective layer according to claim 6 or 7, which is used to collectively form protective layers for a plurality of semiconductor devices at a wafer level or a panel level. (Appendix 9) A method for manufacturing a semiconductor device, comprising: a step of forming a protective layer having spherical fillers on a semiconductor substrate; and a step of forming an anti-counterfeit layer on the protective layer, the anti-counterfeit layer containing a pattern-forming substance that forms an authenticity determination pattern, wherein the step of forming the protective layer comprises a step of supplying a composition for forming a protective layer on the semiconductor substrate and a step of curing the supplied composition for forming a protective layer, and the step of forming the anti-counterfeit layer comprises a step of supplying a composition for forming a counterfeit anti-counterfeit layer and a step of curing the supplied composition for forming a counterfeit anti-counterfeit layer, and the step of curing the composition for forming a counterfeit anti-counterfeit layer is performed before the step of curing the composition for forming a protective layer, simultaneously with the step of curing the composition for forming a protective layer, or after the step of curing the composition for forming a protective layer. (Appendix 10) A method for determining the authenticity of a semiconductor device, comprising: a step of providing an authentic semiconductor device according to any one of Supplementary Notes 1 to 5; a genuine product data generation step of imaging the anti-counterfeiting layer of the authentic product and generating genuine product data indicating an authenticity determination pattern of the authentic product; and a determination step of observing the anti-counterfeiting layer of the product to be determined and comparing the authenticity determination pattern of the product to be determined with the genuine product data to determine whether the product to be determined is authentic or not. (Appendix 11) A method for determining the authenticity of a semiconductor device according to claim 10, wherein the genuine product data generation process and the determination target data generation process each include a process of imaging the anti-counterfeit layer using side lighting and / or direct lighting.

[0102] (Incorporated by reference) This application claims the benefit of priority based on Japanese Patent Application No. 2024-037352, which is incorporated herein by reference.

Claims

1. a semiconductor substrate; a protective layer for protecting the semiconductor substrate; an anti-counterfeit layer provided on the protective layer; Equipped with the anti-counterfeit layer includes a pattern forming material that forms an authenticity determining pattern, The protective layer contains spherical fillers. Semiconductor device.

2. The protective layer is an encapsulant layer that encapsulates the semiconductor substrate, or a back surface protective film that protects the back surface of the semiconductor substrate. The semiconductor device according to claim 1 .

3. the pattern forming material is in particulate form; 3. The semiconductor device according to claim 1.

4. The patterning material includes a plurality of particles that emit different colors. The semiconductor device according to claim 3 .

5. the patterning material includes a plurality of particles having different shapes; The semiconductor device according to claim 3 .

6. A method for forming the protective layer in the semiconductor device according to claim 1 or 2, Composition for forming a protective layer.

7. It is in the form of a film, The composition for forming a protective layer according to claim 6 .

8. It is used to collectively form protective layers for multiple semiconductor devices at the wafer level or panel level. The composition for forming a protective layer according to claim 6 .

9. forming a protective layer having spherical fillers on a semiconductor substrate; forming an anti-counterfeit layer on the protective layer, the anti-counterfeit layer containing a pattern forming material for forming an authentication pattern; Equipped with The step of forming the protective layer includes: supplying a protective layer-forming composition onto the semiconductor substrate; and curing the supplied protective layer-forming composition, The step of forming the anti-counterfeit layer includes: A step of supplying a composition for forming an anti-counterfeit layer; and curing the supplied composition for forming the anti-counterfeit layer, the step of curing the composition for forming the anti-counterfeit layer is carried out before the step of curing the composition for forming the protective layer, simultaneously with the step of curing the composition for forming the protective layer, or after the step of curing the composition for forming the protective layer; A method for manufacturing a semiconductor device.

10. providing a genuine semiconductor device according to claim 1 or 2; an authentic product data generation step of capturing an image of the anti-counterfeit layer of the authentic product and generating authentic product data indicating the authenticity determination pattern of the authentic product; a determining step of determining whether the product to be determined is genuine by observing the anti-counterfeit layer of the product to be determined and comparing the authenticity determining pattern of the product to be determined with genuine product data; Equipped with A method for determining the authenticity of a semiconductor device.

11. the authenticity data generating step and the judgment target data generating step each include a step of capturing an image of the anti-counterfeit layer with side lighting and / or direct lighting; The method for determining the authenticity of a semiconductor device according to claim 10.

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